DETAILS
Our original legendary all-road gravel bike. With bombproof carbon wheels, a crisply shifting SRAM Rival 1x drivetrain, hydraulic brakes, and wide range cassette, the OB1 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 latest lead times for your spec.
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, fewer flats, greater efficiency, and an extra smooth ride.
Gearing for every adventure
- 1x11 drivetrain allows crisp simple shifting with no cross-chaining, chain slap, or chain drop, with a cage-lock feature on the rear derailleur that makes it super easy to swap wheels or fix a flat.
- Slickly integrated dropper post using your left shifter puts you in control when the going gets rough.
- Thesis Hollow-Forged Cranks offer incredible stiffness and durability.
- Ride-specific gearing with your choice of cassette.
Obsessive on the details
- A creak-free bottom bracket with oversized Japanese stainless steel bearings and a 2-piece aluminum shell that threads together for perfect alignment.
- A remarkably comfortable saddle for all day riding.
- DT Swiss hubs for bombproof reliability and easy wheel swaps without brake adjustment.
- Optional dropper seatpost for enhanced control and confidence off-road and on.
- Durable stainless steel bearings, so you can focus on the ride.
Specs
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.
CHASSIS
DETAILS
- Endurance road geometry- Clearance for 650B x 47mm or 700C x 40mm tires
- Discreet mounting points for: (5) bottle cages, racks, bento, and clip-on accessories
- Clean internal routing for hoses and full cable housings, with foam sleeves sheathing for sound dampening
- Round, dropper-ready 27.2 seat tube
- Accommodates up to 46T single or 50/34T double chainrings
- Reinforced Toray 800/700 blend carbon construction
- Fiberglass anti-corrosive layer at seatpost, bottom bracket, and headset interfaces
- 1145g +/-5% (medium, black finish, frame w/o hardware)
Choice of: XS, S, M, L, XL (See Geometry)
WHY WE CHOSE IT
From road to gravel to travel, our OB1 frameset is ready for every road. Its sleek road-bike design hides clearance for wide dirt tires and discreet mounting points for bags, fenders, racks, extra bottles, and everything else the ride demands. From reinforcement at every hole and boss, to anti-corrosive fiberglass where carbon meets metal, to bolt-secured aluminum cable guides, we've invested in the details to deliver you performance without compromise.DETAILS
- Steersafe-reinforced carbon steerer- Clearance for 650b x 47mm | 700c x 40mm tires
- Accommodations for fenders, headlight, light, and bottle cages
- 12x100mm thru-axle dropouts
- Reinforced Toray 800/700 carbon construction
- 495g total with SteerSafe installed
WHY WE CHOSE IT
We created SteerSafe to ensure your carbon steerer is fully supported against stem clamping forces. SteerSafe is an aluminum tube with built-in starnut that gets bonded into our carbon steerers at the factory. To shorten a SteerSafe equipped steerer, simply cut through the carbon and aluminum layers using a guide and a carbon-specific blade as you would a normal carbon steerer, then use ultra-fine sandpaper to create a smooth, slightly rounded edge. Finish by torquing the lubricated stem bolts to 5 Nm.
