As the lines blur between road, gravel, and adventure in the cycling industry, Thesis has carved its own path. We rode the Thesis OB1 bike on singletrack, trail, and tarmac for this review.
Utilizing unique manufacturing relationships and custom builds for each rider, Thesis has created an accessible high-performance, all-road bike. And it may be the quiver-killing ticket to more adventure in the saddle.
Thesis founder Randall Jacobs launched the brand in 2018 around the idea that one size and style does not fit all. The Thesis team instead claims that brands should build bikes around your unique fit, terrain, and fitness needs. The outcome is the Thesis OB1 — an all-road performance bike that is designed to take on everything from spirited road rides to sloppy singletrack.
In short: The OB1 blends performance, versatility, and access to a unique community that can’t be overlooked. High-end build spec, customization options galore, and an impressive price point make this bike a unique and refreshing offering in the cycling space. And with a bike that is as comfortable on sprints as it is packed down for a multinight adventure, the OB1 may be the solution for the n+1 challenge that every cyclist faces.
The Concept: Thesis OB1
Every OB1 ($3,299) is built to order and includes the option of a consultation with the Thesis team to ensure you are getting exactly what you need. Thesis works directly with the industry’s leading brands’ factories to put together, in its words, “one of the most capable and versatile bikes on the market.”
Thesis’s direct relationships and built-to-order model keep overhead low, making it possible for it to offer a carbon frame, carbon wheels, and a premium spec at an impressive price.
Assembling the Thesis OB1 All-Road Bike
Thesis states that its bikes arrive on your doorstep 85% assembled. The company suggests that you either take your bike into your local shop for the final touch or complete the build yourself following the online guide. While I am not particularly handy, I have done enough work on my bikes to take a crack at this assembly.
I popped open the assembly video and went to work, admittedly skeptical. Not 20 minutes later, I had the OB1 fully assembled and propped up against my garage for its first #baaw photo.
All of the parts were clearly labeled and organized, and it was simple to follow the walkthrough. Thesis even had the tires seated so that all I had to do was add sealant and air them up with a floor pump. Assembly is as straightforward as it says.
In the Saddle: Thesis OB1 Bike Review
After assembling the Thesis, my first impression was how tight the bike feels. If you know, you know. There were no rattles or creaks, no rubbing of rotors, or clicking of gears. The bike was incredibly sound and ready to ride immediately after assembly with crisp shifting and responsive handling. The bike felt familiar, even on my first ride.
Maybe this shouldn’t come as a surprise seeing as I went through a custom fit consultation with Randall, but I’ll be honest that I was skeptical about getting a bike to fit correctly without actually sitting on one. A few minor adjustments to saddle height and off I went.
The bike also has a great aesthetic — a beautiful blend of aero-road and adventure-by-bike. I had seen enough photos of OB1s previously, so I knew I liked the look, but it looks even better in person.
Thesis OB1 Bicycle Review: Testing
At the time of writing this article, I have nearly 1,000 miles on the OB1. These miles include road, gravel, hero dirt, and singletrack across Minnesota and Colorado. I’ve used my OB1 for everything from spirited group rides to solo endurance rides and commutes, as well as a multinight bikepacking trip along the Great Divide Mountain Bike Route.
Exceptional versatility is what elevates the OB1 from worthy mention to must-see. Its endurance road geometry makes this bike comfortable on long days. The optional dropper gives you added control and confidence when exploring new gravel roads and singletrack. When you’re ready to burn more KJs, the OB1 happily kicks up a gear while you chase down your local KOMs.
Thesis offers two different thru-axle carbon wheelsets — a wide and aero 700C and an ultrawide 650B — that are both dialed in for efficient, hassle-free wheel swaps. Each wheelset provides you with a different set of advantages to play with on your OB1.
Thesis’s RGC44 (Road-Cross-Gravel) 44mm depth 700c Carbon Wheelset weigh in at 1,595g and feature 22mm internal and 30mm external widths, as well as an offset profile to balance spoke tensions for improved strength and durability. These wheels can work with 28-30mm road tires and also handle higher-volume tires run at lower pressures to smooth out the ride. Thesis hand-builds these wheels with 24 lightweight aero spokes to ensure a precise lightweight build.
Thesis’s GT27 (Gravel|Trail|27mm Internal) Carbon 650B Wheelset is built around an asymmetric XC mountain bike rim, with a 27.3mm internal width and a tubeless, hookless design to support high-volume tires at low pressures. These 28-spoke wheels come in at 1,460g and are also handbuilt to withstand whatever abuse your rides throw at you. I was impressed at the stability of the bike while ripping down a steep descent at over 40 mph, fully loaded with all of my bikepacking gear.
