thesis 650b

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Ridden and Reviewed: Thesis OB1 Carbon All-Road Bike

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.

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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 OB1 long-term review: Good performance, lots of custom options

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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 can do with it and where you can ride. And perhaps most important of all to many buyers, it’s a fantastic value (at least for Thesis’s core United States market).

If spec is important to you, go ahead and try to find something better for the money. I dare you.

Story Highlights

What it is: A do-it-all road and gravel bike with good value and lots of custom options|| Frame features: Carbon fiber frame and fork construction, clearance for 700x40mm or 650x47mm tires, mounts for three water bottles and front and rear fenders, convertible internal cable routing, BB386EVO press-fit bottom bracket|| Weight: 1,257g (actual frame weight, medium size, with hardware); 487g (fork only, pre-cut); 8.99kg (19.84lb, as tested, medium size, without pedals)|| Price: US$3,500 (international prices based on currency exchange rates)|| Highs: Good geometry, great spec, outstanding value || Lows: Average frame, value equation is region-dependent

The idea behind Thesis

Direct-to-consumer brands such as Canyon, YT, Rose, and others have been steadily growing in popularity for their ability to deliver similar performance as traditional brands, but at substantially reduced prices by virtue of their dramatically streamlined supply chain. Setting aside the long-term ramifications this trend will have on brick-and-mortar retailers, the math is simple as far as end consumers are concerned: by eliminating one layer of markup, consumers are basically able to buy bikes at wholesale.

Thesis takes that approach further still.

One little-discussed secret of the bike industry is that many well-known brands don’t actually make anything; they may do the design and engineering, but the actual manufacturing is farmed out to any number of well-established contract factories that produce on an OEM basis. Many of those factories also sell their own products on the side, usually at heavily discounted prices since they don’t have a popular brand name to justify any sort of premium.

This is where Thesis co-founder Randall Jacobs comes in (Alice Liu is the other half of Thesis — the one that makes sure bills get paid, documents are signed, etc.).

The Thesis OB1 is a so-called “open mold” carbon fiber frame. In other words, it’s a frame that a factory also has in its catalog that is then offered up to whoever is interested in placing a minimum order (in this case, it’s also known as the Carbonda CFR-505 ). Jacobs readily admits this fact, and doesn’t make any bold claims as to its novelty, but also stresses that it’s not exactly the same as what someone would buy online themselves.

“We added chainring clearance, we added bosses, we added reinforcement under the bosses, we added fiberglass at interfaces with metal so you don’t get galvanic corrosion, and we added SteerSafe,” he said. “The open-mold frame is available directly, but we do a detailed inspection on every one of the frames that arrive in our facility in Taiwan. We bring all the frames in raw, check all the tolerances on the brake interfaces, dropouts, bottom bracket, and anything else, we do any rework that’s necessary, then send it to a high-end paint facility in Taiwan, bring it back in, and do another round of QC. We have customers who have bought the frames directly [from the manufacturer] coming to us with issues, and that’s one of the things we’re ensuring gets done properly.”

Those frames are then painted in one of five different colors, then dressed in an unusual assortment of components that Jacobs has sourced directly from the manufacturers wherever possible. At launch, Thesis simply had all of these bits drop-shipped to buyers in plain plastic bags, just as an OEM brand would receive them at their own assembly warehouse. The wheels were pre-built and the hydraulic brake lines were assembled and bled, but you otherwise had to figure out how to put everything together from there.

Thesis has since switched to delivering bikes that are mostly assembled at a factory in Taiwan, and it arrives much as how bikes show up to traditional dealers, although Thesis says its bikes are pre-tuned to the point where there’s supposedly almost zero additional work required aside from installing the handlebar and seatpost, fine-tuning the sizing, and pumping up the tires.

Thesis has also partnered with a growing number of local fitters and mechanics to help guide you through the process from start to finish — including offering demo bikes, too.

The original retail price of the Thesis has gone up slightly up as a result, but at US$3,500 as shown here with tubeless carbon clinchers and a dropper seatpost, it’s still a solid deal. Thesis recently added a more upscale build kit with SRAM Force eTap AXS 1x setup for US$5,000, or the 2x version for another US$200. Thesis currently sells the OB1 to 21 countries (including the United States, Australia, the United Kingdom, Germany, and Canada), all with a flat US$99 shipping fee.

Pricing for non-US markets are based on straight currency conversion rates, with the buyer responsible for all taxes and duties (and the value equation unfortunately varying as a result).

