So, I rebuilt (new pistons and seals) both front and back callipers. Also new pads front and rear.

When I hit the front it feels like I am going to fly over the handle bars, great.

When I hit the rear, nothing happens.

The lever is rock hard, no sponginess. If I push it while standing and touch the back I can feel it working, but while riding it does virtually nothing. Engine braking does more. I did the rear master not too long ago also, brake fluid is completely replaced.

Any ideas? Its driving me nuts, had the bike 3 years and rear has never worked that good. The only bit that has not been replaced is the actual calliper.

dogmatic69 wrote:
When I hit the rear, nothing happens..

Isn't this normal?

Not in my opinion ,it's not !

A rear brake will easily lock up the wheel if it is operating correctly.

Are the pads the correct spec for that disc.

A fully applied rear brake should very nearly stall a motorcycle when attempting to pull away in first gear by means of an easy test.

The rear brake set up on these bikes aren't very powerful it's a characteristic of them. A fully overhauled system with good quality pads can improve it very slightly but never by much on any nc30 I've had over the years. You should be able to lock the wheel turning it by hand and pressing pedal but they struggle to lock under bike and riders weight.

davethetrucker wrote:The rear brake set up on these bikes aren't very powerful it's a characteristic of them. A fully overhauled system with good quality pads can improve it very slightly but never by much on any nc30 I've had over the years. You should be able to lock the wheel turning it by hand and pressing pedal but they struggle to lock under bike and riders weight.

My rear brake has stock pads in it and will lock the rear below aroud 30mph quite easily.

it defianly slows the bike nicely, i use it in fast sweepers often to save over-cooking it :)

My one definitely locks up if I stomp on the rear too hard....though the rear has been raised, and I don't weigh much so probably not much weight to help with grip...

I had one of these bike's brand new in 1990.The rear brake was crap at any speed other than slow.

Absolutely no chance of locking up the rear at any speed, could probably force the wheel around by hand while stomping on the lever.

IMO the rear should work quite well, because if your front were to fail the rear is a fail safe (also the reason two separate systems are required for a MOT)

There may have been some corrosion in the seals that I did not clean up 100%. Will strip it off again and give it a once over with the dremel inside the seal slots.

Would be a good idea to make sure everthing is clean,It will restrict it's opperation.
What state is the disc in any amount of scoring will have a big effect on performance.

hunter wrote:Would be a good idea to make sure everthing is clean,It will restrict it's opperation.
What state is the disc in any amount of scoring will have a big effect on performance.

are you still using the original rubber hose? it is well past its best.

Have you rebuild the master cylinder?

They are all well past there best.

Are your pads ok and have you bedded them in properly if they are new?