Took the Uly for her MOT the other day ( 07 on 7700 miles) only for the guy in the overalls to tell me he'll let go this time but on his machine the front brake test pulse very close to a fail.

I was amazed and protested that I feel no pulse at all through the lever, he stated that it could be down the size of the disc that it's possibly not a noticeable as on a small disc, he also mention the bolts could be seized, well all I'm thinking about the apparent cost in the future.

So after some tinternet surfing on replacement disc's and pads and reading what's out there, ( heres the point ) I kind of thinking that the disc is'int floating as it should, some or all bolts not doing their thing,
what if I only replaced all the bolts, would that cure the pulse, I can't even feel, should I ignore it till the next MOT and take some else while hoping it gets through, or he's right and I should replace the lot £££££ damn ( wavy disc looks nice though )

What da ya reckon

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"It is often said that before you die your life passes before your eyes. It is in fact true. It's called living."
Terry Pratchett

Whilst my Firebolt was under warranty, I had deposits on the disc and I had the dreaded brake judder. I took it to Riders and they put it on their brake tester telling me that it would still pass an MOT. The judder gave no confidence so I put as much pressure on them as I possibly could and eventually they changed the disc.

In addition, my X1 (excuse the tube talk here) has a ten bobbin front disc. It came to me from a 'Buell enthusiast', yet it was unloved (maybe I expect too much), one of the faults was worn bobbins and deposits on the disc which you can really feel, yet it still passed the MOT and that particular tester is 'safety orientated'.

You say you can't feel anything, yet it is an advisory... Something is not right here...

My advice would be to forget the disc, unless it is causing you grief (for me that would be to feel judder or pulsation), after all it has passed the MOT.



During the meanwhile, you might want to keep your eye on EBay to pick up a spare.

But, if you do feel judder, it is normally pad material depositing itself on the disc, as per the link posted by Gunter. The recognised method for fixing this was to use Scotchbrite and brake cleaner and use Braking or EBC pads rather than OE, however I recently successfully tried another way after getting rid of the problem with my EBR 5mm finned disc which picked up deposits despite using Braking pads. That method was to temporarily fit a different set of pads, not sure if it works with all, but I fitted Goldfren (which don't really feel that bad to me) and over the course of a few hard stops have taken the deposits off the disc surface.

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08 Specialized Langster

It could also be worth checking to ensure that the wheel is true ...

... if it is marginally out you may be able to use shims to bring the disc back in line.

And check the wheel bearings - IIRC I saw a post once where somebody said the problem went away when they changed their bearings.

I had the same problem last year - still riding it but will have to do something in the next few weeks as the MOT is due - not been too bothered as I have more than one bike so they've been taking turns.

had this on my uly the brake pads leave a deposit on the disc get some brake cleaner or similar substance and clean the disc then try it
mabe different pads as well

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WE AINT ALL THERE COZ WERE HERE

FASTER THAN THE SPEED OF DARK

Thanks for the great feedback every one, I'll think I'll start by fitting some EBC HH pads, get it tested some where after they have bedded in and it still has a problem I'll move on to replacing the disc, can't feel any pulse at all in the lever and she still stops like a good un,

On the subject of brakes, how usless is the rear brake, do'nt really want it to lock up or anything, but it seems like it's next to usless

You finding the same and leaving it or is there a solution for it

Cheers

I had the same thing a few MOTs ago and bought a spare disc on Ebay. I couldn't feel anything so I ignored it and the last two MOTs its gone straight through without comment. I still have the spare disc just in case. The only conclusion I can come to is that any deposits have worn off. It would seem that the gear they use for testing the brakes is very sensitive.

I'm using my rear brake almost solely when speed is below 30 mph (e.g. in town or approaching traffic lights), and I can't complain, I think my XB9 has the best rear brake I ever used. The key seems to make use of the rear brake, as no unused brake will ever work fine.

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"It is often said that before you die your life passes before your eyes. It is in fact true. It's called living."
Terry Pratchett

I use mine in favour of the front, unless I have to stop very quickly... All my rear brakes work fine...

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08 Specialized Langster

Mmmmm I'm thinking I'll have to have a look at the rear brake dept as from you have said some thing is not quite right back there
Cheers

I have a habit of boiling the fluid in the rear brake on the Grenade...

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08 Specialized Langster

Tubbs from Moorespeed gave me some great advice which worked like a charm the last time I had a judder. Behind the disc where the disc is mounted to the wheel are tiny springs. These springs corode and then prevent the disc from floating and ultimately forcing the disc to run out of balance. To resolve this, mark the disc and wheel so that it goes back on the way it came off, remove the disc, clean the springs, seats and disc with some brake cleaner making sure to remove all carbon deposits. re-assemble and enjoy.

Their are however cases that the disc will be warped and the ionly way to resolve it will be to replace it.

Had the same problem last year. After much head scratching and investigation, it simply came down to pitted disc. Probably from leaving the disc wet for long periods of time i.e lazy bastzzd doesn't dry off when garaging / poor pads. Replaced the disc and pads and now dry the disc before storage. No problems so far. If you find a wavy disc supplier let us know please.

I'll post a pic of my old disc when I get time, the bolts had worn grooves in the disc slots. Look after those little springs or swap them for the EBR mounting kit.

Digging through some old posts and found this one and have gone down a similar thought process.

-Wheel bearing were always on the agenda as milage and symptons seemed to suggest it;

So during strip down this evening I found that one of the square shim/washers sat behind the the float spacers was missing. Now having never removed it since owning the bike, and the previous original owner used one of the Riders service centers I can only think its come from the factory like this. So if you have issues it may be worth just checking you have a complete set up before expensive trial and error.

So I need to buy a 0.060" thick, square washer, and I've put a budget of £1 on it or I'll make it.

Just to add, wheel bearing will be nice new SKF ones that I've had sitting on the shelf since the last MOT.