You need a BSA(Briitish/English) external cup bottom bracket for DUB spindle
InnocentGun on
BSA is 1.37” x 24 tpi thread. That’s the major diameter of the male thread, so the minor diameter of the female thread (which is what you’re measuring) would be something like 33.8 mm. Stick the calipers in the shell and measure the actual minor diameter.
What’s the frame? Usually it’s easier to just look up the frame specs than measure….
You probably need a DUB BSA bottom bracket.
Strong_College_21 on
Measure the width of the shell. 68 Its likely BSA while 70 indicates Italian. YMMV
tommyhateseveryone on
if its not french or a raleigh, it cant be anything other than bsa 68/73 or Italian 70mm. check the width of the bb. its probably bog standard bsa 68
BD59 on
Old Swiss made frame, you better double check your measurements before ordering anything. Go to a LBS and ask for some old BB cups. Try a non drive side cup in the frame first. If it threads in without a huge amount of play, you can then try the drive side. Remember the drive side is left hand thread on a BSA bottom bracket.
If a BSA non drive side cup doesn’t thread in, or is so loose that it wobbles, double check the drive side of the frame. If it’s right hand thread, it’s probably Italian thread.
Your measurements for shell width seem to fit with Italian, but there could be enough paint build up on the edges of the shell to make a 68mm wide BSA shell measure at close to 70mm. Especially if the paint is a powder coat, as opposed to a regular wet paint.
gregn8r1 on
It could be Swiss, French, Italian, BSA…. really the best way to know is to bring it to a co-op and see if you can find these parts. A BSA bottom bracket will be easy to find, but Swiss and French are harder.
santiagosds on
Buy something on Ali express! They have great bottom bracket options
Antpitta on
Everyone else is guiding you well on figuring out what your bb shell is.
Beyond that, SRAM dub cranks need specific spacers depending on the pairing of exactly which BB standard you have and which dub crankset you have, so there will be multiple dub BB’s for any given BB standard. Here is SRAM’s compatibility chart:
There’s a similar one for MTB you can easily find by googling if by chance you have a MTB crank there.
tomcatx2 on
Would it kill ya to drag what you have to a shop with a grouchy old fuck who knows the difference between Italian and Swiss and French and English threaded BB standards?
Based on that, if you accurately measure 35 as shown in the pic, and the width is 70 (see the link above), it is probably Italian.
Measuring width is a good way to double check – as Italian is the only one 70 mm wide.
*Edit: press fit (non-threaded) excluded, of course.*
A way to triple check is to see the thread direction: Italian and French standards have right-hand thread on both sides, while other standards have left-hand thread on the drive side – but French has smaller diameter.
[*Right vs left hand thread explained*](https://bike.bikegremlin.com/3965/right-and-left-handed-thread/)*.*
Briefly put: if I measure cup threads’ outer diameter to be over 35 mm, or internal shell thread diameter to be over 34 mm, I suspect Italian. But the above-noted other stuff is good as a double check, because one can make a mistake in one measurement (either me or the manufacturer), but when the other stuff confirms, it helps not mess things up by trying to screw in the wrong cup.
13 Comments
Please measure again, this ain’t 35mm. You need to be exact!
Have you tried to (gently, by hand) start screwing in a bsa bottom bracket?
They have an 34.8 mm thread diameter, which appears to more or less be the measurement you got here.
BSA is 34.8 (1.37”) with a 68 mm shell
https://www.sheldonbrown.com/cribsheet-bottombrackets.html
You need a BSA(Briitish/English) external cup bottom bracket for DUB spindle
BSA is 1.37” x 24 tpi thread. That’s the major diameter of the male thread, so the minor diameter of the female thread (which is what you’re measuring) would be something like 33.8 mm. Stick the calipers in the shell and measure the actual minor diameter.
What’s the frame? Usually it’s easier to just look up the frame specs than measure….
You probably need a DUB BSA bottom bracket.
Measure the width of the shell. 68 Its likely BSA while 70 indicates Italian. YMMV
if its not french or a raleigh, it cant be anything other than bsa 68/73 or Italian 70mm. check the width of the bb. its probably bog standard bsa 68
Old Swiss made frame, you better double check your measurements before ordering anything. Go to a LBS and ask for some old BB cups. Try a non drive side cup in the frame first. If it threads in without a huge amount of play, you can then try the drive side. Remember the drive side is left hand thread on a BSA bottom bracket.
If a BSA non drive side cup doesn’t thread in, or is so loose that it wobbles, double check the drive side of the frame. If it’s right hand thread, it’s probably Italian thread.
Your measurements for shell width seem to fit with Italian, but there could be enough paint build up on the edges of the shell to make a 68mm wide BSA shell measure at close to 70mm. Especially if the paint is a powder coat, as opposed to a regular wet paint.
It could be Swiss, French, Italian, BSA…. really the best way to know is to bring it to a co-op and see if you can find these parts. A BSA bottom bracket will be easy to find, but Swiss and French are harder.
Buy something on Ali express! They have great bottom bracket options
Everyone else is guiding you well on figuring out what your bb shell is.
Beyond that, SRAM dub cranks need specific spacers depending on the pairing of exactly which BB standard you have and which dub crankset you have, so there will be multiple dub BB’s for any given BB standard. Here is SRAM’s compatibility chart:
[https://www.sram.com/globalassets/document-hierarchy/compatibility-map/road/dub-choose-a-road-bottom-bracket-compatibility-map.pdf](https://www.sram.com/globalassets/document-hierarchy/compatibility-map/road/dub-choose-a-road-bottom-bracket-compatibility-map.pdf)
There’s a similar one for MTB you can easily find by googling if by chance you have a MTB crank there.
Would it kill ya to drag what you have to a shop with a grouchy old fuck who knows the difference between Italian and Swiss and French and English threaded BB standards?
Relevant dimensions:
[https://bike.bikegremlin.com/1634/bicycle-bottom-bracket-standards-explained/#3](https://bike.bikegremlin.com/1634/bicycle-bottom-bracket-standards-explained/#3)
Based on that, if you accurately measure 35 as shown in the pic, and the width is 70 (see the link above), it is probably Italian.
Measuring width is a good way to double check – as Italian is the only one 70 mm wide.
*Edit: press fit (non-threaded) excluded, of course.*
A way to triple check is to see the thread direction: Italian and French standards have right-hand thread on both sides, while other standards have left-hand thread on the drive side – but French has smaller diameter.
[*Right vs left hand thread explained*](https://bike.bikegremlin.com/3965/right-and-left-handed-thread/)*.*
Briefly put: if I measure cup threads’ outer diameter to be over 35 mm, or internal shell thread diameter to be over 34 mm, I suspect Italian. But the above-noted other stuff is good as a double check, because one can make a mistake in one measurement (either me or the manufacturer), but when the other stuff confirms, it helps not mess things up by trying to screw in the wrong cup.
Relja *TeachHowToFish* Novovic
https://bikeraceinfo.com/tech/bottom-brackets.html