b-cranks-chainrings-index

Hi, I want to buy new crankset for my "old" bike. It's has 10 speed rear derailleur. 2 chainrings in front. I do not want to go 1-by setup, because I like the range that 2-by chainrings offer (right now I run 50-34 front and 11-40 rear which offers fast speed) . But this year I cannot find any...

Shimano sells different chainrings for double and tipple cranksets, same number of speeds . Are they really that different? Can you interchange them and work fine?

Hi! I repeteadly see 38T as minimum teeth count for 5-bolt 122 BCD chainrings, the only issue is there actually are some (rare) 37T or 36T chainrings, I even have a 36T one. What are the maths to determine that minimum?

The track folks use 130 or best 144 BCD so the chainring doesn't twist. On the other hand for example, you have Shimano 5800 105 cranks which places the crank arms closer at 12 o clock that maximises the power delivery although it's on 110 BCD. So I was wondering which is better for power...

Hi, I am running a 46/30 10 speed setup. My shifters are 10 speed 105s. My problem is that the standard 5700 front derailleur hits the chainstay when the chain is on the inner ring. Off course i can move the FD higher, but that leads to shifting problems 'cause the FD is too high. do you...