First Look/Impressions: On-One Fatty


On-One bikes has been around for quite some time and is a UK brand most notable for it’s figurehead, Brant Richards. His notable work for many is the On-One Midge Dirt Drop handlebar (still my favorite that I use on my monstercross bike I designed/had built), the On-One Mary handlebar, and the On-One Fleegle handlebar. However the On-One Inbred 29er is well known amongst early 29er adopters as it was a versatile, inexpensive frameset with just a hair more style than others available in the price point and even above. For a short time he took time away from On-One to do some work with UK brand Ragley. I had one of their trail orientated hardtails called the Mmmbop (should have never sold it) and I also was sent a Ragley Luxy dirt drop by him way back when for my monstercross side of things to try.

In short, Brant has a knack for design. And now back at On-One, they are keen on making things reasonably priced and accomplish some of that through years of experience, some by dealing direct with the consumer only. Don’t however confuse them with other budget offerings, there is quite a lot of thought that was put into this bike.

Part of why I reached out to Brant to test the bike is that this isn’t your typical fat bike geometry/layout. The goal here was an all around bike for year round riding, and On-One’s interpretation of how this should be accomplished. Short version is they went with more of a “trail” bike cockpit/geometry. 68 degree head tube, short chainstays, low slung weight with incredible stand over clearance designed to be used with a short stem (60mm on my large) and wide bars (810mm wide). Quite the change from the typical spec of longer stems and on average 700-720mm wide bars. My day to day mountain bike is a 140mm squish bike with a short stem and 780mm bars.

Spec is SRAM X5 which no, it’s not hip/flashy…but I was impressed at how well it did work. Aside from my snobish first impressions in the stand vs say the XO I typically ride, once out on the trail I barely noticed any difference. It’s spec’d with Avid brakes, which while I do love the design/action of the lever itself….they do disappoint slightly. But hey, it’s part of why you get the bike at the price you do…you gotta spec the package. For most, and especially someone who just wants a fat bike for the snow or for time to time, you likely won’t notice.

The rest is covered by On-One’s own house brand components. Yes, I too typically cringe at the practice of housebrand parts. I find it uninventive, boring, and lazy design. I get it, it’s a numbers game for many companies. But at least put some thought into some things! At first glance, it appears On-One is as guilty as anyone else. However there are stand outs:

-Floater tires. These are designed for off road use and work well at it. Weight is reasonable and so is the price. Made by Vee Tire Co., you can tell there was a little more input and they’re far better than others from Vee that I’ve tested in the past.  In short, great tires you likely won’t replace until threads start showing. Coming in at 4.0, it’s a nice size tire.


-El Guapo Ancho Bars. 810mm wide with just a hair bit of rise. I thought I’d ride them for a bit then throw on something at 780mm wide. No need. The extra width really made me feel like the tires were a lot smaller. Added to the playful, trail geometry of the bike and the low center of gravity. If these don’t make it back in the box to send back to On-One, well, it’s an by accident I swear! Could be I also think of  The Three Amigos every time I read the name.


-Big Nose Saddle. You know it’s usually the saddle spec that lacks the most. I was really surprised at how nice it was. Nice cush, made getting up on the nose for steep climbs enjoyable. Saddles are of course a personal preference, but I’d bet few will find the need to swap it out right away like you would in most cases.

-Twelfty Seatpost. Seatposts are seatposts for the most part. But I did like the fact On-One took the time to put on a height gauge style graphic for adjusting saddle height. I’d prefer actual numbers, but in the end it was nice to have a mark to reference for small adjustments. I wish all posts had such. Glad to see they added it.

-Frame. I’m a fan of the trail style geometry and I do like aluminum frames a bit. Plenty of tire clearance. And frame weighs in at only 5 lbs for a large. That’s not bad and should put to rest any question of whether or not it’s worthy buying then upgrading down the road the parts. My answer? Yes.

Initial ride impressions have been good so far. I have around 5 hours of ride time on it so far, all on local trails from fun urban singletrack nearby to some fun little trails I typically can’t wait to take the big bike on. Yes, it’s definitely a bit  heavier than the Borealis I reviewed last June and am racing in the Leadville Winter Series. 35lbs is noticeable, but not unbearable and at this price point (and even above by a bit) the weight isn’t out of line. I’m just wee spoiled playing on 23-25lb carbon rigs here and there. I do not have any snow riding time in yet. Here on Colorado’s Front Range we barely get snow that sticks for very long, and our big snow months are actually March and April believe it or not. I do feel that though the Fatty was designed as an all around rig to really play well in the dirt, I can’t help but think they cockpit layout will be help make fast snow covered downhills just a little faster and rough, non-packed snow sections something to look forward to than feared.

The On-One Fatty is full of unique features, subtle smart spec choices, and all at only $1375. If you’re looking for a budget bike that has long term upgrade potential, this is for you. If you are the type who prefers the wide bar/short stem/slacked headtube properties found in trail bikes, the On-One Fatty is a ton of fun and only one in the category for production bikes.

Geomerty/Specs found on

Purchase in the USA via


About Sevo 7 Articles
I've been riding mountain bikes since '89. Have raced mountain and track. Ridden it all. Grew up in Winona, MN and got smarter in Decorah, IA while working for Decorah Bikes(Deke days) and racing of 'em. Worked for LEW Composites in Vegas. Tested stuff for many. Founded Front Range Cyclist in Colorado as well as the man behind the Monstercrosser on FB. Live in Colorado Springs. Founder Colorado Fat Bike. Founder of The Urban Singletrack Project


  1. I am riding my fatty now for about 6 months. I have drilled the rims and made them tubless. (makes a hell of a difference) Swapped the tires for Husker du’s ( amazing)and swapped the brakes and swapped the fork for a Saso suspension fork. The fork makes steering a bit slower but gives a lot more comfort. This is my first fatbike and I am planning to ride the whole year through. What an incredable bike. LOVE IT !

  2. I’ve just ridden the carbon-forked version of this bike 1,000 miles across Alaska in the Iditarod Trail Invitational race – couldn’t fault it. Great ride, great comfort, handled everything Alaska could throw at it. Totally recommend. AndyH.

  3. I purchased the 1X10 version last year and modified it slightly (2X10, tubeless and gobi seat) and rode it across the Simpson Desert, Australia in the Simpson Desert Challenge. Great bike and a real hoot to ride on single track around Canberra and on sand in the desert. The bars are huge but they just simply feel right. The weight was a bit of a downer but with a few modifications you can easily drop a couple of pounds. The wheels easily set up for tubeless, and I had no problems running as low as 4 psi on really fine sand. I purchased the second set of wheels that On-One have available which have regular rims on 135mm front / 170mm rear hubs, which were great for commuting. In 4 months I managed to clock up 4500 kms on this bike. Great all round bike, and good fun. AngusC

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