Replacing crank arms

[w3676]

Hi there everyone

I want to change my front crank arms - Shimano Hollowtech II - r7000 2X11 175mm - swapping it for 170mm. Is it possible to replace only the crank arms, rather than buying a new chainring / whole crankset? Obviously matching up the same make/model etc - just a different length arm. Thanks for any help!

 

[Ajax Bay]

If you mean: get a 170mm crankset and swap rings onto it, then 'yes'.
Tip: In title, amend to make "arm" plural and delete "front".
Obviously the right side of the crankset incorporates the crank (175mm).
You could just change the left hand side crank to a 170mm

 

[fossyant]

R7000 - 105 four arm. Best ordering the same, but just the cranks. The chain rings won't fit other makes etc, so you'll need the same Shimano cranks - possibly Tiagra or Ultegra but the colour will be different.

 

[Cycleops]

A set on eBay of silver 105 arms 170mm for £100 currently. Listed as new.

https://www.ebay.co.uk/itm/14518874...LEiLZ2ZQF6&var=&widget_ver=artemis&media=COPY

Hello and to CC.

 

[w3676]

Thank you everyone really appreciate it! I've now got lost in compact, semi-compact cranksets? Do I need to worry about this if I am keeping the same chainrings?

 

[Cycleops]

No

 

[w3676]

Thank you Cycleops!

 

[faster]

Thank you everyone really appreciate it! I've now got lost in compact, semi-compact cranksets? Do I need to worry about this if I am keeping the same chainrings?

Yes.

Your chainrings won't fit a standard crankset (130mm BCD Vs 110mm). I'm not sure about semi compact, but it should be easy enough to find out.

 

[Cycleops]

Sorry, @faster is right you do have to keep an eye on the BCD. If the eBay set has the same spider as yours you'll be okay.

 

[w3676]

Thank you both, yeh I found one on eBay that does

 

[faster]

Sorry, @faster is right you do have to keep an eye on the BCD. If the eBay set has the same spider as yours you'll be okay.

I've just logged back in to say you're right!

I *think* newer stuff like R7000/8000 uses the same 110mm for both. For older stuff, it is different, but you'd probably notice anyway, as the 110mm is 4 bolt and the 130mm is 5.