I recently acquired a 9 speed Ultegra crank real cheap but would like to run 10 out back. I've searched everywhere and it seems i could probably run as is, but if i wanted to do it right, how much would i mill off the spider for the distance between center of rings to be correct for a Shimano 10 speed? The crank is a double. I guess all i really need to know is the difference in spider thickness between the two? If someone has a set of calipers and a 10 speed crank without any rings on it could you let me know the width? Also i suppose with some creativity and a rotary table i could fix the rings themselves, anyone know the width and pitch of the 10 speed teeth?
Thanks for your time