Bottom bracket length?

[JediPaddler]

Hi

Gradually bringing my old Dave Quinn back to life.

It was dropping the chain at the front with new chain and chainring. Front derailleur was well adjusted, so I checked the chain line which measured 50 mm from between the two rings to the centre of the downtube. My understanding is this should measure 43.5 mm for a double.

So removed the bottom bracket which measures 122mm end to end.

I'm concluding the bb is too long?

Guessing I should have 115 or according to Sheldon Brown a 113 for my rx100 chainset?

Have I done my sums and research right?

Thanks

 

[Midlife]

IIRC back in the 70's the Jap axles I used for my Dura Ace and Sakae Ringyo were 112mm..........mind you that's from memory


ooops............113mm according to velobase LOL

http://velobase.com/ViewComponent.aspx? ... &AbsPos=99


Shaun

 

[JediPaddler]

Re:

Thanks, think I'll go with 113