The truth about shorter cranks

Should You Switch?

Over the past month, I’ve been testing one of the more talked-about trends in the cycling world—shorter crank lengths. It's a topic gaining momentum among WorldTour pros like Tadej Pogačar and Jonas Vingegaard, as well as among bike fitters, influencers, and performance-focused cyclists alike.

For context, I’m 185 cm tall and have ridden the majority of my cycling career on 172.5 mm cranks. Last year, I made the switch to 170 mm when I changed bikes—a small but noticeable adjustment. In 2025, I decided to take it a step further. I added 165 mm and 160 mm cranksets to my fit toolkit, curious to see whether shorter cranks truly offer a performance or comfort advantage, especially for a rider on the taller side.

It’s worth noting that I had no pre-existing issues on the bike—no pain, a stable and efficient position, an above-average aero posture, limited hamstring and hip mobility, and a pretty good understanding of biomechanics through my work as a bike fitter.

For this test, I made fit adjustments for each crank length, refining saddle height, fore-aft position, and bar drop to maintain consistent joint angles and weight distribution across all setups. Each crank length was ridden for at least one full week, covering a mix of terrain and ride types—from easy endurance sessions and long rides to occasional efforts.

Based on common recommendations to allow at least a 5–10 mm step when changing crank lengths, I began with the most drastic option: the 160 mm cranks.

160mm

From the very first pedal stroke, the difference in feel was immediately noticeable. Pedaling felt significantly smoother—especially in a more aggressive position, with my forearms nearly parallel to the ground. I could clearly feel the increased hip angle at the top of the stroke, which made holding an aerodynamic position far more comfortable and sustainable. My legs felt great, my joints were happy, and even my usual hip mobility limitations seemed less problematic. No discomfort whatsoever—no muscular strain, no joint pain. Everything felt spot-on.

That is, until I hit the one-hour mark.

Surprisingly, the issue wasn’t with my legs—they still felt fresh. The problem was my upper body. My shoulders and lower back began to ache, and it became clear there was a significant imbalance between upper- and lower-body comfort. So, what was going on?

Here’s my theory: every time we push down on the pedals, we generate a counterforce that pushes our upper body back, away from the handlebars. With shorter cranks—essentially shorter levers—this force transfer may be less effective. As a result, more weight shifts forward, increasing load on the front end of the bike. This altered weight distribution made it harder for my upper body to resist the push from each pedal stroke, causing increased tension and fatigue in the shoulders and lower back after just an hour. The long 4-5h rides felt REALLY long.

Pedaling Clearance and Cornering

One of the most noticeable advantages of shorter cranks was the improved pedal clearance during cornering. It provided more confidence and safety when taking tight turns at speed—an often overlooked but meaningful benefit, especially for those racing crits or descending aggressively. If you are a crit racer who struggles thru the corners, going shorter might your be solution.

Aero Considerations

There’s a popular belief that shorter cranks improve aerodynamics—and to some extent, that’s true. A smaller pedaling circle means your legs generate slightly less frontal turbulence. But there’s another side to that coin. When you shorten your cranks, you typically need to raise your saddle and increase your stack height to maintain proper weight distribution and joint angles. From my own aero testing, I’ve seen firsthand that increasing saddle height and stack slightly raises your frontal area—ultimately increasing your CdA.

So, while shorter cranks may help you maintain an aggressive position more comfortably, they can also marginally worsen your aerodynamic drag—especially relevant in time-trial scenarios where CdA is king.

165mm

After adjusting my saddle position to accommodate the 165 mm cranks, I was surprised at how natural everything felt. There wasn’t an immediate sense that I had increased crank length from the 160 mm setup the week before. My legs felt just as responsive, joints remained comfortable, and overall saddle stability was unchanged. The only noticeable difference was a slightly more "closed" sensation when holding a deep, aggressive position—but nothing that felt restrictive.

