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What’s the difference between the 700c Space Horse and the 650b Space Horse Disc 46cm

   Last modified: February 4, 2021

What’s the difference between the 700c Space Horse and the 650b Space Horse Disc 46cm

Since the release of our new Space Horse Disc, which utilizes the smaller 650b wheel size on the 43cm and 46cm sizes, and given the emerging prevalence of 650b wheels in general, we've been getting a number of questions about the reasons and method behind our decisions regarding 650b. All-City's Engineer Rachel has taken the time to put together some responses to the frequently asked questions.

What's different between the new 46cm Space Horse Disc 650b and the 46cm Space Horse Canti 700c?

  • The 650b Space Horse Disc has a shorter wheelbase. This means a more responsive feel, better turning radius, and more agile handling.
  • The 650b Space Horse Disc has a lower stack height than the 700c Space Horse Canti. It's lower by 18.5mm to be exact. So if you want to get your hands lower, you can. (It was simply impossible before with the 700c wheels because the head tube was as small as it could go). And if you like your hand position on the Canti bike, you’ll need 15-20mm more spacer stack to get there on the Space Horse Disc.
  • The 650b Space Horse Disc has tighter/quicker/less floppy front end handling. (If you want to get technical, the 650b Space Horse Disc has a lower ground trail, more in line with the 55cm size).

What's the same, or close to the same, between the 46cm Space Horse Disc 650b and the 46cm Space Horse Canti 700c?

  • Bottom bracket height. Although the bottom bracket drop numbers are different, bottom bracket height off the ground (which is what you actually feel) is the same, measuring right around 274mm, or 10.8in, with 38mm tires.
  • Effective top tube is only 5mm shorter on the 650b Space Horse Disc than the 700c Canti version (515 vs. 520mm). It’s a hair shorter, and should improve the fit if the 46cm Space Horse Canti felt a little too long. But it's not enough to make or break your fit. (If our 46cm bikes are too big for you, read on and check out the new 43cm size of our Space Horse Disc!)
  • Standover is 4mm lower on the 650b Space Horse Disc. This is nice, but it’s likely not going to impact the height of the riders this bike fits.

Tell me about the fit/size of this new 43cm bike?

We achieved our lowest effective top tube and standover heights on any All-City bike.

  • Effective top tube is 495mm
  • Standover, with the stock tires*, is 704mm, or 27.7 inches.
  • *If you put smaller volume tires on the bike, say 650bx32s, you’ll likely get a standover closer to 692 or 693m (27.2 inches)
  • Our sizing nomenclature is based on our seat tube length. Even though other manufactures might call a comparable size an XS, or various other numbers, from 38 to 43, the best way to compare sizing is to look at effective top tube lengths, standover, reach, and stack.  

Why did you call it the same model, but make the two smaller sizes built around 650b wheels? That sounds like a completely different bike to me.

We actually used smaller wheels on the smaller sizes to make it more of a consistent ride across the size run. The smaller sizes now have handling characteristics that are much closer to the 55cm and 58cm bikes than they did before with 700c wheels. That’s because to get a shorter top tube with 700c wheels, you need to increase the head tube angle on the smaller sizes, which changes the front end handling of the bike. On our 700c Space Horse Canti, the front end handling on the 46cm bike is drastically different from that of the 55cm bike. Smaller wheels on the new 650b Space Horse Disc 46cm let us tighten up the front end handling on the smaller sizes, giving smaller riders a quicker turning, more responsive bike, while keeping the fit and toe clearance the same.

Why didn’t you make a version with 650b wheels on all sizes?

Because we like the ride and feel of our 700c Space Horse. This is still the Space Horse.

What happens to my 700c Space Horse if I put 650b wheels on it?

Our 700c-optimized Space Horse Disc can definitely be built up with 650b wheels. If you do so, your max tire size goes from 700x42 to 650x47s (I can officially say we have legal clearance with the 650x47 WTB Horizon tires). Some of you might love this.

Depending on the tire size you choose, your bottom bracket height on the bike will drop more or less noticeably. 

  • As designed and sold, the 700c bikes comes with 35mm tires. If you’re accustomed to riding with 35mm tires, then switching to 650x47 will drop your bottom bracket height by 6.5mm. You may feel a slight difference, but you may not. The ride impact of a lower BB height is increased stability, especially when loaded, and higher risk of pedal strike.
  • If you normally ride your Space Horse with 700x32’s, then you’re already riding at a slightly lower bottom bracket height, and the 650x47s will feel very comparable.
  • But if you are used to riding your Space Horse maxed out with 700x42 tires, you might notice the lower bottom bracket height, as that jump from 700x42 to 650x47 will lower your BB by 16.5mm.
  • And naturally, if you put 650b tires on the bike that are smaller than 650x47, your bottom bracket will get even lower.
  • Another effect of dropping your wheel and tire size, in addition to lowering your botom bracket, is that it changes the front end handling of your bicycle. Smaller diameter wheels lower your trail, which could be described as having some of the following effects: your front end handling will get tighter and more responsive, the bike will be a little less confidence-inspiring at high speeds, you will get less fork-flop, and your front wheel will track straight better with a front load.  

    - So should you do it? Sure – feel free to give it a try! But please do switch to shorter crank arms if you plan to ride a tire smaller than 650x47 or 650x45. 



lifestyle 7

Comments image


October 28, 2016

Is that bike in the end photo a 43 or 46?

Jeff Frane

October 31, 2016

It’s a 46cm


November 9, 2016

46cm right with GuardianBikes


January 9, 2018

As a short man, I really appreciate the interest towards the 650b wheels.
Usually, bikes in this frame size really look like s**t.
But this one…this is sweet! Awesome job!

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