“One of our core innovations is our sourcing logistics and fulfillment model,” Jacobs continued. “We don’t have a bunch of pre-assembled bikes sitting in the states tying up cashflow. We work directly with high-end factories and their production engineers — I’m over there speaking Mandarin with the guys — we bring in a limited assortment of high-end components, and then everything is built to order. We don’t even paint the frame until an order comes in. And then we drop-ship out of Taiwan, which eliminates a whole lot of middlemen and price-stacking, which lets us do a fully custom build without having incremental costs.”

An open-mold frame, yes, but a pretty good one, and with a few nice touches

The OB1 frame is about as middle-of-the-road as you can get, and I don’t mean that in a bad way.

The “reinforced” Toray 800/700 blend of carbon fiber is generally considered to be medium-modulus in the industry, the geometry is fairly conservative, and tire clearance is pretty accommodating with quoted allowances for 700c setups up to 40mm-wide, and 650b ones up to 47mm. The internal cable routing setup features swappable aluminum ports that can handle a wide range of drivetrain and accessory configurations, there’s room for 46T single or 50/34T double cranksets, it takes a normal-as-can-be 27.2mm-diameter seatpost, and there are mounting points galore, including five water bottles, a top tube feed bag, and front and rear fenders.

The OB1 doesn’t break any new ground in the handling department, either.

The 72-degree head tube angle and 51mm fork offset on my medium sample yield a semi-quick 60mm of trail when paired with a 700x35mm tire. With a 650x47mm tire, it drops to 58mm, but neither is far off the norm. Likewise for the 73mm of bottom bracket drop, 420mm-long chainstays, and 73° seat tube angle.

One very noteworthy addition that Jacobs made is related to safety. Carbon forks are among the most rigorously tested bits in all of cycling, but they’re still not 100% immune to failure — and if a steerer tube fails catastrophically, the consequences are often severe. To that end, every Thesis OB1 fork is equipped with a SteerSafe aluminum sleeve that is permanently bonded to the inside of the carbon steerer, extending down past the upper headset bearings so as to provide some protection against fatigue-related breakage and crushing from overtightened stem clamp bolts.

The extra chunk of aluminum undoubtedly adds some weight, but considering that the OB1 isn’t trying to break any records in that department, it seems like weight very well spent.

Actual weight for my test sample was 1,257g (including hardware and factory-installed guide tubes), plus 487g for the matching fork with an uncut steerer.

A masterclass in spec with lots of customization options

The spec is where the OB1 really shines.

Rather than offer a complete, or even nearly complete, groupset as would be more typically found, the Thesis OB1’s build kit is decidedly eclectic, using name-brand stuff where it’s most appropriate and cost-effective, but no-name stuff elsewhere.

For example, the SRAM Rival 1 logo is found on the brake/shift levers, rear derailleur, and hydraulic brake calipers (the chain is a SRAM PC-1110), but the 11-46T cassette is sourced from SunRace, and the hollow-forged aluminum crankset comes direct from Taiwanese factory Samox.

Likewise, DT Swiss 350 hubs are used front and rear, but they’re joined to no-name tubeless carbon fiber clincher rims with Pillar stainless steel spokes.

The saddle? It’s shaped like a Specialized Power, but is totally unbranded and made by Velo (who, coincidentally, also manufactures the saddles for Specialized). The aluminum handlebar and forged aluminum stem have no branding on them at all, but the tops are subtly flattened for comfort, the drops are flared by 10° for more control on tricky terrain, and the stem has a convenient (and secure) four-bolt removable faceplate.

The magic comes in how all of this is put together, and the options that are offered.

I can’t imagine SRAM is keen on bike brands mixing its rear derailleur with the cassette from another brand, but the SunRace 11-46T cluster offers nearly the same total range as SRAM’s 10-42T option (418% vs. 420%) at a 73g weight savings (465g vs. 538g). Similarly, the Samox crankset Thesis uses is made with hollow-forged aluminum arms and a 30mm-diameter aluminum spindle. At a little over 700g for the 170mm-long arms and 42T narrow-wide chainring, it’s about 80g lighter than the Rival 1 unit, and also theoretically more rigid owing to the oversized spindle and larger-profile, hollow (vs. solid) arms.

When it comes to wheels, the rise of disc brakes has taken a lot of the worry out of generic carbon fiber clinchers since heat-related failures are no longer an issue, and Thesis is smart to go with generous internal widths across the board (22-27.4mm, depending on build kit). Hubs are where you more often run into issues with generics, but the DT Swiss 350 units that Thesis uses have a superb reliability record, and it’s also easy to find replacement parts if and when they’re needed.

