The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)
The OB1: Bring Your Own Drivetrain (BYOD)

The OB1: Bring Your Own Drivetrain (BYOD)

Regular price $2,799.00

DETAILS


Bring your own drivetrain to the OB1.

Part of the reason so many people love the OB1 is because of its customizability. Now you can get it with a drivetrain of your choice.

The OB1 BYOD includes everything but the drivetrain components and brake calipers, and comes unassembled. Work with your local mechanic to source the perfect drivetrain components you want for your ride.


Lead time: 3-5 weeks
How it works

What is not included?

  • Shift/brake levers
  • Brake calipers
  • Derailleur(s)
  • Crank & chainring(s)
  • Cassette
  • Cables/housings
  • Lever for dropper post (if chosen)

What is included?

  • Frame hardware for mechanical or electronic 2x
  • Bottom bracket (BB386EVO)
  • Rotors (160mm)
  • Chain
  • Everything else on the OB1

What drivetrains do you recommend?

Drivetrains that will work:

  • SRAM 1x Road/Gravel (Apex1, Rival1, Force1)
  • Shimano and SRAM 2x mechanical road*
  • Shimano mechanical 1x**
  • Shimano Di2 1x and 2x***
  • SRAM eTap AXS 1x and 2x

*We strongly suggest using a clutch rear derailleur. For Shimano use RX. For SRAM use GX 2x10 (works with all 11-speed road shifters).
**Using Wolftooth Tanpan with Shimano MTB rear derailleur and road shifters
***Use either RX805 or XT/XTR Di2 rear derailleur.

Drivetrains that will not work:
  • SRAM eTap Pre-AXS (Front derailleur battery interferes with 650b tires)
Maximum Chainring Clearance:
  • 1x: 46 teeth (running on 45.5 mm chainline)
  • Oval Chainrings must not exceed 46 teeth at maximum ovality
  • 2x: All combinations (sub-compact through 53,39)

WEIGHT: 18 lbs - 20 lbs

 


 

Specs

Chassis    |    Cockpit    |    Wheels


Every component has a story. No placeholder parts or marketing gimmicks here. Every detail, down to the bolts and bearings, is selected for the optimal balance of performance, durability, and serviceability. Click on the name of each component to learn more about why we chose it.

To learn more about our approach, check out how we built a high-end carbon dream bike for $2999.

 

CHASSIS

DETAILS

- Endurance road geometry
- Clearance for 650B x 47mm or 700C x 40mm tires
- Discreet mounting points for: (5) bottle cages, racks, fenders, 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 -equipped carbon steerer
- Clearance for 650b x 47mm | 700c x 40mm tires
- Discreet bosses for fenders, racks, and (2) bottles
- 12mm thru-axle dropouts
- Reinforced Toray 800/700 carbon construction
- 545g +/-5% fork, 45g SteerSafe (eliminates compression plug)

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  (+$199)
DETAILS

- Infinitely adjustable
- Premium 7075-T651 aluminum construction
- 1-piece forged upper with 2-bolt head
- Clean integrated cabling
- Proven, serviceable design
- Replaceable cartridge
- Front-shifter actuated
- 495g +/-5% (405/105) + 90g cable set

IMPORTANT: Dropper posts have a limited adjustment range and available options may not work for all riders (particularly those on smaller frames). Please check fit guide before selecting.

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 back and low while 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 downhill sweeper, a dropper is an option well worth considering.

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 2014-T6 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

- Precision-milled aluminum shell
- Premium stainless steel sealed cartridge bearings
- Wide BB386 bearing stance

WHY WE CHOSE IT

Cheap plastic "Press Fit" bottom brackets need to die. Bottom brackets experience extreme loads under harsh conditions. Yet despite years of complaints, many companies are still pressing cheap plastic "Press Fit" or "PF" BB shells directly into their frames to cut cost without you noticing. This practice predictably results in poor bearing alignment and support, increased friction under load, accelerated wear, creaking, and in extreme cases even irreparable damage to the frame.

Our precision-milled aluminum bearing cups thread into each other to create a stiff, robust, and perfectly aligned shell to support our widely-spaced, large-ball cartridge bearings. It's the same $70+ solution that mechanics turn to when others' Press Fit BBs fail. Sure, it adds a few grams and quite a bit of cost, but the result is an efficient-under-load, durable, and easily serviceable BB that won't let you down.

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.

 

WHEELS

THESIS Aero-Wide Carbon 700C Wheels

DETAILS

- 44mm deep | 30mm wide | 22mm internal
- Hybrid U/V aero profile
- Aero-optimized for 28/30mm tires
- Wide enough to support 40mm+ tires
- Tubeless-ready mid-hook design (compatible with tubed tires)
- 2.5mm offset, angle drilling, & reinforced nipple seat
- Toray 800/700 blend with graphene infused resin
- Max pressure 90psi
- 410g +/- 5%

WHY WE CHOSE IT
An all-arounder that's optimized for 28/30mm slicks yet wide enough to support 40mm knobbies, our U/V Aero-Wide 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 offset, 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 and durability
- 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.

