Bottom braket shell widht question

jordic1968

Retro Guru
I have an italian bike with a bb shell of 70mm and thinking to buy a titanium bottom bracket but designed for a 68mm shell. Do you think it will work ? Maybe not enough space for the lockring ?Thanks!
 
Re:

I believe the Italian threaded ones are also a bigger diameter,wouldn't fit the BB shell.Unless someone can correct me?
 
You need to stick Italian cups in there period as your English 68 won’t fit...
 
you're right. I though I had found a 68 italian but it was British of course... I'll stick to a dura ace replacement ;) Thanks for your quick answers!
 
I'm still busy with this and need some advice please... the fact is my bb measures 69mm, and right now has a record 36x24t bb with a 102mm spidle (record crankset).

Intention is to replace it with a DA 7400 bb as I want to fit my DA crankset. I believe I can manage the 1 mm difference with the lockring , what do you thing ?

Other option would be to look for a 68x113 , italian bb, that do exist, but I'm not sure it will fit into the 69mm shell ...(and don't want to trim the bb shell)

And last option is to go for a really nice titanium bottom braket, 36x24 but with a 117mm spindle, that is 5 mm wider than the DA (113). Not sure if 2.5 mm each side will be noticeable.

Thanks!
 
Never seen a 68mm italian threaded bottom bracket?
Seen plenty of bottom bracket shells that have been faced a bit too vigorously though.....

Running the lockring down an extra mm shouldn't make the slightest bit of difference. Might end up (slightly) off centre if the extra mm is off both sides. No big deal.
 
OK, there are two things at play here:
1. Bottom bracket spindle length needs to match the chainset - otherwise the chinline will be wrong or (worst case) the chainrings will be touching the chainstay. It also needs to have the correct taper (ISO for Campag, JIS for Shimano and most others).
2. I wouldn't worry too much if your BB shell actual dimension is 70mm or 69mm. BBs are designed to cope with this, but you need to get it correct for the threads between Italian and English types.
 
clear now. I'll look for a DA bb or better for a Titanium one but 70x113, to save around 150 gr ;) Will post in the wanted section.

Thanks, very helpful!
 
Back
Top