band/clamp on vs braze on

mosa

i made the error of buying a front mech nearly got it fitted until it wouldnt go around my downtube. I need a braze on type. Question is are the braze on type clamps larger diameter? cheers

TommyEss

I think you've misunderstood the terms - braze on types bolt directly onto a threaded stub welded (or brazed) on to the seat tube. If you haven't got the braze on you'll have to find a wider clamp on type.

mosa

Ahhh yes mine is a clamp on type, do I need a large clamp or will it bolt to my clamp ?

TommyEss

Hah! It depends on the clamp!

Most front mechs come in either braze on or clamp on - the clamp on type come already fixed to the clamp. But you can by a clamp with a threaded hole to accept a braze on mech, to allow you to use a braze on mech on a frame without a braze on.

So are you saying you have just a front mech with no clamp attached, or one with a clamp smaller than you need? If it's a clamp on tight that's too small, you're buggered and need a new mech the right size, if it's a braze on screwed on to a clamp adapter that's too small, you need a bigger clamp adapter (cheaper than a whole new mech)

Basically, measure the seat tube diameter where you want to fit it, and buy one the right size. Most clamp on types come in two or three sizes.

And put up a picture/make and model of your bike - there's normally someone round here that will be able to tell you exactly what type you need.

Incidentally - why don't you have the original front mech? Are you building up a frame? In cases like this normally it's easier just to buy the same thing again.

mosa

mine is a clamp on type so thats what bought to upgrade my ultegra. ive just measured mine and now need a 35mm clamp on type cheers for the help