Triumphrat

05-11-2005, 02:16 PM

iv got play between the disk and the centre part asiff the rivits are worn down or is it normal to beable to hold the disk and have play beetween it and the centre part,so if i hold the brake on i can move the bike forward and back and see the disk moving say 3 mm and the centre staying still?

do i need new disks?

Will · 05-11-2005, 03:38 PM

How many miles you got on that bike? You should have some play side to side, but little or none front to back. Make sure that the play isn't a headstock bearing adjustment problem or maybe a worn headstock bearing. No point in replacing expensive disks when you could solve the problem with a $10 bearing somewhere else.

banda · 05-11-2005, 04:52 PM

Well, that's kind of the definition of a fully floating brake... the rotor is allowed some play on the carrier.

As for the question of how much play is allowable, I will consult the shop manual this evening and see if there's a tolerance listed.

I do know that different brakes show different amounts of play: I have a full race Motomaster setup on the front wheel of my supermoto, and it clatters around on the carrier with tons of play... it also happens to be the best feeling and most fade resistant front brake I've ever used under tough race conditions.

plagued · 05-12-2005, 08:30 AM

I didn't think they should have any play (or very little) roationally but a nice bit of play side to side, if it did have play forwards and backwards it would hit every time you broke or accelorated from still and the problem would get worse.
As Will said it could well be a problem with the head bearing unless the disks are very old.
Get a friend to lift the front end off the ground on the side stand and apply the front brake, then go and try rotating the wheel and also pull the wheel back and forth to cheack the headstock.

banda · 05-12-2005, 11:06 AM

The only specs for front rotors in the shop manual are for minimum thickness, and runout.

It's possible that one or more of the "buttons" that fix your rotor to the carrier is worn or cracked. I'm not sure if it's possible to replace the buttons... there's no procedure for it in the shop manual, and everything in there treats the carrier and rotor as a unit.

05-12-2005, 12:46 PM

its defo the disks not the head bearings,has anyone else got rotational play in theres then?
its a 2000 with 16k on,are we thinking these are worn out now then?

Will · 05-12-2005, 01:33 PM

I kinda doubt that anything except the oil is worn out at 16K. Mine has 40K+ on it, and the disks are still fine. You might find brake disks on ebay if you don't want to spring for new ones. Check the carriers, the bolts that attach the disk carriers to the wheel and the buttons that allow the disks to float on the carriers. Check also the brake pad installation and the calipers. Please let us know what you find- it is always good to know how things turned out.

05-13-2005, 01:58 PM

My tt600 has this feature. I believe it's perfectly natural for the floating nature; as the brakes are used, the disk warms and expands thereby taking up the play. It's not noticable when riding. As was as safety goes, just check all the buttons are OK and not damaged/cracked and that the concave spring washers arestill doing their job. Nothing to worry about.