SuzukiHayabusa.org
TECHNICAL => MODS => Topic started by: Coryonbusa on December 20, 2008, 03:53:13 PM
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This is step by step instructions on how to lower inverted forks.
You'll need:
30mm socket
10mm Allen socket. 3/8 drive
3/8 drive extention
Impact Gun
2 Pipe wrenches
2 sleeves: 7/8" o.d. x 5/8" i.d. (for busa) or 3/4" o.d. x 5/8" i.d. (for gsxr) (the length of the sleeves will determine the amount lowered)
Hack saw (or something to cut the factory sleeves)
We are starting with a fork that I've previously cut 2"s. We're wanting to cut it to 2.5"s. The process is the same for starting with an uncut fork.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/01.jpg)
First, turn the fork upside down and hit the 10mm Allen bolt with an impact.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/02.jpg)
Turn it right side up in a drain pan and let it drain for about 10 minutes.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/03.jpg)
Use the 30mm on the top to unscrew the assembly.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/04.jpg)
Slide the assembly out of the fork tube.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/05.jpg)
Let it drain off.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/06.jpg)
Unscrew the lower cartridge housing using the 2 pipe wrenches.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/07.jpg)
Drain it out.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/08.jpg)
Next, compress the spring. This is a crude spring compressor I've built. Works great though!
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/09.jpg)
(http://i124.photobucket.com/albums/p25/coryondrums/springCompressor.jpg)
Now, with the spring compressed, put the 17mm wrench on the nut under the top hat and remove the top hat with the 30mm socket.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/10.jpg)
With the top hat removed, loosen the spring compressor and remove the spring. Use a pipe wrench and a 3/4 wrench to remove the valve assembly.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/11.jpg)
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/12.jpg)
Now install your spacer. This is a 2.5" spacer with a washer on top.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/13.jpg)
Here's what we used for a spacer. You can get it Home Depot. Just measure and cut. :thumb:
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/spacer.jpg)
Now cut the the factory spacer. If the lowering sleeve you have made is 2", cut 2" off of the factory spacer.
If you want to add more preload to your front suspension (heavy hitters), remove less of the factory spacer.
Example:
Normal: 2" sleeve, remove 2"s from the factory spacer.
Heavy hitter: 2" sleeve, remove anywhere from 1.5" to 2" from the factory spacer. A 1.5" factory spacer, in this example, will add the most preload.
Don't remove less than 0.5" from the factory spacer than the total length of the spacer you added to lower the fork.
Spring binding may occur.
We've already taken 1.75 off of this one previously, when we lowered it 2". Now that we're lowering it another .5"s, we'll take .5" more off of this spacer.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/14.jpg)
Put the cartridge all back together in the spring compressor. Be sure to loosen the preload all of the way out on the cap and turn the rebound screw all of the way out. before you reinstall the top cap. Tighten the cap just hand tight, then tighten the 17mm nut up to the top hat.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/15.jpg)
The inner cartridge reassembled with 2.5" lowering spacer and cut factory spacer.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/16.jpg)
Reinstall the lower cartridge housing using the pipe wrenches.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/17.jpg)
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/18.jpg)
Slide the cartridge back into the fork housing, turn it upside down and start the Allen bolt by hand. Then tap it with the impact gun.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/19.jpg)
Turn it right side up and add the fork oil. 16 oz. per fork.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/20.jpg)
Be sure to pump it after every 4oz. you pour in.
(http://i124.photobucket.com/albums/p25/coryondrums/cutForks/21.jpg)
Once you've got 16 oz. in there, let it sit for about 10 minutes before tightening the top hat to let all of the air bubbles escape.
Reinstall the top hat and pump it until you feel the rebound working. Then you're done!
(Insert sweet pics of Dave's bike here once the motor is back in. :D)
Big thanks to Pinky for coaching me through this! :thumb:
And a big thanks to Dave3.4 and Katie for the pics!
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Thanks Cory!!
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Thanks Cory!!
+ 1 :thumb:
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You're welcome guys. :thumb:
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Nice post Cory. :thumb:
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Excellent post,thanks for the info. :thumb:
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Y'all are welcome! :thumb:
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Great write-up cory.
You wrote "Don't remove less than 1/2 difference, spring binding may occur." for the difference in spacers.
Do you really mean "Don't remove MORE than 1/2" difference, spring binding may occur.
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Great write-up cory.
You wrote "Don't remove less than 1/2 difference, spring binding may occur." for the difference in spacers.
Do you really mean "Don't remove MORE than 1/2" difference, spring binding may occur.
If you removed more of the factory spacer, you would have a spongie front end.
Removing less of the factory spacer put's more preload on the spring.
Removing less than 1/2 of an inch of the total legth of the spacer you add, would put the spring in a bind.
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It is worded tricky. I'll change it.
Thanks. :thumb:
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Cory, I hope it is fork oil in your hand and no blood :?
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Cory, I hope it is fork oil in your hand and no blood :?
thats what needs to be watched out for
the forks will bite you if you arent careful
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Cory, I hope it is fork oil in your hand and no blood :?
Yep, it's blood. They do bite back! :lol:
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Nice write up Cory pics make it much more understandable if its a newby trying it :thumb:
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Does anyone know the length of the standard spacer at the top of the fork? Just have to return a set back to stock height and can't remember the length to make the spacer.
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From Shcnitz Racing's instuctions, it says it's 4 1/4". I dunno if that's right or not?