THESIS Ultra-Wide Carbon 650B Wheels

DETAILS

- 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%

WHY WE CHOSE IT
An adventure-lover that's optimized to support popular 47mm gravel tires at low pressures, our Ultra-Wide Carbon 650B rims offer maximumized tire volume for compliance, traction, and stability in the dirt. They feature 3mm of offset, 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 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

- WTB Byway 650B x 47mm
- Supple skinwall casings
- 525g

WHY WE CHOSE IT

A gravel grinder that can hang with the roadies on the way to the trail, WTB's Byway is a dirt-lover's dream. They inflate to around 49mm on our ultra-wide 650B rims and are best at 25-55psi depending on your weight and terrain.

DETAILS

- Famously bombproof 18T star ratchet engagement system
- (4) premium 6902 sealed cartridge bearings
- Centerlock rotor interface
- 28 hole J-bend flanges
- 12 x 142mm thru-axle
- 267g +/- 5%

WHY WE CHOSE IT

Extreme loads and environmental stresses make rear hubs notoriously prone to failure. That's why we invested in DT Swiss's 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.

This hub is more than twice as strong, 5x more durable, and 3x more expensive than the traditional pawl-based models some brands employ to reduce cost, while weighing only a few grams more than the under-built models often employed to achieve attention grabbing weights at the expense of durability.

Don't be fooled. We've reviewed the testing data, talked to mechanics, and have been abusing DT Star Ratchet hubs ourselves for over 15 years. Whether you're ripping it up on singletrack, touring through a remote wilderness, or simply putting in long miles year after year, these are hubs you can trust to keep you rolling.

Learn more about DT's Star Ratchet engagement system here.

 

DETAILS

- (2) premium 6802 sealed cartridge bearings
- Centerlock rotor interface
-  28h J-bend flanges
- 12 x 100mm thru-axle
- 136g +/- 5%

WHY WE CHOSE IT

DT350 front hubs are famously durable, serviceable, and adaptable. They also 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 (Sweden)
- J-bend
- Single length
- 4.3g each

WHY WE CHOSE IT

Why invest so much on so many fancy bladed spokes? Because the same cold-forging process that turns a length of round straight-gauge wire into a light and aero bladed 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, bladed spokes can easily be built into a wheel and later trued without inducing spoke wind-up, further extending the life of the wheel. To cap it off, we went with a single length of J-Bend spoke to make it easier to find should one fail, and avoided low spoke counts to make it unlikely one ever will.

DETAILS

- Durable brass
- Resist 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 uber expensive 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.
 

Shop now

 


 

Geometry

 

Need help finding the right size? Check out our sizing guide.

Frame Size XS S M L XL
A Reach 356 363 378 388 403
B Stack 521 551 571 595 614
C Head Tube 110 138 155 180 200
D Effective Top Tube 515 531 547 570 591
E Wheelbase 987 995 1007 1025 1046
F Front-Center 578 586 598 616 637
G Head Tube Angle 70° 71° 72° 72° 72°
H Fork Offset 51
I Fork Axle to Crown 385
J BB Drop 73
K Chain Stay 420
L Seat Tube Angle 73°
M Seat Tube 440 470 500 530 560
Standover (Midpoint of TT) 720 750 775 805 835
Default Handlebar (C-C) 380 400 420 420 440
Default Stem (7°) 80 90 100 100 110
Default Crankarms 155 160 165 170 175
Default Seatpost 350 350 400 400 400
Dropper Seatpost
Default Length | Travel 315 | 70 360 | 90 405 | 110 405 | 110 405 | 110
Default Saddle Height Range 610 - 660 660 - 735 705 - 790 735 - 820 765 - 850
Alternate Length | Travel 360 | 90 315 | 70 360 | 90 360 | 90 360 | 90
Alternate Saddle Height Range 650 - 705 640 - 690 690 - 750 720 - 795 750 - 825


All figures in millimeters unless otherwise indicated.

 


 

Questions? Get a one-on-one consultation.

We know that finding the perfect bike can sometimes be overwhelming. That's why we offer free personal OB1 consultations over email, phone, video, and in person.

Have a question on fit? Need help choosing the right build kit or configuration for how you ride? Let us help. We'll treat you like a friend and help you find the best bike for your needs, regardless of who makes it.

To get started, schedule a phone call or drop us a note at hello@thesis.bike.

Book a consultation

 


 

What they're saying

“A quiver killer.” - The Gravel Ride Podcast

“A highly attractive build.” - Gravelstoke

“This thing is a no brainer. It’s what I wish an Open or an Ibis Hakka would be. You get way more features, and it costs way less.” - Alex L

“Usually a new bike feels a bit foreign, but the OB1 made sense to me from the second I strapped it on. The bike was an intuitive fit from the first pedal stroke.” - Joshua S

Grab a test ride



 

How we built a high-end carbon dream bike for $2999

Direct from the factory

The bicycle industry is pretty old school, and that means a lot of middlemen. We skip the middlemen and work directly with the top manufacturers behind the leading brands. That's how we cut the price in half.

Every component matters

No placeholder parts, marketing gimmicks, or corner-cutting. If we wouldn't put it on our own bikes, we won't put it on yours. We built the OB1 like a mechanic would: for performance, serviceability, and durability.

See our approach

 

 

Direct from top factories

Every component matters

Radical inclusion

30 day return policy

No bull crash replacement

Personal one-on-one consults

 

Shop now