I mean what in the actual hell is wrong with threaded BSA 68mm shells?!?
Takes both 24 and 30 mmm axles, dead simple, tried and tested, great for dead enders (#squaretaperlyfe), easy to fit UNBB54 (praise be spinning holy mother of tarck) etc mm and so on.
Im the biggest luddite there is. Only 2 of my 11 bikes are not BSA. Dude said that it meant better clearance for tires. I was trying to understand how. A wider shell I guess?I like wide if it means I can do fatter tires.
T47 is threaded, just bigger so the bearings are inboard instead of outboard, IIRC.
I think the better clearance comes from being able to attach chainstays where your cups would be on a BSA.
If it does you can use it as a mobile!
this is it in a nutshell. Really only matters if you’re into that big tire/short chainstay life.
How big tyres do you want to run, like above 2.4 mtb tyres and over?
Or around that 2.0/50mm? That can easily be done without tube-fuckery.
Also 700C or 650B?
T47 seems pretty expensive right now, with only Chris king and Praxis doing BB’s. Even though it’s been around since -15.
BSA is just so great and idiot proof, all my bikes have them.
MTB’s on 73mm shells and they can fit up to 2.8 tyres, just do that if you want the space. Since you don’t care about q-factor anyway.
EDIT:
@adem: my staton switchback is 73BSA with 415mm cs and can fit 2.8 tyres, so not that true…
I was thinking 44mm in 700 and around 2 inch in 650b with compact road-ish cranks. Nothing too silly.
I don’t see the point, maybe framebuilder™ wants to flex?
Weird flex…
I wouldn’t pay someone who says such things to build a frame
It might make it easier to get a given clearance, but it doesn’t give you more clearance.
Tire clearance isnt given, it is earned
T47 is still a 68mm shell. Nothing about tire clearance really is at play here. I suppose you could cut threads into a 86mm wide tube and make a T47/BB386 hybrid system but that seems silly.
Maybe he just has some crazy 3OS down tube he wants to use? I encountered that with some Indy Fab projects. There was some big/thin Reynolds down tube that was designed to be used on PF30 shells.
Thats what I was wondering.
Yep, that’s what he said. 86.5 mm wide.
That’s kindof cool. Utterly unnecessary for the crank/tire dimensions you’re looking for.
Bonus: Chris King shit-canned their 24mm spindle bb for that shell size. Wheels MFG makes one, but it’s north of $100. The seals on those are super underwhelming too. If you’re using a 30mm spindle crank, I suppose it’s not the MOST terrible way to do it.
Sounds like at the best case you’re dealing with short service intervals on an expensive part and at the worst a dead-end standard.
Thanks for that. I am not about making my life unduly difficult or expensive. This will be the only bike I ever get built. I could be convinced to go wider with my tire expectations though. Starting to realise that I need to think about cranks etc. I have nothing so far.This is not going to be my usual parts-bin shitter.
Oh, I thought they were wider. That makes them harder to fit wide tires then.
I was sort of wrong. There is a rare 86 variant with even rarer bottom bracket options.
Maybe that’s the one I saw and then decided I didn’t need to ever do any further investigation.
I’m having a hard time finding some stem binders that I want. I found a 28.6 post binder that I could definitely use for my stem but it’s dumb expensive and doesn’t perfectly match the 25.4 that my stem tubes are going to be.
There’s this one, also for seattubes, that I think I could ream out a recess for a caphead bolt.
https://www.cycle-frames.com/bicycle-frame-tubing/MTB-BINDER-BOSS-FOR-QUICK-RELEASE.html
This is the 28.6 post but like I said, $$$
This is more what I’m looking for but 31.7 too much of a differnce to fudge with.
or should I just get some bar stock and ream/tap my own?