Calling all 636 owners - headshake is killin me

I have a '06 636 that I have been battling w/ headshake all year. I have run D209's both 190 and 180, lowered the rear all way down and raised front flush w/ triples.

Its got ohlins rr shock and 20mm ohlins front internals....sag numbers were good, etc etc. 31/29 psi and all that other jazz.

I have never run any other tire than Dunlops...hate to switch, but would maybe a pirelli be better in this case? or any other tricks...seems these bikes were prone to do this. thx all.

 

my problem is chatter..... no headshake.... you might want to try some bridgestone 002s

 

I don't think turning the bike into a chopper is going to fix your headshake. I would start of by putting the front and rear ride heights as close to stock as possible, countering for any differences in your race tires vs stock/oem tires. Then make sure all your wheel bearings, stearing head bearings, and swing arm bearings are in good shape, and properly torqued. Make sure your rear spring is appropriate for your weight, and the sag is as close as possible to where it should be. If after all those factors your still getting head shake, It's more then likely one of two things. The bike is bent (wheels out of alignment maybe), or rider technique is causing the headshake.

 

Change the lops , Headshake gone !!

 

thx for replies....will try bearings, bike was crashed as a street bike. and start from the bottom i guess....

 

Switch to Pirelli. Problem solved. "Trust me."

 

My 636 does it as well and per T-Man did what you have done. Removed shim in the rear to lower it and flushed the forks in the triples. Mine still does it I just adjusted my damper a little more firm and ride it. It never gets completely stupid just shakes and planes out. It's just one of those things that doesn't bother me, to you it may be too much to deal with. Mines handles superbly in every other area; grip, feel for traction, turn in yaddy yaddy yadda. It only does it on the dunlops. If you do switch tire manufacures only lower the front by 5mm. That ought to put you pretty close to where you need to be for everything else.

 

I've got my 03 636 with the forks about 4 mm down in the triples to help battle that issue. If they are the old style 'lops I read somewhere that they have a tendency of growing like 30mm at full speed.

 

I would try lowering the front or raising rear like Brian said. I've had this same issue using a slick which was a little taller tire than what I normally run. Went away after going back to a DOT.

 

I assure you lowering the front will end in nothing but buying parts.

Brian your 03 has different geometry so what works on yours will not work on ours. The rear does grow alot at speed therefore "raising" the rear which increases instability. Same with lowering the front, it'll turn like hell but with the Dunlops just increases headshake/instability. With the other manufacturers ours does need to be a little more nose heavy to be in the same geometry realm. Because they don't grow you can take advantage of that and lower the front to give a better turn in while maintaining stability at speed and under acceleration. Just ride the hell out of it.

 

Taller front or rear or both. If both how much more than UK209s?

 

I had the same problem with my gsxr, I use the british 209 dunnys and they are so tall I used to get head shake at around top speed. My local suspension guy (GP Suspension North) did the geometery and other adjustments and made the head shake almost completley gone and to a point where the shake is there but I just stopped noticing it. The thing he did to help was to raise the bike up high and get the swing arm angle corrected for the taller tires, I have fork cap extenders on my ak20's so the forks are dropped a total 10mm he also added a 5mm spacer to the rear shock, I used to beable to put my feet flat on the ground but now I have to tippy toe Anyways, the bike IMO responded very well to the adjustments and I love the Dunnys, I know it's not a kawi but I thought it would at least give you some insight.

 

Taller front. At the time I was using PR's and tried the 1200/1800 Michelins. They are taller and peaked more than the PR's. Only ran them at a track day so wasn't worried about pulling numbers and I've never run the Dunlops so I'm not much help there. Is the shake under heavy acceleration or high speed? Mine was under acceleration. Knowing a few more details might help.

 

Yeah The Shake Is Bad Under Acceleration....seems Like When I Change Direction Under Acceleration Its Worse...like Straightaway After Turn 1 And Bowl T2 At Talladega. Have Not Had It At Road A Yet.

If I Go To Pirellis Should I Raise Rear And If So How Much?

Thx For Reply Fellas

 

Start with none. It is a given your bike doesn't handle as is... So one change at a time... Pirelli's for now.

 

I agree, see how it feels to start with the different tires. If it's still shaking start making small changes and see where it's leading.

 

man i do appreciate all the help fellas...will try advice.

 

did you solve your chatter problem? I run the 002's also with a stock suspension with the sag set on a 05 zx6r and was getting very bad chatter at pocono,