You could just order new ones. :idea:
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Followed your instructions, worked perfectly. :D
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Does anyone know the length of the standard spacer at the top of the fork? Just have to return a set back to stock height and can't remember the length to make the spacer.
4.285" :shock:
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Followed your instructions, worked perfectly. :D
:woot: :woot:
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now you need to do a write up with pics to change a seal.... :lol:
mines leaking and i have never took one apart
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now you need to do a write up with pics to change a seal.... :lol:
mines leaking and i have never took one apart
:lol:
Seals are easy.
Remove the fork.
Remove the top 30mm top cap.
Hit the 10mm Allen bolt on the bottom with an impact.
Drain the oil. Slide the cartridge out and set it aside.
Slide the outer fork tube off to access the seal.
The rubber grommet just pops out.
Then, you can pry the seal out with a screw driver.
Push the new one in and put the grommet back on and you're in business.
Repeat the steps in reverse to put it back together.
Just remember to slowly pour in the oil while pumping the fork, to get all of the air bubbles out.
:thumb:
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now you need to do a write up with pics to change a seal.... :lol:
mines leaking and i have never took one apart
:lol:
Seals are easy.
Remove the fork.
Remove the top 30mm top cap.
Hit the 10mm Allen bolt on the bottom with an impact.
Drain the oil. Slide the cartridge out and set it aside.
Slide the outer fork tube off to access the seal.
The rubber grommet just pops out.
Then, you can pry the seal out with a screw driver.
Push the new one in and put the grommet back on and you're in business.
Repeat the steps in reverse to put it back together.
Just remember to slowly pour in the oil while pumping the fork, to get all of the air bubbles out.
:thumb:
thanks buddy, if i mess it up you can take a trip up and fix it. i'll buy you some taco bell :lol:
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Good explanation! :thumb:
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now you need to do a write up with pics to change a seal.... :lol:
mines leaking and i have never took one apart
:lol:
Seals are easy.
Remove the fork.
Remove the top 30mm top cap.
Hit the 10mm Allen bolt on the bottom with an impact.
Drain the oil. Slide the cartridge out and set it aside.
Slide the outer fork tube off to access the seal.
The rubber grommet just pops out.
Then, you can pry the seal out with a screw driver.
Push the new one in and put the grommet back on and you're in business.
Repeat the steps in reverse to put it back together.
Just remember to slowly pour in the oil while pumping the fork, to get all of the air bubbles out.
:thumb:
thanks buddy, if i mess it up you can take a trip up and fix it. i'll buy you some taco bell :lol:
:lol: Yo quero!
Where are you? I don't mind helping, if you're close to south GA. :thumb:
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Where is everyone getting seals the cheapest from? Are you going to the dealer or where? I need to change 2 sets of seals before riding season.
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i'm in the north part of GA. thanks for the offer, i should be able to get it i was just messing with ya
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Good job Coreyonbusa, this is defiantely one on my list. My only question though is what are the tolerances on the o.d and i.d figures you have quoted on your post? Did you get the spacers machined up or did you have an available pipe that meets the dimensions quoted? What material did you use as well?
:?:
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Good job Coreyonbusa, this is defiantely one on my list. My only question though is what are the tolerances on the o.d and i.d figures you have quoted on your post? Did you get the spacers machined up or did you have an available pipe that meets the dimensions quoted? What material did you use as well?
:?:
Good questions. :thumb:
7/8 od is as big as I would go, just because you want the oil to be able to travel freely around it. The 5/8 id a little big for the same reason.
If you have time when you have the forks apart, measure for yourself. Maybe you'll find a size that works better? :thumb:
I had a machine shop make mine for me, out of steel.
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:thnks:
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:thumb: :thumb:
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Fabulous write up, Cory! :thumb: :thumb:
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Fabulous write up, Cory! :thumb: :thumb:
Thanks bud!
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I will have to put this mod on my to do list, thanks Coryonbusa. :thumb:
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:thumb:
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Just to be difficult, I have another question :) I was talking to a local guy the other day who has had his forks modded although he did not take anything off the original factory spacers but just added the extra 2" spacers. He tells me that is what I should do as it preloads the forks and prevents striking the sump on the deck if a wheelie lands too hard. He also mentioned that it is a bit of a mission geting the spacers in due the compression required to fit the additional spacers.
Is there any opinions/experiences on this?
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Just to be difficult, I have another question :) I was talking to a local guy the other day who has had his forks modded although he did not take anything off the original factory spacers but just added the extra 2" spacers. He tells me that is what I should do as it preloads the forks and prevents striking the sump on the deck if a wheelie lands too hard. He also mentioned that it is a bit of a mission geting the spacers in due the compression required to fit the additional spacers.
Is there any opinions/experiences on this?
I can see where he did have a hard time getting the springs back in if he didn't cut down the factory spacer. :D
Adding the lowering spacer does lower the valves assembly into the cartridge. No amount of preload can change that as it is set by the lowering spacer.
By not cutting the factory spacer, you are adding TOO much preload to the factory spring which will cause it to bind and ride REALLY stiff. You might as well tighten down a lowering strap, it's the same thing.
By cutting down the factory spacer, you give the front end back it's suspension. Allowing you to tune it in for your riding style.
Here's a rough illustration I made showing the spring binding.
(http://i124.photobucket.com/albums/p25/coryondrums/forks.jpg)
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Thanks Corey. I am talking about drag only bikes so there wont really be much of a difference in riding style but I can still see how the spring bind could be caused which can be very dangerous if no travel is available in the forks.