DETAILS
- Hollow bolt-on with 6mm hex head- 12mm front | rear
- Thread length and pitch matched to OB1 frame/fork
- Machined 7075 aluminum
- 82g +/- 5% per set
WHY WE CHOSE IT
Each thru-axle is machined from a single billet of ultra-premium 7075 aluminum. With a built-in washer for smooth installation, our bolt-on thru-axles offer stiffness, security, and easy wheel removal without the extra ~100g of weight of levered designs and uses a 6mm hex wrench.DETAILS
- Standard interface for even clamping- Steel bolt & threaded insert for trouble-free adjustment
- Machined 7075 aluminum
- 20g +/-5%
WHY WE CHOSE IT
OB1's seat clamp achieves its integrated look while utilizing a traditional clamping interface that, unlike many proprietary integrated designs, evenly distributes clamping forces. This helps prevent damage to frame or post, post slippage, or post binding (dropper post). We finish it off with a lubricated nut and bolt for a lifetime of trouble-free use. Be sure to coat your seat post with grip paste before installing.DETAILS
- Oversized 1-1/2" stainless steel angular contact lower bearing- Standard 1 1/8" angular contact upper bearing
- Sealed upper cap
- Replaceable aluminum split crown race
WHY WE CHOSE IT
Selected for durability, OB1's extra large 1-1/2” angular contact lower cartridge bearing distributes the extreme loads this component experiences over more and larger balls. The sealed top cap provides an extra barrier to water penetration and its replaceable aluminum split crown race protects the carbon steerer crown from wear while being less prone to creaking than non-split races. While it adds a handful of grams relative to smaller diameter options, we don't believe in shedding weight at the expense of durability.DETAILS
- 1-bolt replaceable- Stiff for use with long-cage derailleurs
- Axle threads directly into the hanger
- Extra included just in case
WHY WE CHOSE IT
Flexy derailleur hangers compromise shifting and are quick to fail. OB1's is stiff and strong to withstand the greater loads placed on it by today's long-cage derailleurs and wide range cassettes, but will still sacrifice itself to protect the derailleur and frame in the event of a major impact. And don't worry - we include an extra just in case.
Mounting points for all your gear:- 2 bottle mounts in the front triangle
- 1 bottle mount below the downtube
- 1 bento mount on the top tube
- 2 bottle mounts on the fork blades
- Front and rear fender mounts (seat stay bridge included)
- Wide central clamping area on handlebar
Note: For optimum performance, load your heaviest items in a frame bag secured in the main triangle.
Max weight of rider + gear: 115kg (254lb)
COCKPIT
STANDARD SEATPOST
DETAILS
- 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 +/-5% (400mm), 210g +/-5% (350mm)
WHY WE CHOSE IT
OB1's seatpost weighs less than some carbon posts yet is safe to use with clamp-on accessories like bikepacking seat bags. Its quill is forged from a single billet of ultra-premium 2014-T6 aluminum for excellent strength to weight. The 2-bolt head and oversized lower clamp plate offer superior saddle security, support, and micro-adjustability.This seatpost can be shortened using a standard steerer cutting guide and 32TPI hacksaw blade. Just be sure that there's at least 105mm of insertion into the frame (more is better) and that you sand or file the cut edges to round them off and remove burrs.
DROPPER SEATPOST (+$149)
DETAILS
- Infinitely adjustable- Lightweight 1-piece forged head and quill
- Secure 2-bolt saddle clamp with broad rail support
- Premium 7075-T651 aluminum construction
- Clean internally-routed design
- Serviceable with readily available parts
- Tests to an ISO MTB standard
- Actuated by front shifter
- 405L|110mm (485g), 360L|90mm (460g), 310L|70mm (425g)
Pro Tip: Choose the longest dropper that fits your frame size and saddle height (see geo chart).
WHY WE CHOSE IT
A dropper post is a total game-changer. Dropping the saddle out of the way allows you to shift your center of mass down and back over the rear wheel, keeping your front end light and freeing your legs to act as suspension. The result is increased control, speed, and confidence over steep or aggressive terrain. They're even great for fast road descents. We've been riding droppers on our drop-bar bikes since before it was cool, so whether you're looking to get shreddy off-road or just want to feel safer on that high speed road sweeper, a dropper is an option well worth considering.Want to learn more? Check out our deep dive.
DETAILS
- 116mm drop | 75mm reach | 10 ° flare- Comfy flat top sections
- Wide 100-180mm x 31.8mm clamp area
- Double butted 6061 aluminum
Choice of: 360, 380, 400, 420, 440mm widths (center-to-center at the hoods)
WHY WE CHOSE IT
Aero on the tops, control and comfort in the drops. With a short reach, shallow drop, and subtle 10° of flare, our handlebar keeps you narrow when motoring on the hoods while offering greater leverage when cornering, descending, or shredding dirt in the drops, all while reducing back and wrist strain. Its wide central clamping area allows you to attach a bell, GPS, bar bag, aero clip-ons, or all 4 at once if that's what your adventure requires.
