Review: Otso Waheela C Carbon Gravel Bike
If you’ve read my other stories about Otso, you’re probably aware that I’m a big fan of their Voytek fat bike. Mostly, that comes from the narrow Q-factor with the ability to run multiple tire sizes thanks to some clever engineering and their Tuning Chip dropout system. So when I heard that they were bringing the same versatility concept to a carbon gravel bike, naturally I was intrigued. More than intrigued. I was downright excited. But as is often the case – would the actual bike live up to the hype I built up in my own head? I wasn’t sure, but I couldn’t wait to find out.
In order to get a bike into my hands as soon as possible, Otso ended up sending one of their final Review samples in a non-descript blacked out finish. Even without any visible branding (or maybe because of it), the bike attracted a lot of attention wherever it went. Mostly along the lines of, “wow, what is that? It looks awesome.” Without spilling the beans as to who made it, riders seemed to like the built in versatility. With three sets of tires and three different drop out positions, it’s essentially an all road bike, gravel race bike, and big tire gravel/bikepacking bike all in one. Three tires. Three positions. All the possibilities.
Tire and Dropout Combinations
If you haven’t read the first post yet, one of the big things that makes all Otso frames unique is their patent pending Tuning Chip dropout system. The dropouts offer three axle positions, with 20mm in total chainstay length adjustment resulting in 420, 430, and 440mm CS lengths. The droput system is also slightly angled, which means that from the front to the back position, the bottom bracket height changes by a claimed 4mm. That’s key when you’re trying to fit anything from a 30mm road slick to a 29 x 2.1″ MTB tire in the same frame, as it helps to compensate for the added bottom bracket height from running larger tires. That doesn’t mean you’ll be able to get the same bottom bracket height across the board, though.
Osto sent three different tires to try out with the Waheela C, all meant to be mounted to the DT Swiss Spline C 1800 wheels. These rims have a 22mm inner width which isn’t quite as wide as you’ll find on modern XC MTB wheels (24-25mm), but it’s wide enough to mount the bigger tires while still allowing for you to run something like the 30mm Schwalbe G-one Speed. With so many tire and dropout combinations to experiment with, I kept track of the various positions and measurements to visualize how the bike changed from tire to tire and chip to chip. So far, I’ve only been able to measure all three positions on the Terrene Elwood gravel tires, and keep in mind that my measurements are only approximate. I ended up seeing an 8mm difference in BB height from front to rear position, but if my measurements were +/-2mm, that could then work out to be the 4mm in difference claimed by Otso. Whatever the case, it seems like good news.
Tuning Chip System
Since I was able to replicate the BB height of both the 700c x 30mm G-One Speed in the front chip setting with the 700c x 40mm Terrene Elwood in the rear setting, you can run slicks or gravel tires without being forced to ride with a higher bottom bracket. Although if you wanted a slightly higher BB for increased pedal clearance, or a shorter chainstay length to quicken the handling, you have the ability to do so with the Tuning Chip system. The front and rear positions use the same chip, just flipped around. A second chip with a centered hole provides the middle axle setting. It may seem like a daunting task to change out the chip position, but all that is needed is a 20mm socket wrench and a 5mm allen wrench. Pop off the 20mm nuts, loosen the brake mount bolt, pull out the chips, replace with whatever position you’re wanting to run, and retighten the two nuts and brake bolt. Once you get good at it you should be able to have it done in less than 5 minutes with a work stand.
As much as I love gravel, there are days where you need to put in miles on the pavement and this gets it done with a simple swap of the tires and change of the dropout position. And it’s not like it’s a dog once you throw on road shoes either. The frame is surprisingly efficient for something that’s made to fit large mountain bike tires from the 90’s. Otso lists tires down to 28mm as compatible with the Waheela C frameset, but to me that would have to be a big 28mm on wide rims. Even the 30mm G-Ones measured just 29.37mm on wide rims and I felt like that was as small as I would want to go with this bike. Of all the tire combinations I tried with the Waheela C however, this one was the most surprising. Most of the time when I’ve thrown a set of slicks in a CX or a gravel frame, the resulting BB drop has been too severe for my liking, leading to clipped pedals and funky handling. On the contrary, when swapped over to ‘all road’ tires with the Tuning Chip all the way forward, the Waheela just gets better. So far I’ve done a number of long training rides with the G-Ones and it really made me think that this really is a quiver killer. The ability to shorten the stays and raise the BB results in a nimble road machine with impressive power transfer. Something that can run 2.1″ MTB tires has no business being this good with 30mm tires. It looks a little weird with all of that empty space around the tire, but it rides well enough to make up for it.
To be honest though, you don’t even need the road tires for it to be quick on pavement. While out riding some dirt trails with the 40mm (but actually 43.69mm) Terrene Elwoods mounted, I ran into some friends. Before I knew it, we were meeting up with a few other riders to start a quick group road ride. Even taking pulls up front, the Waheela motored along, big tires and all. The Elwoods are a little slick in the center for our greasy trails this time of year, but the trade off is that fast performance on the road. They also offer decent amounts of grip when you turn into a corner off road.
Getting even more radical, I mounted up the Schwalbe Racing Ralphs in a full 29 x 2.1″. Surprisingly, these actually fit in the frame in the front chip setting – though I wouldn’t recommend actually riding it that way. There’s just not enough tire clearance to be on the safe side. But in the middle and rear position? There’s more than enough room. Only in the absolute worst mud (the kind that globs over the sidewalls of your tire and doesn’t come off) was there any issue with mud clearance. But the key thing is that even then, the bike kept moving as the stays peeled away the mud (note that these were river bottom trails that were open, I wasn’t out destroying hand built trails).
Overall, the road and gravel tires were my favorite set up, but the ability to run something like the Racing Ralphs is a huge bonus. To me, this would be best for using the Waheela as an offroad bike packing rig. It’s also fun just ride the big tires on mountain bike trails, but the bike is quite a bit slower on the pavement which still makes a gravel tire the best compromise in my eyes. Also note that for me on a medium frame with size 42 shoes, there was the tiniest bit of toe clearance with the front tire in the forward position, but not enough to be a problem.