Crank length: it’s a hotly debated subject these days. Are short cranks just another cycling fad? Should you hold out for another few years until long cranks are back in style? Don’t sell your cranks just yet – Alex Steadman thinks there’s a middle ground.

I keep up with bike trends and new parts, but usually keep them at arm’s length. I don’t need to swap out a perfectly good tire for one that might be marginally faster, or buy a new bike just because it has an updated leverage curve. That said, I’m always fiddling with my fit. Will a few degrees more backsweep, or a few degrees less bar roll, put my wrists in the perfect position? Short cranks were where my curiosity and the latest trend finally overlapped—a chance to improve my fit and try something new.

The internet is full of articles about short cranks enhancing performance and marginal gains. They make your e-bike more efficient, they give you more pedal clearance, they win World Tour stages. There are fewer articles about short cranks related to fit and injuries. I’ve had chronic joint pain for years, and as it progressed, my hips were the first thing to need some attention. A torn labrum due to hip impingement and suggested surgery to fix it led me to seek help in many ways, but the most dramatic improvement came about thanks to shorter cranks.

A Few Sizes Don’t Fit All

As we are slowly accepting, people come in all shapes and sizes. 800 mm wide bars and 143 mm wide saddles don’t work for everyone in the same way size XS or XL bikes don’t work for everyone. So why do cranks have such a comparatively small size range? The difference in reach between the smallest and biggest bikes can be 30%, while the difference between a 165 mm crank and a 175 mm crank is only 6%. Flat bars can be trimmed to fixed gear circa 2007 width or bought off the shelf singlespeeder wide. Drop bars now come in aero road racer narrow all the way to ATB influencer wide. Saddles can be found from 1970s skinny to beach cruiser wide. But for all these options, we still only have a limited range of crank arm sizes.

If stack height was all the same, then tall folks would be folding in half to reach bars that work for short folks, or if saddles were static, you’d either be reaching for the pedals or bent up like you’re on a kid’s bike. Too few crank options are more similar to that last example; if your cranks are too short, your legs don’t bend enough and you lose efficiency. If your cranks are too long, your legs bend too much and you lose efficiency, along with putting power down with your joints at sharper angles, which can potentially cause more wear and tear. That’s what happened to me.

My Body’s Geometry (don’t sue me)

At 5’7” with short limbs, I’ve been riding 165 mm cranks for the past six years – but before that, I spent twelve years on 170 mm or 175 mm cranks. During those years, I was logging big miles on fixed gears and singlespeeds, usually at a faster pace than I ride now. That effort took a toll: I wore through my soft tissue pretty thoroughly. As it turns out, the structure of my hip means my femur and pelvis come into close contact when my leg is fully bent, which eventually led to a torn labrum. That injury is what first pushed me toward shorter cranks. I just wanted to open up my hip angle, reduce bone-on-bone contact, and hopefully ease the pain.

Welcome to my Laboratory

I started my test on my commuter bike: a used cyclocross frame that came with 170 mm cranks. Even compared to 165 mm, those things felt lonnnng. I could feel my knees coming way up, bending more, which increased the pressure on them and made the hip angle at the top of the stroke more acute than was comfortable. To kick off my experiment, I picked up some cheap NOS 155 mm kids’ BMX cranks.
>Right after installing them, I could definitely feel the 15 mm difference. I had to adjust my fit, and – something I figured out later – I also needed a smaller chainring. At first, I dropped two teeth on the chainring just to get a slightly easier gear, but I didn’t notice much difference. That’s when I realized: crank length really does affect leverage.
A year later, with some fine-tuned gearing, the shorter cranks still felt totally natural. Even with skinny tires and no suspension, my hips were noticeably happier on that cyclocross bike than on any of my others.

Going All In

With the success of my initial test, I moved on to my mountain bikes. Since 155 mm had felt totally fine, I figured I could go even shorter and landed on the 152 mm Trailcraft cranks – just a smidge shorter, because why not. This isn’t a review of those cranks, but they’re relatively affordable, available in several short lengths, and use a SRAM 3-bolt direct-mount interface, which offers plenty of chainring options.

I dropped two teeth on the chainring for my hardtail – not because I was thinking about the change in leverage, but simply because I wanted an easier gear. On my full-suspension bike, I initially kept the 30t chainring, but eventually swapped it for a 28t to match the feel of my original granny gear.

Riding up that Hill

Before installing the new cranks, I paid close attention to how it felt pedaling with the 165 mm setup. One thing I noticed: on steeper climbs or when pushing a harder gear, there was a distinct dead spot between power strokes – the moment it takes to get the pedal over the top and back under you again. It reminded me of my singlespeed days, when I’d have to lurch the bike forward like a track racer starting from a standstill just to push through that dead zone.

Switching to the 152 mm cranks noticeably shortened that dead spot. On steep San Francisco hills, it felt like I was almost always in the power stroke.

I also noticed improved traction on technical climbs – something short crank advocates often highlight. Moving more quickly past the dead zone creates a more consistent power output, which translates into more consistent traction. You’re less likely to stall out between strokes on steep pitches.

Another common refrain from short crank fans is that they “spin up” more quickly. I felt that too. I’d attribute it to being able to get the pedals over the top of the stroke more easily. When starting from a stop, the gears don’t feel as tall – it feels like you’re accelerating through them faster. That might come down to a more open knee angle. Think of doing a squat: it’s much easier to stand up from a shallow squat than from a deep one. If your knees are coming up high and bending sharply at the top of the pedal stroke, your legs are simply working harder.