DETAILS
- 3D forged 7050 aluminum- 7° angle
- 105g (100mm)
Choice of: 70, 80, 90, 100, 110, 120 mm lengths
WHY WE CHOSE IT
A top-of-the-line stem equivalent to others retailing at $100 or more, our 7050-series aluminum stem is strong and stiff yet lighter than others' $250+ carbon stems.
DETAILS
- 148 width- 244 length
- Wide, supportive nose
- Pressure relieving padding and cutout
- Hollow Cr-Mo rails
- 261g +/- 5%
WHY WE CHOSE IT
Wide, short, cut-out saddles like this one first gained popularity among triathletes and time-trialists looking for improved comfort over long stints in extremely aggressive positions. Eventually roadies and mountain bikers discovered their benefits and brought them into their disciplines as well. With a bit more cushion for mixed terrain riding and hollow Cr-Mo rails for outstanding strength, this is a saddle meant for long days on rough roads.We spec our Endurance 148 saddle across our entire line of bikes. Our riders love it so much that many have outfitted their entire stable with them.
DRIVETRAIN & BRAKING
DETAILS
- Narrow-wide- Direct mount for stiffness, weight, & easy swapping
- Long-wearing 7075 aluminum
- Standard SRAM-type 3-bolt interface | 6mm offset
- 99g +/-5% (42T)
Choice of: 38, 40, 42, 44, and 46 tooth options
WHY WE CHOSE IT
Machined from a single plate of long wearing 7075-series aluminum to eliminate every unnecessary gram, our chainrings feature contoured narrow-wide teeth for smooth, drop-free operation and direct-mount interfaces for a stiffer and lighter overall system.
DETAILS
SunRace Ultra Wide Range- 11-42T offers a wide 382% range with smaller jumps
- 11-46T offers an even wider 418% range with more low-end
- 404g +/-5% (11-42T) | 465g +/-5% (11-46T)
- Note: 11-46T requires use of included spacer
e*thirteen TRS Plus
- 9-39T offers wide gear range of 433% with minimal weight penalty
- 9-42T offers an extremely wide 467% gear range
- 9-46T offers the widest gearing range available with 511%
- 315g +/-5% (9-39T) | 330g +/-5% (9-42T) | 395g +/-5% (9-46T)
- Note: Requires the use of SRAM XD or XDR freehub (included with casssette upgrade)
WHY WE CHOSE IT
Slick-shifting, and durable, we've been rocking 1x11 drivetrains using these premium SunRace cassettes for years to great effect. With proper chain maintenance, you'll get thousands of miles of trouble-free use before needing a replacement.Immense gear range without a weight penalty makes the e*thirteen TRS Plus range an excellent choice for a number of use cases. The 9-39T offers substantial range and reasonable gear jumps, with a top end bailout gear that won't spin out chasing a fast group ride on the road. The 9-46T has even greater range than our AXS 1x Eagle build kit, while remaining relatively trim, making it well suited to carrying a load while bikepacking when paired with a smaller chainring. e*thirteen's 9-42T is the Goldilocks of gravel gearing: just right.
DETAILS
- Clutched to prevent chain slap or drop- Cage-lock for exceptionally easy wheel removal/swapping
- Long-wearing cartridge bearing pulleys
WHY WE CHOSE IT
Functionally identical to Force 1 except for its aluminum vs. carbon front cage plate (~8g), SRAM's Rival 1 long cage rear derailleur features worthwhile upgrades over Apex 1 that include more durable cartridge bearing pulleys and a 50g+ lighter weight. It's clutched main pivot prevents chain slap and drops when charging through rough terrain, and its clever cage-lock feature makes swapping between wheelsets a breeze.
