Need help before june 23

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Jun 4, 2001
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#1
I hope you guys will help. I'm new here and came because some guys at my track said this place was where I need to do some studying. I tried to find the tuning guide ya'll spoke of but it says coming soon. June 23rd I have my first race and I picked a bad time to start trying to learn suspension. Please help! I'm getting confused. I was riding OK, till a guy at the track put 2 clicks up on my compression for forks, and one click on rebound. I told him I was bottoming on jumps. He also just did one click up on rebound for rear spring. Then I rode better than I ever thought I could. He told me next time at the track I should up compression for rear spring. I did. Unfortunately, next time at the track, it was extremely dry and hard. Lot's of people wrecking due to bald track. Including myself. I didn't get a chance to really test it as there was no dirt to grip. However it did seem, that rear wheel was sliding out more. Was this because I may have went too high on rear compression? Or just the bald track? I also noticed my rear end tended to want to come up alot more on jumps...this is very bad...was this due to too much rebound? Also front dives in a little easier in a way that it's tucking under,...again was this due to bald track...or too much compression? BTW, I'm 200lbs...ride MX, jump high and hard, riding 01 yz250. Thanks a bunch for your help.
 

SATxMotoX

Sponsoring Member
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Feb 6, 2001
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#2
I don't know how much help I'll be since I'm not a suspension expert but I'll give it a shot anyways...

I'm assuming that your suspension woes are most likely due to changing track conditions. You have to change suspension to match conditions just like you have to rejet when the weather changes.

One question. You mention that your front end had a tendency to "dive in easier" and was "tucking under". I may be wrong but I think thats a sign of compression being to soft and reboud being to hard.

Also, when you say "one click up" or "one click down" do you mean up=hard and down=soft? I'd also say it's likely that your back end was kicking up due to too hard of rebound setting but it could also be caused by letting off the throttle too soon.

One other point. If you have a service manual for your bike it should give you the proper spring rates for your bike. If you are running stock springs then I'd bet your undersprung both front and back. For whatever reason the bike makers think we are all 5'10" and 160lbs. When your 5'10" and 220lbs riding those stock springs are a little weak. In any case, it could be a starting point...especially if your riding hard and jumping high.

Hope this helps somewhat. BTW, what race are you racing on the 23rd and where?

Adios.

P.S. If you are looking for E. Gorr's latest book on tuning then check the local Barnes and Nobles. I picked one up there for about $25. If I had it in front of me now I'd probably be able to help you more but I left it at my desk at work.
 
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#4
Thanks for the help, you've definitely given me some ideas to start with and yes up=harder, down means softer.
 

Jeremy Wilkey

Owner, MX-Tech
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Jan 28, 2000
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#5
Getting started, shock:
Setting the rebound:
1.) Find a relatively fast straight with braking bumps leading into the entrance of a corner. Reduce (Turn clicker out) the rebound damping until the rear end begins to hop or feel loose. Finally, increase (Turn clicker in) the rebound damping until the sensation goes away.
2.) Find a jump that tends to launch the motorcycle out. The rear end should absorb and then smoothly lift the motorcycle into the air. If the rear end bounces up, add rebound. (Turn clicker in)
3.) Find some large whoops. The motorcycle should track straight through the whoops with the rear wheel extending to the ground before the next impact. If it does not perform as described as above, it is packing and the rebound damping should be reduced! (Turn clicker out) (Please note the guide for sand set-up, as these rules don't apply for sand.)
Setting the compression:
1.) Find a corner with acceleration bumps on the exit. The rear of the motorcycle should follow the ground. If the rear end "breaks up", soften the compression. (Turn clicker out) (If this fails soften the rebound two clicks.) (Turn clicker out)
2.) Find some rough sections, a large jump and a couple of "G-Outs". The shock should bottom on the roughest section but it should not be a slamming sensation. Add compression to fight bottoming. (Turn clicker in.) But avoid going to far as small bump ride will be sacrificed in the trade. Remember the adjusters have a primary effect on the low speed, so even a large change in setting may only affect bottoming resistance slightly. Remember bottoming your suspension is not necessarily a bad thing. You should strive to bottom off the biggest bottoming load obstacle on the track. If you don't you're not getting maximum plushness from your suspension.
Getting started, forks:
Setting the compression:

1.) The forks should react to all track variations. If the forks seem harsh on small bumps or holes, soften the compression. (Turn clicker out) If they aren't, stiffen (Turn clicker in.) until they do feel harsh and then turn back a click or two.
2.) Now find the rough part of the track again. The forks should bottom over the worst obstacle. If harsh bottoming occurs, add oil in 5 mm increments.
Setting the rebound:
The rebound damping is responsible for the stability and the cornering characteristics of the motorcycle.
1) Find a short sweeper. When the forks compress for the turn, the speed at which the forks return is the energy that pushes your front wheel into the ground. If the forks rebound too quickly, the energy will be used up and the bike will drift wide, or wash. If the rebound is too slow, the bike will tuck under and turn too soon to the inside. Find the appropriate balance for each track.
2). With the bike turning well, the wheel should return to the ground quickly yet not deflect off berms or bounce off jumps.
Going to different tracks:
For hardpack to intermediate:
Set the compression softer, (Turn clicker out) front and rear to help get maximum wheel contact and plushness.
Sand tracks:
(Non-square edged bumps); More low speed compression and rebound are necessary. Start by adding 1-2 clicks (Turn clicker in.) of rebound and as the track gets rough, add compression 1-4 clicks. (Turn clicker in.) (Supplementary sand set-up techniques). Harshness is a result of packing in forks. Remember to add compression (Turn clicker in) to help keep the front end from packing. The rear suspension will exhibit packing by swapping. To eliminate swapping begin adding compression (Turn clicker in) until the bike tracks straight and then add rebound (Turn clicker in) to keep the rear following the terrain of each whoop. Don't be concerned if your clickers are nearly maxed out in sand conditions. Unless of course you had your bike revalved for sand.
Supercross:
(G-load, curb hits); G-loads produce slow piston speeds. This means that less dampening is produced by the shock and forks in a situation that causes more of a bottoming load. To set your bike up for Supercross adjust the compression stiffer (Turn clicker in) on the suspension (2-6), clicks and in some circumstances raise oil level and/or change to stiffer springs.
Unpleasantries?
Headshake:
Adjust the forks lower in the triple clamps.
Excessive rear end kick:
Check for packing, which is identified by kick to side in hard to loam conditions. If you observe packing, soften rebound. (Turn clicker out.) This cannot be avoided if you brake improperly and lock the rear wheel up and/or pull in the clutch, on the entrance to corners.
Keep a record of the different settings if you race different tracks. That way you can start at a point that worked well the previous times.
 
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#6
WOW! Thanks for the info, I'll print this and take it to the track with me. BTW, I ride at Bastrop. So if any of you see a YZ250 with #16. That's me and I could sure use some hands on suspension training. Thanks again for the help.