Disc Brake Question : Rubbing ?

Tiggy777

Hi all

When comparing my two bikes : one with disc brakes and the other with normal block brakes it is very noticeable that when spinning the wheels the block brakes wheel just spins and spins maybe for +30 seconds whilst the disc brake wheels spin about 4 or 5 turns then stops.

I took the disc brake wheel out of the frame and tried again and it span for about +30 seconds fine. My question is why does there appear to be contact between the disc pads and the rota and how can I stop it. Do the pads not return away from the rota after braking as opposed to rubbing?

Any ideas gratefully received and thanks for you time

Regards

Tiggy777

nicklouse

caliper not set correctly. pads need bedding in?

Tiggy777

nicklouse wrote:

caliper not set correctly. pads need bedding in?

Thanks............... pads have done about 1000 miles.

How do I check capliers ?

Regards

Tiggy777

nicklouse

depends on the brake.

the wheel should run the same when fitted. either with or with out the caliper fitted. length of rotation can change if the wheel is not clamped in the fork/frame.

Tiggy777

nicklouse wrote:

depends on the brake.

the wheel should run the same when fitted. either with or with out the caliper fitted. length of rotation can change if the wheel is not clamped in the fork/frame.

Ok I think I have a problem with my pads rubbing! Shimano BR-M485 Caplier

Reading the instructions !!!! it seems I

1 Loosen the caplier fixing bolts so the caplier can move sideways

2 Depress the brake so the rotatis clamped by the pads

3 Then tighten the caplier fixing screws.

Is is that simple or have I totally missed 5 pages ???

Thanks for your help.

Tiggy777

nicklouse

thats it. the bolts are the ones from the caliper to that adaptor. NOT the adaptor to fork/frame bolts.

Tiggy777

nicklouse wrote:

thats it. the bolts are the ones from the caliper to that adaptor. NOT the adaptor to fork/frame bolts.

Wow worked OK.

Much better............

Many thanks nicklouse for the help and advice

Regards

Tiggy777

oliverevilo

Hello, im having a problem with this exact thing, i've already tried centering the calipers like this but it seems the inner of the too pistons moves loads when the lever is pulled and the out hardly moves at all, causing the caliper to bend the rotor. This is only happening on the front brake, the back is okay ish. I have the same bike and disc brakes. There's just so much rubbing too. The brakes are bled and pads are fine, the rotors also look pretty straight.

any help?

thanks

oliver

Tiggy777

oliverevilo wrote:

Hello, im having a problem with this exact thing, i've already tried centering the calipers like this but it seems the inner of the too pistons moves loads when the lever is pulled and the out hardly moves at all, causing the caliper to bend the rotor. This is only happening on the front brake, the back is okay ish. I have the same bike and disc brakes. There's just so much rubbing too. The brakes are bled and pads are fine, the rotors also look pretty straight.

any help?

thanks

oliver

Did your bike come with any documentation stating the caliper is M485....I am having problems confirming this as the pads fitted in my M485 (if that is what it is) are ASH991 as shinamo state they ASH991pads are for mechincal disc brakes ?

I am trying to check how I confirm the caliper is a M485 and then I will know what pads to get (I think) !

Regards

Tiggy777

oliverevilo

Hi, well I just presumed it was the M485 as that's what is spoken of on the limited instructions. I'm not sure what pads are in mine, part number i mean.

ddraver

if it spins for 30 seconds i would nt worry

I can't get my brakes to sit right at all, this "easy set" just makes it impossible to get them properly right anyway

but mine are Avids not shimano