DETAILS
- Hydraulic braking- Flat-mount dual piston calipers
- Adjustable reach
- All OB1s come with front and rear shifters
WHY WE CHOSE IT
SRAM uses the same internals across all its road lines to achieve identical pro-level shifting and braking performance. With the only relevant differences being weight and finishes, we skipped Force's carbon levers (42g difference) and invested in high-end carbon wheels, lightweight cockpit components and other performance. durability, and serviceability upgrades while saving vastly more weight. While Rival and Apex are identical except for finishes, we went with the former due to its availability with a front shifter to allow easy addition of a dropper post or front derailleur.
DETAILS
- Stiff, hollow box-section arms- Lightweight & tough 7075 aluminum
- Wide-stance BB386 spindle (30 x 86.5mm)
- SRAM-type 3-bolt direct mount chainring interface
- 1-bolt removable drive-side arm
- Compatible with 4iiii power meters
- 625 grams (172.5mm)
Choice of: 155, 160, 165, 170, 172.5, 175mm
WHY WE CHOSE IT
Strong, Stiff, Light: Pick 3. How do you create a crank that achieves extraordinary stiffness-to-weight in an easily serviceable package that isn't afraid of a rock strike? Take two billets of ultra premium 7075 aluminum. Smash each under 600 tones of force to form two hollow, box-section arms. Then take another billet of that same alloy and machine it into a large diameter BB386 spindle to push the bottom bracket's oversized bearings as far apart as possible for even more stiffness and durability. Sandblast rather than polish all surfaces to pound-out microfractures, machine out required interfaces, and anodize everything for an even harder and longer-wearing finish. On the non-drive side, press the spindle directly into the arm to reduce weight. On the drive side, use a single oversized bolt to cinch the burly spline interfaces of the arm and spindle together for easy crank removal and chainring swapping.
DETAILS
- Precision-milled, thread-together aluminum shell- Premium NSK Japan 6806 stainless steel sealed cartridge bearings
- Built to the open BB386EVO standard
- 135g
Note: Uses SRAM DUB 29mm spindle adaptors where appropriate.
WHY WE CHOSE IT
Our precision-milled, thread-together aluminum shell is strong and stiff to ensure perfect alignment and support our widely-spaced, large-ball cartridge bearings. It's the same $70+ solution that mechanics turn to when the cheap, plastic press fit bottom brackets creak and fail. It adds quite a bit of cost and a handful of grams, but we think the increased durability, efficiency-under-load, and general peace of mind are well worth the investment.DETAILS
- 114 link- Quick master-link
- 259g
WHY WE CHOSE IT
This chain gets the job done with neither fanfare nor fuss. Designed by SRAM to work with all their 1x11 drivetrains, the workhorse PC1110 shifts and wears as well as far more expensive models. Keep it clean, treat it regularly with a wax-based lube, and replace it the moment your checking tool (you do have one, right?) indicates elongation in order to keep your drivetrain quiet, your shifts snappy, and your relatively expensive chainrings and cassettes free of premature wear.
DETAILS
- Stainless steel- 160mm front | rear
- Centerlock
WHY WE CHOSE IT
SRAM's Centerline 160mm rotors offer a blend of power, modulation, smooth operation, and heat-management. We chose a Centerlock interface for easier installation and removal.
Want to build your own OB1 from the ground up? Check out our Frameset Module option.
