Suspensions Settings

Jotaman

Hero member
Location
Verrierdale, Qld
After much pain and anguish i am still no closer to have a decent handling set up and so i would like to put the question to the collective wisdom:
Rear Shock: Dynamic Sag (rider only), Spring Length, Compression and rebound settings: by make (YSS and Wilburs preferably, but will be quite interested in Gazi)
Front: 38mm Marzochi Standard: Dynamic sag, Fork oil amount and weight/grade (180 and 120)
Front: 38mm Marzochi Race tec emulators, Dynamic sag, Fork oil amount and weight/grade (180 and 120)

Your information is greatly appreciated:
FYR i will tabulate all findings and publish accordingly - might even get some decent handling bikes out of it


Peter
 
Hello Peter,

what exactly is the problem, please? Is the bike waving when cornering or is it just not cornering well? What swingarm does it have (standard, upgraded one or an RGS-type one?)? Does the bike have standard rims/tires (which and what pressure?) and does the fork have a brace?

Here is roughly what I have done to my bike and that one handles (for me) perfectly:

-GSX-R Rims with BT012SS, front 2,4 bar, rear 2,7 bar
-Fork-brace on the front, 10 grade oil in the Marzocchi, progressive springs, all sensitively relaxed so it operates freely, 150mm air gap (forks compressed, springs out, measured from the top
-sage on the front with rider only is set to roughly 30% of overall travel, 10% without rider
-K&J swing arm (similar to the RGS I would say, maybe a bit stiffer), YSS shocks with 370mm length, sage set to roughly 20% with rider on. Rebound damping closed just so that she does not wave in corners

Works very well, handles like a dream and is much comparable with good bikes from the 90's I would say for road usage. For race usage, it would have to be a bit "harder" so the suspension does not compress that much in fast corners.

HTH
 
Hi Lothar,
Thanks for that, can you confirm your compressed spring length (at rest), can you also confirm number of clicks on compression and rebound dampning - counting out from fully closed  (for reference).
The RGS (YSS rear and standard front), is just harsh and not compliant.
The Jota is just plain scary - front and rear (Racetec front and wilbur rear)

Peter
 
This has come through from Mr Suspension improvements (good man).


Rear rider sag 30mm  +- 5mm (From topped out to rider seated)

Initial sag 0 to 10mm

Preload around the 15-20mm

Wilburs and YSS rear sag  will be same as above

Wilbers      start point for dampning

reb          16

Ls comp    16  ( add more adjuster clicks if needed)

Hs comp    16  ( keep H and L  comp within 5 clicks of each other)

Front emulators 3 turns preload on blue springCan go firmer or softer if necessary(1 turn either way)

Oil  15w (can use 12w or 10w for softer feel)

oil level  150mm from top of fork, (collapsed, no spring but valve in place)

Peter
 
Jotaman said:
Hi Lothar,
Thanks for that, can you confirm your compressed spring length (at rest), can you also confirm number of clicks on compression and rebound dampning - counting out from fully closed  (for reference).
The RGS (YSS rear and standard front), is just harsh and not compliant.
The Jota is just plain scary - front and rear (Racetec front and wilbur rear)

Peter

Hi Peter,

not sure that will help you as I weight a lot more than you I guess. I can count the clicks, but to compress the spring completely, it would take me a second person, best 3 in total: 2 pushing the bike down and one measuring. I don't have access to that many people currently... But you can look up maximum travel on the YSS webpage I think.

More importantly though is the travel of the swing-arm compared to the rear-frame. If the full travel of the swingarm measured vertically above the rear wheel axle to the frame rails is - say - 10 cm, the bike shouldn't sink down more than 2 -3 cm when you climb on it. If you can't measure it, one could calculate it (would have to dig out some formulas to really do that, but should be possible...).

The way I set up the bike is typically like that:

-first of all make sure the front fork is fully relaxed: open all screws and nuts that hold the fork on the bike except for the upper tripple-clamp screws (read: axle nut, the screw that holds the axle in place at the lower end of the fork, fork brace and/or mudguard screws, lower triple clamp screws). Now take the bike off the center stand, pull front brake lever and compress the fork as much as you can several times. Next fasten the lower triple clamp screws. Repeat the compression of the fork again several times. now fasten the fork brace, compress the fork several times, fasten the mudguard screws, compress the fork several times, now fasten the axle (first tighten the nut, compress several times, then the screw holding the axle in place). Your front should work as easy as possible now.

