Tire Sizes

One of the simplest and most effective ways to improve the comfort of almost any bicycle is to increase its tire width. Wider tires can be run at lower pressures without exposing rims to damage, providing greater suspension and absorbing road imperfections.

On a commuter bike that will be ridden on varied terrain while carrying a light load, I like at least a 32mm tire. On a utility bike used for hauling groceries, etc., tires up over 40mm wide can be a real advantage. Anything under 30mm on either of these types of bikes is a compromise in my opinion. The heavier the total load (rider plus baggage), the greater the benefit of riding wider tires. For reference, I’m currently running 37mm tires at 60 psi on my commuter.

It’s a common misconception that wider tires are slower, but this is not necessarily the case, particularly at non-racing speeds on rough roads. Bicycle Quarterly has done extensive testing on suspension losses and their conclusions show that on rough roads, up to 50% of a bicyclist’s power output can be attributed to suspension losses, and these losses are best mitigated by wide tires run at lower pressures.¹

One of the main issues with running wide tires is frame clearance. There are simply not that many road bikes on the market that provide adequate clearance for the wide tires and fenders needed for commuting and utility riding. This is one area where the industry as a whole could really improve their current offerings.

Which tire size do you prefer for commuting and utility use?

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At what pressure do you run your tires?

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1. Heine, J., M. Vande Kamp, 2009: Minimizing Suspension Losses. Bicycle Quarterly, Vol. 8, No. 1, p.12

29 Responses to “Tire Sizes”

  • Arleigh says:

    Kudos for an excellent article! Tire pressure and size is over looked by everyone, even mountain bikers. It can either make or break a great riding bike and can add a side of comfort to harder rides.

  • Joel van Allen says:

    That’s an interesting statistic about suspension’s impact on rider power loss. I’ll do my big shopping on a bike with 32s at about 100lbs of pressure to stabilize the load. If I fill them less than 90lbs for a loaded trip, however, it feels like the tires are sloshing around in the rims, especially on turns. Like the bike’s fishtailing from both ends. But am I making things harder for myself by using 100lbs rather than a bit less? I’d like to see the power efficiency stats for a loaded bike with tires narrower than 40mm on paved (albeit potholed) roads. Maybe this is just an excuse to add another bike to the collection– something with wide tires.

  • OmahaBikes says:

    When I started commuting I used a 25c road bike tire. When I moved to 28c, I noticed that the ride was slightly more comfortable and enjoyable. After a few years of commuting, and a lot of reading from sites like Rivendell, I moved to a 35c tire at 60-80psi and a steel frame (Surly LHT). The ride was just so much better. My commute (14 miles each way) didn’t take any longer, and the bike just seemed to disappear underneath me. When I pump the tires up to 80psi, I start feeling the little bumps a bit more, so I tend to stay below 70psi.

    If your not using your bike on long competitive rides with lots of climbing, get off those skinny tires and you’ll enjoy your ride much more. Plus, you can use your tires as a flotation device in a pinch ;-)

  • keith says:

    Hi Alan,
    I have the Jack Browns on my bike, and I was wondering, if you still have them on your Sam, atwhat pressure you run those?

    Keith

  • Ryan says:

    Hello,

    Good post and article. I do think that there should be a < 40 psi category to vote for psi. I use 2.3" (~58mm) tires on my Big Dummy and I run them at about 35 psi. I think quite a few people with these large tires run them in the 30's. On a bike that I don't use for utility and commuting I have 3" wide Hoggy G's that I run at 25 psi when off road, and that is fun! They add quite a bit of suspension to my Surly Rat Ride.

  • John says:

    I also run my 2.35 Big Apples in the low to mid 30’s. These tyres are incredible – the smoothest of rides. I just make sure to pump them up when they start to drop below 30. They can go lower but have found that only useful on very soft or loose terrain.

  • doug in seattle. says:

    My commuting/messabout bike has two inch tires. I run them around fifty psi. I could go lower, but I’m a big guy.

    My touring bike is currently running 32s. I would like to go higher, but I’m not sure how much clearance my touring bike actually has, since it apparently was not designed by someone with a clear idea of what a touring bike is, unfortunately. I just bought a couple of used 37s (a conti and a shcwalbe with mild tread) to test it out today!

