Should you ride shorter cranks?

What's with Tadej Pogačar winning everything on 165mm cranks?

Dear Readers,

When it became public that Tadej Pogačar and Remco Evenepoel have been so dominant this season while riding on 165mm cranks and that Tom Pidcock is also on 165s, lots of people have asked me about shortening their cranks. Here is a sampling of the questions I have received on the subject.

― Lennard

Dear Lennard,

I've been seeing a lot of buzz lately on YouTube and at bike shows about shorter cranks. What are your thoughts on them?

What is a good way to find optimal crank length?

Some videos as examples (but probably also sponsored):

Adam

Dear Lennard,

What do you make of the trend in the professional peloton toward shorter cranks? I'm thinking in particular of Pogačar, who at 5'9" has dropped down to 165s. I gather much of this is trading off cadence for single stroke power, as you alluded to with regard to Magnus Bäckstedt. In Pogi's case, using shorter cranks means higher cadence and lower gearing, with an assumption that this must give him higher overall power over the course of day's racing. I do wonder if there is a tradeoff in terms of riding on the flats vs. climbing.

It does feel like there is clearly a very personal component to this. I talk about riders like me that climb with their lungs (spinners) vs. those that climb with their legs (mashers). Pogi is clearly a spinner. When I think about mashers, Jan Ullrich always comes to mind, although I'm not sure that kind of rider even exists in the modern peloton.

For myself, with an 87cm inseam, the more conservative 20.5% number I've seen bandied about would suggest I should be on 178mm cranks, but one thing I like to keep in mind is that my 172.5mm cranks are only 3% shorter, so it's not clear I could even feel the difference. I actually ride two different crank sizes during the week, 175s and 172.5s, and I can't tell the difference.

So all that said, what are your thoughts these days, particularly with regard to a more average sized, genetically challenged weekend warrior like myself?

Steve

Dear Lennard,

I know you were introduced to extended length crank arms back in your days at the Olympic Training Center. Taking into account rider height, leg length and even foot size. At 6’5”, 36” inseam and a size 14 foot, you recommended them to me when I bought my custom frame and I have been sold on them ever since.

There seems (to me) to be a push toward shorter crank arms coming out of the 2024 road racing season and I wanted to get your take on the current state of/thoughts on crank arm length.

Robert

Dear Adam, Steve, and Robert,

First off, you are not going to measurably gain or lose power with a change of a few millimeters in crank length. For people asking about “shorter” cranks, I ask, “shorter relative to what?”

In last week’s column, I explained how Power = Torque x Cadence, discussed the aerodynamic benefit of having the knees come up less high on shorter cranks, talked about leverage when out of the saddle, and introduced Dr. Jim Martin and his research on this topic.

I have experimented with crank length for over 45 years. Since my inner leg length (from floor to the pubic bone in bare feet—for most people this is around 2” [50mm] longer than their pants length) is 965mm (38”), I tend to experiment more with cranks on the longer side. It is also anecdotal—based on myself and a few other riders, all of whom knew what crank length they were riding.