Shimano Botton Bracket Advice Please

[Wezzo]

Hi, gremmy question but forgive me as this is my first resto. I need a bottom bracket for my frame which has come to me bare.

The BB shell is 68mm and I have established that it’s a 1.37x24 British thread and I have a Dura Ace 7700 twin ring crank set to fit. There are 2 lengths for the Octalink BBs 109 and 118.

Can you advise which one I should purchase please? Thanks

 

[SimonJC]

Fairly certain that the 109 is for a double chainset; 118 would be for a triple.

One thing I do know for certain is avoid the Dura-Ace version at all costs; it wears out instantly. The best model BB is the Ultegra version, but I don't think it is made anymore, so the next best would be the 105 version.