How do you work out BB axel length?

I have a 73 mm BB housing. I was told a 107 BB axel would fit. But its to short :twisted: So how do i find out the correct length? Double chainrings cranks
Thanks

What is the crank model? Usually the correct length is findable.

Depends on the crank not the BB shell width

Stronglight Impact. The shop web site and the company says 107 wide. And to use two spacers for 73 mm bb. But they made it worse. Once removed the drive side fitted and the non drive is far to short.
I looked sheldon brown site and that to tech for me. Lots of tables and spec.

Ah, you are in luck, I have fitted several of them to my family's bikes!

It's a 110mm BB for a 68mm shell, however if you have a fat seat tube the mech may not be able to swing far enough inwards. I ended up using a 113.

hamster":2riea8rv said:

Ah, you are in luck, I have fitted several of them to my family's bikes!

It's a 110mm BB for a 68mm shell, however if you have a fat seat tube the mech may not be able to swing far enough inwards. I ended up using a 113.

Click to expand...

so a 113 for my Trimble in my avatar? Oh and its a TA BB

It just had to be for something odd. :facepalm:
I'd go with a 113 as a starting point. Conventional front mechs generally can run closer to the seat tube than low band types.

hamster":v05qr3gc said:

It just had to be for something odd. :facepalm:
I'd go with a 113 as a starting point. Conventional front mechs generally can run closer to the seat tube than low band types.

Click to expand...

I brought a 116 in the end must fit now? Treated to a Ti version this time. x fingers.
I wish the first shop hadn't said 107. eBay at the weekend.
Thanks.

Re:

http://www.sheldonbrown.com/bbsize.html

I always go here. The man.

tintin40":2uh9s54f said:

hamster":2uh9s54f said:

It just had to be for something odd. :facepalm:
I'd go with a 113 as a starting point. Conventional front mechs generally can run closer to the seat tube than low band types.

Click to expand...

I brought a 116 in the end must fit now? Treated to a Ti version this time. x fingers.
I wish the first shop hadn't said 107. eBay at the weekend.
Thanks.

Click to expand...

There is fitting and there is having too much distance from the frame.

The 116/113 will likely have the same distance on the drive side.
The 116 will be a further out on the none drive side.
116 is an odd length, it's normally 115 unless it is ISIS/Octalink.

Assuming the i do above is correct
110 would give you the 47.5 traditional standard chain line and 113 would give you the traditional wider 50mm chainline.
Both would be the same on the none drive side.

Anyway, fit and find out.

107 fits the same as a 110 except the nonedrive side is in the 2-3mm.

The super low profile (basically the m900 shape) used 107/113 with 110 being a later infill for some situations.