-next: check the sage of front and rear without and with rider on. Front can be adjusted by spacers between the top-cap and the spring, the rear with the spring-compression-rings. If there is no sage without a rider on, spring preload might be to much. More important though is the sage with the rider on.
-now pull front brake and compress as much as possible. if you can fully compress the fork, you need to fill in more oil (less air-gap) until you can't bottom it out.
-now you check the following: warm the bike up on a ride so that the oil in the fork gets to a working temperature. Stop for more adjustments:  if you pull the brake lever and compress the fork with a short but massive push, the bike needs to come up above the upper resting point and sink down to the upper resting point without waiving or a second move. if it does, everything is fine. if it waives/bounces a second time (or even more), the rebound damping is to low and you need to fill in a higher grade oil (or mix some higher grade oil with your existing one). If it does not flex out beyond the upper resting point, your rebound damping is to stiff and you need lower grade oil.

If front works fine, go to the rear and repeat the process. if that seem to work fine, go for a ride and first focus on the front again: When you brake seriously, does the front shatter or the fork bottoms out? if so, increase oil-level/reduce air-gap again. 1 cm can make a big difference, so be careful. Does it take bumps from the road easily or is it to hard for your wrists? To hard: wrong oil grade. if the bike gets lifted out to much after your front wheel left a pothole, your rebound damping is to low => higher grade of oil or spring is to stiff.

Same on the rear. Correct sage adjusted, make someone hold the bike at the front with front brake engaged while you push down the bike as much as you can and release it quickly (simulating a ride over a bump). if it goes a bit beyond the upper resting point and goes back to that point - rebound is set correctly. always start from fully open, so you see the result of wrong settings a bit more obviously. Now close the rebound damping by 5 clicks and check again (YSS has something like 50 clicks... Wilbers I think have just 12 or 15 or so; no quality difference here, it is just different. On Wilbers or ?hlins, please always just do 2 clicks at a time max.). Repeat that step until the bike  does not go up beyond the upper resting point. now go 2 clicks at a time more open, until it does go beyond the upper resting point to go down to it again and stops there.

-Now you have the basic adjustment done and will for sure recognize an improvement already. Go for a ride and check if the bike waives in long curves. If so, close the rebound on the rear on each side by 2 clicks and check again. if its better but not yet gone, another 2 clicks closed etc. just until it stops waiving (on Wilbers and ?hlins always just 1 click at a time)

Have done several bikes this way, all to the satisfaction of the riders.
 
Lots o' Lav riders swear by Race-Tech
http://www.laverdaforum.com/forum/index.php/topic,91234.msg301799.html#msg301799
 
mauricejota7604 said:
Hey Pete are you sure she hasnt got a bend???

The RGS did have a bent fork tube, which is odd as i have never crashed her, have since swapped out for a new set.

Overall the RGS is greatly improved based on the recommended set up from Steve, that and putting the dampner seal unit round the right way/wrong way to the book, based on yesterdays testing its almost like a motorcycle again, just need to drop a little more pre-load on the rear.

The issue with the Jota appears to be a combination of insufficient fork oil, set up on the racetec emulators and rear shock being way out - i should have her finished shortly and will report back accordingly.

Hey Lothar: Thanks for the detailed procedure, once i get the basics of the set up in place i'll refine accordingly - it is a process, but one that i'd like to have in place before i soul stir the Couger again.

Peter
 
dont really want to see that again old son-kinda target fixated on the show-was impressed when you rode her out
 
So I now have an RGS that has a semblance of decent handling (need to change out the head bearings), the basis of which is as follows:
Rider 'dry' weight 86kg's
RGS:
Front end: standard set up, based on 150mm of air gap with a 10wt fork oil, it should be noted that the manual reference at 300cc produces an airgap of ~110mm.
Rear shock:
YSS
Preloaded spring length 222mm (rider sag is 35mm)
Compression dampning: 17clicks out
Rebound dampning: 28 clicks out

Jota remains a work in progress, but has moved on from trying to kill me, i am currently chasing an electrical issue (cooking fuses) though so suspension progress has been slowed.
Wilburs Rear
Preloaded spring length: 203mm
Compression: HS 16 clicks
                  LS 17 clicks
Rebound:      16 clicks

Front End: Racetech emulators (38mm Marzochi)
Preload: 3turns (i am contemplating further reducing the preload by a quarter of a turn), 150mm air gap with 10wt fork oil


Peter
 
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