Even better, Thesis provides a surprising amount of choice during the buying process, including 700c vs. 650b wheels, chainring and cassette size, crankarm length, stem length and handlebar width, and even frame and handlebar tape color — all at no additional charge. A dropper post can be added for a modest US$199, too, and power meters are supposedly coming in the near future.

Want to be able to easily switch between both 700c and 650b wheelset? An extra US$1399 not only gets you a second set of hoops, but also the matching tires, cassette, and rotors, all pre-taped, sealed up, and ready to run.

There’s even quiet wisdom in parts that you can’t even see.

Although the frame is equipped with a press-fit bottom bracket shell, it’s filled with a generic machined aluminum thread-together unit to keep creaking at bay. And better yet, the bearing cartridges are Japanese-made bits from highly reputable brand NSK. The internal routing isn’t guided from end to end, but foam sleeves are included to help prevent rattling inside the down tube. And if you want to run a dropper post with a single-ring drivetrain, Thesis will even gut the left-hand shifter so that you can use it as a remote lever for an ultra-tidy setup.

Detail-oriented buyers will love that Thesis provides the thinking behind every component choice on its web site, right down to the thru-axles, chainring, and rear derailleur hanger. It’s an intimate look into Jacobs’ product manager mindset, and one that many potential buyers will appreciate. After all, usually you get no rationale at all behind why a bike is equipped as it is, aside from the assumption that it was the cheapest way to hit a certain price point.

Where the rubber meets the road

All of this sounds fine on paper, but what’s the Thesis OB1 actually like to ride?

I’ve had the pleasure of riding a veritable fleet of superbikes over the years. There are ones like the Scott Addict Gravel that are so stiff, light, and responsive that they feel almost like they pedal themselves when you apply the slightest bit of power. There are ones like the Trek Checkpoint and Cannondale Topstone that are so smooth that you swear your tires are flat. And then there are ones like the Allied Alfa Allroad that take a less aggressive path toward tackling off-road terrain, but feel so much like a good road bike that you’d be happy riding the same bike for both.

Let’s be honest here: the Thesis OB1 is not one of those bikes.

But if I were in the market for a do-everything drop-bar bike on a limited budget, and still wanted very good overall performance, this would still be in the running.

As one would expect, the medium-modulus frame delivers average stiffness at the bottom bracket and head tube. It’s neither spongy under power nor vague under hard cornering loads, but it also doesn’t feel lightning-quick when you stomp on the pedals or particularly reactive at the slightest hint of steering input.

Nor does that medium stiffness come with copious amounts of rider comfort. It seems to damp most high-frequency vibration just fine, but I wouldn’t otherwise describe the OB1 as being particularly compliant, despite the pencil-thin seatstays. Ride quality on any bike always relies heavily entirely on the tires, but it feels even slightly more so here, especially with the unyielding dropper seatpost that was fitted here. Compounding the issue is the fact that the fork continues that theme, but yet is still flexible enough side to side that it’s possible to induce slight brake rub without too much effort.

Handling-wise, I found the 650b setup to be a tad quick for my liking. Lots of gravel bike options now offer the flexibility of running 650b or 700c wheel-and-tire setups, but switching to the smaller and wider setup still speeds up the handling, which I’d argue is the opposite of what you’d want (I ended up spending much of my time with the OB1 on a 700c setup). Granted, tackling that issue in the way that Cervelo has with its new Aspero would likely be cost-prohibitive given Thesis’s current business model, but perhaps a second fork specific to each fork diameter would be more feasible here.

There are some more minor nuisances. There isn’t a hatch underneath the bottom bracket to help you run the internally routed cables and hoses, so you need to make sure everything is where it needs to be before installing the bottom bracket. It’s critical to get the front brake hose length just right so that it doesn’t rub the paint off of the head tube. And as much as I appreciate the thought process behind the aesthetic design of the profiled seatpost collar, the shape doesn’t quite match the surrounding carbon fiber so it just comes off as a bit sloppy.

The OB1 chassis may not be especially noteworthy, but it’s good enough that it isn’t at all distracting, either. Rarely did I think about any of that when I was riding it; mostly what I concentrated on was how much fun I was having. The OB1 isn’t showy, it’s not prohibitively expensive (relatively speaking, of course), and it isn’t packed with the latest-and-greatest technology. It just gets the job done, and in a manner that’s almost too quietly competent for its own good.