I will be sticking with your described set up but with a little less off the factory spacer, heavy hitter style as I am big boned "not fat" :hys:
:thumb: :thumb:
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I hear ya! I'm in the same boat! :lol:
Good luck with it. :thumb:
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Thanks Corey. I am talking about drag only bikes so there wont really be much of a difference in riding style but I can still see how the spring bind could be caused which can be very dangerous if no travel is available in the forks.
I will be sticking with your described set up but with a little less off the factory spacer, heavy hitter style as I am big boned "not fat" :hys:
:thumb: :thumb:
We aint fat!!!
We're just fearful cuddly! :hys:
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Did mine today, good writeup. If you heat up the threaded joins on the damper tube & valve assembly with a hot air / heat gun they undo alot easier (factory use loctie). Just becareful of the damper seal. Make sure the inner hole in your new spacer is big enough to sit on the flat edge of the valve assembly, not jam on the taper where the threaded section is. Leigh
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Did mine today, good writeup. If you heat up the threaded joins on the damper tube & valve assembly with a hot air / heat gun they undo alot easier (factory use loctie). Just becareful of the damper seal. Make sure the inner hole in your new spacer is big enough to sit on the flat edge of the valve assembly, not jam on the taper where the threaded section is. Leigh
So that would then be a minimum id of :?: :?: :?: to avoid jamming on the taper.
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Did mine today, good writeup. If you heat up the threaded joins on the damper tube & valve assembly with a hot air / heat gun they undo alot easier (factory use loctie). Just becareful of the damper seal. Make sure the inner hole in your new spacer is big enough to sit on the flat edge of the valve assembly, not jam on the taper where the threaded section is. Leigh
Why do you not want the spacer on the tapered edge of the valve assembly?
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I used alloy spacers. On take off as the forks extend & top out it will hammer the spacer on to the taper section, flairing the end. Leigh
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I see your point. :thumb:
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I like your spring compressor design, will help out people who dont have a press at home.Mine is similar, has a bearing sperator on one end. Its always good to see people like you, who share info, so others can learn to do things them self. The photos make it better. :idea: :thumb:Leigh
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Matt, check your other pm's. leigh
[/quote]
So that would then be a minimum id of :?: :?: :?: to avoid jamming on the taper.
[/quote]
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I like your spring compressor design, will help out people who dont have a press at home.Mine is similar, has a bearing sperator on one end. Its always good to see people like you, who share info, so others can learn to do things them self. The photos make it better. :idea: :thumb:Leigh
Thanks! I plan on re-writing soon, with better pics. :thumb:
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that mean your going to lower them a little more?
I like your spring compressor design, will help out people who dont have a press at home.Mine is similar, has a bearing sperator on one end. Its always good to see people like you, who share info, so others can learn to do things them self. The photos make it better. :idea: :thumb:Leigh
Thanks! I plan on re-writing soon, with better pics. :thumb:
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that mean your going to lower them a little more?
Yeap! :wink:
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Got my spacers made and am getting ready to fit them. A mate asked me today how much lower the forks will be after fitting a 2" spacer and I said........Good question.
Is it a 1:1 ratio with the fitment of the spacer? ie 2" spacer = 2" lower on the forks
Also what weight fork oil do you suggest for a heavy hitter?
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A 2" spacer will reduce fork travel by 2" (lower the front 2"). Fork oil? I use Automatic transmission fluid on lowered street/strip bikes, heaver fluid will only slow the valving. You ALWAYS spring the bike for rider weight. The shim stack or oil weight wont help. I would only trim 1.50"-1.75" off the factory spacer :wink:
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:thnks: :thumb:
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Did mine today, good writeup. If you heat up the threaded joins on the damper tube & valve assembly with a hot air / heat gun they undo alot easier (factory use loctie). Just becareful of the damper seal. Make sure the inner hole in your new spacer is big enough to sit on the flat edge of the valve assembly, not jam on the taper where the threaded section is. Leigh
These are good words of advice from Lee re. tapering the spacer and heating up the threaded spots. I did my forks on the weekend and even a heat with the wifes hairdryer was enough to soften the loctite to make it easier getting the threads loose. Definitely suggest making the spring compressor as well. I added a retainer to both ends on the spring compressor for safety sake. No blood spilt
Thanks again Corey and Lee :thumb:
P.S I took 1.5" off the factory spacer and the my fork travel has dropped by roughly 2.5" (Although I haven't put the oil in yet as I am waiting for some new seals). I did not measure my new spacers beforre I put them in but I assume they are the 2" that I asked for.
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Mo bettah pics! :thumb:
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perfect instructions :thumb:
The pics should help out alot,anyone should b e able to do it
hopefully I'll be able to post up the pics of them on the bike in a week or so
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Mo bettah pics! :thumb:
:thumb: :thumb:
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perfect instructions :thumb:
The pics should help out alot,anyone should b e able to do it
hopefully I'll be able to post up the pics of them on the bike in a week or so
Thanks buddy! :thumb: :D
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Those pics made a big difference
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I'll be doing this asap. What is the best amount to cut off if you want forks to not expand to run with out a strap. If I use a 2" spacer for example what needs to be taken off the factory piece?
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I'll be doing this asap. What is the best amount to cut off if you want forks to not expand to run with out a strap. If I use a 2" spacer for example what needs to be taken off the factory piece?