WHEELS
DETAILS
- RCG44 = Road Cyclocross Gravel 44mm depth
- 22mm internal | 30mm external
- Asymmetric U/V aero profile
- Aero-optimized for 28/30mm tires
- Wide enough to support 40mm+ tires
- Tubeless-ready mid-hook design (compatible with tubes)
- Angle drilling & reinforced nipple seat for durability
- Toray 800/700 blend
- 30 - 90psi
- 430g
WHY WE CHOSE IT
An versatile performer that's aero-optimized for 28-30mm slicks yet wide enough to support 40mm+ knobbies, our RCG44 700C carbon rims let you take advantage of the improved rolling resistance and comfort of today's more voluminous tubeless performance tires without sacrificing aerodynamics. They feature 2.5mm of asymmetry, angled spoke hole drilling, and a reinforced nipple seat for high and balanced spoke tensions, which in turn create a stiffer, stronger, and more durable wheelset. Their tubeless mid-hook design improves impact strength and tire stability at low pressures. With a bias toward speed, these rims are ideal for road, cyclocross, gravel, commuting, and speed touring.DETAILS
- 700c x 30mm- Supple tubeless-ready casing
- Slick dual compound tread for efficiency, durability, and grip
- 335g
WHY WE CHOSE IT
A fast-rolling road slick that isn't afraid of the dirt, WTB's Exposure 30 Road tires employ a supple tubeless-ready casing and a dual-compound tread to offer a great balance of rolling speed and off-pavement capability. Matched to our Aero-Wide Carbon 700C tubeless rims, they're equally suited to all day epics and the the local hammerfest. Run them at 55-90psi depending on weight for optimal performance.
DETAILS
- GT25a = Gravel Trail 25mm internal width
- 28mm external | 18.3mm deep
- Optimized for 45mm+ tires
- Tubeless-ready hookless design
- Asymmetric profile
- Welded seam
- Matte finish
- 425g
WHY WE CHOSE IT
Our GT25a alloy rims are a high performance yet budget conscious alternative to carbon. With an asymmetric tubeless profile and a 25mm internal width, they support higher volume tires at lower pressures for traction and stability in the most demanding conditions, while balancing spoke tensions for improved wheel stiffness and durability. With a bias toward comfort and traction, these rims are great for technical gravel, bike-packing, speed commuting, and speed touring.
DETAILS
- Sits a generous 49mm on our wide 650B rims
- Supple yet robust casings
- Tubeless
- 555g
WHY WE CHOSE IT
The WTB Venture is the perfect all-arounder, with a file tread center for rolling efficiency on tarmac and pronounced side knobs for cornering grip in the dirt. Its supple casing and tubeless compatibility give it a smooth ride that holds up in the most challenging conditions. They inflate to around 49mm on our ultra-wide 650B rims and are best at 20-40psi (max) depending on your weight and terrain.
DETAILS
- GT27 = Gravel Trail 27mm internal width
- 33mm external | 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
WHY WE CHOSE IT
An adventure-lover that's optimized to support popular 47mm gravel tires at low pressures, our GT27 650B rims' wide internal profile enhances tire volume for compliance, traction, and stability in the dirt. They feature 3mm of asymmetry, angled spoke hole drilling, and a reinforced nipple seat for high and balanced spoke tensions, which in turn creates a stiffer, stronger, and more durable wheelset. Their hookless design improves impact strength and tire stability at low pressures. With a bias toward comfort and traction, these rims are great for technical gravel, bike-packing, speed commuting, and speed touring.
DETAILS
- Sits a generous 49mm on our wide 650B rims
- Supple yet robust casings
- Tubeless
- 555g
WHY WE CHOSE IT
The WTB Venture is the perfect all-arounder, with a file tread center for rolling efficiency on tarmac and pronounced side knobs for cornering grip in the dirt. Its supple casing and tubeless compatibility give it a smooth ride that holds up in the most challenging conditions. They inflate to around 49mm on our ultra-wide 650B rims and are best at 20-40psi (max) depending on your weight and terrain.
DETAILS
- Bombproof 18T Star Ratchet engagement system
- (4) 6902 sealed cartridge bearings
- Centerlock rotor interfaces
- 12 x 142mm thru-axle
- 267g
WHY WE CHOSE IT
Rear hubs are notoriously prone to failure due to the extreme loads and environmental stresses they experience. That's why we invested in DT Swiss' rightfully venerated DT350 rear hub. It features the famously strong and durable Star Ratchet engagement system, large 6902 sealed cartridge bearings, tool-less serviceability and convertibility to other axle or freehub standards, and a centerlock interface for easy rotor installation and removal.The DT350 hub is 2.5x stronger, 5x more durable, and 3-5x more expensive than the pawl-based models most brands employ to reduce cost. Whether you're ripping it up on singletrack, touring through a remote wilderness, or simply putting in long miles year after year, these are the hubs you'll want to trust to keep you going.
