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 46 and 49, 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. All-City's Engineer Rachel has taken the time to put together some responses to the frequently asked questions.
- Tighter/quicker/more spritely/less floppy front end handling (SHD has lower trail, more in line with the 55cm size. Ground trail is now 66 vs. 72 on the 700c canti bike. For reference, the SHC 55cm has a trail of 59, and SHD 55cm has a trail of 64).)
- Shorter wheelbase = more responsive feel, better turning radius, more agile
- Lower stack, by 18.5mm. 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 where you are on the Canti bike, you’ll need 15-20mm more spacer stack to get there on this bike.
Stuff that’s the same, or close to the same:
- BB height. Although BB drop numbers are different, BB 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 SHD than the 700c Canti version (515 vs. 520mm). It’s a hair shorter, but not enough to make or break your fit by any means.
- Standover is 4mm lower on the new SHD. This is nice, but it’s likely not going to impact the height of the riders this bike fits.
And 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
- *If you put smaller volume tires on the bike, say 650bx32s, you’ll likely get a standover closer to 692 or 693m
- 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 sized 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 55 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. In our Space Horse Canti, the front end handling on the 46cm bike is drastically different from that of the 55cm bike. Smaller wheels 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 BB height on the bike will drop by more or less of a noticeable amount.
- As designed and sold, the 700c bike comes with 35mm tires. If you’re accustomed to riding with 35mm tires, then switching to 650x47 will drop your BB 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 BB 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 BB 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 BB will get even lower.
- Another effect of dropping your wheel and tire size, in addition to lowering your BB, is that it changes the front end handling of your bicycle, by lowering your trail number. These are some ways to describe the impact of a lower trail number: your front end handling will get tighter and more responsive, the bike will be 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.