Kakuweb Blog Rants and raves. Some interesting stuff, most of it not.

Bicycle Wheel Sizes

TL;DR Version

Q. Are mountain bike wheel sizes some marketing bullshit for the brands to sell more crap?

A. No. They’re not.

Q. Does wheel size actually make a difference in how the bike handles?

A. Yes it does.

Q. But how?

A. Read on.

I’ve been riding bikes every since I was about 5 years old. That’s 31 years ago. Back then there was only 1 type of bike, the ol’ banana-seat bike:


Mine was green. This bike took you everywhere. Up and down mountains, to the beach, to the park, to school, there was nowhere this bike could not take you. No terrain this bike couldn’t tackle. It was the most awesome bike around. It was also the only bike type around. I mean, you could get it in different colors and with or without tassels on the handlebars (tassels were a must if you wanted to be cool) but that was it.

Then I grew up a bit and got one of these:

Not as fancy though, not a Raleigh. It was awesome. No terrain would stop it. I even took it into into a river. It was unstoppable.

At the ripe old age of 23 I got a mountain bike. The mighty Yokota Terminator! Something like this but in red:

This bike had no suspension of any type. It was awesome. Nothing could stop it. This bike took me to Canaima

and back, through 4 days lost in the jungle. It climbed like a gecko and descended like a flying squirrel. No rapid-fire gears or any other niceties, just the tough levers you had to wrestle with to get the gear you wanted. There was nothing this bike couldn’t do. I also took it up a couple of rivers.

Then things got complicated. These days, you need a bike for going up, a bike for coming down, a different one for the flats and another one to go to the market.

If you want to buy a mountain bike, you have to know what type to get. Do you want a Hardtail (what the fuck is that?), or a full suspension bike? What type of riding do you do? Do you like Enduro? Or maybe you’re more into Trail. How about an XC or Cross Country bike? Perhaps a Downhill or Freeride bike?

Damn, dude. I just want a fucking mountain bike. Is that so hard?

Today, yes it is. And then there’s the wheel size. Once you’ve spent months and weeks understanding the difference between all these bikes you need to decide what size of wheel you want.

Wheel Sizes

OK, first of all, let’s get this out of the way: Wheel size does matter and it’s not a marketing ploy to sell you more shit. Now that that’s out of the way, let’s find out why.

In the beginning, there were only 26” (inches) wheels. That’s what you got, that’s all there was. Recently, some brands started introducing 29” wheels. And there was much rejoicing. But there was also some bitching. So an in-between number was introduced: the 27.5” wheels or 650b as they are known in Europe. And things didn’t stop there. Now we also have the 650b Plus which are 27.5” wheels but with a much wider tyre, bringing their total circumference close to 29”. There’s actually only 1 millimeter difference between the 29” and the 650b plus. And let’s not even talk about Fat Bikes.

Wheel Size Differences

So, let’s talk practical differences between these sizes.


Forget them. Nobody wants them any more and they’re hard to find. As of right now they are a thing of the past (they can always come back so don’t throw your equipment away just yet).


What’s the big deal with the 29” wheels? Why are they supposed to be better than 26”?

  • They make it easier to go over rough terrain
  • They make it easier to pedal
  • They make the bike more stable
  • They give you more clearance on the pedals meaning you can lean more on corners and ride over obstacles without the pedals hitting them

That sounds great. What’s all the bitching about? They’re clearly superior to anything else out there.

Not so fast. They also have their downside.


  • They make the bike harder to corner
  • They change everything about the bike. Meaning you need a new frame, new suspension, new chainstay. New everything except maybe your gear levers
  • Components (suspension, etc) are not compatible with any other wheel size
  • Suspension travel is reduced because of the longer overall lengths
  • They make the bike slightly heavier because there’s more material for the rim, tube and tyres

Damn, so they suck?

No, they don’t suck. They’re great. But it’s not all unicorns and rainbows.


So these must fix all the issues that the 29” have, right? These are definitely the ones to get?

Not so fast. 27.5” wheels are great. They have the advantages of the 29” over the 26” and few of the detriments.

What I said, they’re awesome, get these.

It all depends on what you like. How you like to ride. The 29” will still ride better over rough terrain than the 27.5”. And it will still be a more stable bike. But it will also still have all the cons of a 29”.

How Do I Decide?

Unless you compete or race. There is an easy way to decide:

What do you like best:

  1. Going downhill at high speeds, jumping over huge obstacles (rocks, dogs, ravines, etc) and not stopping until you hit a brick wall
  2. Climbing like a mountain goat and riding on level ground

If you answered 1, then get a full-suspension (that’s both front and rear suspension) 27.5” bike like the Giant Reign. Sure, you’ll cry going uphill but you’ll bomb downhill on 160 mm of pure pleasure with your supple suspension.

If you answered 2, get yourself a Hardtail (that’s front suspension only) 29” bike like the Conor WRC Pro 29er. You can still bomb downhill albeit slower and with a sorer arse and legs. But you’ll be thumbing your nose in uphill and on flats at all the downhill, full suspension boys and girls.

For anything else in between, you’ll need to do your homework. The truth is, the best way to decide is to ride the bike and see how it feels. Don’t listen to anyone trying to talk you out of a bike you like. Ride it, even if it’s only in the shop. And see how you like it. A good bike will feel so incredibly different and better than your old crappy/cheap bike, regardless of wheel size, suspension travel or secret compartments.

It is true that on a 29” bike, the suspension travel is reduced compared to a 27.5” simply because the geometry is bigger. But 20 mm of travel don’t make as much difference as a lot of other factors in the bike (frame disposition, head angle, chainstay length, stem length, etc).

So, again, ride that bitch and go with whatever feels good.

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