AMoney

I have a spare 105 R7000 crankset with 160mm long crank arms. I am thinking about putting them on my pit road bike, because I like the shorter crank length. My road bike has a 2 x 10 Shimano drivetrain with a 105 5700 crankset. I can't even find a 5700 crankset with 165mm long crank arms, much less 160mm. I know Shimano doesn't recommend mixing and matching. However, I was wondering if people have used an 11 speed Shimano crankset with a 10 speed drivetrain? If so, how did it work out? If it won't work well, I could sell my R7000 crankset.

Kontact 

It will work fine.

SoSmellyAir

According to Lennard Zinn (VeloNews Tech FAQ), it will work just fine.

Bike Forums - View Single Post - SHimano R7000 crankset on 10 spd

What is a "pit" road bike? How is one different from just a road bike?

AMoney

Thanks for the link. A better term would've been my spare bike. The reason I called it my pit bike is that I have left in the pit when I've competed in crits.

AMoney

It's good to know that the 11 speed crank is compatible with a 10 speed drivetrain. Out of curiosity, would a 10 speed crank be compatible with a 9 speed drivetrain?

Kontact 

6-11 will all work, because the inner chain dimensions are all the same. You will get certain cranks that are noisier in crossover gears (Campy 10?) when you use wider chains, but most all of them will act the same and will be perfectly useful if you don't crossover.

And most 5 speed cranks fit in the same category. Chainline has not changed since 120mm hub spacing up through 130 (for road bikes).

Lombard

It will work fine. The crankset doesn't care how many speeds are on your cassette. Granted the chain is different for these, but the difference is too small to make a difference. I just put a 12-speed crankset on an 11-speed drivetrain and it still shifts flawlessly.

Kontact 

An 11 speed crank on a flat top SRAM 12 drivetrain probably will not.

Lombard

i was comparing 12-speed Shimano to 11-speed Shimano. Is there something about 12-speed SRAM that is different? What do you mean by "flat top"?

Kontact 

You are comparing putting a wider chain on a narrower chainring, but the opposite does not work. SRAM road (flat top) 12 speed chains (and from what I've read) Shimano road 12 speed chains are narrower at the rollers and inner links than previous 5-11 speed chains, so when you put one of those narrower chains on the 5-11 width chainrings they don't fit very well. Like trying to push a penny into a dime width slot.

https://www.evo.com/chains/sram-riva...12-speed-chain

Up until 12 speed road, all the different chains worked on all the different chainrings because they were only different widths on the outside.

So the crankset does care.

Lombard

Interesting.

AMoney

It's good to know that a 9 speed chain works with 10 speed chainring. However, does the crankset care about chainring width? In other words, is there any reason I couldn't put 10 speed chainrings on a crankset that was designed for 9 speed?

Lombard

As long as the bolts line up, it won't matter. I'm not sure if there is any difference between the BCD of the two.