thesis 650b

The OB1 AXS Custom

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• The OB1 Frameset
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• What They're Saying
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Overview                    Specs                    Geometry                    FAQ

The original, reimagined. With a crisply shifting wireless electronic SRAM AXS 1x drivetrain, hydraulic brakes, and wide range 12 speed cassette, the OB1 AXS 1x is equipped to handle the steepest pitches you point it up, or down. Our premium aluminum cockpit components  round out  a parts spec that won’t let you down or leave you wanting.

Chase down roadies, explore some new singletrack, or load up for a long adventure. Join the N=1 revolution.

Current lead time:  Current inventory is limited by COVID related supply chain interruptions.  Please contact us for the most up to date lead times at [email protected]. Weight:  ~18.5 lbs (size M, standard seatpost) Arrives 85 % assembled ( see prep guide )

Why you'll love the OB1

• Endurance road geometry for all day comfort and balanced handling.
• Bombproof carbon wheels  built for speed, strength, and durability at a race-ready weight. Choose between 650Bs and 700Cs, or swap 'em in  90 seconds .
• Tubeless done right with high-volume tires matched to wide rims for easy set-up, lower pressures, fewer flats, and an extra smooth ride.

Gearing for every adventure

• SRAM AXS wireless electronic drivetrain offers crisp shifting with a light touch.
• Massive range  cassettes  gives you a bailout gear for the steepest climbs and loaded bikepacking trips, while maintaining the top end you need to keep pace on a spirited road ride.
• SRAM GX AXS clutched derailleur prevents chain drop and chain slap, with a cage-lock feature on the rear derailleur that makes it super easy to swap wheels or fix a flat.

Obsessive on the details

• A creak-free bottom bracket  from Wheels Manufacturing with silicone dust covers, oversized stainless steel bearings, and a 2-piece aluminum shell that threads together for proper bearing alignment and support.
• A remarkably comfortable saddle for all day riding.
• Dual-sprung star-ratchet hubs  for outstanding strength and reliability.
• Optional dropper seatpost   for enhanced control and confidence off-road and on. 

Chassis     |     Cockpit     |     Drivetrain & Braking     |     Wheels

Click on the name of each component to learn more about why we chose it.  Every detail, down to the bolts and bearings, is selected for the optimal balance of performance, durability, and serviceability.

To learn more about our approach, check out how we built a high-end carbon dream bike .

WHY WE CHOSE IT

STANDARD SEATPOST

DROPPER SEATPOST  (+$149)

DRIVETRAIN & BRAKING

Want to build your own OB1 from the ground up? Check out our Frameset Module option.

Lōgōs Epoché 700C

• 24ID|32W|30D
• Aero-optimized for 28/30mm tires
• Wide enough to support 40mm+ tires
• 2.5mm of asymmetry for balanced spoke tensions
• Bead hooks for blow-off prevention & non-tubeless compatibility
• Angle drilling & reinforced nipple seat for durability
• Blended-modulus T800/700  unidirectional construction
• 20 - 110psi

Thesis GT27 650B

• 27.4ID|33W|24.5D
• Optimized for 47mm+ tires
• Tubeless-ready hookless design
• 3mm offset, angle drilling, & reinforced nipple seat

Have a question? Check out our FAQ or reach out to us directly at [email protected] to talk to a real human. We're always happy to talk bikes.  

All figures in millimeters unless otherwise indicated.

What they're saying about the OB1

“LOVE my Thesis. It's really astonishing how fun it is to ride. The 650b wheels make it incredibly fun to shred fire roads and gravel, and the 700c wheels with 30mm tubeless tires are fast and make chip seal feel like glass. You guys have a winner.” - Kelly F. "My appreciation for the thoughtfulness that went into the bike increases the more I ride it. I love what you guys are doing." - Rich J.

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Ridden and Reviewed: Thesis OB1 Carbon All-Road Bike

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In the bike industry, he found his calling, moved to Asia and learned Mandarin. For a decade he learned how the global bike industry worked.

Through this experience Jacobs thought he could deliver a better experience to the rider and local bike professionals. His observations:

• The bike industry is hurting because of internet-price driven consumer
• Local bike shops are saddled with inventory, but service is where the LBS excels.
• People don’t know what bike to get.

