650b vs 700c on small frame sizes? Which direction for future bike(s)?

Hello, looking to get some additional information, tips, perspectives on wheel sizes. I am short so ride a small framed bicycle, 48cm, XS, XXS (2XS), …
I was looking into Canyons and based on their 2 quick questions, height and inseam, they recommend a 2XS for me. I see that a 2XS comes stock with 650B wheels (140mm discs) and 165mm cranks (I know not all bike brands do this for their smallest frames, but I am curious if Canyon is doing this for a reason and based on evidence to provide a better experience for their customers?).
I currently have 170mm cranks and was thinking about trying 165mm anyway one day, however, the wheel size I am really unsure about. I thought that keeping everything 700c would just be the most simple for a variety of reasons (most compatible in case needed to borrow or share parts, interchangeability between other bikes, easier to source and buy parts, maybe less expensive if more common products, …).
However, if these parts provide a better, more proportional experience for small frames, I should take the experts/Canyon’s recommendation I think?
Parts is actually a non issue for me as I will be moving from a rim brake bike to a disc brake bike anyway so I cannot port over my wheels.
I am also looking to get a gravel bike in the future and there too I have read debates on 650b vs 700c. From what I read it almost seemed that the gravel industry is moving to 700c too?
However, for me and my frame size if 650b is better, I guess I should just go all in and for all future bikes I have and get just keep it all consistent with 650b across all my bikes if this is the way to go?

Unfortunately I don’t think it is that easy to test bikes with 650 wheels to see if I can tell the difference and if I prefer one over the other.

Any feedback, information, personal experiences, … would all be appreciated.
Thank you in advance.
Happy Holidays.

Most of the difference that you’ll experience on the bike has to do with the circumference of the wheel +tire combo (this is what will affect handling, like steering).

So it’s more about the tire size that you run on the wheel.

I really appreciate Canyon’s approach to those sizes. We already have proportional handlebar widths, stem/cockpit reaches, and saddle and crank lengths.
Proportional wheel sizes just make it easier to get better standover height, or run larger tires.

Think of it this way - you can run wider tires, at a lower pressure, and be more comfortable with the 650bs than you could with 700c. And wider tires are definitely more comfortable, and just as fast (maybe faster) as narrow ones.

Are you expecting to need replacement wheels during races? Unless you are concerned about neutral support (which is a pro racing scenario, so I would say good for you!), all the parts except the rims can be the same. And road rims don’t wear out easily, especially with disc brakes.

Also I just picked up a size XS road bike (Lynskey R260), and I specifically bought 650b wheels for it. I’ll run 42mm or 48mm tires, instead of the 32mm I would have had to run with 700 wheels.


When you start getting down to the 2XS sizes, 650 wheels make a lot of sense. When you use 700c wheels for smaller sizes, you have to start making too many compromises on the front end geometry to avoid toe overlap. So you end up with longer than necessary reach, slacker head tube angles, more fork offset, etc all of which impact handling vs. larger frame sizes.

So 650 wheels allow you to maintain more “normal” geometry and handling….overall, a good thing.

The challenges with 650 wheels are:

  • wheel / tire choices. The best equipment options are not always available in 650 sizes
  • gearing - you typically need larger gears to match the speeds of riders on 700 c wheels
  • inertia - 650 wheels “spin down” faster than 700c wheels so you’ll need to pedal at times when others are coasting

On the whole, those are small trade offs compared to compromising the overall handling of a bike.

As for the cranks, without doing a complete fitting, it is hard to say for sure…but I would think 165’s are a reasonable option (if not smaller) for a bike that size. There is no reason for you to be running 170’s.

Hope that helps!


I think everyone has covered the major parts. For me 700c is easier to deal with on road bikes but would rather have 650b off road. Toe overlap starts to become a major issue there as you get to wider tires and 650b gives you some more room to play with

Several years ago I got my wife a 3xs (~44cm) Canyon Ultimate. The bike looks very proportional. Canyon adjusts the gearing to make that aspect similar to 700c. E.g., the 700c version came with a compact crank (50-34) but the 650b version has mid compact (52-36).

For upgrades, I got Roval 650b CLX 32 wheels and Continental GP5000 650b tires. So yes you’ll have fewer choices, but there are good ones. I run the exact same tires in 700c.

Unfortunately, she only rode the Ultimate once and the wheels/tires are still brand new. Pfft.

Small canyons are 650c aren’t they?

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Can’t speak to all of them, but my wife’s 3xs Ultimate came with 650b. I just had a look to be sure.

2XS and 3XS from my experience. I bought a 2XS Grail for my dad that is 650B. I have an Ultimate XS in 700C.

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In most ways it seems obvious 650 wheels and 165mm cranks should be the obvious choice small framed bicycles.
However, why is Canyon the only manufacturer doing this?
I checked all other major bicycle companies and for my size (47, 48, xs) and EVERYONE had 700c wheels and 170mm cranks.

Are the Canyon 2xs specifically designed around 650 wheels?
Can you just put 650 wheels on another company’s bike that came stock with 700c wheels and it would be the same thing? Although at an additional cost and hassle.

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I have to agree with all here: if you are on a smaller frame, putting 650b wheels on your bike makes a whole lot of sense. Wheels are the only thing that are (traditionally) not scaled when going up and down sizes.

The geometry is adapted to the smaller wheels, and you should get a more balanced bike as a result. (This is purely theoretical for me.)

Technically that should be possible on a disc brake bike, but the bike’s geometry isn’t made for that. The thing is that the tire radius enters into the bike geometry calculation. That is why e. g. most gravel or quiver killer bikes have you go down a size when you want to put very wide tires on it: wider tires also have a larger radius. And to keep handling more consistent, they recommend that you use 650b wheels for larger tires (e. g. 45 mm and up).

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No. That would be a bad idea. Frames designed for 700c wheels should run 700c wheels to keep the intended geometry. If you put 650b on a bike designed for 700c the wheels will be a smaller diameter than intended, so you will have a lower bottom bracket and strange handling.

The main advantage of 650b is having more freedom in the frame design for small riders, because as the rider gets smaller the wheels get too large relative to the rider. This means you cannot get the desired geometry or you get good geometry only with having toe overlap. Toe overlap is when your toe overlaps the front tire, so when you turn while pedaling, your front wheel can get stuck on the wrong side of your foot and cause you to crash. I would not ride a bike with toe overlap. It’s dangerous.

Although 650b is not common on smaller sized road / gravel bikes, that’s only because companies are trying to keep their profits higher. Custom builders and several mountain bike brands do in fact use 650b on the smaller bikes. It’s the best size to use for small riders if the frame is designed for that size wheel.

One thing that you might find confusing is there are “road+” bikes out there, usually on bikes intended to use on both road and gravel. These bikes are designed to take 700c wheels with ~28 mm road tires as well as 650b wheels with ~50 mm (2”) gravel tires. These are actually the same overall diameter because the tire and the rim sizes both affect the total wheel diameter. So (with disc brakes) you can swap wheel sets on the same bike for road and gravel and still keep (almost) the same handling. But that is still something for larger bikes. It wouldn’t avoid toe overlap on smaller bikes. So ignore that marketing if you see it.

TLDR: I would get a 650b bike if I was your height.

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