front brake problem

lef Posts: 728
edited April 2011 in Workshop
So since I recently swapped over brake blocks for some nearly new ones (worn Koolstop salmons and put on some dura-ace ones, they are virtually new) as well as swapping over a front wheel (RS80 to a IRD Cadence) the front braking isnt quite performing as it should. Its grabbing as the wheel revolves so it goes from feathering to grabbing. The wheel is true and spins freely. I removed the cable and put some cable magic lube in the housing and on the cable and its still the same. Im going to have a closer look tonight but looking for any suggestions so when I tackle it this evening I can look at specific things.

I have concerns it could be the rim, though it is true. I hadnt used the wheel before the change of pads. I will swap it onto another bike tonight to check.

I will check the brake blocks are right and lefts as Im aware theyre handed but I do remember checking this so shouldnt be this, though I hope it as simple as this! This isnt a request for comparisons between Koolstops v Shimano pads. The shimano ones have been used before and have performed fine.

Clearly some possibilities above but if anyone has personal experience of this problem and solved it I would really like to hear your suggestions

Thanks, Leon


  • Yossie
    Yossie Posts: 2,600
    One thing I can think of offhand is that the pads were run in on a different wheel that that which you have now put in.

    The pads will bear the wear surface of the wheel that they were run in on. This will cause little ridges and indentations that will match exactly the wear on the rim they were run in on.

    These will not match the wear on the "new" rim and so they will be grabbing and relaeasing at different points to the wear in the rim.

    Theoretically it should get better as they bed in - ie the rubber on the brake pad wears down to match the "new" rim.

    Also, check that the front brake is all done up and that its not moving backwards and forward as the braking process happens - ie more force it moves forwards and tries to pull itself off, returning to the normal position once the braking force is released. It will only take a tiny bit of pressure to move it from the "sitting in position" position to the "trying to pull itself off" position.


  • lef
    lef Posts: 728
    thats a very good suggestion! I will swap the pads for some new ones and see if that solves it. Good call on the tightening of the brakes too, its relatively new so I guess they could have loosened of a little.