Rear brake no worky - not properly anyway. I have to really stand on it to get any sort of retardation. I haven't ridden my bike for a couple of months, but I'm sure the rear brake used to work better than it did last night...

Could I have buggered something up in the master cylinder by standing on the rear brake really hard when I torqued the rear wheel nut up the other night? Or is it more likely to be a result of my recent OCD with the paraffin around the chain area (pad contamination)?

I tried a few test stops on an industrial estate, but couldn't get it to work any better, but the disc did get quite hot. I managed to get it on the Abba stand last night after the ride and the rear wheel span ok when I turned it by hand. I also managed to stop the wheel by using my hand on the lever. I ran it in 2nd on the stand, and again the wheel turns and stops ok after repeated cycles of applying the rear brake by hand.

I realise the rear brake is not having to stop the momentum of the bike on the stand, but I'm still confused that it stops/starts fine on the stand but feels shit on the road. And there's also the fact that I managed to apply it enough to torque up the rear wheel nut...

They are crap as standard, try brake cleaner as the paraffin may have soaked into the pads and then after some use you may get the stopping power back.
If not, I'd stick in new pads.
I stripped my rear caliper down, new pads and seals and can now actually lock the rear up

I did keep the paraffin away from the brakes, but was spraying it on the chain... If it is that I've probably made it worse by trying a few stops to "clean them up".

I've got proper brake cleaner, so I'll give it a go. I'm going to have to take a closer look in daylight anyway. The disc thickness was fine last time I measured it, but I haven't checked the pads for a while.

Oh, and "I don't really go fast on this bike, so I don't need my rear brake..."

if the brake holds you on a hill, it works.

they are pretty shit as standard considering how big they are.

It does hold on a hill, but I like to use my rear to stop around town, because my front brakes are vicious at low speeds and don't really help with slow control.

As long as I haven't pushed a seal or something too far in the master cylinder.

It does feel like some sort of pad contamination... (paraffin/WD40/chain lube... )

Mine's rubbish. It's had new pads several times, the seals done, and I've even changed the master cylinder, and still relatively bugger all seems to happen. When the bike was MOT'd earlier this year, I watched the figures no the braking machine, and was astonished to see that the rear braking effort was actually a very significant percentage of the front! With brand new discs and pads up front that had done literally less than a dozen miles, there was enough force to actually hop the bike forward clean off of the rollers, and the rear brake bit hard enough to pretty much bottom out the rear end (although being a standard shock with six figures on it, that' not exactly a surprise!).

If you're that worried, whip the pads out and see if they're suffering from odd wear, glazing, damage or contamination. If they're scored, glazed or pitted, you might be able to bring them back to life by roughing them up a bit with a file or fairly coarse emery paper. Failing that, they aren't expensive, so whack a new set in. While they're out, check that the pistons aren't corroded and jamming, and that the sliders aren't either.

I'd be more concerned about the front brakes. What exactly do you mean by viscious? Do you get nothing, followed by hitting a brick wall, or do you simply touch the lever and get a huge hit straight away? You might want to fiddle with the adjuster on the lever to see if you can alter the point where they bite....

speedy231278 wrote: whip the pads out...

I like your optimism, but whenever I try to undo anything brake related, it's always something more that "whipping" - stuck bolts etc.

speedy231278 wrote: I'd be more concerned about the front brakes. What exactly do you mean by viscious? Do you get nothing, followed by hitting a brick wall, or do you simply touch the lever and get a huge hit straight away? You might want to fiddle with the adjuster on the lever to see if you can alter the point where they bite....

The front brakes work fine - they're just not much use for under 10mph because they're too good and make the front end dive - causing me and my short legs stability issues.

The biggest issues with the rear caliper are that you need to put the socket through the rear sprocket to get at at least one of the mounting bolts (or do on the NC35 anyway). Your only other 'sticking' point will be the cap over the pad pin, as these have a habit of welding themselves in no matter how much copper grease you use when putting them back. Probably best to loosen that before taking the caliper off if you can get decent access.

I've always been able to lock up the rear with my brake. Always thought it was quite good!

Cheers, Speedy.

Oh, and the MOT brake test - I took my car to an unfamiliar garage and the guy there remarked that my car did most of it's braking at the rear, which he thought was odd. It doesn't really, it's just that being rear engined that is where the weight is when it's on the rollers. When it's on the road, you get weight transfer to the front as soon as you apply the brakes. When it's on the rollers there's no forward momentum so no weight transfer... that's my theory anyway.