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.

Otso Waheela C all road gravel dropbar MTB bike review prototype

In order to get a bike into my hands as soon as possible, Otso ended up sending one of their final test 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.

Otso Waheela C all road gravel dropbar MTB bike review prototype

Otso Waheela C all road gravel dropbar MTB bike review prototype

Three tires. Three positions. All the possibilities.

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.

Why? 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.

Otso Waheela C all road gravel dropbar MTB bike review prototype
Tuning Chip system from the original Otso Voytek
Otso Waheela C all road gravel dropbar MTB bike review prototype
The front and rear positions use the same chip, just flipped around. A second chip with a centered hole provides the middle axle setting.

Otso Waheela C all road gravel dropbar MTB bike review prototype

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.

Otso Waheela C all road gravel dropbar MTB bike review prototype Otso Waheela C all road gravel dropbar MTB bike review prototype Otso Waheela C all road gravel dropbar MTB bike review prototype

Chips help you get skinny

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.

Otso Waheela C all road gravel dropbar MTB bike review prototype

Gravel Master

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.

Otso Waheela C all road gravel dropbar MTB bike review prototype

Dropbar MTB? Monster Gravel? Yes.

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.

Otso Waheela C all road gravel dropbar MTB bike review prototype Otso Waheela C all road gravel dropbar MTB bike review prototype Otso Waheela C all road gravel dropbar MTB bike review prototype Otso Waheela C all road gravel dropbar MTB bike review prototype

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 overlap with the 2.1″ tires. As in my toe would just touch the tread blocks, but if you pushed the bars to the side, the knobs would flex over it. Obviously bigger shoes may have more issue, so keep that in mind.

Otso Waheela C all road gravel dropbar MTB bike review prototype

Suspension? Sure

Want even more? Don’t forget that the Waheela C is suspension corrected so it’s designed to work exceptionally well with a Lauf Grit, Fox AX, or similar gravel oriented suspension fork. It’s also set up pretty well for in terms of frame mounts, though many bike packers would probably want to see 3 pack mounts on the forks and possibly internal dynamo wiring.

If this was my bike, I’d have a set of 30mm slicks and something like the WTB Riddler 45s as the main set up which could easily cover all of my drop bar needs. That seems to be the beauty of the Waheela C – you can make it your ideal drop bar build without much work, whether that’s all road, gravel, or bike packing. If you’re tight on space and/or cash, you can do all of this with a single wheelset and a few tires. Or, you can have a second or third wheelset ready to go so you could transform the Waheela into a different bike in minutes. There are a few gravel bikes out there with a little more compliance when it comes to the ride, but most of them are not nearly as versatile.

Otso Waheela C all road gravel dropbar MTB bike review prototype

Dropper compatible

Heck, you can even run a dropper post which I’ve been playing with on this build. Is it a necessity? Absolutely not. Did it make it easier to bunny hop big trees and send sketchy chutes? Certainly. You know your riding style. If you think a dropper post might help you in your riding, it probably will. If you don’t understand what all the fuss is about, skip it. It definitely adds some weight to the build, but as pictured, the bike came in just over 20lbs with the gravel tires mounted.

Otso Waheela C all road gravel dropbar MTB bike review prototype

One thing is for sure – Otso’s bikes deserve more attention than they currently get. When I talk about the brand to many riders I’m met with blank stares. But mention the fact that it’s the bike arm of Wolf Tooth Components, and then it clicks. But if they keep putting out bikes like the Waheela C, I get the feeling that they won’t be flying under the radar for long.

otsocycles.com

20 COMMENTS

    • Did some research on their site. Yes on fender mounts, maybe on the rack mounts? Prices is ~$2000 for the frameset.

    • Hey Brad,
      Yes, there are are both fender and rack mounts.
      The fender mounts are hidden on the top of the seat stay down near the dropout, in the yoke of the seat stays and in the yoke of the chainstays. We include threaded eyebolts that go into these seat stay mounts.

      The rack mounts via our tuning chip system with this a kit just like this (will be sold without the rack…the Voytek needed a specific rack so that is why it is in the Voytek kit):
      https://otsocycles.com/collections/accessories/products/voytek-rack-kit
      That rack mount kit will be up on our site in the next couple days for $39.95

  1. Zach – where is that gravel you tested the bike on 🙂 Still looking for a good route not too far from home. Nice looking rig by the way, looks more versatile than my Diverge with the larger clearance and Axle chip system. Scott

  2. Was thinking this might interest me if it was steel instead of carbon. Lo and behold, went to the Otso website and there’s a steel version, too! Waheela S!

  3. Is there any reason why 650b tyres wouldn’t clear on this frame? Lowering the BB 19mm would be a good thing for me…

    • 650b up to 2.1″ (or 53mm) definitely fit. With the tuning chip, it is all about options and “tuning” to your preference. I am personally am with you, especially during shoulder seasons when gravel can be squishy around here, and run my 650×47 (Terrene Elwoods) or 27.5×2.1 (Schwalbe Thunder Berts) in the long position for a stable low supple bike.

  4. Seems all their R&D goes into the frames then when it comes to the fork they just give up. External brake hose/cable routing and no eyelets for extra gear… wut?? Pretty much every single bike in this category has better fork design and utility. Otso has some catching up to do.

    • Thanks for the fork input.
      Routing external front brake housing is a preference thing (we know how to do internal and considered it).
      Storage on the fork is something we are working on… something clever…stay tuned for future updates =)

  5. Frame weight is listed as1024g (M), but I assume that doesn’t include the rear brake mount. How much extra does that add? 100g or so? Also wondering if there is any compromise in braking performance with this type of setup?
    This is very intriguing and almost want to take the risk and order one, but I prefer to demo a bike before I make a decision…

  6. Hey Lee,
    Yes, the dropouts add around 100g to that weight.
    The brake is affixed to the frame very securely with a bolt, t-nut and slot and there is no braking performance change at all. We have this same system on our plus/fat bike, the Voytek, and it has been flawless stopping really big heavy tires and some big strong riders.

    Email us at sales@otsocycles.com to ask about the next/nearest demo opportunity. We are confident you will love the bike!!

COMMENT HERE: (For best results, log in through Wordpress or your social media account. Anonymous/fake email comments may be unapproved or deleted. ALL first-time commenter's posts are held for moderation. Check our Comment Policy for full details.)

This site uses Akismet to reduce spam. Learn how your comment data is processed.