Understanding Wheel Size

We hope the mere fact that you clicked on this article means that you’re thinking about buying a new bike. In fact, we’re just going to assume that’s the case!

And in that light, we’re so excited for your first new bike day! I know it sounds really corny to tell you that in a blog post, but I don’t care—Molly and I get all smiley just thinking about. Donating that old, rusted Schwinn from 2000 to the Salvation Army and taking the plunge into a new ride is a seriously big step. For one thing, you’re going to have so much damn fun on a light, responsive, and powerful rig that biking might just become your new favorite sport. I’m serious! A good bike will make a believer out of you, too.

Then you get to the bike shop and have decision OVERLOAD! There are so many freaking choices! Trail bikes, XC bikes, downhill bikes, fatbikes, road bikes, gravel bikes, hybrids, and BMX bikes. There are skinny tires, knobby tires, smooth tires, and studded tires. There are 1x (pronounced one-by), 2x, and 3x. There are 10 speeds, 11 speeds, and 12 speeds. There are 26er’s, 650b’s, and 29er’s.

How’s a girl supposed to know what to choose?

For now, let’s focus on tire size in the MTB world, which comes in these flavors: 26, 27.5, 27.5 plus, 29 and 29 plus.

26 in tires

Does anyone still ride 26er’s?

Short Answer: No, not really.

Most bike shops don’t even stock 26er’s anymore, and most manufacturers stopped making them. There are a few left on the shelves, but not many. The XC (cross country), Singlespeed and All-Mountain world have written them off entirely. (Okay, maybe not entirely, but pretty much.) The voices that still champion the future of 26er’s are loud but few. While they may make a lot of noise, screaming into the void and demanding that 26ers’ long history will keep them current won’t be enough to save them. Probably because, no matter how nostalgic people feel about the tire size, it’s hard to argue physics: bigger tires roll over bumps more easily and faster than smaller ones.

I’m not saying you should never buy a 26er (I want you to have all the bikes in your stable!) and I’m not trying to shit on someone’s beloved 26er—on the contrary, I’m inspired by those of you who keep on loving them up. A challenge for mountain bikers is that MTB culture and marketing promotes riders upgrading their crazy expensive bikes every few years to an even crazier, more expensive bike. It seems like the second someone buys a bike it’s outdated, as if at the moment of purchase the bike gods transformed it into retro crap. Ugh!

I digress. Anyway, I’m bracing myself against the full blow back of the 26er-nostalgia-love-fest-internet because I want first time buyers who are just getting into All-Mountain or XC to get the truth: 26 in tires are heading out the door, along with perms, Sum 41, and argyle. I’m saying this because a few cats in the blogosphere might try and convince you otherwise. For example, this was the top article when I searched for “mountain bike tire size.” (Granted, the article is out-of-date, but because it was clearly getting a lot of traction online I’m going to pick on it.) The author makes a few claims that are so outdated they are absurd. In an effort to list the benefits of 26ers they write, “Spares [for 26er’s] are much easier to find than 29in and far far more common than 650b replacements.” Sure, maybe a decade ago. Today, you can rest easy knowing you absolutely, 100%, will find an ample supply of 29 in tubes and 27.5 in tubes in every single bike shop across the country (unless that shop owner is stuck in the same decade as that article). Furthermore, should you double flat on trail (flat twice, meaning you’re already using your spare tube), and find yourself in the scenario in which you must rely on your fellow trail riders, said Samaritans are infinitely more likely to carry a 27.5 or 29 inch tube in their kit than a 26er.

The second point the writer makes is this: “Lots of shops are already selling 26in frames and components cheap too, so there are tons of upgrade bargains about.” …! Sorry, I was just laughing out of my chair. Shop owners aren’t getting rid of their 26 in frames to give you a deal—they are getting rid of them because no one wants them, and therefore they can’t sell them. That means when you want to upgrade, you won’t be able to sell it, either.

The author’s final argument was that 26 in tires are burlier. They state, “[26 in tires] can also be made stiffer and stronger too, which is why most top downhill riders are still sticking with 26in wheels.” Again, maybe five years ago. Chris Sugai, President and Co-Founder of Niner Bikes, has this to say in response: “Most people say that a comparable 26-inch wheel is stronger than a 29er, and I’d have to agree in theory that this is a valid point. In real life, though, top wheel builders like Gravy (Steve "Gravy" Gravenites) and well-known wheel companies like Mavic all say that the return rates of 26 and 29-inch wheels are the same, so wheel-strength is not an issue. When we have product meetings, we discuss materials, rim-widths and axle spacing. Wheel-strength is never a topic.” The last myth is that while 29er’s (and 650b’s) are better for XC, single speeds, etc., 26in is still the right choice for downhillers. I’ll let Sugai take it away again: “We have all-mountain and downhillers riding our 29ers and on every course, in every case, the times are lower and the riders are faster on 29-inch wheels.” To read this great article with Sugai, click here.

The take away:

Unless you are a die-hard fan of 26er’s, I don’t recommend one. It will make climbing more technical and will seriously impede your ability to carry momentum up and over crests. You’ll wonder why your not-so-fit-friend is faster than you. The handling will feel finicky. What’s more, your local shop won’t be able to easily replace broken parts as 26er’s continue to go out of stock.

