Juddering While Braking

[aerobrain]

Hi

I'm getting a juddering when applying the front brake. I've done the test when stopped with the brake applied to see if there's any play in the headset but there doesn't seem to be. Is it still likely to be the headset and if so is it a case of disassembling it all, cleaning up and putting back together or is it likely to be more sinister.

It's a Specialized Allez Elite and the web site say's it's got sealed Cr-Mo cartridge bearings if that helps?!

Might be a bit vague so if there's any other info I should, be giving just shout!

Cheers :-)

Lee

 

[TissoT]

Wheel out of true ... brake callipers not in line with the rim ...Any play in the wheel bearings ..
pull the front brake when stationery to see if the headset is lose !

 

[compo]

If you have no discernable play in the headset then before getting too technical I would give the rims and brake shoes a good clean with some degreaser. Then check the brake shoes are not catching on the tyre wall. If that doesn't help, and having done @tissot's suggestions, then you may need to look at the headset.

 

[MontyVeda]

i got a strange juddering when applying my back brake a few years ago... turned out the rim had started to split at the join (only visible on one side), so have a good look at the rim.

 

[aerobrain]

Wheel out of true ... brake callipers not in line with the rim ...Any play in the wheel bearings ..
pull the front brake when stationery to see if the headset is lose !

I just tried grabbing the rim and moving side to side and there is a very small amount of play. The wheels are brand new, they're Fulcrum Quattros, do you think something needs tightening around the bearings/axle or is it a case of taking them back to the LBS. Want to try to sort it myself as I don't get many chances to get to the shop!

Appreciate all the advice!

 

[TissoT]

I just tried grabbing the rim and moving side to side and there is a very small amount of play. The wheels are brand new, they're Fulcrum Quattros, do you think something needs tightening around the bearings/axle or is it a case of taking them back to the LBS. Want to try to sort it myself as I don't get many chances to get to the shop!

Appreciate all the advice!

Would nt of thought a small amount of play would cause a lot of juddering...
easy to do (Brearings) ...small black ring on the cone with a allen key fixing ... undo with the key and rotate then use the key to tighten
Start to eliminate...

 

[aerobrain]

Yeah I'll try it. I'm getting a creaking from the headset area so need to take it apart to grease at some point anyway.

 

[TissoT]

Yeah I'll try it. I'm getting a creaking from the headset area so need to take it apart to grease at some point anyway.

I would say its more a problem with the head set .. if the amount of juddering you mentioned
try to see if the brake callipers are fixed tight to the Frame ! just a thought

 

[aerobrain]

If it is the headset is it more likely to need tightening or replacing?!

 

[TissoT]

I would say its more a problem with the head set/stem .. with the amount of juddering you mentioned
try to see if the brake callipers are fixed tight to the Frame ! just a thought

Tighten the allen key fixing on the center of the stem undo the two clamp (stem) bolts first
rotate the forks after to make sure you have nt over tightened the center bolt of the stem

 

[aerobrain]

Cool cheers. Starting to get to know how to do most things but not really touched that bit yet.

 

[TissoT]

If it is the headset is it more likely to need tightening or replacing?!

Would say tightening !

 

[oldroadman]

Headset needs adjusting (try to avoid the word "tightening"), it should have zero play when tested by applying the front brake and trying to rock when standing still. By the same token, overtightening will lead to pitting of the bearings and a notchy feel with the head wanting to fall into a straight on position. SO be careful. Other things have been covered, but do check them all and don't assume once one thing is correctly adjusted the others don't need a check. Brake caliper fixings, pad alighment and even application, rim integrity and surface, and wheel bearings should run free with no discernable play at all. Again don't just tighten, adjust by small increments and check after each. Good luck!!

 

[aerobrain]

Headset needs adjusting (try to avoid the word "tightening"), it should have zero play when tested by applying the front brake and trying to rock when standing still. By the same token, overtightening will lead to pitting of the bearings and a notchy feel with the head wanting to fall into a straight on position. SO be careful. Other things have been covered, but do check them all and don't assume once one thing is correctly adjusted the others don't need a check. Brake caliper fixings, pad alighment and even application, rim integrity and surface, and wheel bearings should run free with no discernable play at all. Again don't just tighten, adjust by small increments and check after each. Good luck!!

Fair point, I can be a bit ham fisted at times!!

Will definitely check the brakes as well

 

[raleighnut]

Fair point, I can be a bit ham fisted at times!!

Will definitely check the brakes as well

Brake pads should be fitted so that the front of the pad touches the rim before the whole pad comes in to contact in order to take up any play/flex in the caliper you should aim for about 0.75 mm of "toe in". I find the easiest way to do this is to place a piece of cardboard under the back of the pad then pull on the brake lever align the pad then tighten the nut/allenscrew. This can take several attempts to get right and be aware that the higher the quality of the caliper the less "toe in" is required due to better pivot bushes and less arm flex. This is assuming that rim and pads are both A1 condition.