Both Thesis wheelsets use DT Swiss’s DT350 hubs and SRAM centerline lock rotors, so there is virtually no recalibration when you switch wheelsets. Thesis says that wheels can be swapped in 90 seconds — often without any adjustments — and I found that was true; swapping is a cinch.
The simplicity of the wheel swap, and thus of transitioning between tarmac and singletrack modes, is what makes the OB1 special. The same bike that I was hammering on a Friday night road ride could be transformed into a gravel-crushing machine for a Saturday morning adventure ride.
Thesis offers SRAM mechanical 1×11 and SRAM AXS electronic 1×12 drivetrains with its builds. Within each ecosystem are different chainring and cassette options to calibrate each wheelset’s gearing to your fitness and terrain.
During the custom fit process, the Thesis team will guide you through each drivetrain option. While there are too many options to walk through here, Thesis offers detailed information and helpful guides on its website.
Mounts & More
The OB1 offers mounting points galore and the option to add a dropper post. I put both through their paces during a multinight bikepacking trip along the Great Divide in Colorado. Admittedly overpacked, I utilized nearly all of the available mountain points with a mixture of Blackburn’s Outpost Elite bikepacking bags and Ortlieb’s Fork Bags.
The OB1 pleasantly surprised me by how well it carried the weight. At times, I found myself forgetting that I was riding a fully loaded bike. During longer endurance rides. I outfit my OB1 with a Handlebar Bag and Frame Pack from Post Carry Co.
Thesis isn’t shy about sharing its business model and where it has its bikes and components made. It is quite the opposite, in fact. Jacobs and the Thesis team welcome this discussion and see it as a driving force behind why they can make a custom performance-driven bike at a relatively low price point for consumers.
The brand has built direct, in-person relationships with their manufacturing partners and facilities. Their frames and components are made at the same manufacturers as some of the “premium” brands in the space.
My Thesis OB1 Bike Build
The Thesis team recommended that at 5’8″, I roll on a medium frame size. I opted for the Slate Gray Gloss frame color with Caramel Matte bar tape. And I wanted to get a feel for the bike with both wheelset options. The 700c wheelset is set up with a 9-46T gear ratio and the 650b wheelset with 10-50T. My OB1 had SRAM’s 12-speed AXS drivetrain with Thesis’s hollow-forged crank and a 44T front chainring.
Randall recommended 165mm crank arms to achieve their recommended 22% ratio of crank length to saddle height. (But Thesis offers lengths down to 155mm for smaller riders.)
Finally, they equipped my OB1 with a 405mm dropper post for getting extra sendy. The stock OB1 with Thesis carbon wheels comes in at 18.5 pounds (size medium).
The available options for building your custom OB1 are too long to outline in total here, but you can check out every option and detail on the Thesis website.
Why I Love the Thesis OB1 All-Road Bike
- Versatility in a performance package
- Simple and quick wheel swaps, completely changing the ride
- Tailored fit, with rider-specific gearing
- Tons of mounting points for water, bags, racks, etc.
- Beautiful aesthetic
- Active and engaged community that is committed to inclusion
- Affordable (relative to comparable builds from other brands)
- Responsive support, warranty, and crash/theft replacement
- Currently in stock and ready to ship (October 2020)
- From a purist’s perspective, the OB1 is a do-it-all bike and not focused on one discipline
- Currently 2-5 weeks out for design and shipping; no availability at local shops for test rides
- If you’re introverted, you’ll hate the attention that this bike draws
More Than a Bike: The Thesis Community
Thesis places a unique emphasis on inclusion and creating a community around its bikes and those who ride them. Thesis owners have access to a Slack community forum where other riders share ride photos and stories, routes, new ideas, and bike questions. And they connect with people who live close for social rides.
The brand started RidersClub, its umbrella project that includes several initiatives to make Thesis bikes accessible to more people, foster relationships and connections within the cycling community, and have an impact beyond just riding bikes.
The InThisTogether program provides at-cost replacements in the event of damage or theft. And their BringAFriend program rewards owners and new riders with a $100 gift card as a thank you for helping to spread the word. It even offers the option to donate said rewards to nonprofit organizations that provide bikes to underprivileged populations.
With Thesis, you don’t just get a versatile all-road bike — you become part of a community.
A high-performance gravel bike that is versatile enough to chase down roadies and rail singletrack turns, the Thesis OB1 is the closest bike I’ve seen to a true quiver-killer. While purists may argue that it’s not top in any one category, the combination of versatility and performance proves it is a contender to anyone looking to diversify their riding.
When you add a price point that is significantly lower than similar builds and a brand ethos focused on community, it’s hard to ignore what Thesis built.