I’ve got an old Specialized Allez with what look like unbranded Tektro brakes. The old pads say Tektro P451. Some Tektro 453 pads arrived this morning in the post but they don’t fit. (The gap between pads is not enough to clear the rim). I ordered tektro because the 105 pads I got before this don’t fit either. There are some clarkes on the front that I bought years ago and must just have got lucky.

How do I source pads that will fit? How do I know what size I need?

you have tried releasing tension right so the caliper opens up further to accommodate unworn pads ?

no reason the 453s shouldnt fit

^^ this

I screwed the barrel adjuster to the zero position and even with the quick release in the open position the pads touched the rim. But I could reset the cable in the clamp. I didn’t do this because well I thought I must have the wrong size. I’ll go try it, thanks.

That’s what you need to do, they don’t really vary except for Shimano/Sram and Campag, but you’d have to try hard to get Campag twice without knowing!

Shimano do do two subtly different ones – one have an RC2 suffix, but they don’t even publicise the fact they’re different, and they’re totally cross compatible, certain brakes just ‘sit’ better with different ones.

All sorted, thanks. Feel slightly stupid because it was pretty obvious