Commuting On A Mountain Bike: Caveats & Top Tips

Categorized as Bicycles, Bike questions & beginner guides

Last updated: January 19th, 2023

The best way to try bike commuting is with the bike you already own. And for some of us, what’s on hand is a mountain bike.

But when you look at those chunky tires, burly frame, and perhaps suspension, you might wonder…

Do mountain bikes make good commuter bikes?

The answer isn’t quite black and white. I’ll give a quick version just below, then we’ll dive into details you might not have considered.

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First, are mountain bikes good for commuting?

Mountain bikes are good for commuting on extremely rough roads, or unpaved sections. Otherwise, they’re too slow and cumbersome due to knobby tires and unnecessary suspension. You can put faster-rolling tires on your mountain bike, but it will always be harder to fit racks and fenders.

While traveling extensively in Southeast Asia, I noticed a surprising portion of commuters riding mountain bikes. The reason? Torn-up roads and zero bike infrastructure. When you have to dodge potholes and hop curbs continually, you need a bike that can take a beating.

Fortunately, most of us face a less demanding ride.

If your commute doesn’t require a mountain bike, then you’ll be happier with a city, hybrid, or road bike. It’s possible to work around their tire and accessory limitations, but it will never be as easy or efficient as a purpose-built bike.

What works well when commuting on a MTB?

Comfy riding position

Mountain bike posture is comfortable for most people. It’s moderately upright, and quite similar to typical hybrid bikes.

It’s not the bolt-uprightness of a Dutch city bike, but not the neck-cramping lean of a typical road bike, either. I prefer a truly upright commuter bike, but MTBs are still a good balance between pedaling efficiency and comfort.

Powerful brakes

Your mountain bike is also very likely to have mechanical or hydraulic disc brakes. When properly adjusted, these have more than enough stopping power for commuting purposes, and they work equally well in the rain. Many MTBs use extra-large brake rotors for even greater power.

In fact, good rim brakes are sufficient for most commuters, so suffice to say you’ll be fine in that department.

Ready for gnarly roads

Some cities are, shall we say, more tolerant of potholes and endless construction. MTBs fare better over these obstacles than any other type of bike. After all, it’s the closest on-street equivalent to the rugged trails they’re designed for.

It’s still safer (for rider and bike alike) to avoid what you can. But if some hair-raising road conditions are unavoidable, then it’s worth

What are the problems with MTBs for commuting?

Tires are slow & heavy

Virtually all mountain bikes have wide tires with deep tread, usually run at very low tire pressure. That adds up to great traction and bump absorption, but it comes at the cost of rolling resistance. (Not to mention several extra ounces of rotating weight, given all that extra rubber.)

Now, traction and bump absorption are top priorities on rooty climbs and rocky descents. But on plain old pavement—or even smooth dirt and gravel—the rolling resistance takes its toll. Compared to street tires, it’s just plain hard to keep up a decent pace.

There’s no free fix, but the solution is often cheaper than buying an additional bike.

Budget option: swap to slick tires

If your MTB’s new purpose is mostly or entirely commuting, then replace the knobbies with slick or semi-slick tires.

Look for a pair that’s close to the width you’re running now, or at least not more than about a quarter-inch narrower. (Otherwise, the bike’s handling characteristics might feel different than you’re used to.) Options are limited for 26″ wheels, but choices abound for 27.5″/650b and 29″/700c.

Better option: a second wheelset

What if your MTB needs to do double-duty, e.g., weekday commutes plus weekend trails?

Nobody enjoys changing tires twice a week. If you have a little more cash to spare, then consider buying a second wheelset to use as a dedicated, slick-tired commuting pair. They start around $200-$300 for something sturdy but heavy, using quick-release hubs with older axle-width standards. High-end rims with thru-axle hubs can easily cost several times as much.

Note: it’s often possible to use narrower tires on larger wheels for city riding. The increase in one offsets the decrease in the other, which keeps the total outside diameter about the same. It’s worth talking to a bike shop first, since there may be other constraints around brake mountain, frame/fork clearance, and bottom bracket height.

Lack of rack & fender mounts

There are basically three essential accessories for commuting:

Lights are a breeze. Nearly all of them use a rubber strap or screw-clamp mount, which comes on and off in seconds. (Dynamo lights are another story, but they seldom belong on mountain bikes anyhow.)