I would take 2" off of the factory spacer. :thumb:
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A+ pics :thumb:
Very good instruction Cory :D
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New photo's are great, you have done well with the whole post . :thumb: Leigh
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Aloha and thanks to everyone who helped with this post this is exactly what I needed to know. I'm about to change a leaky seal on my 750 and lower my busa.
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Thanks fellers! :woot:
I home this saves some of you "do-it-yourselfer's" some money! :thumb:
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Well done on the new photos. Much Better. No excuses now for not doin your own.
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Well done on the new photos. Much Better. No excuses now for not doin your own.
:thumb: :D
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hey baldy (inside joke)
this round of pictures looks great
very well done
and the spring compressor you made works much better then the old way doesn't it lol
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hey baldy (inside joke)
this round of pictures looks great
very well done
and the spring compressor you made works much better then the old way doesn't it lol
:lol:
Thanks buddy!
Yeah, that compressor does work really well. Saves the cuts to the hands! :D
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Here's a couple pics with the lowered forks that Cory did for me.The forks are lowered 2.5" and the bike still has the lowered tree also. I think it's roughly 3" total...............thanks again Cory
(http://i263.photobucket.com/albums/ii149/davidbeitler/Busalow003.jpg)
(http://i263.photobucket.com/albums/ii149/davidbeitler/Busalow005.jpg)
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Low and not so slow! Looks great! :woot:
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Thanks the new pics answered all questions.Now the garage just has to drop below 110 degrees. :1:
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Thanks the new pics answered all questions.Now the garage just has to drop below 110 degrees. :1:
I hear ya on that one! Stay hydrated! :thumb:
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Just lower my forks 4'' they work great and only cost me seven dollars.
The only problem i had the bottom allen would not come out had to
go threw the top of the forks to get them apart.But went back together
with no problem.
THANKS Coryonbusa
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Just lower my forks 4'' they work great and only cost me seven dollars.
The only problem i had the bottom allen would not come out had to
go threw the top of the forks to get them apart.But went back together
with no problem.
THANKS Coryonbusa
Awesome!
You are welcome! :woot:
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great info. i have wondered about this.
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If I put in say a 3" spacer how should I cut the factory spacer to have the least up travel. I don't want to use a strap, I am 195 and the bike is 70"?
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If I put in say a 3" spacer how should I cut the factory spacer to have the least up travel. I don't want to use a strap, I am 195 and the bike is 70"?
With a 3" spacer; Remove 2.5" from the factory spacer, reassemble the forks and tighten your preloads all the way in. This will make the front end very stiff. :thumb:
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thanks, A 3 inch spacer should leave about an inch of travel correct?
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Not 100% sure on that but it'll be close, for sure. :thumb:
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mine turned out perfect. Put in a 3 inch spacer and cut 2.5 out the stock spacer. Got about 1.25 inches of fork left showing. Put new seal in as well. Thanks for the info on this.
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mine turned out perfect. Put in a 3 inch spacer and cut 2.5 out the stock spacer. Got about 1.25 inches of fork left showing. Put new seal in as well. Thanks for the info on this.
Awesome! Glad it worked out for you!!! :thumb:
Post some pics!
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Thanks for the info i did mine today and they are perfect now.As soon as the bikes is ready to go out i make some pictures.
:thumb:
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Cory is the God of the Fork! :mrgreen:
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
Okay,, if it will make you feel better - Cory is a wacky drummer that wrote a fare article about lowering motorcycle forks that works for some people and not for others using a set of pipe wrenches! And, if he had an eye missing,, he would have been a guy with an eye missing that wrote a fare article about lowering motorcycle forks that works for some people and not for others using a set of pipe wrenches!
Remember this saying - "Not all naked people smell good!" :mrgreen: I made that last part up :lol:
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
:bigfu:
If you got a better way, post it!!!
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
what the hell is your problem
Cory has taken time to do this take picts and show people how to do it to help out the board
WTF have you done
dont come on here haten on what somedody has done to help others
reminds me of a sayn--if you aint got nothing nice to say dont say anything
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
Hey it works so whats the fucking problem........ :?: :?: :?: :?:
At least he took the time and helped a lot of people who didn't know shit about opening the fork or lowering it......
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What an
ingrate asshat :grnt:
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yup we got another azzhole. :finger:
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
what the hell is your problem
Cory has taken time to do this take picts and show people how to do it to help out the board
WTF have you done
dont come on here haten on what somedody has done to help others
reminds me of a sayn--if you aint got nothing nice to say dont say anything
You have no idea. I replaced my 00 forks with 05 units. He replaced the original compression valves with Traxxion 25mm units with a unique shim stack. The hydraulic bump stop was removed to further improve compliance. Traxxion springs were installed and fork oil height was measured in mm not ounces. He will be replacing the compression and rebound needles with units he told me to get from GP suspension for real adjustability....not the basically on/off operation with stock needles. Then there is the rebound valve which can also be replaced with a recently released valve by a well known suspension company. He shit works better than the GMD modified pieces I've seen at Loudon and he has done many forks for many racers. He can bury any of us in experience and working suspension knowledge.
I noticed he didn't disagree with the concept but was commenting on execution. He obviously feels using pipe wrenches on the damping rod etc and using galvanized pipe as the spacer isn't very professional. I'd also say measuring oil in ounces insted of actual height caught his eye. He is probably wondering what, if anything is done to the springs and other parts of the fork to compensate for shortening them. Maybe he'll get on and ask those questions but I doubt if anybody here will be able to answer them.
