Changing BB ST/DT angle

[BigPoser]

I'm on my second frame and I need to modify my ST/DT angle by a couple degrees. If I leave it as is, then my top tube length will be longer than desired. Having never changed the angles of a BB before, what is the best way to do this? I've seen the bars sold by Oasis, and this is an option, but how exactly is it done? Do you just put the bars in the lug and bend as needed? Should I add heat and hammer away?


Thanks for the advice in advance.


Brandon

[EricKeller]

my first suggestion is to try it to see if there is a problem.

[Doug Fattic]

Brandon, getting the angle right starts before brazing anything together. BB shells come in different angles and it only makes sense to choose one that is closest to your design. This process then may involve grinding some inside the shell sockets to so the tubes aren’t under tension when they are at the correct angle. Usually there is some play in the seat tube/shell and when they 2 are spotted to hold them together before brazing the seat tube is rotated in the direction it needs to go. Once the seat tube is brazed in then you can see what needs to be ground or bent so the DT isn’t under tension. Afterwards the socket walls need to be banged into closer contact with the tubes. It is almost impossible to get clean shorelines if you don’t do this last step before brazing.