OS Bikes Blackbuck frame

Twenty Nine Inches will be testing this frame (and a rigid fork) in the upcoming months from OS Bikes. As we have reported before, the frame only comes in one size, and it just happens to fit me. Since that was the case, I went ahead and ponied up for the frame and fork option. (The Blackbuck is also available as a complete single speed with a Reba suspension fork.)

OS Bikes Blackbuck seat tube/stay detail

The obvious feature of the Blackbuck is the gracefully arching seat stays, but there is a lot more going on here. The frame appears to be very well constructed and attention to detail is evident throughout. The attachment point for the seat stays to the seat tube is a good case in point.

Disc caliper tabs

The chainstay mounted disc brake will be another unique feature and the minimalistic look is different from the usual braces and whatnot that seat stay mounted calipers usually entail. The drop outs are also pared down versions of the old Breezer type and look dainty compared to alot of drop outs I’ve worked with on 29″ers. (Note: The two holes in the driveside drop out are for the optional pinned derailluer hangar which comes with the Blackbuck.)

Detail of split shell EBB

You have your Bushnell type EBB’s and your “pinch bolt” type EBB’s, now I’d like to introduce you to a split shell EBB! Yep, it is an old idea that has been around a long time, and the Blackbuck utilizes it. I’ll be interested to see how it holds up to off roading and if the dreaded creaks come calling. Only time will tell!

Serious reinforcement!

Here is the idea Mark Slate, OS Bikes creator, had for a head tube reinforcement. His belief is that this needs to be done due to the ratio of short head tube to long fork leg that causes more leverage to be exerted on the lower part of a 29″ers head tube. I don’t think I’ll be having a problem here!

I’ll be setting the OS Bikes Blackbuck up with parts swapped over from another single speed that I own. I will be using several different forks on the Blackbuck to acertain the effects of different off sets and axle to crown lengths on the handling of this particular 29″er. Specifically of interest will be the 440mm axle to crown Blackbuck fork, which at first glance looks to be a wrong choice for this bike. I have been assured that it works really well, so I will be very interested in the results of using this fork/frame combination. Other forks I will be testing on the Blackbuck include the Reba, an On One Superlight Carbon fork, and a RST M-29 80mm fork.

Of course, I’ll be passing along my thoughts on the Blackbuck and most importantly….riding it alot!

Stay Tuned!