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
Okay,, if it will make you feel better - Cory is a wacky drummer that wrote a fare article about lowering motorcycle forks that works for some people and not for others using a set of pipe wrenches! And, if he had an eye missing,, he would have been a guy with an eye missing that wrote a fare article about lowering motorcycle forks that works for some people and not for others using a set of pipe wrenches!
Remember this saying - "Not all naked people smell good!" :mrgreen: I made that last part up :lol:
WTF, Cookie you ben drinkin some homemade hooch or somethin :lol:
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
Okay,, if it will make you feel better - Cory is a wacky drummer that wrote a fare article about lowering motorcycle forks that works for some people and not for others using a set of pipe wrenches! And, if he had an eye missing,, he would have been a guy with an eye missing that wrote a fare article about lowering motorcycle forks that works for some people and not for others using a set of pipe wrenches!
Remember this saying - "Not all naked people smell good!" :mrgreen: I made that last part up :lol:
WTF, Cookie you ben drinkin some homemade hooch or somethin :lol:
Hey, DaveyBoy,,, I am pretty DAMNED sure that not all naked people smell good! :lol: :thumb:
,,,maybe i should start drinkin,,, it's almost friday somewhere, isn't it? :drink: :talk: :duh: :whaa: :bmp:
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
did you mean "not all butchers work with knives"?
because you're trying to take a jab at his tool selection, not what he is working on...
"not all self proclaimed geniuses work with their brains" eh Mr speedingdckless?
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
what the hell is your problem
Cory has taken time to do this take picts and show people how to do it to help out the board
WTF have you done
dont come on here haten on what somedody has done to help others
reminds me of a sayn--if you aint got nothing nice to say dont say anything
You have no idea. I replaced my 00 forks with 05 units. He replaced the original compression valves with Traxxion 25mm units with a unique shim stack. The hydraulic bump stop was removed to further improve compliance. Traxxion springs were installed and fork oil height was measured in mm not ounces. He will be replacing the compression and rebound needles with units he told me to get from GP suspension for real adjustability....not the basically on/off operation with stock needles. Then there is the rebound valve which can also be replaced with a recently released valve by a well known suspension company. He shit works better than the GMD modified pieces I've seen at Loudon and he has done many forks for many racers. He can bury any of us in experience and working suspension knowledge.
I noticed he didn't disagree with the concept but was commenting on execution. He obviously feels using pipe wrenches on the damping rod etc and using galvanized pipe as the spacer isn't very professional. I'd also say measuring oil in ounces insted of actual height caught his eye. He is probably wondering what, if anything is done to the springs and other parts of the fork to compensate for shortening them. Maybe he'll get on and ask those questions but I doubt if anybody here will be able to answer them.
It's one thing to come here with questions and concerns and another to call someone that's trying to help others a butcher, which is exactly what he did...
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+1
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I posted this around on a few boards and people are really laughing at you idiots.
I guarantee if any of you stepped up and set your forks out to a suspension shop to have the length shortened the difference between the workmanship and the quality of the ride.
This site has really gone downhill since I first joined it years ago.
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On the way out, don't let the door hit ya where the good lord split ya. Stay on the other boards then since your so perfect and make no mistakes.
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He is a hater :finger:
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He is a hater :finger:
No, a mechanic.
You can see how chewed up the damping rod got in the close up pic. How is that going to work with the coated bushing in the cartridge head?
Do you really think grabbing those soft aluminum parts with pipe wrenches is the right way or a good way to that?
Do you think the cylinder is still round where the pipe wrench clamped down on it?
You are reducing the travel to pretty much the very bottom of its range. The hydraulic anti-bottoming out piston kicks in around there which pretty much locks up the fork making it harsh. Why don't you do anything with that? There are some good options out there.
What is the amount of spring preload now that you cut the spacer?
The stock spring rate is 8.5 on the 99 to 07 which is way too light for that bike. The 08 and up uses a 9.3 which is still on the light side. Wouldn't you want to change the springs to help keep the bike from bottoming?
I am guessing that you have no idea about the shim stack so you throw in some really thick oil. Not the best solution IMO. Then you just dump in xx amount with no idea of what the oil height is. The oil height is considered an air spring that acts progressively. Too high the forks will feel stiff. There is no way you are bleeding all the air out with your four pump chump method either.
The spacer looks like conduit cut with a hack saw. You ever hear of a tubing cutter or God forbid use a lathe to make some nice spacers?
I know its the cheap way so that makes it great to some of you but come on. Is there anyone out there that is going to tell me that this is the correct way to work on these forks?
Would you grab your crankshaft or camshaft with a pipe wrench?
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Here is a good kit to get you started in the right direction here -
http://traxxionstore.com/detail-12.aspx (http://traxxionstore.com/detail-12.aspx)
(http://traxxionstore.com/images/products/detail/CFTK1.jpg)
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He is a hater :finger:
No, a mechanic.
You can see how chewed up the damping rod got in the close up pic. How is that going to work with the coated bushing in the cartridge head?
Do you really think grabbing those soft aluminum parts with pipe wrenches is the right way or a good way to that?
Do you think the cylinder is still round where the pipe wrench clamped down on it?
You are reducing the travel to pretty much the very bottom of its range. The hydraulic anti-bottoming out piston kicks in around there which pretty much locks up the fork making it harsh. Why don't you do anything with that? There are some good options out there.
What is the amount of spring preload now that you cut the spacer?
The stock spring rate is 8.5 on the 99 to 07 which is way too light for that bike. The 08 and up uses a 9.3 which is still on the light side. Wouldn't you want to change the springs to help keep the bike from bottoming?
