I spent a few hours today making a much needed improvement to my GS. With no knowledge of the procedure I was about to do, I delved into an area I probably had no business being in. However, after reading the Clymer manual it seemed easier than I was imagining.
My RaceTech springs came in the mail earlier this week and I had been waiting rather impatiently to get them put in. Today was the first day I'd had any free time to do the job properly.
After pulling the forks out and figuring out what I needed to do to change the fork oil (as well as searching for the correct volume needed) I managed to somehow change out the fork springs with .8kg/mm RaceTech springs, change out the fork oil for 375mL of 5W, and install preload spacers based around how I ride; all without incident. I was surprised with how easy it was to do, especially the second fork after I figured everything out on the first one.
It's really not that difficult, even if you're still using the stock springs. Just dump the old fluid out, pump the fork leg until most of it comes out, then measure out 375mL of new fork oil (be it the stock 10W or a different value dependant on your weight), pour it in and you're set. It wasn't described very well in the Clymer manual, so I figured it'd be a good help here.
Measuring and cutting the preload spacers was as easy as hacking an included piece of 6061 aluminum tubing to the specified length you measure (I measured out 20mm of preload, 143mm from the top of the spring to the top of the fork leg, minus 15mm of cap, plus 20mm preload = 148mm spacers).
A test ride proved that these things feel amazing. The difference is mind blowing. I went for a short jaunt down a 3 mile semi-twisty bit (30-35mph reccomended speed turns) and couldn't believe how utterly crappy the stock suspension was. It soaks up bumps better, doesn't bobble or crap its pants in turns, no heavy nose dive under braking. Night and day difference.
I love my RaceTech springs! :thumb:
You probably mentioned this elsewhere, but how much did the Racetech springs set you back? Also, where did you get the info on your optimal shock setup(ie. which oil, spacer length...)? Congrats on the much improved suspension :thumb:
Quote from: manofthefield on April 15, 2006, 07:24:46 PM
You probably mentioned this elsewhere, but how much did the Racetech springs set you back? Also, where did you get the info on your optimal shock setup(ie. which oil, spacer length...)? Congrats on the much improved suspension :thumb:
I got my RaceTech springs from their website for $109.99 + 15.28 shipping = $125.27
As for the optimal shock set up, RaceTech sends a thing of paper with how to measure and calculate the necessary preload and sag (my sag was ~20mm, good for agressive street riding). It isn't the "optimal" setup, as I would need a professional suspension tuner, but the best estimate based on my riding style, weight, and the stock setup.
http://www.peterverdonedesigns.com/introduction.htm has a more in depth look at what the RaceTech paper had.
The reccomended spring weight for me by RaceTech was somewhere in the vicinity of .72 kg/mm. Since the closest they had was .8 kg/mm I went with those. I figured that since I'm using the larger spring weight I should go with an oil that is thinner than stock, as it would feel even stiffer with the 10W. I put in Silkolene 5W fork oil too (fancy stuff. Like $15 a bottle) because that's what we had in our garage.
This just in... Alpha finally saw the light... Praise my dog, and pass the Sam Adams thisaway...
I dumped in Progressives a couple years ago and have never looked back. The only caution I have is be careful when you're threading the fork tube caps back on with the new springs and spacers in there. You don't want to cross thread one of those.
Jake
Quote from: jake42 on April 15, 2006, 10:19:26 PM
I dumped in Progressives a couple years ago and have never looked back. The only caution I have is be careful when you're threading the fork tube caps back on with the new springs and spacers in there. You don't want to cross thread one of those.
Jake
Oh man, I had my cap cross thread on me so many times before it finally stuck just right. It was such a pain in the ass.
And just a note: I went with straight rate springs for a reason. ESPECIALLY for agressive riding, I like knowing what my suspension will be doing. The "progressive" feel just isn't right for me. Plus, those Progressive springs cost $50 anyways, might as well drop the buck and get some higher quality suspension.
Does anyone have any tips on what I should look for (or feel for, I guess) when I'm riding in order to tune my suspension to its ideal settings? Like, behavior in corners, behavior over bumps, deep bumps, "pogoing"?, and stuff like that?
Good write up, Alpha. I've been trying to build up the guts to take on this project. I have the Clymer manual that follows through until 2002, no differences between those and '04 forks?
