Cannondale scalpel crank arms

[Williepotch]

Looking at swopping my current 172 Cannondale si hollowgram crank arms with 165. Any other brand that will fit on the spindel or do I need to replace the whole crank set ie xx1 Eagle ??The Cannondale crank arms are crazy expensive!

[Me rida my bicycle]

Pretty sure only cannondale arm's will work on the si axle. Sram xo1 on my bike with 165mm length and they are no to expensive. The difference between xo1 and xx1 was not worth the price.

[DieselnDust]

You'll need to find a BB30 crank that has both arms separate from the axle.  As far as I know thats only the Hollowgram units

[letsride]

What size bike are you riding Willie?

[letsride]

You'll need to find a BB30 crank that has both arms separate from the axle. As far as I know thats only the Hollowgram units

The team is riding xtr cranksets... but you are spot on BB30 cranks with separate axles. Surely then Rotor, Raceface etc would also be an option?

[DieselnDust]

The team is riding xtr cranksets... but you are spot on BB30 cranks with separate axles. Surely then Rotor, Raceface etc would also be an option?

 

 

Those are sold with one arm attached to the spindle, often loctite on. So you're buying a whole crank set.

Cannondale factory racing uses a custom Shimano XTR cranks with a longer spindle with the bearing lands ground into the correct location to mate with the PF30-83 BB bearings and Ai drivetrain. The bearing lands on a Ai PF30-83 spindle are not symmetrical in relation the distance from the crank position.

 

A rotor crank will fit the Scalpel Ai with very little clearance but it fits. Its purchased as a complete unit as far as I know

Race face Cinch cranks do not seem to be compatible so you will need their axle and crank arms. I don't know whether the BB30 tapered splines are off axis from the Cannondale crank arms or what makes it incompatible but that was the info from Race Face when I was looking for a PM for my Scalpel. Their Cinch unit won't fit. Could be the axle isn't long enough

Edited June 23, 2020 by DieselnDust

[Williepotch]

Thanks guys. I ride a large.

[letsride]

Why are you wanting to go for a 165 crank? If you are riding a large frame the 172,5 should be good.

[Williepotch]

Have some knee problems,had a couple of ops. Was recomended by a friend and said it made a big improvement on his knees.

[Mongoose!]

I have a set of 170mm SI Cannondale crank arms, but ques you looking for 165mm

[Quagga]

Have some knee problems,had a couple of ops. Was recomended by a friend and said it made a big improvement on his knees.

Just because it worked for him does not mean it will work for you.

Unless you are the excat same height / build / muscle etc.

 

You need to get what works for you.

 

I would suggest 1st try a smaller chaining, Try oval vs round , bigger cassette at back like 52  etc

[100Tours]

Have some knee problems,had a couple of ops. Was recomended by a friend and said it made a big improvement on his knees.

 

It is a reasonable idea.

 

shorter cranks will mean your knee doesn't have to flex to the same extent over the top of your pedal stroke - e.g. track cranks are generally 170s, not 172 or 175 on almost any size frame. There doesn't seem to be a lot of difference to your riding performance either if you believe Sheldon Brown's work.

 

you would probably see an improvement already at 170 vs. 172.5 (basically the top of your pedal stroke is 5mm lower for a 2.5mm shortening of the crank).

Edited June 26, 2020 by 100Tours

[Williepotch]

Already have a smaller oval chainring. Its exactly as you said 100Tours.Limits the extreme flex on the power stroke dowm as I understand it.

[DieselnDust]

It is a reasonable idea.

 

shorter cranks will mean your knee doesn't have to flex to the same extent over the top of your pedal stroke - e.g. track cranks are generally 170s, not 172 or 175 on almost any size frame. There doesn't seem to be a lot of difference to your riding performance either if you believe Sheldon Brown's work.

 

you would probably see an improvement already at 170 vs. 172.5 (basically the top of your pedal stroke is 5mm lower for a 2.5mm shortening of the crank).

 

 

??? Top of the stroke is 2.5mm lower. The degree that the knee flexes through is reduced because the saddle is effectively raised by 2.5mm but linear distance at top of the stroke is still only 2.5mm shorter.

 

or have I not had enough coffee yet? What am I missing?

Edited June 26, 2020 by DieselnDust

[DieselnDust]

https://cannondaleexperts.com/collections/cannondale-single-crank-arms?constraint=165mm

 

 

The left arm is out of stock.

 

https://cannondaleexperts.com/collections/cannondale-single-crank-arms

 

Both in stock but $500-00 for the pair!!

[J Wakefield]

I would run a smaller front chain ring, the knee flex and hip angle wont change much as you having to lower the saddle now due to shorter crank arms and more than likely change saddle set back and with it being a large frame this is where additional problems may come into play.

If you have knee issues, smaller front, work on glute muscle as often knee issues come from there  and ride you bike and smile.