This is ona 93 CBR900RR with 56,000 miles. Here's a description, I apply brakes maybe using about 50% effort on the lever and from higher speeds (approx 40mph) you'll get a pretty severeshudder. I began watching through the triple clamps/bodywork at the axle/brakes area and could see it literally BLUR as the front end chattered away. This kinda worried me so I got new (Galfer) pads and replaced them a few days ago. The problem is still there and most would assume a bad rotor. But the odd thing is, I don't feel it pulsate at all in the lever. I checked bearings in the front wheel and all looked well. Greased up the slide pins and noticed one thing though, it looks like the speedo side is slightly closer to the left fork. Almost off center, a little to one side maybe? Is there a washer/spacer that may be missing? Can I warp a rotor and not feel it in the lever? If I use less pressure, it doesn't chatter. If I use more force it seems to slow okay with little or no chatter. Kinda strange because I always hear you should feel a pulsating in the lever. That's what Ive'read using the "search" function so thought I'd ask and include some details. Thanks for any input/advice, etc.

 

Oh and I checked thickness on the rotors. They were both in spec, .440 (ish) if memory serves me correctly.

 

I'm guessing this bike is new to you, so you really don't know how it was ridden previously. The first thing that came to is that the bearings should need to be replaced. W/ that many miles on it's bound to have been wheelied. When the bike comes out of a wheelie hard, it can cause a flat spot on the bearings.

I don't know about the older 900's w/ a speedo drive. Some else should chime in....

If you've pulled the front wheel off, thumb thru a parts manual, and see if all the parts listed were there when you worked on it. Check Ron Ayers if youwant to see it online.

 

Could be a couple of things, (1) bearing in the steering head, or not correct torque. In Spec this one first! (2) Bushings on the fork could be a bad bushing Check for play.
Easiest thingto do is jack up the front end off the ground remove wheel and check everything for play.

 

Thanks for some input... I've actually owned the bike since 2880 miles. And rarely wheelie it (sad but true). I'll check steering stem torque again. And Robert82, by bushings, do you mean in the forks themselves? If I remember right, if you see brass showing through, they should be replaced? I was thinking of fresh oil in the forks since it's been 3+ years since I swapped some in. The wheel bearings are 4 years old with about 10,000 miles on them max but they may be the culprit. Maybe a bad button on the disc? I triple checked on the way home, no vibrations in the lever but you feel/see the front end itself shudder.