judder with front brake

[duggyr]

Hi can anyone
when i brake using front brake i get a severe judder though the bars. It happens at all speeds high and low. the higher the speed the worse the judder. Doesnt happen with back brake. Just had MOT and passed with no advisories? Although they did say the needle on the Kg meter when testing the front brake did flucuate?
any ideas pls?

[alexwitham]

Common problems associated with a brake judder are:
A Lose Mudguard
Warped Discs
Warped/Damaged Front Wheel (this was what was causing my juddering)

[duggyr]

front mud guard not loose. not sure about the disc warpage but MOT yesterday didnt show any probs, as for damnged front wheel it looks ok?
thanks for your input

[alexwitham]

The below is how I do it and it's a total round about way of checking for a problem with warping:

Put your bike on both stands, bluetac some dowel rod or similar to both of your fork legs (one at a time) ensuring the dowel is touching the disc ever so slightly and slowly spin the wheel. If the discs are incorrectly seated/are warped/the wheel hub is not true then the discs will scrape against the dowel rod and make an intermittent chafing sound implying there is a problem (the sound symbolised the disc moving to and fro). Use a feeler gauge to check tolerances cross-referencing with the Haynes as there is an allowed tolerance.

[spud]

might be worth checking your head set isnt loose , put ur front brake on and put ur hand under the top yoke and around the stem where the dust seal is and with front brake on rock ur bike back forward to check for any play/movement , if so take top yoke off and tighten the bottom lock nut up to take any play out ,

spud

[skinnydog0_0]

I would go with Alex and spud. Probably starts as warped discs, and then shakes the headstock loose.

[CMSMJ1]

If you can feel it in the lever at high adn low speeds then warped discs are what you are looking at.

[Neosophist]

Yep!

How are your pads?

If you don't have a front stand, you can jack the bike up under the engine with a block of wood to get the front wheel off the ground.

If not you can push the bike backwards and forwards.

Dowl, Rod, anything you can fix to the fork and get to just make contact with the disc... high and low spots will show up as increased / descreased sound of scraping.

If you have a dial-gauge use that instead while rotating the disc. :-)

[porndoguk]

also check the fork bushes after all else has been rulled out,