I am guessing that you have no idea about the shim stack so you throw in some really thick oil. Not the best solution IMO. Then you just dump in xx amount with no idea of what the oil height is. The oil height is considered an air spring that acts progressively. Too high the forks will feel stiff. There is no way you are bleeding all the air out with your four pump chump method either.
The spacer looks like conduit cut with a hack saw. You ever hear of a tubing cutter or God forbid use a lathe to make some nice spacers?
I know its the cheap way so that makes it great to some of you but come on. Is there anyone out there that is going to tell me that this is the correct way to work on these forks?
Would you grab your crankshaft or camshaft with a pipe wrench?
Alright! See, now that's a good post! :thumb:
Lot's of good points and suggestions in there. :thumb:
No need to hate on me or anyone for trying to save someone $200.oo+ on having their forks cut.
I guess I could change the first post to say that if you have the money, have your forks done professionally. If not, here's a cheap way that will work. I dont work on bikes professionally and I dont know it all. I wrote this article with the help of a few others that have built forks for some pretty quick bikes. :thumb:
Addressing yor concerns:
You can see how chewed up the damping rod got in the close up pic. How is that going to work with the coated bushing in the cartridge head?
Do you really think grabbing those soft aluminum parts with pipe wrenches is the right way or a good way to that?
Do you think the cylinder is still round where the pipe wrench clamped down on it?
Pipe wrenches will scar up aluminium. It will not crush the pipes because pipe wreches dont work that way. They grip only enough to hold. Where you hold on to the rod will be under the lowering spacer and will not travel through the bushing.
You are reducing the travel to pretty much the very bottom of its range. The hydraulic anti-bottoming out piston kicks in around there which pretty much locks up the fork making it harsh. Why don't you do anything with that? There are some good options out there.
I'm not %100 sure what you're talking about. The cut fork should bottom out the same as an uncut fork?
What is the amount of spring preload now that you cut the spacer?
The preload will be the same, if you remove the same amount of the lowering spacer from the stock spacer. :thumb:
The stock spring rate is 8.5 on the 99 to 07 which is way too light for that bike. The 08 and up uses a 9.3 which is still on the light side. Wouldn't you want to change the springs to help keep the bike from bottoming?
Yeah, the stock springs are light. Adding a heavy spring, especially for us big guys, is not a bad idea. :thumb:
You can accomplish close to the same result by adding more preload. Though you can't add too much preload or you'll bind up the spring...
I am guessing that you have no idea about the shim stack so you throw in some really thick oil. Not the best solution IMO. Then you just dump in xx amount with no idea of what the oil height is. The oil height is considered an air spring that acts progressively. Too high the forks will feel stiff. There is no way you are bleeding all the air out with your four pump chump method either.
You are correct on the shim stack or oil height, I have not idea what you're talking about. :D If you want to share some knowledge, please do! As far as bleeding the air, what do you suggest? This way seem to work well for me and countless others. :thumb:
The spacer looks like conduit cut with a hack saw. You ever hear of a tubing cutter or God forbid use a lathe to make some nice spacers?
What can I say? When you're working in a hot garage, you'll do anything to get it done! :lol: If you'll notice the 2"ers we took out were machined sleeves that I put in there the first time...
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Made my own fork tools for free. :wink:
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I agree that using more suitable tools, machined spacers, and replacing the shim stack may make for a nicer job, however, someone wanting suspension capable of providing better damping than stock likely would not be in trying to lower them and reduce travel at all. This mod is intended for dragracing (or I supose for posers with wide tire kits who don't need better suspensions anyway) and not for applications requiring a great deal of suspension energy dissapation.
It could be done in better ways, however for this application, this method will produce the same ET as a more expensive solution.
Kent Stotz performed quite well in streetbike shootout. Ever look at his bikes? Stock extended swingarm, cut off and re-welded footpeg mounts to make "rearsets", not the most mainstream or pretty applications, however, they function just fine.
Hundreds of Hayabusa's run an intake cam on the exhaust side, even though the lobe spacing is "wrong" and is an "improper" way to build an engine.
Ever design a chain drive? Motorcycle chain drives violate general design practices by an order of magnitude or more with respect to countershaft pitch diameter for the torque they transmit.
Removing the countershaft and transmission input shaft nut with an impact is "improper" as well....
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Here is a good kit to get you started in the right direction here -
http://traxxionstore.com/detail-12.aspx (http://traxxionstore.com/detail-12.aspx)
(http://traxxionstore.com/images/products/detail/CFTK1.jpg)
Is there a tool in there that eliminates the pipe wrenches?
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I posted this around on a few boards and people are really laughing at you idiots.
I guarantee if any of you stepped up and set your forks out to a suspension shop to have the length shortened the difference between the workmanship and the quality of the ride.
This site has really gone downhill since I first joined it years ago.
go back to your other websites then :thumb:
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I guess I could change the first post to say that if you have the money, have your forks done professionally. If not, here's a cheap way that will work. I dont work on bikes professionally and I dont know it all. I wrote this article with the help of a few others that have built forks for some pretty quick bikes. :thumb:
There is a right way and a wrong way and any way that damages parts is the wrong way.
Pipe wrenches will scar up aluminium. It will not crush the pipes because pipe wreches dont work that way. They grip only enough to hold. Where you hold on to the rod will be under the lowering spacer and will not travel through the bushing.
