Rear disc fitting

[Dan505]

Need to fit a new rear disc as somehow i've managed to score the old one nearly all the way thru any tips on fitting? I.e grease placement, tips for ease of stripping it down?

Thanks

[Rabb]

1. New bolts to hold them on.
2. Ensure you have cleaned the facing surfaces so that they are completely flat to the new disc.
If it's not you will have problems.

That's about it - easy to do and you shouldnt have any problems.

[Gooz]

Make sure you clean and regrease the rear wheel spindle too whilst your at it Dan, its an ideal time to clean those hard to reach parts. check your chain and sprocket too whilst the wheel is out.

[Mitch9128]

Threadlock the bolts..

[Snowy]

You will need new Brake pads as well.

[Crosbie]

You will need new Brake pads as well.

I would hazard a guess he needs new pads anyway.

Dan would i be correct in assuming your current pads have worn down to the extreme that the fixing surface has scored the disc?

If you have copper grease put a teeny tiny amount on the rear of the pads - this will help stop any squealing moments unless thats your thing.

Oh and do the job with a pair of cheap cloth gloves on - saves having to scrub the skin off your hands later/walking around the office/house with mucky hands for the next week.

[Scotty]

Check both sides of the new disc to see if the bolt boles are counter-bored (recessed) on one side - if they are, this in the side that the bolt head sits in so it faces away from the wheel. This might sound obvious but ten years ago I bought a ZX-9R from a muppet who worked at MCN and he'd refitted the rear disc the wrong way so the bolt heads were proud and they fouled the calliper bracket badly. It would have been impossible to rotate the wheel or push the bike anywhere as the foul condition was that bad so what had he done? Simply ridden it like it and the bolt heads had chewed themselves some clearance into the bracket. I couldn't believe what I was seeing when I discovered it. Anthony Orfeo, hang your head in shame...

Another important point; use a good hex drive bit on a socket to remove the disc bolts and ensure that it's fully engaged before trying to turn it. Chewed-up bolt heads are never easy to remove, especially when thread-locked in. It isn't necessary to replace the bolts, up to you if you want to but if they're undamaged they can be re-used (with thread-lock)

[Jon_W]

As with scotty.

You don't need to replace the bolts if they are in good condition. Just make sure you clean off the old thread lock and degrease the bolts and holes befre applying the new threadlocker.

[Dan505]

Cheers for advice guys, yeah have new pads as well. Whats best way to remove threadlock? Bolts only 3 yrs old so will re-use them. C&S is brand new so no dramas there, have no torque wrench so guessing just over hand tight should be enough for the disc bolts?

[Scotty]

The best way to remove threadlock residue from threads is with a wire brush.
A decent torque wrench is a good investment, I'd recommend either buying or borrowing one for this. Most M8 disc bolts will need around 20Nm of torque (or just over) which is a bit more than just over hand tight. These are important fasteners so it's worth doing the job properly. 8-)