CB500 rear brake drag

[Marci]

Wotcha peeps... the CB500 failed it's MOT this time around. Sprocket Carrier bearing, rear brake pads, and front brake sticking.

Replaced carrier bearing. Cleaned rear caliper, put new pads in. Now the disk drags on the inner pad. There's a good 1mm gap on the outer piston-side pad, but the inner pad just grates on the disk. As soon as I pull the clutch in, it locks up the back wheel.

Haven't gotten round to doing front brakes yet - intend to pop the pads out and give the pistons a thorough cleaning, but any suggestions for this back brake problem besides beatin' the crap out of the thing with a lump hammer?
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FAB-Racing MiniMotoSidecars - Back with a vengeance - F1 Class 2011...
CBR170 engine, custom chassis - www.minimotoscene.co.uk

[spikenipple]

Did you push the pistons back into the caliper before putting the new pads on?
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C50 > GN250 > XJ600 > SV650S K7 > 2001 RSV Mille R > MT-09, XR400R > 2005 Fireblade (trackbike) + 2022 MT-09 + ZXR400 race bike

[Marci]

Yep... all the way back... and haven't pumped the brake to make them touch the disk yet.
____________________
FAB-Racing MiniMotoSidecars - Back with a vengeance - F1 Class 2011...
CBR170 engine, custom chassis - www.minimotoscene.co.uk

[spikenipple]

In that case, I can only suggest slightly sanding down the part of the pad that's dragging on the disk to match the profile of the disc.
I had the same problem with new pads on my XJ front discs due to the profile of the discs and this sorted them out a treat.
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C50 > GN250 > XJ600 > SV650S K7 > 2001 RSV Mille R > MT-09, XR400R > 2005 Fireblade (trackbike) + 2022 MT-09 + ZXR400 race bike

[Gazdaman]

Is it a sliding caliper? I.e only pistons on one side, and the entire caliper body slides? If that seizes up a bit it'll drag. That's how my bandit rear brake worked.

Gaz

[Marci]

Aye - tis one o' those gaz... front and back are both sliding calipers... same problem front and back mefinx...

Wots the best way to attack em? Rear is Brembo single pot, Front is Brembo twin pot.

EDIT: n/mind - just found your previous topic
____________________
FAB-Racing MiniMotoSidecars - Back with a vengeance - F1 Class 2011...
CBR170 engine, custom chassis - www.minimotoscene.co.uk

[Gazdaman]

Wow, nice find, forgot I wrote that! Hope it helps.

Was just gonna say, separate the sliding body bit from the caliper, and grease the arms thoroughly and work it in and out until it moves smoothly.

Gaz

[Marci]

Helped a treat...! Had to whack em apart with a rubber mallett they were that jammed...

They obviously hadn't been touched since the bike was built... got the front apart and had to take a file to it to get it back to as-new... copperslip'd and refitted and all peachy... but by that time I'd gotten sick of sitting on my arse in a puddle in the backyard working by the light from the kitchen window... couldn't be buggered with the back, so I've just dropped it off at the local bike-shop for them to sort, along with the added challenge of stopping the speedo drive spinning backwards when you push the bike backwards, as it snaps the speedo cable every time.
____________________
FAB-Racing MiniMotoSidecars - Back with a vengeance - F1 Class 2011...
CBR170 engine, custom chassis - www.minimotoscene.co.uk

[Pete.]