“Young fool. Only now, at the end, do you understand. Your feeble skills are no match for the power of the dark side. You have paid the price for your lack of vision.” – Emperor Palpatine
I wanted to do a mid drive build that would be dirt cheap and still work equally well both on single track and on the road as a commuter. In the end, I created a monster that performs well in both arenas, but is the master of none. The old school nuvinci N171 performed well even under tremendous amounts of power, but it was just too heavy to be that much fun in the woods. The Dark Side build did well on the road, but the self-steer of the Mission Command 4 tires and the shorter wheelbase, when compared to Burning Chrome, made this ebike feel a little more squirrely on the road than the solid steel cruiser frame of the Soul Stomper. The Dark Side also can’t hold a candle to Burning Chrome when it comes to how awesome it looks on the street. I guess not every ebike build can be a winner, winner chicken dinner.
I still learned a lot from this build and The Dark Side still performs way better than anything you will ever be able to buy in this price range in the factory-built ebike market.
The older version of the Deadeye Monster single speed from Bikesdirect shipped with a 68mm BB, 50mm rims, 100mm front dropouts and crappy Mission 4 tires. The newest version ships with a much more standard 100mm BB, 80mm rims, 135mm front dropouts and the much-less-crappy Mission Command 4 tires for the same low price of $399 shipped right here. To date, I can find no deal for a fat bike that really compares to that. For an aluminum framed fat bike that doesn’t suck for less than $400 shipped it’s likely the best deal you will find, and I’ve spent a lot of time looking. If you are considering an IGH setup like the Nexus 3, Sturmey Archer 3 speed or a CVT like the N380, N360, N330 or N171 then this is the budget donor bike to use as it has adjustable horizontal rear dropouts. The Deadeye Monster does not have the right rear axle tensioning M5 bolts for installing a IGH or CVT, but you can buy them at McMaster Carr or any hardware store. Make sure they are really long and have lots and lots of thread on them, then screw them in through the existing holes in the front of the dropouts.
The Cyclone 3000W drive system with the 100mm axle kit mounted to this frame without any real issues (instructions are here). I was worried that the giant chainring would interfere with the chainstay, but the chain wheel on the cyclone mounts on the crank arm and is pretty far away from the frame of the bike. Although the chain line was pretty whacked, the chain has yet to fall off even once. I started out with a 32T chainring on the front but then switched to a 36T chainring so that I could increase my top speed to around 35mph with a steady slow pedaling cadence. I started out with an 18T freewheel but that quickly self-destructed on my second trail ride so I replaced it with a 18T steel fixie instead. The cyclone comes with a double freewheel so the fixie works well with this setup and it will never break. White industries makes nigh-indestructible freewheels, but I couldn’t see springing $100 on a freewheel, and the 18T steel fixie was only $15 brand new on ebay.
On the Cyclone kit I had trouble with the 5 bolts on the chainring that mount the giant steel chainring to the freewheel on the pedal. All 5 of those hex bolts need to be removed and fitted with blue Loctite. In fact, pretty much every single bolt on the Cyclone should be removed and fitted with Loctite so that they don’t work their way free. I also recommend bagging the giant black tie wrap which also broke on my first time out, and replacing it with a couple of cheap stainless hose clamps from your local hardware store. They should run about $1 each and they do a much better job of keeping the motor from twisting on the motor mounts under load.
The 3000W Cyclone performs well in deep snow, always seeming to have enough power. I wish I could say the same for the Mission Command 4 tires, if you want to ride in the powder you will need to use chains.
The Cyclone drive system works much better at 52v than at 48v. It’s important that you have a pack that can put out at least 40Amps continuous, or you won’t be getting all the power that this drive system can offer. Lunacycle has 60v packs available now and is working on designing some 72v packs in the not to distant future. The Cyclone is geared very low and produces a lot of power at slower pedaling cadences. The N171 weighs in at almost 9 lbs and it adds a lot of rotational momentum to the rear wheel. My feeling is that while the N171 seems to be able to take the power of the Cyclone kit, it is ill-suited to singletrack trail riding mostly due to the fact it is just too darn heavy. If I was to do this build again I’d probably opt for a Nexus-3 IGH instead of the N171. The range would have been far less (186% vs 350%) but it would have been about 7 lbs lighter in the end.
The N171 was discontinued 6 years ago but there still seems to be plenty of them floating around the internet. I bought mine brand spanking new last year from someone on Endless-Sphere for $100 +$28 for shipping. I’ve had no issues with mine, but it was quite a pain to install. The new N380 shifter is much less trouble to install and configure than the N171 system is. Once you figure it out it makes sense and the manual is here, but it took me about an hour of serious head-banging to get it right.
This build easily goes over 35mph on the flats with a 52v pack that can put out 40 amps. It also seems to scream up most hills. There are several serious problems with this build though.
- When you go as fast as you can up hills you consume massive amounts of power. You can burn through a 20Ah pack surprisingly fast on a big hill.
- When you go over 35mph for extended periods you consume massive amounts of power. Tire friction and air resistance combine to make a formidable foe.
- The bike goes wicked fast on slight downhills at full power. No cop would let you just scream by without stopping you and writing you a ticket OR just telling you how awesome he thought your unlicensed, unregistered, uninsured ebike was. This ebike is not even remotely street legal in any state.
- I’m not sure how reliable the Cyclone drive unit is for long distance commuting. Time will tell.
- It seems to do decent on singletrack, but the back end feels pretty heavy with the N171.
These things are to be expected when you build a bike that is not necessarily a special purpose ebike. If you can only have one ebike, and you need something cheap that goes fast and you can ride it in the woods, then this might be a decent build for you. I recommend that you spend a little more and build a dedicated trail bike and a dedicated commuter. In the end, you will be happier for it.
Welcome to The Dark Side. We have cake. (The cake is a lie)