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Discussion Starter #1
Hey guys ! I need some help with wheel chatter, Im riding a 2002 crf450r, its lowered 1.5 "'s in the front with stock valving and the rear is stock, Im running michelin pilot sm slicks usually about 24 PSI both front and rear, also have 20 mm offset applied triples, stock front and rear brakes with a 320mm EBC rotor on the front. Like I said at OVRP i was getting some wicked wheel chatter both front and rear. Im thinking its the lowerd front forks which im thinking about going back to stock on. let me know what yall think !!!!!
Thanks in advance
 

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I'm running red barron triple clamps with adjustable offset between 12mm/14mm offset and the forks are internally lowered one inch...I had a little chatter and a high speed weave when the clamps were offset at 14mm. When I switched to 12mm offset and slide the forks through the clamps about 5mm the bike feels sweet.Im running the same tires in the softest compound at 22psi cold. Aren't 20mm offset clamps for motocross? I'd say try slidin the fork tubes up to reduce trail and make the steering angle a little steeper but your front end is pretty low already. Is your sag set properly? just throwin out ideas:hmmm:
 

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Could be lots of things.

Did you say the front was short but the rear is still stock? That can be a huge issue if the chatter you get is really just lack of grip. Also- does the course you run have a dirt section?

At that psi- what is the differential between cold psi and hot psi? Should be + 2 to 3psi.

If after fixing those and checking head bearings, swingarm and suspension bearings and bushings (to eliminate extra inputs to the handling) I would watch some video of yourself and anyone faster than you. Pay attention to the body positioning at time of chatter and make changes.
 

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Sometimes reducing rear ride height will help with front chatter. Dropping the front without dropping the rear may be the source of your trouble.
 

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Discussion Starter #6
The forks are internally lowered with delrin spacers and the usual, the rear is stock, all bearings are brand new with 3 rides on them all tourqed to spec, yes we run on dirt at all my tracks, good sized doubles and whoops and berms. Umm forks are set at stock position in the clamps because already lowered 1.5 inches. ill need to check the sag as i havnt done it in a while whats your suggestions on that ??? 90 mm ?? Im unsure exactly where to put it because of the front being lowered ?????
 

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I run 80mm sag on my '02 CRF. Chatters at some tracks, not on others. Try moving around on the seat too.
 

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When you internally shortened the forks did you decrease the amount of fork oil. If not it will affect the air spring which is very progressive. I had a shortened fork once with the same amount of oil I had been running and it was like a solid front end after a certain amount of the stroke.
 

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Try a different tire.

I fought with chatter using the 17in michelin all last season.

I'm running an Ohlins front end on my 04 CRF and tried going back to the stockers to make it go away, I tried a bunch of different triple clamps and offsets and it was still there.

I swapped the front tire for a dunlop 17 and the chatter went away.

A bit disappointing because the only brand paying contingency here was michelin.

I've now gone to the 16.5 bridgestone SM front and I'm not sure I could make this tire chatter if I wanted to.
 

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Try a different tire.

I fought with chatter using the 17in michelin all last season.

I'm running an Ohlins front end on my 04 CRF and tried going back to the stockers to make it go away, I tried a bunch of different triple clamps and offsets and it was still there.

I swapped the front tire for a dunlop 17 and the chatter went away.

A bit disappointing because the only brand paying contingency here was michelin.

I've now gone to the 16.5 bridgestone SM front and I'm not sure I could make this tire chatter if I wanted to.
Did you get to try the SMF29F Michelin?
 

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Discussion Starter #11
Nope im running the older version with the tread all around, i think they are the early SM14's its tire for new tires as i have 2 races on them so i think im going to bite the bullet and buy a set of the new dunlops in a soft compound. It didnt seem nearly as bad at Englishtown on the "big Track" then it did at OVRP................
 

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Discussion Starter #12
I think im going to go back to stock - 1/4" on the forks just to speed up the steering a little as I cant slide the forks up too far. Im also going to have them re valved and set up for my weight and height/ riding style. Also the rear shock needs some attention so that wil get a rebuild, new gas charge and a stiffer eibach spring................ any more suggestions that arent too expensive, im open to them

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