hi, ive got a cotic bfe (16″) its not one of the new ones with a tapered headtube, just a standard, ive just ordered a hope seatclamp at 31.8 and it dosent fit, its just the same size as the frame :s can anyone tell me what size i need pls thanks!

Mine was an older one with the 30.9 seat tube, it took a 34.9 clamp. The 31.6 version is probably the same though.

i guess the 31.6 is smaller than the 31.8 though…. hmm how do i found out what my frame needs is there a way?

Check the Cotic site or email them .

No no, what you’re doing wrong is confusing seatpost and seat tube external thickness- the sizing of the clamp has to be the seatpost, plus the thickness of the seat tube. So you can’t tell from the seatpost size, what size the clamp is, ever.

I would bet you 10 scottish pence it takes a 34.9. Stick a ruler on it, it’ll not be exact but it’ll be close enough.

You could always measure it.

what ive done is wrapped some paper around it and measured it in mm and divided by pi, which is what i got told to do, it comes to 35… i guess thats a 34.9 so u could be right what u rekon

34.9

right cheers guys