Front shaking violently!!

Just installed a set of brand new Dunlop 218 on my VFR-- they came off of a friend's GSX R and were never used. Since then, the front shakes very hard when I let go of the handle bar and decelerating around 45 mph! It never did that before and only does it during around that speed.

Took the bike to a suspension shop. Tires pressure and balance checked OK. The forks are fine too-- bike only has $7k miles on it. But, can't figure out why the bike does that

The only thing left is to change the tires. Any one had a similar problem? Any other suggestions? Also, which tires work best on your VFR for sport riding?

Thanks.

 

The steering head bearings have a preload spec of X amount of torque on the steering head nut. If the bearings are not preloaded at the spec'd torque you will get a bar wobble under decel. It isn't like the old days where you could just wiggle the forks and check for play. They are preloaded.

 

Yep, they do that. Tires are the main cause, hate to tell ya, but if it bothers you a lot you'll need to swap em out. i've gone all over this one, unless you want to go to the trouble to install tappered timken head bearings yu'll have to put up with it that said the cure is to get some Diablo as in Pirelles, head shake is gone..

 

Yep. The preload was checked too and adjusted-- unfortunately that did not cure it either The mechanic suggested steering damper, but I think I will try new tires before doing the damper. I have not seen a VFR out there with steering damper

 

Have heard great things about Diablo tires. As much as I hate to waste new tires, I think I will try another set of tires before other more expensive options. :lever:

 

Also just what is your tire pressure? 33psi in front should be all you need on any tire. Also look for cupping, if it's there thats another reason as new tires wear, some will wear different with different results in feed back. I know the 208 did quiet a bit of shaking nothing bad only when hands of coasting thru like the 40mph range, once your hands are back on it's gone. Bugged me so I went and got the bearings, but before I had time to do the swap I put new tire on not thinking that was the cause and Bingo! wobble gone, so thy bearings are sitting in a drawer, maybe some day they'll get installed but for now all is Good.

 

That is exactly what is happening on my bike with the Dunlop 218s When hands off coasting around 45-50mph is when the shaking happens. I am so glad that you saw the problem going away by changing the tire. Thanks for the info.

 

It may be the balaning of the tire to.. If it is out of ballance then it will do that.. the rim weights may be placed just a tad bit off..

 

one other thing i can think of and it is the hardest to detect if during the install some of the belts in the tire itself were damaged,it would not be readily visible to the naked eye or to a wheel balancer because the tires mass is relatively unchanged.sometimes you will have a slight swelling. when you change the tire and it goes away then you will know.

 

Glad to help..