What drop brakes?

Cookie87

I presently have Tektro R356 brakes fitted to my commuter bike. The nut for adjusting right-left alignment on the rear brake has rounded off so that my allen keys don't fit it anymore, so I am trying to find out whether I can replace just the bolt (which would need drilling out) or whether I need a whole new calliper.

Having visited three bike shops over lunch (all major chains, unfortunately), I have received three different answers! For what it's worth, I think I would rather just replace the calliper, especially since the bike is due for a service so I won't have to pay any additional labour - I'll just get them to do it during the service.

However, I haven't got a satisfactory answer as to whether the brakes presently fitted are 49mm drop or 57mm drop. Having compared them to the various road brakes in the Shimano range on bikes in the shop, I think mine are longer, but of the three shops, one thought they were 57mm, one thought they were 57mm but that 49mm drop should fit and one thought they were 49mm. Does anybody know whether Tektro R356 brakes are 49mm max drop or 59mm max drop?!

Any help gratefully received.

whyamihere

Measure them? It's vertically from the centre of the brake bolt to the furthest end of the slot for the brake pads.

Cookie87

Thanks for the clarification - one of the guys in the shop measured diagonally from the bolt to the brake pad and another guy measured the vertical distance from the bolt to the end of the slot - I guess I know which one to believe now!