Blackbuck G2 frames are available in three sizes for 29″ wheels. Forks (rigid) come in three lengths to vary steering character. Head tube and seat tube angles are designed to perform as one would expect from a range of 74 degrees (435mm length fork) to 70.5 degrees (100mm travel at ride height fork). You can tune the character of your Blackbuck to suit your needs.

Blackbuck uses a split shell Eccentric Bottom Bracket that serves to tension a one-speed chain in the simplest manner. Due to a very close fit between the EBB insert and the BB shell inner diameter, the Blackbuck performs in silence with disassembly to grease mating surfaces easily done if needed. The EBB can be positioned to suit your choice of fork length.

Blackbuck frames can be fitted with a derailleur hanger if a multi-speed is what you want. There are cable stops on the down tube only. Full length cable housing and zip-ties are needed to run gears. (A post illustrating details is forthcoming.) The derailleur hanger is steel (which can be retro-fitted to G1 Blackbuck frames) and is mounted with just one small screw. The axle holds the hanger from rotating during use.

Blackbuck is intended as a mount that will take you anywhere you choose to go. 29” wheels roll faster than smaller diameters due to a longer tire contact patch (less friction) and get greater lateral traction. A bigger wheel rolls over obstacles more easily than smaller wheels due to approach angle, and the inertia contained in big wheels helps to smooth out small bumps at speed. With more control and a tuned ride you will experience greater joy in the big wide world of riding. Let the Spirit take you!





For a look at the geometry of each OS Bikes Blackbuck in all three sizes, including fork options, click on each pic. Thumbnails are arranged as follows: By height w/rigid fork and suspension travel in each size, left to right, beginning with Small. Note: axle to crown defines how ‘tall’ the rigid fork is as measured from the center of the front wheel to the bottom of the head tube. A smaller A/C number results in a lower front end and steeper head tube angle.


Small 80mm

Small 100mm

Small 435 A/C

Small 455 A/C

Small 475 A/C


Medium 80mm

Medium 100mm

Medium 435 A/C

Medium 455 A/C

Medium 475 A/C


Large 80mm

Large 100mm

Large 435 A/C

Large 455 A/C

Large 475 A/C

Order & Pricing

OS Bikes uses Paypal for money transactions. To purchase an OS Bike product, you will need to log in to your Paypal account (or establish one…free and easy to do) and submit the payment to

Pricing is as follows:

Blackbuck steel SS Frame Only = $600

  • CroMoly steel
  • Available in three sizes
  • Split shell Eccentric Bottom Bracket
  • Can be fitted with a derailleur hanger
  • Affordable price

Steel Rigid Fork = $100

  • 435mm (S435)
  • 455mm (S455)
  • 475mm (S475)
  • All have a 51mm offset
  • See sizing for details

Thanks so much for your order and we know you will be stoked about your new bike!