I own and have used pipe wrenches (but not on fork internals). I have also disassembled the cartridges so I am very familiar with the amount of force required to remove the cartridge head from the cylinder. Kayaba uses some type of epoxy on them as residue on the threads is white. Trust me, if you were to run a bore gauge through the sections of the cylinder where you grabbed it with the pipe wrench you will see it is no longer round.
While you are correct that the marred up end of the damping rod will not come in contact with the bushing in the cartridge head while the spacer is there what happens if you have to put it back to stock?
It would be one thing if there was no other way to do it, but Race Tech sells a shaft holding tool for that purpose. They also sell a cartridge holding tool for cartridge disassembly so that you do not damage the cylinder.
I'm not %100 sure what you're talking about. The cut fork should bottom out the same as an uncut fork?
They bottom out the same but you have reduced the range of travel. About half the time that fork is moving it is much harsher than it needs to be. There a couple of options to change this. There are two methods that are free and will improve the forks function. There is another option that requires you buy some parts, but IMO offers a much better solution.
The preload will be the same, if you remove the same amount of the lowering spacer from the stock spacer. :thumb:
OK then, what is the base preload on a stock set of forks?
When you set up a set of forks you install the springs with a base preload on the springs, usually 10 or 15 mm (unless you are working with Ohlins stuff).
Yeah, the stock springs are light. Adding a heavy spring, especially for us big guys, is not a bad idea. :thumb:
You can accomplish close to the same result by adding more preload. Though you can't add too much preload or you'll bind up the spring...
You shouldn't be binding the spring up. If you are worried about binding up the spring then I would suggest running a stiffer rate spring than you would normally run but installing it with less base preload.
You are correct on the shim stack or oil height, I have not idea what you're talking about. :D If you want to share some knowledge, please do! As far as bleeding the air, what do you suggest? This way seem to work well for me and countless others. :thumb:
To bleed the cartridge you want to install the cartridge (using a different type of cartridge holding tool to hold the cartridge while you torque it) with the damping rod installed and no spring. I open up the compression adjuster all the way and pour some fork oil in, usually about 150mm from the top of the outer fork tube. I work the damping rod up and down several times and then let drop in all the way. I then extend the fork a little longer than its normal fully extended length, put my hand tightly over the top to seal it and then push down on the fork. This pushes the oil through the cartridge. Once I do that several times I then install a bleeder tool on the damping rod and work it up and down until I no longer see any air bubbles. It takes a long time to bleed the air out.
I then use a fork oil height tool to set the height as this is something you can tune with. Oil height is dependent on what type of valving you are running and somewhat of a personal preference. Depending on the set up and the rider's class I usually start a new rider out with 130mm to 120mm and then experiment from there.
Remember, the space left in the fork by the oil acts as a progressive spring. The higher the oil level, the stiffer it gets as the fork compresses.
Also, that Bel-Ray 20wt fork oil is thick as hell. They run that damper rod forks.
What can I say? When you're working in a hot garage, you'll do anything to get it done! :lol: If you'll notice the 2"ers we took out were machined sleeves that I put in there the first time...
Metal on metal wear creates particles that contaminates the oil which wears the valve faces and shims.
Personally I would machine up spacers made of Delrin and install them with a washer at the spring end. And if anyone thinks the Delrin is no good, Ohlins uses Delrin spacers to adjust fork length in all of their Superbike, new style R&T forks, and Superbike Cartridges.
I know that you are not going for handling when doing this mod, but you can make changes to so that it improves the ride quality. I can only imagine how rough that front end feels. In the end you want the forks to move as smoothly as possible. If you look at the forks you will see other things that need to be addressed to make them work correctly.
You want everything super clean as you do not want to contaminate the oil.
These guys here -
http://www.dirtrider.com/tech/141_0806_race_tech_fork_rebuild_secrets/index.html (http://www.dirtrider.com/tech/141_0806_race_tech_fork_rebuild_secrets/index.html)
are servicing a set of dirbike forks. While Busa forks do not have all the parts they have, you can see some of the tools they and methods they are using.
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Is there a tool in there that eliminates the pipe wrenches?
Not in that set up, but look at the tools used in the link I posted in my thread before this one.
Also -
Tool for holding cartridge in place so you can torque the bolt at the bottom.
http://www.racetech.com/HTML_FILES/CARTRIDGE_HOLDING.html (http://www.racetech.com/HTML_FILES/CARTRIDGE_HOLDING.html)
Shaft and cartridge holding vise adapters (these are the tools that eliminate the pipe wrenches).
http://www.racetech.com/HTML_FILES/SHAFT_HOLDING.html (http://www.racetech.com/HTML_FILES/SHAFT_HOLDING.html)
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http://www.dirtrider.com/tech/141_0806_race_tech_fork_rebuild_secrets/photo_14.html
Really?....Really? Grinding or filing on the parts?
How about using a lathe to turn the mushroomed portion off and then remove the nut. Jeeze....Racetech must be a bunch of idiots.... :lol:
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Good post spdingtkts. :thumb:
Your points are valid and I hope that someone finds it usefull.
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The stock spring rate is 8.5 on the 99 to 07 which is way too light for that bike. The 08 and up uses a 9.3 which is still on the light side. Wouldn't you want to change the springs to help keep the bike from bottoming?
Yeah, the stock springs are light. Adding a heavy spring, especially for us big guys, is not a bad idea. :thumb:
You can accomplish close to the same result by adding more preload. Though you can't add too much preload or you'll bind up the spring...
When I first read this I originally thought by adding more preload you were talking about via the adjuster at the top.