People often say that short cranks are better for spinners than mashers. I am a spinner (something I trained myself to become to reduce joint stress), but that doesn’t mean I never stand up. I don’t race up climbs, but I do like getting up technical features – often by standing and mashing to clear a shelf or root without stalling. On technical desert climbs, the 152 mm cranks didn’t feel worse, and sometimes they felt significantly better. A few times, when stalled partway up a rock, I was surprised by how easily the cranks turned. While trying to slowly climb tech sections for photos during this article, I kept stopping – until I realized I could crawl through them more easily than expected.

On Mormon Trail at South Mountain, I made it up a long, technical climb I’d never previously cleared in one go. I think the cranks had something to do with that.

High Centered

The clearance is also noticeable. I’m still adjusting to it and learning where the pedals will clear or hit. I’ve pedaled over things and braced for contact that never came. Less ratcheting naturally helps with clearing climbs and keeping the power going. With low bottom brackets and squishy full suspensions this is certainly welcome, and pedaling through corners on my hardtail and commuter with no fear of pedal strike feels like I’m using a cheat code. Going for a ride on a borrowed enduro bike with 165 mm cranks had me pedal striking all over on a climb that wasn’t even very rocky. Those 13 millimeters make a difference.

Aches and Pains

It was no surprise that short cranks improved my fit by helping to keep my hips open. I knew shorter cranks would let me raise my saddle and reduce the severity of the hip angle at the top of the stroke – and that’s exactly what happened. I could feel the difference, especially when comparing it to my tandem with 170 mm cranks (which I’ve since downsized). At the same time, I raised my bars to match the 13 mm increase in saddle height, just to make sure my hip angle stayed open and my leg extension remained consistent.

Raising the bars is another way to open up the hips, but there are limits to how much you can do there – and I was trying to cover all my bases. I feel like you’d need to adjust bar height quite a bit more to get the same benefit as simply running shorter cranks and raising the saddle … but I’d have to check with my homie Pythagoras on that one.

Naturally, opening up hips with existing impingement made them feel better – something that doesn’t seem to get much attention in the short crank conversation. Even if you’re not dealing with pain bad enough to land you in an MRI machine, chances are your hips are tight – especially if you’re a cyclist living in a society where most of us spend a lot of time sitting. I’d bet nearly everyone reading this has tight psoas muscles. Open them up!

Downhill Domination

Short cranks have affected my descending experience, too. I’d heard this from others, but it was the absolute last thing on my mind. My hopes were simple: I wanted to adjust my fit without negatively affecting climbing or descending.

My first bunnyhop felt weird. My second bunnyhop felt like I had more pop. I did raise my bars 10 mm, so that could’ve been a factor. In the air, the bike felt more nimble. Whips and tables took less effort than before. The whole bike just feels shorter – maybe because of the narrower stance, which gives you more flexibility.

Try standing with your feet in your normal pedal stance and twisting your shoulders as far as you can to either side. Then bring your feet close together and do the same. You’ll get more movement with your feet closer – which must help explain the more maneuverable feel on the bike.

Normally, this is a tradeoff in the bike world: stability vs. maneuverability. But in this case, I didn’t lose any stability – even at speed or on rough trails – despite the bike’s increased nimbleness.

Is this – dare I say it – a hack?

Other Fit Accommodations

The one area where shorter cranks might not be all upside is the fit limitations of the bike itself. Raising your saddle usually isn’t a problem – in fact, it gives you an excuse to run a longer dropper – but sliding your saddle back might not be possible, or it could require a setback post if you ride with your seat high. I have short femurs, so my saddle is often all the way forward anyway. This change worked in my favor.

The bigger issue is handlebar position. Moving your saddle back increases your reach to the bars, and raising the saddle lowers the bars relative to your pedaling position. If you’re already using a 35 mm mountain bike stem, you might not be able to bring your bars any closer. And if you’re running drop bars, raising them can be tricky. You might not even want your bars to move – they might be perfect for descending in their current position. Sure, there are ways to fix all this, but they often mean buying new parts – which I’d rather not do. Luckily for me, I’ve been slowly raising my bars ever since I stopped slamming my stem, so this gave me yet another excuse to bring them up.

One last bonus: toe overlap. The classic “you rarely even encounter that while riding” line from the bike shop is just not true – especially if you’re stopping and starting a lot. Most riders who’d benefit from shorter cranks are also on smaller frames, which tend to have more toe overlap than larger ones. It’s almost like those bikes should come with short cranks in the first place! My commuter is a cross bike with an oversized front tire and a wide fender wrapped around it, so toe overlap was obscene with longer cranks. It’s much more manageable now.

Should You Adjust Your Crank Length?

The point of all this isn’t to convince you to buy short cranks; it’s to convince you to buy the right size cranks for your body. You’d certainly help a friend adjust their seat height if it looked wonky or help them figure out the right bar width, and this is no different. If you’re riding a small bike, there’s a good chance you’d benefit from shorter cranks. If you’re on a medium, lucky you, you have options for sizes and cranks and… whatever, I don’t care, I’m not jealous. If you’re riding bigger bikes, you might even need longer cranks.

Also, consider your fit for the sake of longevity. Many people don’t think about bike fits because that’s for “serious riders” and because they aren’t especially cheap. I used to be one of those people until I started hurting pretty early into my cycling career. We spend all this time finding the right parts for our bikes and figuring out the exact right size frame we need, so why cut corners once that’s done? Why not spend that money on parts that actually improve your riding experience?

Where to Go From Here

I based my crank length on several sources: the Appleman Bikes Crank Length Calculator, information from a bike fit, and personal experience. From there, I just tried stuff out. While there has been progress in bikes coming equipped with a wider range of cranks, there’s still room to grow. Until then, I suggest investigating and experimenting with the bike trend that will do more good for your body and cycling lifespan than whether or not your bike goes beep boop.