Topic: front end bounce...... caliper or rotor?

[EMONTANA]

my front end bouces from about 30-40mph then gets less noticable at greater speeds....... i took the front tire to get it balanced and they said that it was already in balance and the rim is true...... i didn't think it was the forks becasue the bounce increases and decreases in time with the speed of the bike..... could this be a warped rotor(looks fine) of bad pads?

btw....this site is the shizznizzz........ thanks

[Einyodeler]

How old is the tire,sounds like it could be cupped or not fully seated on the rim in one spot.

[EMONTANA]

the tire is fairley new and the tire guy said it looked like it was seated correctly........... maybe i should get a second opinion but when i lifted the front tire and spun it everything seemed to be running in a straight line.... ie tire bead and rim

[Raul CB750K1]

It could sound stupid to ask this, but does it happen in any road? If a wheel is unbalanced, at low speed is not noticeable, but the higher the speed, the higher the effect.

In your case, the effect dissapears when speed increases. Some roads have slight bumps, and at low speed the bike cath them all. When the speed increases, the bike cross all of them in the crests, so you don't notice so many bumps.

[EMONTANA]

yeah.....it is all roads...... i think i'm gonna take it in to another shop and see what they say.....

Thanks for your responses.

[mcpuffett]

hi , if it was the front disc buckled you would feel it through the lever, are your spacers and bearings ok?    mick.

[mcpuffett]

just a thought but is everything ok at the back end of your bike? worth checking  mick.

[EMONTANA]

I haven't checked the back yet.....  that would seem an obvious possibility...... I'll check and post the results......

[cjackel]

I have exactly the same problem on my 78 750k.

I used a dial indicator on the wheel with the bike on the center stand and the front jacked up slightly.

An obvious out-of-round was it one area and I used a spoke wrench to loosen/tighten spokes to correct.
It seemed to improve the visual aspect of the problem but the bike still bounces at 30-40 mph and decreases
with speed, just your bike.

I checked my brake pads, caliper, rotor, tire, etc. No obvious problems.
It will be interesting to see what you find out....

[dusterdude]

hell my bike does it too,but at least for the time being im going to attribute it to the old tire and leaky forks

[Uncle Ernie]

You wouldn't notice a warped rotor until you apply the brakes. Check to make sure the tire is seated properly. Also, something a lot of people overlook- what are the bearings like and are they adjusted properly.