Warped brake disk?
 

I've noticed over the last couple of weeks that my bike (K4 faired, if it makes any difference) is feeling a bit rough under braking. It feels like the front brake pads are 'bobbly' (scuse the technical term).

I had no idea what this could be - other than perhaps worn pads, but the bike only has 3k on the clock.

However, in a bizarre occurence of Small World Syndrome, I bumped into someone from this forum whilst on a training course who said it could be a warped front disk.

I've done a search on old messages for folks with similar problems, but they all seemed to have a shuddering under braking, whereas mine isn't that bad - it's just feels a bit rough. The front braking power (under gentlish braking) doesn't feel as great as my old K1 either - it feels somewhat spongy.

The front braking power in an 'oh ****!' moment is in no way spongy....seeing as I inadvertently tested it out a couple of weeks back, and ended up on the floor!

I'm thinking of taking it to a garage to get it checked out, but am torn between waiting until the 4k service is due (in about 5 weeks time) or getting my peace of mind back.

So, does anyone know if this does sound like a disk problem, and if so...<sound of credit card sqealing in the background>...how much a new one would be, fitted?

Ta
Jo

hmm,
check make sure you havent any stones caught in your pads

also check tyre pressures,

you sure its not just the surface of the road ?

Definitely not down to the road - it's happening on smooth tarmac as well. Dunno about stones - maybe I'd get the problem all the time - but then again, I had been having to ride daily along a few streches of road being resurfaced (loads of grit).

Tyre pressures - bl**dy good idea.......seeing as I just tend to swing me leg over the bike and ride...rather than remembering to do the routine checks :oops:

Will check em out tomorrow.

Ta very much

Jo

and while your checking your tyre pressures, check your oil :!: :shock:



im gonna check mine in a min after reading "the mass" thread :)

Yeah, I read that thread and my stupid demon starting laughing at me.

Note to self - check oil, and trye pressures (well, check manual for correct trye pressures, then check trye pressures).

On a positive note, I did check my chain and refilled my scottoiler on Saturday (but then...the scottoiler had been empty :oops: :roll: )

Jo -> liability to own life and bank balance

A warped disc will most commonly manifest itself as a 'pulsing' of the lever, often most noticeable when using the brake lightly.

At this time of year, the grime and junk that builds up on the discs can sometimes make the brake juddery and uneven in use, make sure the discs are clean before condemning them.

One other thing to check is that your head race bearing isn't loose.


.

your local dealer should have some sort of tool to assess if they are warped, or if they take them off and lie them on a flat surface eg glass, should then see if warped.

with mine i had an irritating squeak from the front, speed related. the brakes worked fine unless as squid says at low speed, and then it was literally just before stationery they'd go all weird (another technical term similar to bobbly!)

just had new discs on my k3, the dealer diagnosed it very quickly using the method above, without charge.

There's a few things you can check mate if you have brake judder. Check one of your brake pistons isn't stuck inside the caliper, that can cause it too :)

Thanks for all the tips. Fortunately, Bikageboy seems to have come up with the solution....put some bl**dy air in the tyres!

The front was down to 20 (the rear was 28 ), but now it's back up at the correct pressure, all seems well. Will check it again tomorrow morning to make sure I don't have a slow puncture.

I'm glad it does seem to be the tyre, because the thought of me taking my brakes apart is not worth even contemplating :shock:

Am making a mental note to myself that the term 'routine maintenance' implies having some sort of maintenance routine :oops:

Thanks again
Jo