Then I thought about your statement about coil binding the spring so it occurred to me that you are talking about leaving the spring preload spacer long to provide more base preload to compensate for an incorrect spring rate.
You do not want to that. If you preload the spring too much it will not work like it is supposed to and I am not just talking about coil bind issues.
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Cory is the God of the Fork! :mrgreen:
Using pipe wrenches?
While his technical info is current his workmanship reminds me of the saying "Not all butchers work with meat."
did you mean "not all butchers work with knives"?
because you're trying to take a jab at his tool selection, not what he is working on...
"not all self proclaimed geniuses work with their brains" eh Mr speedingdckless?
Apparently not all chooch's live in barns Sparky. Tkts is a big Glock fan too....you minga fach. :lol: He answered questions.
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you should come hang out at work with me mike, i'm sure you'd have a blast.
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you should come hang out at work with me mike, i'm sure you'd have a blast.
:lol:
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you should come hang out at work with me mike, i'm sure you'd have a blast.
I believe I would. :wink:
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I posted this around on a few boards and people are really laughing at you idiots.
I guarantee if any of you stepped up and set your forks out to a suspension shop to have the length shortened the difference between the workmanship and the quality of the ride.
This site has really gone downhill since I first joined it years ago.
go back to your other websites then :thumb:
:hys: :thumb:
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:D
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It is funny to read it all again. :lol:
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It is funny to read it all again. :lol:
:thumb: :D
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So did anyone figure out some off the shelf spacers you could use, As far O.D. and I.D.?
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So did anyone figure out some off the shelf spacers you could use, As far O.D. and I.D.?
Looked like conduit in the first pic's. Could just take a pair of calipers to a supply place and check.
Or
http://www.schnitzracingstore.com/catalogs/catalog.asp?prodid=2704270&showprevnext=1
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So did anyone figure out some off the shelf spacers you could use, As far O.D. and I.D.?
what od and id are u looking for
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Looked like conduit in the first pic's. Could just take a pair of calipers to a supply place and check.
DO NOT use conduit or PVC pipe. It cracks and breaks apart over time and that can cause BIG problems.
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Wanna say great post thanks for the help, but i have a question tried this on my 02 gsxr 750 forks apear to be different internally could not get lower tube off? any help? thanks
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I know I'm resurrecting an old thread, but I have a related question. How do I go about EXTENDING the forks an inch or two? Can I just get a longer allen bolt and put a spacer between the bottom of the cartridge and the bottom of the fork? Building an adventure tourer kind of thing, and need some more ground clearance.
Thanks.
Charles.
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Nice write up Cory, I did notice that on the Gen 2 busa the Allen screw on the bottom of the forks are #8. I will be lowering mine this weekend after I make the tool to compress the spring.
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Hello my name is XLNTS, I'm new here and thought I would just introduce myself....and comment on this :D
In layman terms: It's just relocating the suspension to a different area of the fork tubes is all. Genius idea, people have been doing it for years and I thank you sir for taking the time to write this up and take photos of it all for us to follow.
I did mine with machined pieces and did a 3 inch drop and thicker oil.. I fucked up the first time I did it, making the small pipe you insert too long making the bike too low but when fixed I found it rode better and its probably because I'm a heavier guy who is short and felt safer when I came to stop signs and while leaning into turns it felt as though I could almost lean right over with out the feeling of loosing stability. This is great and for anyone who doesn't want to buy the tools...just use rags so it doesn't mar up the internals.
For anyone short considering this; you'll love it and chicks like it when they can sit on a man bike and have their feet touch ;)
Speed: had my bike up to 321kmh for extended periods of time while rocking this mod. (Saskatchewan is very flat and straight in some parts)
(EDIT: Next time I'll be taking my bike into a guy who knows how to do this properly and paying him the $200 he wanted to do it for me while I work a double time weekend)
(http://i18.photobucket.com/albums/b144/weldorguy/toys%20and%20stuff/IMG_0040.jpg) (http://s18.photobucket.com/user/weldorguy/media/toys%20and%20stuff/IMG_0040.jpg.html)
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Great writeup . I'll be doing mine soon .is there anything in there that I can cut to lighten up as I'm lowering it 2.5 in .can I cut inner tube down ? Thanks
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No. Just what's in the tutorial here.
Go slow and think about it, it's easy to get confused and make it sit on the bottom like mine did.
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I haven't took it apart yet but after lowering it .I'm sure there's a extra two inches of inner fork that ain't doing nothing ??
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It's tapered. If you want it lower after that....buy the spacers.
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Is it a bad idea to make these spacers out a aluminum.say 7075
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has anybody tried this on a gen2 ??
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Anybody ????
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its the same concept on the gen2. If you have some old pistons, you can use the wrist pins as the spacer. Its the perfect length and is strong enough.
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cheers Battman.....yeah all done,one thing i did notice though is that with a 3" spacer on the Gen2 still left me with 2" of travel,was hoping to get closer to 1" ......take that back got 1" all good
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Great write up and very informative!
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When I first lowered my bike via a new triple we could only go 3/4". Hadn't considered doing anything more till now and came across this searching. I'm more than willing to go this route and it seems it's been accomplished on a Gen2 already. Since winter is coming up, I may send them off to get professionally done.. My question is, is there any opinions on the "sweet spot" to lower a Gen2 and looks the best without giving up too much ride quality?
Thanks for any advice!
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lower it 2" internally and then fine tune the height by lowering it or raising it in the top triple tree.
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Perfect, thanks!!