And remember that this is a bike that costs a modest US$3,300 in stock trim – a little more than half what a Moots Routt RSL frame alone costs. Value is always an important thing to consider for any bike, and in the case of the OB1, it’s such a core attribute that it’s impossible to ignore what you’re getting for the money (although, as mentioned earlier, that value equation will vary depending on relative currency values).

Although the frame isn’t unusually light, the complete build fares much better thanks to the smart spec. My medium “Shredder” build with the more dirt-oriented 650b wheel-and-tire package and dropper post tipped the scales at a a hair under 9kg (19.84lb, without pedals or accessories). The smaller-diameter wheels, relatively fast-rolling tires, and low rim weight help the OB1 feel lighter than that number would suggest, and using a standard seatpost would lop another 200g or so off that total, too. Not bad at all.

A big part of that is the wheelset. Carbon hoops aren’t typically found until you spend far more than what Thesis is asking here for the OB1, and these seem quite good. The properly generous internal width offers great support for the 47mm-wide WTB tires, they set up tubeless very easily and hold tires securely, and if only judging by the handful of times I bottomed them on the square-edge chunks of granite that typify Colorado singletrack, they’re apparently rather tough, too. And the fact that they’re built around actual DT Swiss 350 is a huge boon for long-term durability.

As I’ve noted previously in my experience on the Otso Warakin , the SRAM Rival 1 transmission is a hugely under-heralded workhorse — hardly lustworthy, but functional and reliable nonetheless. Together with that Sunrace cassette, the whole setup works great, offering plenty of range for exploring backroads and trails, and delivering consistently reliable shifts from the 46T sprocket down to the 11T.

The crankset likewise goes about its business with no headaches despite the lack of conspicuous branding, and creaking was a total non-issue.

The same goes for the unbranded handlebar and stem. The flattened tops are pleasantly comfy on bumpy ground, and even for someone like me that normally prefers non-flared drops, the subtle outward flare on these still seemed just-right when things got rowdy. And as far as I’m concerned, aluminum is way to go here given the expected crashes a bike like this is likely to see. Hell, even the saddle is comfy.

I could have done without the dropper post, though. In my opinion, it adds too much weight for the modest amount of drop it provides (at least for my frame size and saddle height combo), and the frame design’s modestly sloping top tube inherently limits how aggressive you can go in that department, anyway.

I’d also like to see a more trail-oriented tire option. The WTB Byway is a safe choice for mixed-terrain riding, but the low-profile side knobs just don’t provide enough security through loose corners, and leave too much fun on the table. Not everyone will need or want it, of course, but given the breadth of options Thesis already provides, adding another one — particularly one that has such big implications — seems like a reasonable ask.

Nevertheless, this is mostly nitpicky stuff.

Spec vs. chassis

Still, the question remains: is it more important to have a great frame with so-so parts, or a so-so frame with a fantastic build kit?

For the sake of comparison, a similar amount of money to what Thesis asks for the OB1 will also get you a Canyon Grail CF SL 8.0 SL , which offers a more refined frame and SRAM’s nicer Force 1 groupset, albeit with lesser DT Swiss aluminum clincher wheels than the fancy carbon ones on the Thesis. Weight-wise, Canyon says it tips the scales at 8.4kg, or about 400g lighter than the OB1 on an apples-to-apples basis.

The Canyon offers a smoother ride, more cutting-edge technology, and arguably better handling since it’s purpose-built around a single wheel diameter. But it’s also more limiting in terms of scope if you want to ride off-road, and there are no customization options from the factory: no stem length or bar width swaps, stock gearing, one frame color, one wheel diameter. Anything else you want to do will cost you extra.

And then there are other direct-to-consumer gravel bikes that are built around high-quality aluminum frames, like the Mason Bokeh, which costs about the same as the Thesis with comparable spec and offers similar levels of customization, albeit with an alloy chassis that’s a few hundred grams heavier.

When viewed against that sort of tough competition, the Thesis’s value equation still looks pretty good, but it’s not quite the knockout blow that it might seem to be initially.

More than a passing grade

Take a look inside your closet. Do you prefer mixing things up fashion-wise, or do you mostly wear the same thing everyday? Do your tastes vary from season to season, and do you like to keep up with the latest trends?

Think of the Thesis OB1 as the tailored black t-shirt of the gravel bike world: It fits you well, but is rarely the most eye-catching. It doesn’t cost a ton, and is never the front-page image on the magazine. But there’s a reason why it’s the most-worn item in your wardrobe.

There are always things that look better and command more respect than the nice black t-shirt. But then again, with perhaps a little extra accessorizing, it also almost always suits the occasion. Whether or not it suits your style is another matter entirely.

www.thesis.bike

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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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