Please can anyone help?
I have just bought a 99 XX with 11500miles on the clock. The performance is awsome but i find that when i use the rear brake i get alot of vibration through the pedal and handle bars it feels just like ABS, but when i use the front lever there is no vibrations and the bike stops as normal. Is this normal or could i have a dodgy disc (perhaps the rear).

Chris

Yep, something is amiss, alright.....

Start by yanking the pads, and ASSuming they are basically okay, scuff them up with emery cloth, then carefully clean both sides of the rotor with brake cleaner, and re-install the pads.

If you still detect that shuddering/vibration, you might suspect a warped rotor, which would be kinda unusual for a rear rotor, still...

And, of course, you should check all components involved in the rear brake system to ensure it's not a matter of something just loose....

Thanks for that Warchild, when i got the bike i didnt' notice the problem as bad but on inspecting the rear pads found that they were nearly on the limit,i checked the fronts at the same time and found the front left ones had wore uneven but from what i have seen on the forum this is normal. I decided to replace all of the pads and put EBC HH all round. After removing the pads i sprayed the insides of the calipers with brake cleaner but i must admit i didn't spray the rotars. I have noticed that the vibration seems to be more noticeable since changing the pads. I have covered about 200miles since changing them so i assume they will have bedded in.What i have noticed is that for the first few miles it dosn't seem to be there,as if it comes in when they become warmed up.

Chris

If you have access to a mag base and dial indicator slap them on right after a few trips around the block using the rear brake a lot in order to heat them up good. Check the face runnout on the inside and out. I bet one of the folks in here with a manual handy can tell you what the limits are.

Thanks for that scott, i will look into checking the disk out. The thing i can't understand is that when i brake hard with the front lever it is perfect and the bike comes to a halt very quick without any vibes,you would think that with the LBS you'd still get it if the rear disk was out of true?

chris

The max disc runout is .3mm. You probably wont get the vibration using the front brakes as they activate a seperate line to just one of the back brake pistons making the lever too remote to feel the vibration/pulsing as there is less back braking force than using the pedal. I've got EBC HH all round and havent got a problem apart from the zinging noise you get from the sintering. Did you replace the pads and put the shim on the back if so there is a tolerance issue, the EBC are thicker and dont need the shim, could be dragging when they've warmed up and expanded and the friction caused a bit of warping. Is your rear wheel running true?

When i took the old pads out there was no seperate shim, they were just like the new ones (EBC HH) i.e on the back of the pads there is what seems to be a crimped on plate with lots of round holes in,so i put them in as they were. Something i did notice today was that when the bike was on the centre stand i spun the rear wheel and there was an intermittent squeek as a certain part of the rotor went between the pads. If it looks like i have a warped rotor can anyone advise what make of replacement i should get and the best place to obtain one,and an approximate price.

Chris

http://www.ronayers.com/main.cfm

or as you're in the UK try-
http://www.davidsilverspares.co.uk/
for OEM Honda discs they're usually cheaper than the dealers, other than that its a trawl though M&P/MPS, Busters or similar for aftermarket stuff.
BTW have you checked the runout just to make sure?, its a lot of money to waste if it turns out its just the rear wheel slightly out of alignment.

Excellent call, Mick!

Thanks for that Mick about the rear wheel possibly out of align,this i asume is alterd with the chain adjusters.

Chris

Yes it is. Measure the distance from the swingarm pivot point to the center of the rear (both sides). They should be the same. If not adjust as needed. :bike:

Thanks for all the info,i took the bike into my local Honda dealer for the 12k service and asked them to check it out for me. They got back to me and said the rear disk has got a high spot so they are going to fit me an EBC replacement rotor for about £90.
All been well i should be able to brake without my teeth chattering!!

Chris