Originally Posted by
racefacelefty
That crank looks seriously nice. Could you please explain the respective BCD, as twocircle pointed out, there appears to be a combination of 110 for middle and inner and 130 for the Gates. What does the spider look like?
I think he is actually using a compact 110bcd
double spider with the 52/36 chainrings mounted in the normal positions, then tacking on the spacer ring to the outside + the gates ring.
While this implementation cantilevers a lot of stuff on the outside of the spider tab (more so than when using a triple spider), with the spacer ring mated next to the big ring it makes for a solid spider connection and a good foundation for the gates timing ring.
It must have been tricky to figure out the fitment of the chainring bolts attaching the gates ring to the spider and not hitting the 52t chainring. Perhaps the inside of the spacer ring has counter sinking for the bolt heads?
Then for the captain's timing ring to align with the rear, guessing that it has an extra thick spacer ring mounted directly to the front spider?