  • Saddle Up says:

    32 is the magic number.

  • rdhd says:

    I have a stupid/naive question: how do you find wheels that fit tires >28 or 30mm? Everything I’ve seen on various website seems to take nothing more than about 25-28cm tires. I have a frame I’d like to build up (with help from a friend obviously) and it’s made for 700c wheels, but I’d like a wide tire.
    thanks.

  • Cassidy says:

    @rdhd: While rim/wheel manufacturers generally give recommended compatibility with a range of tire width, you have to remember that they’re covering themselves. In practice you can greatly exceed the recommendations with little or no risk. I have a bike with Mavic Open Sport rims (19mm width, recommended for tires up to 25 or 28 or so) that until recently had 42mm tires. I never had even a hint of a problem. The downside is that your tires will be a millimeter or two narrower than the stated width on narrow rims, and you should probably be more careful about tire pressure (as in not letting it get too low) than you need to be normally.

    What you don’t want to do (and I doubt this will be much of a problem for most on this site) is mount narrow tires on wide rims. This is dangerous. The tire needs to be at least as wide as the rim, and I think it looks funny if they’re exactly the same.

    Back on topic, the reason I switched tires on the bike was so that I could fit fenders. It’s now running 35s, usually at 60-70 psi, although I am less careful about tire pressure than I probably ‘should’ be. Call me guinea pig. I got them low enough to pinch flat not too long ago, and never had any threat of them rolling off the rims.

  • Alan says:

    @rdhd

    Velocity makes a number of nice 700c touring rims, as does Mavic and others. I’m a a fan of the Dyad with machined braking surfaces:

    http://www.velocityusa.com/default.asp?contentID=584

    Alan

  • Finley says:

    Speaking of wide tires, I really love the looks (as well as the reported indestructability) of the schwalbe fat frank tires, particularly in the cream and brown colors. Unfortunately, they are just a hair too wide for a lot of applications. I have been shopping around for some wide 26 inch tires that aren’t all black, something in the two inch to 2.1 inch range, and I came across the Felt Quick Brick tires. Has anyone tried these? I haven’t been able to really find any reviews of them. They look good, but I don’t know if they are durable or not.

    Thanks!

  • Andrew says:

    I’m currently running 28c Vittoria Zaffiros @ ~100 psi on my commuter (only ever had one pitch flat from riding on very rough roads) , but I picked up a set of 35c Schwalbe Marathon Supremes that I’ll be using for ~2000 km bike tour this summer, so I’ll hopefully have a pretty good idea of what I like after that.

  • Roland Smith says:

    Currently using 40-406 Schwalbe Marathon Plus on my Hurricane recumbent.

    You could pressure these up to 6.5 bar (95 psi), but that’s a harsh ride and slow because you’re bouncing a lot and that takes energy. Between 4 and 5 bar (60-75 psi) seems to be the sweet spot for these tires. Anything below 3 bar (45 psi) feels like you’re dragging a boat anchor!

    And these tires have a really good anti-leaks layer built-in. Much better than the regular Marathons in my experience.

    It would be nice is manufacturers published standardized roll-out test results. Some informal testing by Dutch Velomobile enthousiast Wim Schermer pointed to large differences in rolling resistance (up to 20%) between different types.

  • brad says:

    The one thing that has always made me leery of low tire pressure is the risk of pinch flats. As someone who rode road and touring bikes for years, I’m used to tires rated at 100psi, and if you run them much below that you end up with frequent pinch flats.

    I now have Schwalbe Marathon Supremes on my touring bike that are rated at a max of 80 psi, which is where I keep them, but my city bike’s tires are wider and are rated at a max of about 60. The thought of using a lower pressure never occurred to me because I just assumed it would increase the risk of pinch flats, but is that less of a risk with wide tires? And if so, why? Is it just because the wider surface area makes it less likely that you’ll bottom out against the rims?

  • Alan says:

    @brad

    “Is it just because the wider surface area makes it less likely that you’ll bottom out against the rims?”

    I believe that is correct; I think it’s the greater mass of the wider tire. Also, the sidewalls of wider tires tend to be thicker/stiffer.

