Bicycle Mechanics - Sugino XD600 vs XD2 BB spindle length

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aroundoz
09-18-05, 09:33 PM
I could really use some help with this. I am somewhere between a beginner and pro when it comes to working on bikes. I have assembled several bikes with no or little problem and have tuned mine and friends for the last 15 years.

I am buidling a Gunar Crosshairs for a friend and usually use a Sugino XD600 but they were on back order. I got a XD2 instead. Can anyone tell me if there is a difference?

I used a 113 spindle length on my touring bike which has the XD600 and it worked great. I was told to use the same for the XD2 but it placed the crank too far out. When it's in the middle ring and either first or second gear in the rear, it will down shift to the small chainring on it's own due to the chain angle. Realizing my touring bike has 135 rear spacing and the Crossahairs 130, I tried a 110 and then a 107 only with the same problem. What perplexed me even more was the distance between the carnk arms and the seat tube remained the same between the 113 and 107 while remaining equal distance on each side. Based on that, the 107 didn't bring the crank arm any closer. I am using an eight speed cassette and yes I was using proper torque and even a little more hoping to bring the drive side in.

Advice will be greatly appreciated.


aroundoz
09-19-05, 11:33 AM
Well I found the answer by talking to RBW. They said on some setups the pinning and ramping on the middle chainring will cause it to down shift on it's own. They are sending a chainring minus the pins and ramps. It only down shifted at one point on the chainring so this sounds reasonable. At least I learned a bit about bottom bracket sizes etc....

genericbikedude
09-19-05, 12:00 PM
thats weird--a different size spindle didn't affect the position of the crank visavis the seattube?


aroundoz
09-21-05, 10:23 PM
I can't figure it either. The difference between the 113 and the 110 is the drive side is shorter. The difference between the 110 and the 107 is the non drive side is shorter with the drive side being the same. However, the difference between the crank arm and seat tube was the same for all given the same amount of toque on the cranks. I don't know know if the taper is different or what. Anyway, looking forward to the new chaingring and if that doesn't work I am not sure what I will do.