Will ultegra/dura ace cranks fit onto a compact chainset?

[montage]

I have heard that 165mm cranks are better for the knees than 175mm? true or false?

If I want to upgrade my cranks (holotech will be lighter than my current ones) then can I fit ultegra/dura ace (or even 105 ) cranks onto my compact chainset?

Cheers

 

[Will1985]

With your knee situation montage, a kinesiologist should be advising you. Forget the formulae bandied about on here.

The part about cranks doesn't make sense - cranks are a significant part of the chainset. Or do you mean "can I use my current chainrings on some new cranks?"

 

[montage]

With your knee situation montage, a kinesiologist should be advising you. Forget the formulae bandied about on here.

The part about cranks doesn't make sense - cranks are a significant part of the chainset. Or do you mean "can I use my current chainrings on some new cranks?"

Yer this....sorry

 

[RedBike]

I have heard that 165mm cranks are better for the knees than 175mm? true or false?

False? - I suppose it all depends on whats wrong with your knees!
In order to get the same power from smaller cranks you either have to spin quicker or exert more force. The chances are on step hills you'll be pushing harder which is often bad knews for the knees.

If I want to upgrade my cranks (holotech will be lighter than my current ones) then can I fit ultegra/dura ace (or even 105 ) cranks onto my compact chainset?

I'm a little confused as to what part you're calling cranks and chainset.
I understand chainset to be the name for the crank arms complete with the chainrings.

As far as I know you can't buy hollowtech chainsets anymore, you can get a compact hollowtech 2 chainset at every level, even Sora. You will need the appropriate bottom bracket to go with the cranks. This will need to be fitted by a LBS as to be installed correctly the frame needs to be faced. If the store don't want to face the frame go somewhere else.

 

[andrew_s]

False? - I suppose it all depends on whats wrong with your knees!
In order to get the same power from smaller cranks you either have to spin quicker or exert more force. The chances are on step hills you'll be pushing harder which is often bad knews for the knees.

Shorter cranks are easier to spin fast.
In terms of knees, what does the damage is applying force on a bent knee, and with longer cranks your knee is bent more than with shorter ones

 

[redddraggon]

Cranks will come with Chainrings