What’s the difference between a 10 and a 9 speed crank?
with respect to what? they share many similarities and some differences. are you trying to do something in particular?
They’re one faster.
Spacing between the chainrings is slightly different.
There is little difference, the differences are small and most of the time you can interchange the two. I use a Shimano DA 10-speed drivetrain with Shimano DA 9-speed cranks.
That said, for specifically designed 9-speed and 10 speed cranks, there are some small differences. First, 10-speed chainrings are fractionally (but measurably) thinner than 9-speed chainrings (but chainrings can be switched out). Second, 10-speed cranks are designed so the distance between the two chainrings is also fractionally less than that same dimension on 9-speed cranks.
What I’m trying to do is build up 10 spd components from a 9 speed. I just see some 10 speed cranks and wondered if I could just use my 9 speed cranks? I know about the shifter but…
99.9% chance you’ll have no problem with 9-speed cranks. I’d use them. But use a 10-speed chain if you’re using an otherwise 10-speed drivetrain.
I use 9-speed cranks on my race bike and on another bike both with 10-speed drivetrains (except the cranks). And both shift great.
I’ve been thinking about upgrading my road bike from a 9 to a 10 too, but wasn’t sure what needed to be replaced. Do I understand correctly that in order to do that I will need the following (currently everything is shimano 105) :
- Shifters
- FD
- RD
- cassette
- chain
- but I can continue to use the cranks
is this correct?
I’ve used a 10 speed rear deraileur on a 9 speed bike with 9 speed shifters/chain/cassette.
I would imagine that you could go the other way too.
If you are using Bar end shifters then you could use the front deraileur too.
Actually the derailleurs are close enough you don’t HAVE to swap, either. The absolute minimum is just shifters, cassette and chain. Since the spacing is tighter, the chain is narrower, and thus the front chainrings are slightly thinner, but it’s not a big enough difference that you’ll notice while riding. I’ve mixed both 9-spd cranks with an otherwise 10-spd drivetrain and 10-spd cranks with an otherwise 9-spd drivetrain before (because the 2 cranksets were different BB types and I didn’t want to bother swapping BBs at that point).