Q-Factors: Campy vs. Dura Ace

[BikeCranky]

I had a major headache these last few days, trying to determine if I could replace my DuraAce 9psd with the new Campy cranks, in regard to Q-Factor. Campy has good tech. info on their web site. DuraAce/Shimano seemed to all be hearsay. Attached are my findings: 145.5mm each. They appear to be the same Q-Factors.
-Cranky

 

[hd reynolds]

I had a major headache these last few days, trying to determine if I could replace my DuraAce 9psd with the new Campy cranks, in regard to Q-Factor. Campy has good tech. info on their web site. DuraAce/Shimano seemed to all be hearsay. Attached are my findings: 145.5mm each. They appear to be the same Q-Factors.
-Cranky

You can replace your DA 9s crank with any crank brand/model as long as you use the recommended BB spindle. Unless you have a leg/hip condition, Q factor is not that crucial than getting the proper chainring(s)-to-bb and chainring(s)-to-chainstay tolerances (these are more important).

 

[bobbyOCR]

You can replace your DA 9s crank with any crank brand/model as long as you use the recommended BB spindle. Unless you have a leg/hip condition, Q factor is not that crucial than getting the proper chainring(s)-to-bb and chainring(s)-to-chainstay tolerances (these are more important).

It is also slightly more aero and a bit more efficient. Also puts less strain on joints.

 

[hd reynolds]

It is also slightly more aero and a bit more efficient. Also puts less strain on joints.

Q factor differences are so small that it will hardly make any aero difference. - one would benefit more with over-shoes or practicing the pedaling technique where your knees just almost brush the top-tube.

 

[bobbyOCR]

Q factor differences are so small that it will hardly make any aero difference. - one would benefit more with over-shoes or practicing the pedaling technique where your knees just almost brush the top-tube.

Very true. Bottles on the seat-tube make more difference than an aero front wheel aswell. People won't believe it though.

 

[BikeCranky]

For me, every mm counts - I can tell the difference of 1mm on my seat height. I can also tell the diff between a 105mm and a 110mm stem. The guys here in San Diego tell me I'm full of it, well there it is. Maybe that's true too.

My mechanic guarantees this will fit just fine on the Moots frame I got - it's not going on the Litespeed. Interestingly, the Moots will have DuraAce 10speed for shifters and deraulures, only the BB and crank will be Campy. That combo works, as I have seen others with this combo.

 

[Tech72]

I had a major headache these last few days, trying to determine if I could replace my DuraAce 9psd with the new Campy cranks, in regard to Q-Factor. Campy has good tech. info on their web site. DuraAce/Shimano seemed to all be hearsay. Attached are my findings: 145.5mm each. They appear to be the same Q-Factors.
-Cranky

Kudos for finding D-A's true Q-factor. Good, solid hands-on research and magnificently anal with that home-made report. All good.

 

[BikeCranky]

Kudos for finding D-A's true Q-factor. Good, solid hands-on research and magnificently anal with that home-made report. All good.

ROTFL!
Yeah, well I was really ****** after tons of Yahoo and Google searches for real values of the Q-Factor. So I measured the bloody thing.

Of course, my mechanic dogged me out totally for doing this - he said basically I should not have to worry about that - he takes care of those details for me, etc. etc. I got a great mechanic.

And yes, I am known to be totally a-retentive and detail oriented about the bike parts dimensions. Fit is important. And when you set up a new bike, and your old bike is a perfect fit, you want to new one to be as close as possible.
-Cranky