Dream Build Breakdown: Why a Mixed-Wheel Yeti SB140 Works So Well

This dream build belongs to Simon Stewart, an old friend of ours here at Beta. We worked together long before this title existed. So he, of course, showed up day one of our first project, The Beta Tests in Ely, Nevada. That’s where he told us about the mixed-wheel Yeti SB140 he had been dreaming about from behind the bench at the shop he co-owns, Buena Vista Bike Co. in Buena Vista, Colorado. That dream became a reality just recently, and he’s had some time to ride the bike, put together some early impressions, and tell us; does he think he knows how to design a bike better than Yeti does?

The idea to build this bike came from my time spent riding a Yeti SB130 Lunch Ride and a stock SB140. First of all, I need to mention that, out of the box, they are outstanding machines and both benchmarks in their respective categories. In the 130, Yeti has created what I think is the quintessential Colorado bike. In a nutshell, it can climb all day long with zero drama and then absolutely demolish descents – exactly what you want if you live in the mountains. However, it’s a bike with a personality that really shines at the business of harnessing speed, anything above 7/10ths and it’s unbeatable, but below that, it’s just a little less inspiring.

Now enter in the 140, which, besides the wheel size, shares almost identical geometry numbers to the 130 yet has an entirely different personality. Yes, it still likes speed (it is a Yeti, after all), but it’s got this goofy side which encourages coming off of race pace and seeking out the fun lines. And not always the fastest ones. Colorado is undoubtedly 29er country, especially the terrain where I live, which has a mix of the classic big mountain rides and quirky, rocky, technical town trails –  but the smaller wheeled 140 left an impression, I couldn’t stop thinking about it when riding the 130. I didn’t think I was the cheating type, and wasn’t ready to give up the bigger wheels. But what if…

Before moving on, I think a bit of a background check is in order. I’ve worked on the production side of the bike industry, specifically with SRAM. During that time I worked with many engineers, spent time in the test lab, and visited factories in Taiwan. I’ve seen first hand what goes into making awesome shit ,and 100 percent don’t think I could do better. Perhaps I drank too much Kool Aid, but even mismatching drivetrain components makes me itchy – meddling with factory designs isn’t typically my thing. 

So, when I did decide to take on this project, it had to be well thought out. Keeping as close to the stock SB140 geometry numbers was integral, lots of measuring was done. A stock 140 has a 160mm fork, in order to keep the axle to crown length close that meant shortening the travel of the 29er fork. I initially thought a custom air-spring length would be needed, and was prepared to make one, but it turned out that a stock fox 140mm pring put that axle to crown number right where it needed to be. The end result is a 140/140 bike with 44mm of fork offset, and in this configuration all the geometry numbers are within a few millimeters of stock – mission accomplished.

Since it is a dream build, I’ll just touch on some of the highlights of the build. The Fox 36 factory heritage edition in the root beer color is stunning. The Zipp Moto wheels are my new favorites, taking over from the Crank Brothers synthesis, and I have to say that, even as nerdy as Tyrewiz pressure-sensing valves are, they’ve really grown on me.

SRAM AXS is, of course, superb. Initially, I had reservations about the 52-tooth cassette as I preferred the 50t for shifting performance, but the accuracy of AXS made me forget about it. The AXS reverb is a straight up luxury, and who doesn’t love a two-cable bike?

As I mentioned earlier, I like to keep the drivetrain all in the same ecosystem, so there are no ultra pimp cranks or flashy chainrings here. Brakes are Codes because I love them. Would I have liked to try some Trickstuff brakes?. Hell yeah, but then the bike wouldn’t have been built for another year or two.

At this point, I have about two dozen rides on it, and I think it’s really bloody good. Everything from my first ride impression to now has been exceedingly positive. I absolutely love the way it corners. The front end precision is amazing. In short, I can put the wheel anywhere I want. I think some of this credit belongs to the shorter travel 36 being incredibly stiff, in combination with the Moto wheels having the perfect amount of compliance.

The back end feels super snappy coming out of corners and has a wonderful tendency to get loose and rowdy – this kinda seems like the epitome of the mullet essence right? With the cliched business in the front and party in the rear thing. I find it way easier to get the front end up and manual than the 130, again aligning with the party theme.

On the business side, its climbing performance is on par with the 130, it does get hung up in the rear a bit more on ledgy weird stuff, but the ability to get the front end up easier makes it a wash for me. On fire road climbs, it shares the same efficiency and ability to sit in and grind away for hours as the 130. Where it falls a bit short is downhill speed, it simply can’t match the 130, especially in Lunch Ride trim, for flat out speed when things get steep and chunky, but then again I didn’t expect it too. So far, I haven’t found any black eyes in this build, beside the obvious inconvenience of having two different tire sizes, but that’s it.

Is it a better bike than an SB130? No. Is it a better bike than a stock SB140? No. Is it a fantastic, wickedly fun bike for the place I live – that’s a big yes.

Shop Photos: Satchel Cronk

Beauty Shots: Anthony Smith