The Doppo mountain bike frame, developed as the third and latest in the Doppo series, was thoughtfully created with the intention of “going alone”.

SimWorks believes that the most important consideration of “going alone” is above all- trust. There’s the trust that your equipment will carry you as far as you wish to go and then back again.  And there’s the trust that the details were ironed out to produce a machine that you can feel playful with and connected to. 

How did we want the Doppo mountain bike to be used? What kind of people will trust Doppo to  be a worthy companion? The conclusions drawn from these critical questions gave rise to a timeless design infused with some modern versatility and flare. First and foremost, the durability and reliability of the frame should provide ease of mind. Furthermore, the overall performance of the machine is a blend of characteristics meant to lend themselves to versatility in riding styles and environments. Simworks believes that by placing an equal emphasis on dependability and versatility, a more reliable and enjoyable Doppo bike would be created.

The main tubing of the Doppo MTB uses the world-famous Tange high-quality chromoly steel tube set-similar to our Doppo ATB.  Emphasizing front end rigidity, the 44mm head tube provides a modern MTB standard for equipping the bike with either the included rigid Tange fork, or your favorite suspension fork. Doppo MTB frame is equipped with an original disc mounting system with a unique shape providing for easy adjustments for owners and service people.

Specified with a 73mm JIS threaded bottom bracket shell and 148×12 rear Boost TA spacing, in addition to a 110mm Boost-spaced fork provide the bike with a stable pedaling platform and an axle spacing that lends itself to strong wheels accommodating wider footprint tires. In addition, 2 standard bottle cage mounts on the frame and an additional 3-hole on the underside of the down tube allow installation of an oversized bottle or cargo cage, etc. A port for an internally routed dropper post adds to the trail-ready credentials. 

The original fork produced by Tange is especially designed in concert with current bikepacking/trail standards. Drilled for a diving-board plate and with dual 3-pack bottle boss mounts that you could piggy-back rack struts to, the fork will accommodate a compact front rack with ease. The Chromoly fork is at home with the on/off roads that inevitably occur during your usual exploration ride. No one is going to tell you not to mount a basket to the front end and aimlessly wander from town to the forest. 

When you want to enjoy a more enjoyable trail ride in Satoyama, or Coyote Wall, Simworks believes that most cyclists will prefer the use of a suspension fork. Of course, the Doppo MTB is designed with the option to equip the front end with moderate suspension.

By installing a fork with approximately 120mm of travel, you can use it as a plush trail bike. In conjunction with a slightly longer wheelbase and capacity for 27.5 tires up to 2.8”- the Doppo MTB oozes stability and mild trail manners. Swapping between rigid and suspension minimally impacts the bike’s geometry. 

As with the beloved Doppo ATB frame, the new MTB frames are produced by Shin Hattori, an accomplished builder based in Aichi prefecture. Shin has demonstrated his skill and care in each of these frames.

Built in small batch runs- each frame is mitered, milled and welded methodically, and then hand-finished to tight tolerances.

A well-designed frame crafted by an experienced and thoughtful frame builder can be the greatest companion when facing the task of “going alone”- whether in the mountains or on forgotten roads.

Born as a trail bike, the Doppo MTB is not a bike that pursues outstanding speed and intense action, but as a spirited mountain bike- to embody the concept of the Doppo series, “to go alone”, the Doppo MTB is a tool for exploration- both within yourself and in the natural world.

SIMWORKS / Doppo MTB Frame Set

Size : Medium / Large
Color : Blue
Price : $1880.00- (USD)

Main Specifications

Uses Tange Chromoly Steel Tube Set

  • 44mm head tube
  • Light weight and high strength TIG welding
  • Recommended suspension stroke: 120mm stroke for 27.5″
  • Can be used with up to 180mm disc rotor
  • Rear 12mm×148mm BOOST
  • Max tire clearance: 27.5 x 2.8″/ 29 x 2.4″
  • 73mm JIS Threaded BB Shell
  • Seatpost size: 30.9mm
  • Seat clamp size: 34.9mm
  • Front chainring single up to 34T
  • Seat tube has holes for internal routed dropper post
  • Eyelets compatible with anything cage under the down tube
  • Front and rear thru axle included
Seat Tube Length C-T(mm)430460
Effective Top Tube Length(mm)585610
Reach (mm)413436
Stack  (mm)593598
Standover with 27.5×2.8″(mm)749761
Head Tube angle (deg.)69.569.5
Head Tube Length (mm)110115
Seat Tube angle (deg.)74.074.0
Chain Stay Length (mm)440440
BB Drop (mm)6060
Wheelbase (mm)10981123


*Tange fork included with the frame set can be purchased separately. However frame is priced only for sale with included fork


A stylish, segmented chromoly fork with a wide range of eyelets, ideal for bike packing, and trail riding, is a multi-purpose rigid fork manufactured for that discerning rider looking for a solid front end connection. 

Will accommodate up to a 27.5″ x 2.8″ or 29″ x 2.4″ tire 

By using a standard oversize (1-1/8”) for the steerer size, we are leaving the option open for riders with straight 1-1/8″ head tube bikes to spec the Doppo MTB fork.

Simworks contracted Tange- a globally recognized manufacturer, to construct the fork.



ED Coat : $260.00- (USD)
Black Powder Paint : $330.00- (USD)

Fork Specifications
TANGE-Doppo original segmented fork
Axle – crown base: 465 mm
Rake value: 47mm
MAX tire clearance: 27.5×2.8/29×2.4
Material: Tange chromoly tubing
Column length and crown size: 280mm / 1-1/8” straight

Axle standard: 15mm x 110mm BOOST spacing
Reference weight: 680g
Eyelets compatible with 3-hole cage on both fork legs
Thru-axle included

If you have any questions regarding various SimWorks original products, please feel free to contact us at: contact@sim-works.com