Last updated: December 21st, 2022
Chainstay length has a noticeable effect on ride quality, but it’s hard to isolate from other factors.
There’s no magic length that suits all bikes and situations, so this article will clear up some confusion about what chainstay length actually means (or doesn’t mean) for your ride.
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Here’s whether bike chainstay length matters
Longer chainstays create a more stable ride on rough ground and increase heel clearance around panniers. However, they’re harder to maneuver in extremely tight, technical situations, and may flex more under hard pedaling. Shorter chainstays are not any faster, since they don’t significantly affect the mechanical efficiency of the drivetrain, but may feel “snappier.”
The reasons are all fairly intuitive, but I rode for years without giving it much thought. Only when I purchased a couple of Rivendell models (with their famously elongated bike geometry) did I realize what a difference this under-explored design choice makes.
Background: How to measure chainstay length
As a quick refresher, bicycle chainstay length is measured from the center of the bottom bracket shell to the center of the rear axle.
This measurement is a straight line, so it’s useful for comparing between bikes. However, actual bicycle chainstays themselves are often contoured to accommodate rear suspension, ensure pedal clearance, and improve stiffness.
Exactly how do long chainstays help?
Long chainstays position you farther from the rear axle, which reduces the impacts you feel, and therefore feels smoother.
Picture the bike as a lever that’s fixed at the front axle and free at the rear.
The closer you are to the rear wheel axle, the more you’ll move up and down with it. Hypothetically, if you sat behind the rear axle, the bump would actually feel even bigger than it is!
Conversely, you experience less jarring (i.e., less vertical movement) when you’re farther ahead of the rear axle.
It’s analogous to a see-saw: you move less as you get closer to its fixed point (the fulcrum) and farther from its freely moving ends.
What are the drawbacks of long chainstays?
I’ve owned bikes with phenomenally long chainstays, even beyond a typical touring bike. The only drawbacks were awkward handling in extremely tight singletrack, and a hard time hauling or storing the bike in tight spaces.
Less nimble handling
Very long chainstays (around 480 mm and up) give superb ride quality as long as corners are mild. But when you’re trying to snake through a rocky corner while popping the front wheel up over a log, they feel like parallel-parking a limousine.
That’s exactly why modern mountain bikes lean toward short chainstays and a long top tube. That increases the wheelbase for overall stability without sacrificing nimbleness in low-speed technical situations, and without inducing toe overlap.
(Road and urban bikes usually don’t do that, since they can’t rely on chunky tires and even rear suspension to mitigate the harsher ride of short chainstays.)
Difficulty moving & storing
The other issue is more mundane: they’re just plain awkward to carry and store.
I learned this firsthand during a year of hauling my Rivendells up stairs and through our apartment’s living room. That was challenging in our relatively spacious building, and would have been a non-starter in most older ones.
Along those lines, some folks have issues with the bike racks on city buses. I never had trouble, but there are reports of long-wheelbase bikes sitting perilously close to the ends of the wheel trays on some racks.
Are shorter chainstays faster to ride?
There’s a common perception that shorter chainstays are faster, but it’s not physically plausible. Speed is mostly the result of torque, rolling resistance, and aerodynamics. Chainstay length doesn’t significantly affect any of these.
However, shorter chains tend to have a slightly rougher ride, as discussed above. Our brains tend to conflate bumpiness with speed, so it’s easy to understand why all those road vibrations make us feel faster.
What’s more, ultra-light racing bikes have aerodynamic posture and components, which objectively make bikes faster. They also tend to have the shortest chainstays.
So, are shorter chainstays part of the secret to their speed? In short, it’s just a coincidence. Short chainstays ensure a snappy, agile feel especially when riding in the middle of a tight pack. But speed is the result of posture and aerodynamics, not of a couple inches’ difference in rear wheel position.
(Strictly speaking, longer chainstays do require more chain links, which add a minuscule amount of friction. All else being equal, that would theoretically slow you down. But practically speaking, the difference exists only in the lab—and barely even then.)
What chainstay length is best?
Not-competitive cyclists should consider moderately long chainstays (e.g., 430-460 mm) for bikes with drop bars and forward-leaning posture. When sitting more upright, look for at least 450 mm (but even 500+ mm, if available).
As you sit straighter up, your center of gravity shifts backward toward the rear wheel, so extra chainstay length keeps you relatively more centered (while maximizing smoothness). Anyone using panniers will also appreciate the extra heel clearance!
The above applies to road and city/commuter bikes. MTB chainstay length is typically as short as possible to maximize agility. That’s often around 410-430 mm, but it depends on wheel size, tire width, and the bike’s intended purposes.
What about rear wheel traction?
All else being equal, longer chainstays reduce rear wheel traction, since they place proportionately less weight over the rear axle. This isn’t usually a problem on pavement, but may become noticeable during aggressive cornering on loose surfaces.
However, “all else being equal” seldom holds true. It’s rare to find two bikes that differ only in chainstay length, so it’s hard to attribute real-world traction differences entirely to just one variable.
Will chainstay length matter for you?
All else being equal, longer chainstays absolutely do create a smoother, more stable ride.
Mountain biking is another story, but for paved roads and gentle trails, you won’t regret erring toward the longer side.
That said, there are scores of reasons why two bikes ride differently. Chainstay length is just one of many, and it coexists with other key differences in geometry.
It’s not remotely the end-all, be-all of bike design and ride quality, but it’s an important factor that few brands fully exploit.