March 2020 Posts

T47 and associated matters

T47 and associated matters

I was recently asked if I would be able to make a bike with an oversize bottom bracket and full internal cable routing, amongst other things. Although this project may come to nothing it has been on my mind for some time to use a T47 bottom bracket, my only personal reason for this would be that it gives the space to potentially run cables and cable guides right through. I have never been keen on partial internal gear cable routing which always looks untidy, and I have never been happy with the idea of drilling holes in chain stays.
I would choose T47 over press fit, do I need to say why, though I did make a press fit bottom bracket shell for a balance bike and it was OK as far as I am aware.
Ceeway do stock PF30 press fit bottom bracket shells, which appear to be the same dimensions as T47, so I presume it would be feasible to cut threads in a PF30 to make a T47. Paragon in the USA make both Stainless and Plain steel T47′s and Bear frame supplies do plain steel ones but both were out of stock at the time I looked. The upshot of this is I decided to make my own, how difficult could this be, well a lot more difficult than anticipated, but I got there.