Cranks and rings and different speeds - what makes an 11 speed crankset 11 speed?

[thatmattwooding]

Thanks! Especially for the links.

 

[ishaw]

There are plenty more on eBay, people don't fill in all the fields so better off not filtering by brand etc.

 

[misterfixit]

Chain internal dimensions don't change by gear no. Rings are the same width. Gap between rings can change but not between 7 to 10 speed for shimano.

There is a difference between gaps on road and mtb cranks.

Q factor between road and mtb is different too.

Incorrect. 7-8 is the same. 9 is less, 10 is even less. Some rings have offset on them (m552 10speed for example) that removes the effect on spread, but the spacing 9-10 speed is different