Whats the difference between english and italian bottom brackets and why should I care?

Triathlon Forum
1

I want/need some new cranks and I have no clue what the difference is. I ride a Lucero if the type of frame matters.

2

The difference is in the cup size, and the Italian’s are larger than the British ones (isn’t it always that way).
English standard and ISO standard is 1.37 x 24tpi (ISO actually 1.375) and Italian is 36mm x 24tpi. There are others Swiss and I think French, but ISO and English are the majority. You have no choice, your frame builder does. Contact them for the spec.

3

that bike and 99% of the ones made currently are English threaded, 68 mm shell width, 1.37" diameter by 24 tpi.

-SD

4

Besides crank length and type of threading, what other information do I need before I buy? On ebay, this is usually the only information given.

5

crank and BB interface need to be the same.

ISIS cranks and ISIS BB go together.

Same with spindle width. You need to get teh appropriate width for your application (almost always the narrowest width made for road bikes, unless you are talking square taper stuff.)

Well if you are going in blind, you may consider another source outside of eBay that will offer accurate free advice.

-SD

6

what if the crankset has an integrated bottom bracket (new Dura Ace or Ultegra)? Does this eliminate those issues?

7

actually, maybe. Dura Ace and Ultegra BBs have been interchangable since the abandoned square taper cranks. But a Dura Ace BB with external bearings wont necessarily work with a FSA mega Exo crank.

-SD

8

thanks for the help.