Quote from: groff22 on April 16, 2006, 05:26:10 PM
Good write up, Alpha. I've been trying to build up the guts to take on this project. I have the Clymer manual that follows through until 2002, no differences between those and '04 forks?
I used a Clymer manual for 1989 to 1996 bikes, so yeah the forks are the same. Do you want a full detailed write up of what to do to do new springs? I can do that pretty easily if you want.
Quote from: AlphaFire X5 on April 16, 2006, 05:53:16 PM
Quote from: groff22 on April 16, 2006, 05:26:10 PM
Good write up, Alpha. I've been trying to build up the guts to take on this project. I have the Clymer manual that follows through until 2002, no differences between those and '04 forks?
I used a Clymer manual for 1989 to 1996 bikes, so yeah the forks are the same. Do you want a full detailed write up of what to do to do new springs? I can do that pretty easily if you want.
That would be good. I'm not personally doing this soon, but it's a pretty common topic on the forum and adding a write-up to the FAQ would be handy. Include the link to where you calculate the spring rate or whatever.
Yes, it would quite a beneficial thing for all :) Then maybe John can add it to the How Tos 8)
Quote from: AlphaFire X5 on April 15, 2006, 06:43:54 PM
It wasn't described very well in the Clymer manual....
Not to be disputing the "bible" but is anything described well in the Clymer manual? The carb section is a study on how not to fix your carbs. It uses vacuum gauges that you can't find to balance them, methods for measuring float height that don't work, it doesn't tell you how to adjust the air/fuel mixture, and it doesn't tell you how to remove the emulsion tube and piston guide. I would have never gotten my carbs adjusted right without this site.
Handy Guide to Suspension Adjustment
Reprinted without permission.
Bike turns too slow or runs wide at exits or requires significant force on handlebars:
Lower front end (usually in 3mm steps), or if you are in a hurry, remove a line or two on the preload adjuster on the front. If you lower the front, double-check the mechanical bottoming.
Raise the rear by adding ride height. Remember that on most sportbikes 3mm at the shock is about 6mm at the axle.
Bike is nervous mid-turn, particularly in fast sweepers:
Raise front end. If this makes the bike turn too slowly, try raising the rear as well.
Bike head shakes beyond acceptable limits:
Raise front end or lower back end.
Bike head shakes on deceleration:
Check/adjust steering head bearings.
Bike steers well in single turns, but steers too slowly in quick transitions (R-L-R):
Lower both ends of the bike equal amounts or lower center of gravity some other way or work out more, you big sissy.
Bike dives too much on brakes, too easily lifts rear wheel:
Add fork oil, add compression damping to forks, raise front, lower rear.
Bike's rear wheel chatters at entrance to slow turns:
Rider should slip the clutch into the turn after the downshift or buy a bike with a slipper clutch, like a ZX-6RR.
Front wheel chatters:
Add rebound damping to forks (or check to make sure you don't have too much damping) or try a different front tire.
Bike doesn't have rear grip:
Check free sag, try softer rear spring, try less low-speed compression damping, lower rear of bike, make sure the rider isn't entering the turn too slowly and trying to accelerate out too hard to make up for it, make sure the rider is hanging off the bike.
Quote from: AlphaFire X5 on April 15, 2006, 07:42:23 PMhttp://www.peterverdonedesigns.com/introduction.htm
I used to live kinda close to that guy... Right here (http://maps.google.com/maps?f=q&hl=en&q=608+Amaranth+Mill+Valley,+CA&ll=37.911023,-122.573004&spn=0.039141,0.096817). Some of those roads are just insane... I used to ride my mountain bike on them all the time.
So, Alpha... You wanna do my springs for me? :icon_mrgreen:
did the clymers manual say to measure the amount of fork oil to put in by volume? the haynes manual gave a volume of oil, but says to go by oil level in the forks. this is measured while the fork is fully compressed, from the top of the tube to the top of the oil. i think the proper level changed a few times, but on my '89 it was 99 cm from top of tube to top of oil. measuring this way corrects for any extra oil that may be left in the fork after pumping out the old oil.
i don't have the manual with me and don't remember if the spring etc was supposed to be in the fork for the measurement as well.
Spring out.
For my write up, see this thread:
http://gstwins.com/gsboard/index.php?topic=25706.0