Jacobs and his co-founder Alice Liu self-funded Thesis Bike and created one bike, the OB1, designed to be ridden anywhere.

The company’s website outlines the Thesis: “Keep it Simple” tops the list. So One Bike, with a nod to old Ben Kenobi: OB1, “Now that’s a name I have not heard for a long time.”

Thesis sent us a blue review OB1, and we put it to good use on all kinds of roads and trails.

Does Thesis pass the test of providing an all-road bike at home everywhere? Find out in our review.

The OB1 has a Toray carbon fiber frame with an open mold design. Jacobs sourced the frame from a reputable Taiwanese manufacturer he knows.

Thesis produces the OB1 in small batches and sources materials from Asia with components curated from companies that follow the ethos of the Thesis founders.

Jacobs and Liu seek to offer a bike at a reasonable price with complete transparency about where the cost goes while helping support local bicycle professionals.

As a fluent Mandarin speaker, Jacobs is able to work with Asian companies to customize aspects of the frame.

The geometry of the OB1 is fairly standard for a road bike with a 72-degree head tube angle, paired with a 73-degree seat tube, 42cm chainstays and a 7.3cm bottom bracket drop. Those measures combine to yield a 102.5cm wheelbase with a 616mm front center.  

Our size L frame has a 57.0cm effective top tube and a tall 180mm headtube giving a reach of 388mm and a stack of 595mm.

The fork axle-to-crown height is also a road-bike-like 385mm, as compared to a cyclocross standard of 395mm.

Longer fork blades accommodate ’cross tire clearance with 700c wheels and mud clearance. This did not present a problem when I put a 700c wheel with a 40mm tire into the OB1 fork.

There is no cable access below the bottom bracket; the control lines run through the frame above the bottom bracket and are foam padded to keep them from rattling. There is a drain hole on the BB shell. The area behind the BB shell is smooth with no mud shelf.

A provision for a direct mount front derailleur is on the seat tube, either electronic shift or bottom pull cable.

There are attachment points for fenders, a bento box, a rear rack and five water bottle cages, two in the usual spot, one on each fork leg and one beneath the down tube.

Fork blade mounts often have three bolts for a large format cage like the Salsa Anything Cage, but Jacobs did not like the idea that riders would load too much weight outboard on the fork. Low rider pannier racks will also fit on the fork, and the crown has a piercing for a front rack mount.

A notable detail of the frame is the integrated reversed seatpost clamp. It offers a nice aesthetic while clamping the post in a secure fashion, unlike hidden bolt compression or wedge systems.

Jacobs is equally proud of the parts mix he’s curated for the OB1. So much that on the website he explains his reason for choosing every part of the build.

One remarkable example his attention to detail is the DT Swiss 350 hubset on the Thesis-branded wheelsets.

If a buyer chooses to purchase two wheelsets with the OB1, Jacobs seeks out two hubsets from the same lot to assure easier exchange of the wheels without a brake caliper adjustment.

There are two basic build packages available for the OB1 presently based around wheel size and tire width. “The Shredder” is the 650b model and “The Roadie” is the 700c version.

Thesis also offers an “Omni Edition” package that offers two wheelsets, both with tubeless tires set up, rotors and separate cassettes for $1,300 more. (That’s four wheels, four tires, four rotors, and two cassettes!)

Our review sample Thesis OB1 had SRAM Force 22 shifters with a Rival 1 long cage rear derailleur that shifts across a wide-range SunRace 11-46 11-speed cassette.

The hollow-forged crankset has a direct mount single wide-narrow chain ring with 44 teeth, leaving a 108-inch top gear with a lower than one-to-one 26-inch low gear.

The left shifter actuates an internally routed dropper post cable, which is an option available for an additional $200. The post and cable add 250 grams.

The drop section of the black aluminum handlebar has a mild flare, the stem is forged aluminum. The slotted saddle has a short nose and wide rear, similar to the Specialized Power saddle.

The Thesis OB1 comes with bar tape that matches the color of the frame, in the case of our review sample, a brilliant blue.

