Disc Warp

[steve_rt]

I have had the K-Tec fast road kit on for about 6000 miles now, and afetr about 5000 miles i started noticing a kind of "wobble" in the brake pedal under braking, feels like the disc may have warped? its quite uncomfortable now every time you have to brake! is there any other explanation for this sensation (oo er), and should they be warping this early?!

 

[hon_n_gem]

i do believe that if u really CANE ur breaks then they might do that steve

Nah only jokin sonny, send them back and give them a good thrashing!! grrr

 

[BenR]

warped..........yay!

 

[Chris_H]

discs dont warp laddie.

They do wear unevenly due to bad fitting though which causes judder.

 

[steve_rt]

so is the term "warping" just another way of saying uneven wear?

how can they be fitted badly chris? i fitted them myself, but am by no means any expert so where might i have gone wrong?

in any case, i take it i need new discs?!

 

[Chris_H]

warping is a miss used term, for something to warp it must bend. For something to bend it has to bend on both sides.

If you ever spin a so called warped disc up on a lathe you will see its worn unevenly not actually warped.

Anyway when it wears unevely you get judder.

The main problem when fitting discs is actually mounting them. The hub flange has to be perfectly smooth and flat with no rust.

Lets say a bit of sand is stuck between the hub flange and the disc bell, this bit of sand is 0.1mm in dia, now that may sound a lot but at the discs edge that 0.1 is magnified to 1.5mm or something now a spinning discs wobbling back andf forth 1.5mm is a fair bit of wobble and will cause a pretty severe judder through the pedal.

Anyhoo this is the main prob. What i do is get the wire brush attachment in the drill and clean the flange up or use a file to make sure its flat.

So what you could try is taking your discs back off, cleaning up the hub flange and cleaning the inside of the disc bell out then sticking it back on. The judder should hopefully nigh on dissapeared, it wont completely go because the disc has now worn unevenly but it shouldnt be noticeable unless you are braking very heavily.

You could also get the discs turned up true on a lathe, usually about a tenner a disc.

 

[steve_rt]

ah chris thanks v.much for that you have cleared it up for me, ill try that then!

cheers again