    Alan

  • Andrew says:

    Think of it this way, brad – because you have a much greater volume of air in the tubes, they’re able to compress considerably more before they achieve a sufficiently high internal pressure that they’ll no longer compress (hopefully with sufficient clearance remaining between the ground and the rim!) Spreading the impact of road bumps over that larger distance and time in compressing the air in the tube is where the comfort comes from.

    On a tire with very little volume, there’s very little spare clearance between road and rim to prevent pinch flats, so you always need to keep the pressure high in order to minimize compression.

    …reading that again, that’s a terrible explanation (and longwinded, to boot!) but I tried.

  • Alan says:

    @Andrew

    I thought that was a great explanation… :-)

    Alan

  • Jim says:

    I weigh 220lbs, and run 700×35 @ 100psi for my commute that is 8 miles each way.

    If I let the pressure drop, I feel the drag. The ride is better, but the resistance goes up and I clearly slow down. Fortunately, my route is generally pretty smooth. The rough spots are three bike path underpasses, but that isn’t a situation where the roughness will soak up my power (coasting down, which is where the roughness hits). There are a couple of rougher spots where I’m on the street, but again, it doesn’t appear to be enough to soak up power.

    From what I’ve read, weight has a huge impact on tire size, pressure, and resulting rolling resistance.

    I’m building a new bike, and will go with either 32 or 35 Marathon Supremes.

  • Mohjho says:

    I’m running 35mm Schwalbe Marathon Supremes between 50 and 60 psi. on my Travelers Check single speed. I wanted a smooth and comfortable ride that I could bounce off of curbs and ignore road hazards. So far so good.

  • David says:

    Just ordered some Marathon Supreme 32’s from Peter White as well as some lightweight tubes from Jenson. I’m hoping for a nice increase in ride quality, responsiveness, and flat resistance (despite the light tubes) versus my battered old Continental Top Tourings.

  • Larey says:

    Love 32mm Marathon Supremes 50-60 psi for my twice-a-day mini tours. Very smooth.

  • David says:

    Good to know, thanks.

  • rdhd says:

    @Cassidy and Alan and others — Thanks for your replies. That is very helpful information. This whole thread has been really useful.

  • Alan says:

    @rdhd

    You’re welcome. Thanks for participating…

    Regards,
    Alan

  • Hercule says:

    I run Panaracer Hi-Roads on my distance (aka touring) bike, 26 x 1.5″. Seemed very wide to me at first, being used to 32 or 28mm 700C wheels, but they have proved just as quick. I have however laboured for years running them at maximum pressure (85psi) and always found the ride a little harsh compared to the 700Cs. Last year I experimented with reducing the pressure to 70psi and had a revelation. Just as quick, far smoother. More is not always better!

  • Dave says:

    I think a couple of things that are also important to note in this discussion are that wider, lower pressure tires often wear more slowly, and (if they’re high quality) have much less risk of puncture and blowout. For instance, I have an Electra Amsterdam that came with cheap Chinese 700x38C tires on it, and they went a couple thousand miles before I replaced them, and still had 3/4 of the tread left. I now have Continentals on that bike, and Schwalbe Marathons on my old Raleigh, and not only have I gone probably a couple thousand miles of city riding on the Continentals and probably around a thousand on the Schwalbes without any punctures, but they are hardly worn. They also grip better in rain and snow. In general, I think going with wider and lower pressure is simply more practical for everyday transportational riding in just about every aspect.

  • Mike says:

    I run Fat Franks at about 28 psi in the back and 25 psi in the front on my urban cruiser. They don’t accelerate as fast as my skinny road tires but the ride is ten times more enjoyable. I love heading out with cargo shorts, sandles, a tee shirt and sunglasses sans helmet for a cruise. It’s like being a kid again.
    If I had to choose, it would be fatties every time.
    Rock the fatness!

  • Graeme says:

    I’ve just bought some Marathon Supremes for my hybrid bike. I was originally planning on getting some Big Apples (700X50), but there just wasn’t enough clearance on my forks, so I had to opt for the larger Supremes.

    After running 700X32 and 700X35 tires, I went for the 700X40c ones, to get more suspension, after having lost a back axle on the kerbs and cobbles of my city. I was a bit concerned that my 622X19 rims wouldn’t take them, but have bought some bigger inner tubes, and I guess we’ll see what happens!

    Fingers crossed…

 
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