The bottom bracket is EVO 386 and Thesis uses a BB with cups that thread together, similar to the Wheels Manufacturing design.

The Thesis 650B wheelset has asymmetric rims with a 27.5mm internal width, perfect for the 47mm-wide tires. The wheels have 28 spokes with external nipples laced 2x around DT Swiss 350 hubs with Centerlock rotors for a durable build.

Our build came with 650b x 47mm WTB Byway tires that feature a relatively smooth tread.

The claimed weight for the tubeless wheelset is a reasonable 1,400 grams. Both the 700c and 650b wheelsets are available separately.

Our review bike weighed 21.3 pounds without pedals and 12.6 pounds with no wheels. That’s a bit heavy for a carbon bike, thanks in large part to the dropper post. The company said it is working on a lighter frame.

​While reviewing the Thesis OB1, I got the chance to ride with Jacobs after a rainy day. With most of the ride off-road, it became evident that despite the large contact patch of the 47mm tire, the slick tread disallowed traction on wet soil or grass, even with the advantage of staying seated using the low 26 inch gear or descending with the dropper down and in the drops, butt hanging over the rear tire.

He’d set the bike up for me initially with the tires at 35 psi, which is a lot for me with such a high volume tire. Jacobs is a former XC mountain bike pro and intuitively knows that knobs are necessary for any serious off-road pursuits.

He will offer some knobby tire options in the near future as a customized request. He later swapped the WTB Byway smoothies for 650b x 47mm WTB Senderos that have a knob pattern similar to the WTB Resolute or CrossBoss .

That changed the experience for the off-road adventures, especially since rain punctuated our review period.

Though Jacobs likes the single ring option, he also knows some riders like smaller steps between gears and don’t feel the need for a dropper, so he will offer a double ring setup. I don’t mind the single ring set up as it frees up the left shifter to actuate the dropper post.

I dislike the look and shifting over the ultra-wide range cassette. I would prefer a 38t front ring with a 10-40t cassette on an XD driver.

However, Jacobs explained that availability, cost and weight made him decide on essentially the same range over larger cogs and freewheels, with an added benefit of offering slightly better wear properties.

The 42mm chainstays are 0.5 to 1.0cm shorter than most cyclocross bikes today. That has the theoretical advantage of making the bike more responsive, since more weight is over the rear wheel or because there is less flex of the stays.

These subtleties are not really felt on a bike with big soft tires. However, put on the road wheels and tires and you may think differently.

As discussed earlier, the 700c wheels with road tires have the same rolling diameter as the 650b rims with 47mm tires. That means with a wheel swap, the bike standover and geometry should be the same.

To me it made little difference. I rode the bike with 700c wheels and tires between 30 to 40mm wide and there were no dramatic handling differences. The standover height was noticeable but not bothersome since I primarily ride cyclocross bikes.

Compared to standard 7.0cm BB drop of many modern cyclocross bikes, the lower BB drop was not even noticeable. If I was coming from a high BB bike like the Sage PDXCX or the Fuji Altamira CX 1.1 , then it might be apparent.

On the Thesis OB1, 700c wheels with slightly larger rolling diameter than cyclocross tires felt like a normal modern cyclocross bike due to the low bottom bracket the bike starts with.

The limitation of the shorter chainstays is that with 700c wheels, 40mm is the tire clearance limit, perhaps 42mm with a squeeze.

The widest part of the inner chainstays is for a smaller diameter. The bigger diameter also runs close to the seat tube. That’s not a problem, just a consideration.

The OB1 is available with a package that includes both a 700c and 650b wheelset, each with appropriate tires, rotors and cassette.

Jacobs specs those bikes with the same DT Swiss 350 hubsets from the same production lots if possible for an easy “hot swapping” of the wheels. That means no brake caliper adjustments when switching between 700c wheels with 30mm smooth road tires and 650b with 47mm gravel tires.

The OB1 is a stiff platform. Take into account that I rode the bike with 47mm tires at 20 to 25 psi, much wider than habitual for me. I also rode the OB1 with various other 700c wheelsets with a variety of tires from 33 to 40mm, most typically at 25 -30 psi.

