Thursday, October 10, 2019

Wide Gliders Part 2

The OS Bikes Blackbuck with the "new" wheels.
Well, this has been a crazy beginning to the week. I had plumbing issues (resolved) and a car to get serviced, plus I had to commute by bike after the car was dropped off and to go get it. Then.....well, you get the picture. It was one of those busy days which left very little time for bicycle stuff.

This did leave me time to finish the wheels and get rotors, tires, and a freewheel mounted to the rear wheel. So, the Blackbuck is up and functional again. The Blackbuck may not be familiar to you, so let me give you the background on it, if you are not familiar with this model.

The Blackbuck is an OS Bikes model. The "OS" stands for "Of Spirit", for whatever that is worth to you. I think it is significant. Anyway.... The brand only had one model, the Blackbuck, and the brand only made two production runs of the Blackbuck. Mine is from the first run produced in late 2006, which came out in 2007, and that is when I got mine. OS Bikes was the brand belonging to one of Wilderness Trail Bike's founders, (WTB) Mark Slate, a Mountain Bike Hall of Fame member, designer of many famous tires and saddles, and is still working as a designer of tires and saddles to this day for WTB.

The first run of Blackbucks, as I was told, was 500 pieces. These were CroMoly steel, and were sold as either a frame set with a special, very short, very long offset fork, or as a complete with the OG Reba, which was a bit unfortunate, since by 2007 everyone was all buzzing about longer offset forks, and the original Reba still had the old 38mm offset. So, the original Blackbucks were hard to sell.

Slate made another run of these under the OS Bikes moniker around about 2010, in a different factory, with a different paint scheme from the originals. These were slightly different, had a tiny bit less tire clearance, and for whatever reason weren't quite as well liked, which I suppose had something to do with OS Bikes still running "Gen I" 29"er geometry.

The freewheel is a White Industries one as well as the hub.
So, take a look at that head angle! This looks impossibly steep these days, but let me tell you, this bike slices up twisty single track like nothing out there on today's market. The head angle is nominally 72° with a fork suspension corrected for 80mm of travel. The rigid Blackbuck fork was even more radical! With an axle to crown measurement of something like 430-ish millimeters, and an offset of 51mm, this made the head angle of the Blackbuck a super-steep 74°!

Amazingly, this was how Mark Slate liked to ride his personal Blackbuck on the super steep trails around his home in Marin County. I tried it around here- the super steep set up- and while it was blazing quick in terms of handling, it required such attention to riding that it was no fun. You had to be on your game or you were crashing. So, I ended up letting my co-worker, Joe, have the fork for his Xtra-Cycle conversion.

The Blackbuck was the bike I did my "Fork Tests" on where I ran forks from 420mm AC to 510mm AC both rigid and full suspension. My favorite fork on the bike was the one I have on it now- a Bontrager Switchblade fork with 470mm AC and 38mm offset. Another odd thing about this bike is the crank set. It is square taper, (of course), and vintage Sugino from the late 90's. I had it anodized by some local guy that was doing this back over a decade ago around here and it turned out really nice. Perfect antifreeze green! I had these little chi-chi caps made from alloy that screwed over the crank bolts from back in the 90's and I used those on there as well. Now for the weird part- they are 170mm long. Something about short cranks, 29"ers, and single speed.

So, this bike has been in and out of rotation in the stable for years. I haven't been riding it a lot over the last several years, since I have been focusing on gravel, but I love this bike. I have always just really liked how it handles single track around here. Of course, another thing I really like about it is that it is a dedicated single speed. No derailleur hangar here! Although, you could get a pinned hangar from OS Bikes and make the bike into a geared bike. I never did any of that malarkey!

One other thing this bike has, and which was a foreshadowing of the "three pack boss" idea, is the triple bosses on the down tube which were meant for a Blackburn Bomber Cage. I happen to have a Bomber Cage too. The thing is, it's tough to find a water bottle that'll fit the dang thing these days! But that is a neat feature of this bike too.

So, anyway, there are the wheels. The rear Kenda Honey Badger 2.4" tires barely clears, so I may look for a 2.25"er to put on these wider rims. If I keep this for drier rides, it'd be alright, but we'll see. I'd probably be best to switch out the rear tire. Oh! I taped these for tubeless but I stuck tubes in there for now. I need tires that are easy to get up and running after long periods of no usage. So, tubes it is.

That's a wrap on this project for now. Hopefully I can get into the woods soon and ride it.

1 comment:

S Sprague said...

GT, I was wondering what happened to the OS! Nice to see it up and running. I like the colored lacing of the wheels! Gives me something to think about for my next wheelset. I'm sure it looks better in person.
I've been running 170 mm cranks on all my 29ers even my 27.5+ bike! Maybe I'm an odd duck! Ha! Yeah, that headtube angle is steep! I thought my Moots Mooto-X had a steep headtube, 72+. So interesting how the 29'er geometries have changed! Look forward to some reports on your Blackbuck adventures!