There’s some discussion over this side of the Atlantic via Paul at Ellis Briggs on designing and sourcing a T47 lugged BB shell.
https://www.patreon.com/posts/127351754?utm_campaign=postshare_fan&utm_content=android_share
All the best,.
Dan Chambers
All I can suggest is to make the chainstay ports angle out at nine or ten degrees… all of the current bb shells (except for the Rene Herse ones) date from the days of 126 or 130mm spacing, extinct in most of today’s projects. And ditto, make the seat tube/down tube angle tighter, like 57 or 58 degrees - must of the current shells at 60 degrees date from the era of 25mm-tire-clearance forks with a short axle to crown. Modern forks need to clear 35’s or 38’s…
Many thanks, Mark.
I’ll add those points into the mix.
All the best,
Dan Chambers
My thoughts exactly! 10 deg chainstay ports.
Reynolds have already made some chainstays to suit.
Also I was thinking of making the angles a bit more friendly to lower bottom brackets.
Another consideration is the tube sizes. My thought when I was considering designing and casting a T47 shell a few years back was to use XL tubing sizes (1-3/8" DT and 1-1/4" ST). The seat post selection for 1-1/4" ST remains poor, with very limited selection of 30.6 seat posts with setback. Nonetheless, I opted for XL sizes when I designed my tapered lower head lug.
Alex
Hi Alex,
I’ve been wondering about this too. I’m not convinced about an 1" 1/4 seatube. My original concept had a 1" 1/8 seat tube.
Not sure how many versions you are considering, but I have been drooling over some of the chainstay yokes that are now available. Would it be worth it to create a hybrid BB shell WITHOUT chainstay sockets so builders can have classy lugs with modern, customizable rear spacing?