You can learn more about DT's Star Ratchet engagement system here.
DETAILS
- (2) premium 6802 sealed cartridge bearings
- Centerlock rotor interface
- 12 x 100mm thru-axle
- 136g +/- 5%
WHY WE CHOSE IT
DT350 hubs are renowned for their durability, serviceability, and adaptability. They achieve their light weight without resorting to durability-compromising tricks. What do we mean? Just as there are brands that will use failure-prone aluminum nipples to shave grams, there are others who may spec a hub with tiny bearings and a narrow hub shell to achieve an eye-catching weight. However, those small bearings wear out fast, and that narrow shell may not withstand the torsional loads associated with disc brakes.DETAILS
- Cold forged
- Aero bladed
- Sandvik T302+ stainless steel
- Single length
- 4.3g each
WHY WE CHOSE IT
Why invest so much on so many fancy wing-shaped spokes? Because the same cold-forging process that turns a length of round straight-gauge wire into a light and aero wing spoke also improves strength-to-weight and elastication by realigning the grain flow of the metal and reducing its cross-sectional area. The result is a spoke that can be run at high tension while experiencing less change in tension and thus fatigue with each wheel rotation or impact. Furthermore, unlike cheaper round "butted" spokes that are in fact cold-forged in a similar process, wing,-shaped spokes can be tensioned without inducing spoke wind-up, further extending the life of the wheel.Our rims are asymmetrical, allowing us to balance spoke tensions for even more durability and stiffness while also allowing a single length of spoke to be used throughout the entire wheelset for ease of repair.
DETAILS
- Durable brass
- Resists seizing, splitting, & other failure modes
- Can be trued with tires and rim-tape in place
- 1g each
WHY WE CHOSE IT
Why do mechanics love externally-adjustable brass nipples? Aluminum nipples are a trick used by some brands achieve attention-grabbing weights at the expense of durability and serviceability. Aluminum oxidizes and is much softer than brass, making aluminum nipples notoriously prone to seizure, splitting, and failure. The result is that a simple wheel true can turn into a costly rebuild with new nipples and spokes. Weight savings? Less than 18 grams per wheel.As for the hidden nipples used by some brands, no one envies having to remove your tires, sealant, rim tape, and valve stems just to perform necessary maintenance. Aerodynamic advantage? Zero. Zilch. Nada.
DETAILS
- Each wheel is built by a single, skilled professional
- 2-cross lacing for lateral and rotational strength
- 28 spokes for durability and stiffness
WHY WE CHOSE IT
Strong, durable wheels require more than the best components. That's why we invested having our wheels professionally hand-built and machine checked. With a professional touch-up at 1200 miles and regular check-ups for tension and true, our wheels will continue to perform year after year.
Have a question? Check out our FAQ or reach out to us directly at support@thesis.bike to talk to a real human. We're always happy to talk bikes.
Geometry
All figures in millimeters unless otherwise indicated.
What they're saying about the OB1
"I've been playing bikes for over twenty years now. This bike inspires a mix of speed, fun and confidence I've never felt before. I had high expectations for this bike, and I’m happy to say it has blown me away." - Rachel C.
“I've been loving my OB1. It's opened up a whole other world of riding for me with many new places to explore. Every time I'm on a new trail, I'm blown away by the beauty of the new places I'm discovering, excited to go out and try a route I've never done before and very thankful I have the OB1 to take me to all these places I previously couldn't go to before.” - Andy W.
Find your perfect ride
THE OB1
Starting at $3299
Our original legendary all-road gravel bike.
THE OB1 AXS 1x
Starting at $4299
The best of the OB1, now with electronic AXS 1x.
THE OB1 Custom
Starting at $3299
The best of the OB1, your way.