I am lucky to ride a lot of different bikes with various wheelsets and tires repeatedly over the same terrain. Tire compliance helps a lot, but you can still feel the heart of the bike.

Despite what some say, frame compliance plays a role in the overall ride quality. The stiffness is not objectionable and makes the bike feel racy and offers great road manners on pavement . Its ride quality is on par with the Fezzari Shafer .

With cyclocross wheels, 700c with knobbies , or with a monster cross setup, 650b with 47mm knobbies , the fun really began. The frame stiffness, short chainstays and quick front end made tight courses fun.

Despite my preference for a more compliant frame, this bike feels quick, responsive and racy. It handles fast courses with smoother track very well.

When the knobby WTB Senderos were on the Thesis, I can’t help but think of Jacqui Phelan’s drop bar Cunningham mountain bike. Only the brakes are better now, and the dropper post is better than a Hite-Rite.

The dropper post offers the novelty of moving the saddle out of the way for a steep descent or lowering the center of gravity for corners, all adding to the fun.

With the dropper down you can slide back over the rear wheel more easily and brake from the handlebar drops which increases your feeling of control on steep drops. There is no denying this makes descents addictively fast and fun.

I even found myself lowering the saddle a bit when approaching a corner on the road to better rail it. Sometimes I’d lower the saddle at a stop light to stay in the saddle with my feet on the ground just because I could .

The added weight, 250 additional grams up high from the seatpost is noticeable when you carry the bike and when you throw the bike around chicanes. The dropper post is certainly fun to have, especially handily paired to the left shift lever, and it makes the bike more capable.

Many riders don’t have the luxury of multiple wheelsets easily swappable on a disc brake equipped bike. With the OB1 two wheel package, that becomes possible for an affordable premium considering the second wheelset comes with tires, rotors and a cassette.

Then you can have one bike that offers great on-road performance and very capable off-road performance.

Though swapping wheels is only a minor inconvenience for someone who likes to work on their own bike, the luxury of having the wheels pre-matched for rotor spacing is nice. You can make your ride decision on a whim knowing it will be adjusted.

The ability to fit 650b with wide tires and all the mounting points makes the OB1 a versatile bike, ready for bikepacking or a long adventure. The stiff frame will be advantageous with a load aboard. The chainstays are short so panniers are not ideal.

Jacobs prefers a frame bag to keep the heavy items low and centered, a preference of modern bike packers anyway.  Long haul tourists will likely look for a longer bike specific for the task.

The Verdict

There’s no such thing as a quiver-killer, perhaps a quiver-reducer though. This is Jacobs’ thought of what that best one bike might be.

The Thesis OB1 is a versatile, fun bike, especially with the dropper post and the design around the 650b wheels with the ability to accommodate 700c.

Other similar bikes exist out there, but where Thesis differs is Jacobs’ thought for the sustainability of the bike industry, partnering with shops and local bike professionals. He also is delivering a great bike at a lower cost to the consumer.

We recommend the two wheelset package and the dropper post option. If you are looking for a bike that will cover a lot of ground, the Thesis OB1 should be on our short list.

For more on the Thesis OB1, see the specs and photo gallery below.

Thesis OB1 Specifications

MSRP: $3,300, $3,500 as tested with dropper post option Frame: Thesis Carbon fiber, 12mm thru-axle, flat mount disc Fork: Thesis Carbon Fiber with carbon steerer: 1 ⅛” -1 ½”, 12mm thru-axle, flat mount disc Weight: 21.3 pounds, no pedals; 12.6lbs without wheels or pedals Shifters: SRAM Force 22 HRD, 11-speed Crankset: Thesis hollow forged aluminum, 44t Narrow-Wide profile Brakes: SRAM Force HRD, SRAM Centerline rotors 160mm front, 160mm rear Cockpit: Thesis 10cm stem, 42cm flared bar Seatpost: Thesis Aluminum dropper, internal cable routing , 27.2mm, two-bolt clamp Saddle: Thesis ergonomic Wheels: Thesis 650b rim, 27.4mm internal width, Centerlock disc hubs, j-bend bladed spokes, external nipples Tires: WTB Byway tubeless, 650b x 47mm Warranty: Five years, frame and fork (original owner) Country of origin: Taiwan More Info: thesi s.bike

Photo Gallery: Thesis OB1 All-Road Bike

Our demo bike was set up with 650b road-plus tires and a dropper post. Thesis OB1 Do-It-All Carbon Bike. © C. Lee / Cyclocross Magazine

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Thesis The OB1 — 650b

• AUS $ NZD $ USD $ CAD $ GBP £ EUR €

Size / XS, SM, MD, LG, XL

At a glance

Where to buy, specifications.