In fact, everything continued to feel familiar and comfortable throughout the rides.

While I still experienced some upper-body tension—particularly in the shoulders and lower back—it was noticeably less severe than with the 160 mm cranks. I could now ride comfortably in that position for 3 to 4 hours. In simple terms: what became uncomfortable after just 1 hour on 160 mm cranks was now manageable for over 3 hours with the 165 mm setup. That’s a significant improvement in sustainability, at least in my case.

Pedaling clearance and cornering

With 165 mm cranks, I didn’t notice any dramatic change in pedaling clearance compared to the 160 mm setup. I was still able to resume pedaling relatively early when exiting corners, especially during technical descents. It felt natural—perhaps even like a “sweet spot” between mechanical leverage and on-bike agility.

Aero considerations

From an aerodynamic standpoint, the 165 mm cranks offered a compelling balance. I was still able to maintain a low, aggressive position with a relatively open hip angle, which made it easier to stay aero for longer periods. This comfort is likely due to the increased leverage compared to 160 mm cranks. As mentioned earlier, the crank arm acts as a lever: the slightly longer length helped generate counterforce more effectively, reducing the tendency to overload the upper body and improving overall positional sustainability.

170mm

The 170 mm crank length has been my default setup for the past 10 months—and returning to it felt like coming home. This is the position my body knows best. There’s no discomfort, either in the lower or upper body. While the pedaling doesn’t feel quite as smooth as it did with the shorter 165 mm or 160 mm cranks, the difference is marginal.

Riding in a low, aggressive aero position may not feel as effortless at the top of the pedal stroke compared to the shorter cranks, but I can still hold it comfortably for long durations. That’s likely due to my body being fully adapted to this setup over time.

Pedaling Clearance and Cornering

Admittedly, pedal clearance isn’t as optimal with 170 mm cranks—there’s slightly more risk of clipping a pedal when cornering aggressively. But here’s the tradeoff: I can ride longer, with more comfort and stability, which ultimately translates to more confidence on descents and through technical turns. Even if the biomechanical or aerodynamic gains aren’t as sharp as with shorter cranks, the ability to train longer and ride pain-free could very well outweigh those marginal losses.

Aerodynamic Considerations

While the 170 mm setup may not allow me to ride quite as aggressive a position as the 165 mm or 160 mm setups, it still gets me close—crucially, without any upper body strain. For now, that balance of position, power, and comfort makes it a solid all-rounder, especially for long training blocks and race efforts where durability matters just as much as marginal gains.

Conclusions

As with any positional change on the bike, there’s a natural adaptation period. In bike fitting, we typically allow around three weeks for the body to fully adjust to a new setup. So, where does that leave me? Will I stick with 170 mm, commit to 165 mm, or gradually transition to 160 mm? Honestly, I’m letting time and feel guide the decision.

Right now, I’m continuing with the 165 mm cranks. After two weeks of consistent riding, I’ve already noticed a reduction in upper body fatigue—an encouraging sign that my body is adapting. Whether I ultimately stick with 165 mm or return to 170 mm will depend on how this trend evolves over the coming weeks.

Using formulas from Martin & Spirduso — which estimates optimal crank length, either 20% total leg length (ankle joint to hip joint) or 41% of tibial length (ankle joint to the intercondylar eminence) —my ideal range falls somewhere between 167 mm and 170 mm. This aligns well with my real-world testing and subjective experience.

A word of caution

If you're considering a switch to shorter cranks, I strongly recommend getting a professional bike fit first. Factors such as leg length, flexibility, pelvic structure, and spinal mobility all play a significant role in determining your ideal crank length. While there’s growing consensus that traditional industry standards tend to overestimate crank lengths for many riders, that doesn’t mean shorter is always better. And yes—you can go too short, as I discovered first-hand with the 160 mm setup.

Ultimately, crank length is a powerful lever (literally and figuratively) in your fit and performance. Choose it intentionally, not reactively.