Peer-reviewed data on 165 mm cranks shows reduced perceived fatigue and lower knee-joint loading. The pro peloton has been quietly migrating for two years while amateur bikes still ship with 172.5 mm.
Tadej Pogačar has now won the Tour de France four times. In three of those wins, his Colnago has been fitted with 165 mm cranks.
That is 7.5 mm shorter than the standard 172.5 mm most stock road bikes ship with.
It does not sound like much.
It is enormous, biomechanically.
And it is a change your local bike shop will almost never suggest, even though the peer-reviewed data has been sitting there for a decade.
We are going to walk through what changed for Pogačar, what the studies actually show about the knee, and whether the migration to shorter cranks is right for you.
Walk into a bike shop and buy a new road bike.
You will be measured for saddle height, reach, stack, bar width, and sometimes stem length.
You will almost never be asked what crank length you want.
he bike will come with what the manufacturer specified, which is usually 172.5 mm.
For a rider who is 5'10", that is not obviously wrong.
For a rider who is 5'6", it is a physiologically punishing choice that they have never questioned.
Pogačar himself is roughly 1.76 m tall.
He rides 165 mm cranks by choice, not necessity.
The two variables that shift are knee flexion at top-dead-center and cadence-friendliness.
At the top of the pedal stroke on a 175 mm crank, the knee is forced into a tighter angle than it needs to be.
That tightness compounds thousands of times per hour.
Shorter cranks open up that angle.
The knee travels through less range of motion, the hip closes less at the top, and torso rotation drops.
A 2018 Cal Poly study found that riders on 150 mm cranks moved their hips through about 45 degrees of motion, compared to roughly 51 degrees on 180 mm cranks. Knee flexion tracked similarly.
Less flexion means less patellofemoral compression.
That is the single biggest driver of the anterior knee pain that plagues serious amateurs.
Shorter cranks do not cost you power at the same cadence.
That has been shown in multiple studies going back to Martin and Spirduso (2001), who found no significant difference in maximal power across crank lengths from 145 mm to 190 mm at optimal cadence.
What shorter cranks do change is your preferred cadence. It shifts up.
Riders who move from 172.5 to 165 mm typically settle into a cadence about 5 to 8 rpm higher, and their knees feel better for it.
That is the mechanism behind why Pogačar can climb Jebel Hafeet at a spin rate that visually looks unsustainable.
The most useful recent study on this was published in the Journal of Exercise Science & Fitness in 2025.
Researchers tested high-level amateur road cyclists on 165 mm, 170 mm, and 175 mm cranks, measuring cycling efficiency, sprint performance, and perceived fatigue.
The efficiency numbers were statistically similar across all three crank lengths.
That surprised nobody.
What was striking was the fatigue data. Perceived fatigue on 165 mm and 170 mm cranks was significantly lower than on 175 mm.
You can read the full study on PubMed Central.
The authors concluded that high-level amateurs should use shorter cranks to reduce fatigue, not because they generate more power but because they generate the same power with less accumulated strain.
Lower strain over five hours is a bigger deal than a marginal power gain.
That is the mistake most amateurs make when they dismiss crank length.
There is a second reason Pogačar's team switched.
horter cranks let you slam the saddle further forward and drop the front end without your knees hitting your chest at the top of the stroke.
That opens up a more aggressive aero position. UAE Team Emirates knew this before they made the change.
The aerodynamic gain from a lower torso is real, and it stacks with the fatigue reduction.
Two gains for one component swap.
This is not a universal upgrade.
Three groups should think carefully before switching.
Track sprinters and pure sprinters may lose peak torque at the very top end of their sprint.
The evidence is mixed, but if you race criteriums where the last 200 meters is everything, 172.5 to 175 mm may still be optimal.
Very tall riders (above 6'2") may not benefit as dramatically. Their leg proportions already tolerate longer cranks without extreme knee flexion.
Riders with an already-optimized position may create more work than they solve by switching.
Every 5 mm reduction in crank length requires a corresponding 5 mm increase in saddle height, and often a saddle forward shift.
Get the bike fit right first. Our guide to how to fit a road bike walks through the sequence in order, and crank length sits later in that sequence than most people think.
Knee pain is the most common overuse injury in cycling.
The two most common causes are saddle height error and crank length mismatch.
Amateurs almost always get the first one investigated.
Almost none of them touch the second one.
If you have chronic anterior knee pain and a proper bike fit has not fixed it, crank length is the next variable to look at. Our complete guide to cycling knee pain covers the full diagnostic sequence.
The mechanism is worth restating.
Every unnecessary degree of knee flexion at top-dead-center compresses the patellofemoral joint slightly harder than it needs to be.
Do that 90 times per minute for five hours, once a week, for a decade. That is 14 million compressions your knees did not have to absorb.
A new set of cranks with a power meter will cost between $600 and $1,400 depending on brand and groupset.
Without a power meter, quality aluminum options exist under $200.
You will also need a bike fit adjustment.
Budget another $150 to $300 for a proper session with a fitter who understands the shorter-crank shift.
Total realistic cost: $800 to $1,700 for the full change with a power meter.
That is not cheap, but it is significantly cheaper than a new bike, and the biomechanical return is bigger than almost any other upgrade in that price band.
Pogačar is not the only pro on shorter cranks.
Primož Roglič moved to 170 mm several seasons back, and multiple WorldTour sprinters have shifted to 165 mm.
The trend is not marketing, it is biomechanics.
The industry has known for years that stock 172.5 mm is a compromise that suits no one perfectly.
Manufacturers ship it because they can only afford to stock one length per size band.
That is a supply chain decision, not a performance recommendation, and you should treat it accordingly.
The most consequential number on your bike is the one nobody measured you for.
Get it right, and thousands of hours of unnecessary knee load disappear.
Get it wrong, and no amount of saddle sliding will save you.
Pogačar knows this, his coaches know this, and now you do too.
The question is whether your bike shop will admit it when you walk in and ask.
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