Help required; FSA ISIS Bottom Bracket Q



Bigbananabike

Active Member
Dec 29, 2004
967
30
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I've got a couple of Truvative / Bontrager cranksets (doubles) that I need BBs for.
They're ISIS.
A guy on an auction here has 2 ISIS BBs. He's measured the length of the axle at 113mm.
He says thats for a triple.
Is that correct? How would that length axle go for a double? Would it really be too long?
Cheers :)
 

alfeng

Well-Known Member
Jul 23, 2005
6,723
254
63
Bigbananabike said:
I've got a couple of Truvative / Bontrager cranksets (doubles) that I need BBs for.
They're ISIS.
A guy on an auction here has 2 ISIS BBs. He's measured the length of the axle at 113mm.
He says thats for a triple.
Is that correct? How would that length axle go for a double? Would it really be too long?
113mm would not be too long ... that's only a 2.5mm difference in the so-called Q-factor on each crank arm ...

AND, less than the Q-factor for those who have triple cranksets for which I believe a 118mm is also a suggested spindle length ...

AND, the resultant Q-factor of using a 113mm ISIS spindle instead of a 108mm is less than whatever Q-factor you may have if you have a MTB.
 
Dec 30, 2007
2,111
8
0
Bigbananabike said:
I've got a couple of Truvative / Bontrager cranksets (doubles) that I need BBs for.
They're ISIS.
A guy on an auction here has 2 ISIS BBs. He's measured the length of the axle at 113mm.
He says thats for a triple.
Is that correct? How would that length axle go for a double? Would it really be too long?
Cheers :)

108.5 for a double and ISIS. Beware tho, these BBs, all of them from any manufacturer, were very short lived.