Of course, a 26 inch bike can be a good option for someone with a marginal budget looking for a mountain bike or for parents looking to buy their 10 to 13 year old kid their first full suspension. They may put a lower ceiling on your fun having abilities while climbing steep, technical mountains, but you’ll still be outside riding a bicycle, so……. Shred it anyway!

To read more about the current trends and get someone else’s opinion on 26er’s, check out this forum.


29er’s

Are they really faster?

Short Answer: Yep.

29 inch wheels (29er’s) offer their riders a lot of benefits.

  1. They will make you faster and more efficient!

    (Says this study, not just me.)

  2. Larger tires carry momentum up crests.

    If you ride a lot of flow trail, this could end up being a big deal to you. Every grade reversal takes a lot of power to get back up.

  3. They are grippier.

    More surface area means more friction which means you’ll climb better, with more traction.

  4. 29er’s roll over rocks better.

    Ever come to an obstacle on your bike and just sort of bounce off of it? Having a larger tire changes the angle between the tire and the obstacle, or angular momentum, making it easier to clean rock gardens and log rolls and whatever else you fancy.

I’m short. Are they too big?

Short Answer: Probably not.

It’s common for bike shops to recommend 29er’s for their tall customers, and 650b’s for their short customers. The reasoning is that proportionately, each person should feel a relatively similar effect from each tire size. The problem with this kind of thinking is that when that shortie goes out riding with their 6 foot giant of a pal, all other things being equal, the 29er will be faster than the 650b’s. If you can imagine yourself racing (especially XC) I encourage you to consider a 29er. It will feel cumbersome to corner at first, but you will get used to it, and you will be faster because of it.

Some people think that riders less than 5.5 shouldn’t ride 29er’s because of “significant geometry tradeoffs, possibly resulting in toe overlap, high handlebar height, and less standover clearance.” However, the frame size of the bike should adequately compensate for those variables.

You don’t know until you go, so find a 29er that fits you and get it on the trail.

27.5’s and 650b’s

What’s the difference?

Short Answer: There isn’t one

27.5’s and 650b’s are the same thing. Enough said!

Why would I want one?

So many reasons!

  1. 650b’s are lighter

    6% lighter, to be exact. That doesn’t sound like much, but a light bike is a fun bike.

  2. More agile

    You’ll likely feel a bit snappier on a 650b, and cornering will feel easier. If you’re interested in nerding a bit, check these guys out.

Some people tout the 650b as the sweet spot between responsive, agile 26er’s and efficient, powerful 29er’s. Still others say they are perfect for smaller riders, giving them the same benefits as 29er’s for taller riders.

Many downhill riders prefer the 27.5 inch wheel because they allow the bike to feel more in the riders control than a 29er will. You can let the bike do the hard work of picking lines and staying snappy, freeing up the rider a bit more to focus on body weight maneuvering.

27.5 Plus & 29 Plus


For areas with looser terrain, many riders swear by plus tired bikes. The line is pretty blurry about where these fall in actual width, but anything between 2.8 inches and 3.5 inches is the fuzzy, grey, plus zone. (compared to their 2.3 inch counterparts).

These wider contact patches allow for more traction at any given time, most advantageously, in corners. For newer or less confident riders, these are a great option. It can be much harder to carry the same amount of momentum as your friends riding regular ole 2.3 inch tires, but come downhill time, you might be able to thrash through loose corners that had your friends slowing down from yards away.

These bikes aren’t incredibly popular, but have found their practical application in bikepacking or all-terrain riding (for folks who don’t see enough snow annually to commit to a fatbike but want to ride year-round).

Bottom-line: Don’t knock ‘em until you’ve ridden one downhill. The extra traction just might leave you smiling and looking for another hill to shred.

Fatbikes

Fikebikes are generally rigid bikes (although there is a Bluto fork available) designed for winter riding. They have massive, studdable tires for better traction in the snow.

Fatbikes take a lot of flack from people who have never ridden one in the winter. I was just reading an article the other day by a guy who took one out in four measly inches of snow with a PSI of 15lbs (that’s crazy high for most conditions!) and then complained about other riders with skinny tires passing him on the trail.

If little of that rant made sense, just know this: that dude just doesn’t get fatbiking.

Fatbikes (and their monster-truck tires) have a few practical (and shreddy!) applications.

If you live in a place that gets snow over half the year, a fatbike will enable you to keep riding. Whether you just need an entry-level whip to get you to work in the winter or you want to be able to ride outdoors when the snow flies, a fatbike will seriously increase your ability to spend the most time possible on a bike.

Having trouble deciding? Go out and ride some bikes! Your local bike shop will be more than happy to let you try out a bike. Be sure to ask them if there is any singletrack close by so you can get the feel of the bike. Some shops will say “hell yeah!” others might say something like, “we can’t even let you take it off the curb.” Go ahead and ask--it will be worth it if they say yes! If they decline your excursion off the beaten path, yet you’re committed to the cause, ask if you can demo a bike. Most shops should have a rental you can take out for the day for $50 to $75.