• Frame Thesis OB1 Carbon
• Fork Thesis OB1 Carbon with SteerSafe
• Hubs DT Swiss DT350
• Wheels Thesis Ultra-Wide Carbon 650B ⸱ 650B, 27.4mm internal, 33mm wide, 24.5mm deep ⸱ Optimized for 47mm+ tires ⸱ Tubeless-ready hookless design, also compatible with standard tubed tires ⸱ 3mm offset, angle drilling, & reinforced nipple seat ⸱ Toray 700/800 construction ⸱ 370g +/- 5%
• Spokes Pillar PSR X-TRA 1420 Cold-Forged Bladed
• Tires WTB 650B Venture ⸱ WTB Venture 650B x 47mm (555g) ⸱ Supple tanwall casings ⸱ Tubeless
• Chain SRAM PC1110 with Quick Link
• Crank Thesis Narrow-Wide Direct Mount Single
• Bottom Bracket Thesis 2-Piece Aluminum Interlocking
• Rear Derailleur SRAM Rival 1 Long Cage Clutched
• Shifters SRAM Rival 22 Hydraulic
• Brakeset SRAM Rival 22 Hydraulic
• Handlebar Thesis Compact Ergo Flare
• Saddle Thesis Endurance 148 Saddle
• Seatpost Thesis Ultralight 3D Forged ⸱ 1-piece 3D forged 2014-T6 aluminum quill ⸱ Micro-adjustable 2-bolt clamp ⸱ Broadly supportive lower clamp ⸱ 0 offset to match OB1's 73° seattube angle ⸱ 230g
• Stem Thesis Ultralight
• Headset Thesis Oversized Integrated

Q: How much is a 2020 Thesis The OB1 — 650b?

A 2020 Thesis The OB1 — 650b is typically priced around $3,299 USD when new. Be sure to shop around for the best price, and also look to the used market for a great deal.

Q: Where to buy a 2020 Thesis The OB1 — 650b?

The 2020 Thesis The OB1 — 650b may be purchased directly from Thesis .

Q: What size 2020 Thesis The OB1 — 650b should I get?

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• Rider Notes

2020 Thesis The OB1 AXS 2x — 650b

A carbon frame gravel bike with high-end components and hydraulic disc brakes. Compare the full range

Manufacturer Price

For This Bike

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Based on frame geometry and build specs.

A bike with lower gearing will be easier to ride up steep hills, while a higher top end means it will pedal faster down hills.

The OB1 AXS 2x — 650b

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Do you have this bike? Help other riders make a decision about which size will work for them by sharing your own size and fit notes. Report your fit

Thesis BringAFriend program helps you & a friend get on a new custom-built OB1 carbon gravel bike, saving you both $300 - now in olive green or plum...

Read Review

Aug 2019 · James Huang

The Thesis OB1 isn’t flashy, and the upstart brand name carries no prestige. It’s not particularly light, it definitely isn’t aero, and in fact, there’s not a ton about it on paper that will blow anyone’s doors off in general. But it’s a very good bike nonetheless, and wonderfully versatile in terms of what you […]

Good geometry, great spec, outstanding value

Average frame, value equation is region-dependent

Apr 2019 · Clifford Lee

The Thesis OB1 is a carbon all-road bike that fits wide 650b and skinny 700c tires. Is it ready to do it all and help reduce the number of bikes you need?

Last updated 2 March

Thesis OB1 All-Road Bike Review: Where Performance and Versatility Intersect

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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.

Wheelset(s)

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 .

Manufacturing Transparency

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)

Potential Drawbacks

• 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.

Final Thoughts

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.

