Stronglight 49D cranks and bottom bracket issues

I've got a 1950s English road frame and have decided to ditch the cottered cranks I fitted and replace them with some Stronglight 49Ds. I was at first intending to fit some old TA cranks and was told that I would need a 111mm ISO bb to run a fixed hub, so I bought an old 111mm Campagnolo cup and cone bb (Record, I think). As they're very similar, I assumed that the Stronglight cranks would fit with the same length axle as the TA cranks. l fitted the bb, but found that the right Stronglight crank touches and rubs against the fixed cup even without it being tightened onto the axle; also, the chainring bolts stick against the fixed cup so that it cannot turn (it's like the fixed cup has a diameter that is bigger than that of the bolts).

I'm using a 1950s BH Co. Eureka flip-flop hub (I'm not sure what the measurements are right now).

So, is this a problem with the BB - do I need something with a slightly thinner fixed cup? It originally had a 1950s Bayliss Wiley bb and the fixed cup does look to be thinner, and looks to be small enough to fit inside the ring of the crank bolts.

Or, have I made a mistake by assuming that TA and Stronglight cranks both need the same axle length? And, if this is the case, could someone tell me what length axle I ought to get (and, preferably, where I might get one)? I have a 118mm ISO Stronglight axle but fear this might be too long.

Any advice will be gratefully received.

Cheers
TT

Try the 118mm axle, what do you have to lose? If it's too long, sounds like you'll need 114/115 ish one.

Try the 118mm axle, what do you have to lose? If it's too long, sounds like you'll need 114/115 ish one.

Nothing. Yes, that's what I plan to do, but I had to give up late last night and thought I'd ask on here to see if anyone knew any better before I make a second attempt this evening.

The hub seems to have loads of thread on it too, so I might be able to play around with spacers to fiddle with the chainline.

I'm running 49ds, and have played around with TA axles and cranks, and Stronglight axles and cranks.

Don't suppose you've still got any of the axles you've played around with and discarded, have you...?

Ah, fair enough, thanks. I'll do as Skully says and try my 118 axle, but if that's no good I'll be on the hunt.

Brilliant. That could be a great help - thanks!

So, for the record, I got a TA 344 115mm axle, which I am using with TDC cups. This seems to have done the trick. The chainline isn't far off, and is virtually silent with a 1/8 chain.