Several months ago I started looking seriously at creating ‘the ultimate fatbike’. I knew it had to be 2 Wheel Drive and I knew it had to be full suspension, but I had no idea where to start. Once I saw the Quigley Full suspension fatbike from Bikes Direct I fell in love.
Before Doug’s 100mm axle conversion for the BBS02 had even come out, I was planning on mounting a BBS02 on this bike even if I had to grind down the BB and space out the chain-wheel to clear the rear tire.
I couldn’t buy the Quigley FS till spring, so I did what any ebike obsessed person would do, I started buying a bunch of fat-bikes. My first fatbike was a Borix X9 from Bike Island, a site where they sell all the dinged up bikes that normal people don’t want. I got a black 22 inch fatbike for $750 that had a bunch of scratches on the downtube. This is the nicest fatbike I have ever purchased to date. The rims are 80mm instead of the narrower 50mm that the cheaper bikes direct fatbikes come with. The brakes, derailer, cassette, chainwheel, chain and shifter were all good enough to keep. I built up two 500watt qq motors from elifebike which burned out the 3rd time I had them out. I ran them as All Wheel Drive with the stock 17A sketchy chinese controllers. It was the clutches that died, they were just not powerful enough for fat-biking in the snow. I was devastated because I had put about 40 hours into the wheel builds and had built them up about 8 times before I got it right. I put the bike on the work shelf and ordered my next bike in a long line of bikes. Meanwhile I only had my old Full Suspension 26er with a BBS02 that I rode every day in the woods in the snow for several weeks and still had a really great time with as long as it wasn’t over 6 inches deep.
The Bullseye Monster looked from the pictures to be a perfect donor for a BBS02 and an angle grinder to the BB but when the box arrived I was disappointed to find out that the frame I got looked nothing like the picture and instead the chain stays went right into the BB without any room for the BBS02 gearing reduction wheel. Back to square 1.
Salvation came in the form of Doug’s 100mmm kit from California Ebike. I immediately bought 3 kits right as they came out and set out to start converting axles on my existing BBS02s. The conversion kit worked great and only added about 1lb to the weight of the BBS02 drive unit. The only problem I had was the chain would fall off to the inside of the chain-wheel and get stuck if I tried to shift more than one gear at a time. You also need to shift gears with the power off or you risk breaking your chain or skipping gears.
To keep the chain from getting wedged behind the chainring the Nstop chainguards work pretty well. The only problem is that it is too far of a reach from the seattube to the chainring so the metal guard has to be bent. The chainguard doesn’t keep the chain from coming off, but it does keep it from getting jammed down in between the chainring and the housing and bending your BCD104 adapter.
The biggest problem that I see with creating a Full suspension Fatbike with is the inability to mount a standard hub motor (Upgraded Mac) on the front wheel due to the proliferation of the through-axle movement. The Rockshox Bluto, which is the only fatbike fork on the market right now only comes with a through-hole axle and completely non-standard 150mm spacing. You would need to cut slits in the bottom of the fork and epoxy Endless Sphere’s Dr Bass Torque arms to the inside of the forks to mount a standard Rear Upgraded Mac Motor from em3ev to the front fork.
My latest BBS02 Bikes Direct build is out of a singlespeed Deadeye Monster and the results really blew me away. The build thread for that bike is here. This configuration is highly recommended and you can do the conversion from start to finish in about 4 hours.