Front Brakes - Shimmy

[srfjm]

Has anyone else experienced an ugly front end shimmy when braking hard? Under normal use, all is well, but a couple times now when braking hard, I get an ugly vibration/shimmy on the front end. I guess a trip to the dealer for a check is in order... warped rotor maybe?

[szowinista]

I am experiencing the shimmy on front wheel while braking hard also.
It usually occurs with the second and third hard breaking during a ride.

If you know the reason let us know.

[MacBandit]

Have you checked your front tire air pressures.

[szowinista]

good point.

Actually I have my pressure below standard. 2,30 instead of 2,50
I will up the preassure, and see if it helps.

[MacBandit]

Standard pressure is 2.35bar so your fine at 2.3.

[MacBandit]

Something to consider is that maybe your front suspension is too soft. Remember the more you compress the front suspension without compressing the rear the steeper the steering angle becomes and the shorter the trail. This causes the steering to become quicker and less stable. If you have an R or have replaced the suspension I can give you some tips on adjustments that will help prevent this.

[srfjm]

Yeah I'm running my tire pressure on spec. The front suspension may be an issue, but I don't think it's causing this... though I could be wrong. I really hope it's something wrong with the brakes that can be fixed (under warranty hopefully). I wouldn't want to have to replace my forks in order to have safe braking

[MacBandit]

If it's only occasionally then it could be a combination of hard braking and the specific road conditions you are going over. Another question would be how much tire do you have left?

[srfjm]

Only 1500 miles on the bike... plenty of tire left.

What I did notice today though, is that the outer rotors have play in them where they're attached to the inner gold mounts. Is that normal?? I never noticed that on any other bike I've owned, and when I check my buddy's 848, his were solid - no play.

[MacBandit]

Yes the rotors are suppose to have play. They're called floating rotors. It allows the rotors to be a little out of true during heat up and cool down and over the life of the rotor and still allow you to have maximum braking without pulsation.