Front brake judder

Hi everyone,

When I try to use the front brake to slow down, my bike has recently developed quite a strong juddering sensation. The front brake does still work, but makes a bit of a racket and I can feel the juddering through the bars.

Does this mean I should replace my front brake shoes, or do I have a more serious problem with the rim or the forks?

The bike is a Vespa Sprint 1966.

Thanks,
KK

No worries,

I had the same on a '63 Sportique back in the early 80’s. the head bearings just needed a slight tightening.

Might not be the problem for sure but a good place to start.

Cheers,

Jimmer

If your brake drum is oval, it is safer to replace it. There are specialists that might be able to skim the brake drum to re-true it, but it will probably be cheaper to buy a new one. You may be able to get used to it and use it as is for a while but I wouldn’t recommend it long term, an oval drum will effectively work like an ABS antilock system cos the brake will grip on the round part and release on the oval part, you will feel it at the brake lever and notice the vibration. Vespa drum brakes are crap when new so I wouldn’t risk using a knackered one. My advice would be to put a disc brake on it, worth the extra money for the improvement it gives. But in your case check the bearings first. Save your money til you are sure you find the problem.

Thanks mate,

I haven’t checked them but I will, that would make sense.

The bike did very recently pass its MOT, I’m sure it would have failed with loose steering head bearings.

KK

Thank you all for your input.

By the way, if the brake drum is oval, then does this need to be changed for a new one, or can i continue to use it. I guess what I’m asking is, is an oval brake drum safe to use?

Thanks again,

KK

Thanks all, I’ll check out the head bearings first.

KK

If the head bearing castle nuts are slightly loose they will undo themselves over time so you will find the problem getting worse. If that don’t cure it check to see if the brake drum is oval cos that will cause a judder. I’d guess it is the castle nuts loose on the head bearings though. How old are the head bearings? sometimes (rarely) the cage holding the bearings can wear out and break up, but you would notice this all the time not just under braking.

Hi KK,

Have you checked your steering head bearings to make sure they are not loose?

Your head bearing castle nuts may have been ok for the mot, but worked loose after, when they go loose they can go downhill quick. I doubt it is your rim cos you will feel it all the time, not just on the brake.