Simple Stoke: New Specialized Stumpjumper Has Arrived and Needs No Introduction

This short trail riding edit from Specialized will make you ooh and ahh. It's raw, filled with crazy drone shots, gorgeous fall foliage, and — well, it's just really good. Read more…

Zach Burton is a Contributing Writer for GearJunkie. He has been writing about hunting, fishing, fitness, and outdoor pursuits for over 5 years. Prior to that, he spent as much time outdoors seeking adventures that pushed his limits and expanded his life experiences. Based in Minneapolis, Minnesota, Zach can be found fly fishing, hunting, riding or racing bikes, shooting photos, in the gym, or planning his next adventure.

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• Thesis The OB1 — 650b 2020

156cm - 166cm

163cm - 174cm

171cm - 182cm

179cm - 189cm

185cm - 195cm

Bike summary

Bike components.

Thesis OB1 Carbon

Suspension Fork

Thesis OB1 Carbon with SteerSafe

Rear Derailleur

SRAM Rival 1 Long Cage Clutched

Shift Levers

SRAM Rival 22 Hydraulic

SunRace Ultra Wide Range, e*thirteen TRS Plus, SRAM XG-1150

Thesis Narrow-Wide Direct Mount Single

Bottom Bracket

Thesis 2-Piece Aluminum Interlocking

SRAM PC1110 with Quick Link

DT Swiss DT350

Thesis Ultra-Wide Carbon 650B ? 650B | 27.4mm internal | 33mm wide | 24.5mm deep ? Optimized for 47mm+ tires ? Tubeless-ready hookless design, also compatible with standard tubed tires ? 3mm offset, angle drilling, & reinforced nipple seat ? Toray 700/800 construction ? 370g +/- 5%

Pillar PSR X-TRA 1420 Cold-Forged Bladed

WTB 650B Venture ? WTB Venture 650B x 47mm (555g) ? Supple tanwall casings ? Tubeless

Disk Rotors

SRAM Centerline Centerlock 160mm

Thesis Ultralight

Thesis Compact Ergo Flare

Thesis Oversized Integrated

Thesis Endurance 148 Saddle

Thesis Ultralight 3D Forged ? 1-piece 3D forged 2014-T6 aluminum quill ? Micro-adjustable 2-bolt clamp ? Broadly supportive lower clamp ? 0 offset to match OB1's 73° seattube angle ? 230g

Bike geometry

About this model

The OB1 — 650b is a Thesis Ob1 model. 6 bikes variations carry this model name so far. Check out the entire range from 2020 of this model, by clicking this link .

Model range prices

The most economical model, the Thesis The OB1 — 650b 2020 has a starting price of 3299 $ . Thesis The OB1 AXS 2x — 650b 2020 on the other hand is the most expensive at 5199 $ .

When you go for a ride, don’t forget to put your helmet on. Moreover, ride with traffic, not against it. This will help you stay visible to drivers and also makes it easier for them to see you.

Average price for Gravel bikes

According to our math, the average price for a trustworthy Gravel bike is 2462 $ . However, even if your budget is less than the average, you might still be able to get a top-quality Gravel bike. In short, before purchasing your ideal bike do some research about its components, and also check for reviews online.

At the moment of the release date, Thesis The OB1 — 650b price was 3299 $ . Comparing the average cost of a Gravel bike to this one, you will see that The OB1 — 650b price is 34 % higher .

Overview of components

Fork material.

The OB1 — 650b has a carbon fork, so, it is super light and stiff. In conclusion, a carbon fork gives you great control when steering, and is also more forgiving.

Wheels size

When leaving the production line, the The OB1 — 650b model has carbon wheels. After 700c wheels, 650b is the second most popular choice for road bikes. However, if you want higher speeds, you should look for a bike with 700c wheels.

When you want to stop the bike in time, the brakes are vital. The The OB1 — 650b has Hydraulic Disc brakes. These kinds of brakes are among the most popular models used on bikes. To sum up, these are ideal for anyone.

This bike is available in 5 sizes . They vary from 156 cm – 195 cm (5.12 ft – 6.4 ft) . In conclusion, it won’t take much to find one that’s right for you.

Thesis Ob1 models from 2020

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