Question about retrofitting brake calipers

[dyzio]

Pardon the derail, I've noticed something similar on your pic.

Why is it that in front brake callipers one of the pistons is bigger than the other?

[Dave20046]

Brakes are loads better than before, knew it was the calipers. Will have to see what was going on with the old ones but for now I'm sorted, didn't dare service these seeing as they seemed in good order and in case anything went wrong!

Went for a test ride and they still suffer from a lack of feel that I've had a while, they seem to work just squeeze the lever beyond a point and you can feelyourself slowing rapidly but you get no feedback, very almost locked up the front in testing at 40mph but reckovered with a mini 'tankslapper'/headshake.
Next test of the brake was rounding a bend to find a massive ****ing donkey in the middle of the road....
....once I started slowing and revving as it ran off it became clear it was just a freakishly tall dear with an ugly face but a memorable test.

The lack of feel, has bugged me for a while and while looking into brakes found it's a common complaint from SRAD riders. One fix* I noticed was a guy that lengthened the pin in his span adjustment and reported it sorted everything, didn't fancy that but it reminded me that I'd already done something about this last years and bought some spazzo levers. Not road tested them but the usable travel seems much much better, solid feel to the lever. Will see how I get on.
Once I'm back from France I'll service the calipers and address the hoses.

Cheers for your help guys




*the most common fix is a radial mastercylinder though.

[yorkie_chris]

Originally Posted by dyzio

Pardon the derail, I've noticed something similar on your pic.

Why is it that in front brake callipers one of the pistons is bigger than the other?

To make up for the camming action of friction, which basically tries to make one side of pad grip harder. So there is a smaller piston to make the forces even.