Does anyody out there know what the difference is in the Q factor between these DA 9 speed and the Sram Force?

I have ridden both of these extensively - recently all SRAM and it just feels more comfortable - why is this?

Any thoughts are appreciated.

Does anyody out there know what the difference is in the Q factor between these DA 9 speed and the Sram Force?

I have ridden both of these extensively - recently all SRAM and it just feels more comfortable - why is this?

Any thoughts are appreciated.

One is made by SRAM, the other D/A. Both have chains, cassettes with teeth, brake calipers, shifters, and front and rear der's. If you look on each part, it will have a different name and logo on it. That is your difference.

9 speed? That is so down-tube shifterish.

One is made by SRAM, the other D/A. Both have chains, cassettes with teeth, brake calipers, shifters, and front and rear der's. If you look on each part, it will have a different name and logo on it. That is your difference.

And he asked specifically about the Q factor. Maybe you should lay off the weed (4:20) a little and start reading for comprehension :)

One is made by SRAM, the other D/A. Both have chains, cassettes with teeth, brake calipers, shifters, and front and rear der's. If you look on each part, it will have a different name and logo on it. That is your difference.

9 speed? That is so down-tube shifterish.

OK, no more wake and bake.

BTW, D/A is made by Shimano.

Here are the Shimano Q-factors. 9-speed Dura-Ace double is FC-7700 and FC-7701. Don't know the SRAM Q-factors.

http://www.paul-lange.de/produkte/shimano/support/Handbuecher_Explosionszeichnungen/2006/TN_GE/TN_04_EN.PDF

Thanks wim - very useful information

There is only so close together the crank arms can be before they hit the chain stays, thus Q factor for just about all modern road cranks is within a couple mm's of each other - off brand carbon cranks excluded.

There is only so close together the crank arms can be before they hit the chain stays, thus Q factor for just about all modern road cranks is within a couple mm's of each other - off brand carbon cranks excluded.

Actually, Campy is about a cm narrower than Shimano. If that is a couple of mm to you, then fine :)

Actually, Campy is about a cm narrower than Shimano. If that is a couple of mm to you, then fine :)

There may have been old Campy cranks with narrow tread widths, but I think you'll find all modern models in the 145-150mm range.

Actually, Campy is about a cm narrower than Shimano. If that is a couple of mm to you, then fine :)

How can they be a cm closer together when Shimano crank arms come within 10mm of hitting the chain stays on most frames?

There may have been old Campy cranks with narrow tread widths, but I think you'll find all modern models in the 145-150mm range.

The latest numbers I've seen (not measured by me) says 2007 Record = 146mm tread width, 2007 DA = 159. This was published in the most recent issue of Bicycle Quarterly.

My SRAM Force crank had a q-factor of 144mm from outside edge of the crank to the other outside edge....

The latest numbers I've seen (not measured by me) says 2007 Record = 146mm tread width, 2007 DA = 159. This was published in the most recent issue of Bicycle Quarterly.

Interesting. This link
http://www.paul-lange.de/produkte/sh...E/TN_04_EN.PDF gives the DA 7800 a width of 146mm.

My SRAM Force crank had a q-factor of 144mm from outside edge of the crank to the other outside edge....

144mm is about the closest together you can go without resorting to a special frame of some sort with S-bend chain stays. My current bike has a DA10 crank (listed as having 146mm spacing) and the ends of my 172.5mm cranks come within 10mm of hitting the chain stays on each side. When I'm tired after a long day of riding, I've been known to occasionally kiss the heal of my shoe on the chain stay thus any crank with an appreciably narrower Q-factor would not work.

So after reading this thread it seems that higher end Shimano, SRAM, and Campy cranks all fall in the 144 - 146mm range. Not enough difference to matter.

Interesting. This link
http://www.paul-lange.de/produkte/sh...E/TN_04_EN.PDF gives the DA 7800 a width of 146mm.

Curious. I know the guys at Bicycle Quarterly are fanatics about measuring stuff, so I wonder where these differences come from. I guess we need some dedicated RBR member to just go out and measure their new DA crank set.

Curious. I know the guys at Bicycle Quarterly are fanatics about measuring stuff, so I wonder where these differences come from. I guess we need some dedicated RBR member to just go out and measure their new DA crank set.

Just measured mine and got 146mm. Now to find someone to measure some Campy cranks.

Just measured mine and got 146mm. Now to find someone to measure some Campy cranks.

Just measured mine at 145 mm. I wonder where the Bicycle Quarterly got the 159 mm number they reported.