But things get trickier with the others.

Ideally, fenders and racks screw into little eyelets near the axle and farther up the frame/fork. That gives a rock-solid fit that won’t shift around despite shifting weight and vibration.

However, very few MTBs have such eyelets. That leaves a couple options, which I’ll outline below.

Can you put fenders on a mountain bike?

Yes, but options are more limited due to tire width and the lack of dedicated fender mounts. Stick with MTB-specific fenders to avoid compatibility problems and installation headaches.

If you’re still running knobby tires, then MTB fenders are the only kind that’s wide enough to accommodate them. But if you’re running slick tires for commuting, then you’ll still need MTB or clip-on road fenders. The lack of mounting eyelets is one factor, and you might also have trouble where conventional fenders attach near the bottom bracket and fork steerer.

My suggestion: Look into clip-on fenders like the SKS Mudrocker for MTB tires (buy front and rear) or SKS Raceblade for road tires (buy the pair). They don’t wrap around and protect you as fully as standard fenders, but they’ll mount to any bike up to the specified tire width.

Can you put a rear rack on a mountain bike?

Yes, but you’ll need one that mounts to the seatstays or seatpost. Few MTBs have mounting eyelets, so regular city-style racks will not work.

Racks can be especially tricky to mount on full-suspension bikes, due to moving parts and simply a wider variety of frame designs. Seatpost-mounted rear racks aren’t as strong or stable (since there’s no support from below) but they’re by far the most universal.

My suggestion: Start with a clip-on rack like the Thule Pack ‘N Pedal Tour Rack (available here). It works on many mountain bikes and essentially all road bikes, but you may need to measure your seatstay circumference to confirm.

If you have a carbon-fiber frame, then take particular care. They’re designed to maximize strengths only in certain directions, so the shear force of a rack may risk damage and even void your warranty.

Suspension bob saps energy

A tiny bit of our weight moves up and down while we pedal. On a rigid (unsuspended) bike, this is almost imperceptible. It compresses the tires a few millimeters, and that’s it.

But with front or full suspension, that vertical motion creates a repeated bounce known as suspension bob.

There are basically three ways to prevent or mitigate bob when you’re riding your MTB on the street. From most to least effective, you can:

  • If the fork/shock has a lockout lever, then use it!
  • If you have adjustable compression damping, then max it out. That’s almost as effective as a simple lockout switch, but you’ll need to reset it to “normal” when you hit the trails again.
  • Finally, the least effective but most universal option is to dial up the preload. It’s the least effective of these three, and arguably the most annoying to undo for trail rides, but it’s also the most universal.

What’s the best mountain bike for commuting?

The best mountain bike for commuting is a 29″ rigid MTB, such as a bikepacking bike. A hardtail works well if the suspension fork has lock-out, but a rigid bike is lighter, cheaper, and more efficient. The ideal commuting MTB also has rack and fender mounts. If you’ll mostly ride on asphalt, then replace the stock tires immediately with slicks or semi-slicks.

Fortunately, there’s no need to spend much. Virtually all modern mountain bikes have disc brakes and relatively wide gearing. As long as you stick with a reputable brand, even an entry-level bike is totally fine for getting from A to B. Better to put your money into essential commuting gear than overkill specs!

So, should you commute on your MTB?

If a mountain bike is the most convenient way to try bike commuting, then by all means do! But if you plan to commute for the long haul, then buy a separate commuting/city/leisure bike if it’s feasible.

No single bike can excel at everything. It’s more fun to have a couple that serve different purposes excellently than one that serves most purposes sufficiently. It’s also more convenient to leave parts and settings as-is, rather than swap them back and forth for commuting and trails.

Secondhand is always an option, so you can even resell it at little or no loss if commuting just doesn’t work out.

Still, if you’re tight on cash or storage space, then a second wheelset (or at least a tire swap) will help your MTB feel more at home on pavement.

By Erik Bassett

Erik Bassett is the founder and editor of Two Wheels Better. He draws on three decades of cycling and scooter experience to help you find the right ride, incorporate it into daily life, and safely enjoy the journey.