Suspension Tuning

[Chili]

Let me preface this question by saying I'm a total newbie at adjusting suspension and am quickly trying to learn the ropes since I will be the chief mechanic/cook/bottlewasher etc since my son started racing this year. My question is I want to make sure his suspension is giving him what it should for performance but with him being a newbie racer I can't really rely on any feedback from him since he doesn't know how a properly tuned suspension should handle. I noticed a few issues in the last race since he has recently started to really pick up some speed and become more aggressive on the jumps that I never noticed in previous races and I think they may be suspension tuning related, although they could also be skill related as well. On a corner this weekend that had some bad braking bumps he couldn't keep the back tire grabbing and overshot the berm, the back tire just kept hopping it seemed, not severely but enough to lose braking power. The second issue I noticed that since he has started jumping farther he seems to land harder than the other kids landing in the same area (flat landings when not clearing a table) when he lands he seems to hit real hard and the bike swaps left and right a small amount, he is able to regain control by being on the gas but it costs him time as the other kids get on the gas that much quicker. To try to give you a complete picture I have set his race sag by the instructions in Eric's book, he is riding a 99 KX80 with what I assume is stock suspension (we bought the bike used) He weighs 110 lbs wearing his gear. Any advice would be appreciated in tinkering with the setup as our race season ended this past weekend and I would like to play with the settings and some other stuff on the bike before the snow arrives here. :(

 

[JTT]

My first suggestion would be to use video, as is suggested in Eric's book. That way you can slow things down enough to actually see whats happening.

As for the braking bumps problem, first question....is the rear wheel locked? If it is then hopping is inevitiable. If not, then a little faster rebound may help. The swapping on landing may also be related to too much rebound as well. Try a couple of clicks at a time and see if this helps. Remind him to land "on the gas" whenever possible, as it assists with the bottoming and the swapping issues.

 

[Chili]

The rear is definately locked when he is coming into the turn. He knows to land on the gas but that is something that he certainly isn't doing everytime he jumps.

 

[JTT]

If the rear is locked, no amount of suspension will help him. Explain to him that he must brake as hard as he can, WITHOUT locking the rear wheel. It's not an easy skill, but one that will pay dividends :)

 

[Jeremy Wilkey]

Not that this is a technique forum, try to get him to not pull in the clutch. This is the first step!

 

[Chili]

Thanks for the replies guys, I was more curious about tuning his suspension than technique tips but I understand that technique will affect the suspension reaction. Being a total newbie to this I was more concerned with the hard flat landings in comparison to the other riders who are also landing flat. I was just not sure where to start to look as far as adjusting his suspension and didn't want to make an adjustment that would make the bike react harshly and buck him over the bars or something. I may take some video and host it somewhere for some of you to take a peek at to give you a better idea of the situaton.

 

[Jeremy Wilkey]

Chili,
Sounds fine, take a look at my tunning guide, it will give you some valuable help.

BR,
Jer

 

[Papakeith]

FWIW from one suspension newbie to another, the tuning guide that Jeremy speaks of works wonders. I was able to dial in my nephews suspension(as much as possible with stock components) in just about 2 hours. We now know what setting to use for him when he's riding rocky trails, Sand pits, loamy tracks, well basically all the conditions we could play with. We took plenty of notes on which setting did what. He couldn't believe the difference. :) Good luck!

 

[marcusgunby]

One thing worse than too little feedback, is too much and some of it contradictory.