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| the FitNord Rumble 300 ready for action |
Cargo trikes/bikes are handy, but there are more efficient ways to transport just yourself. Our starting point was Danish-style straight-bar bikes, beasts of burden, one per person. Then there is a cool old bike at the fleamarket, then you need a bike to stand at a train station, then you need a bike while you fix another one, an e-bike would help, a fatbike looks fun, etc. Somehow over the years we ended up with 10 working adult bikes plus two niholas. (I'm a geek, almost all the bikes are substantially tweaked.)
Fatbikes are interesting. If you don't know, they have tires 4-5 inches wide (lets say 100-120mm) and are usually sort of old-school MTB is design. A bit upright but not too much, comfortable to sit on for long periods. (There are "cruiser" fatbikes, but those don't look like serious transport. YMMV.) One fatbike application is some mix of mountain-snow-exploration-biking, so a good number of fatbikes come with all the mounts for fenders and racks, and without flashy nonsense like a suspension fork. Basically, its easier to find a fatbike to set up as a no-frills commuter than a MTB.
In 2023 I bought a used (and inexpensive) fatbike and built it up with a Shimano Alfine 8 hub, permanent lights, rack, and full fenders. Great bike, been riding it to town all winter, worth a blog post. This contributed, along with a snowy and messy winter, and the near-failure of an e-bike ("snowy and messy winter"), to a situation where we were open to trying an e-fatbike for getting to work. Also this coincided with a local-ish bike brand putting their e-fatbikes on a substantial almost-spring sale. So now we have a FitNord Rumble 300 from the model year 2022, in 2024.
Let us begin with the company (FitNord). They are based in Finland, but there is no doubt that a lot of the product is straight from China. This is both good and bad. The good part is a lot of bike for the money, especially at those sale prices, the bad part is that some elements are done to a minimal standard. I guess the Finnish part is what gives us a purposeful fatbike ready to mount the full-coverage fenders (purchased separately), the rack (also purchased separately), and even equipped with a solid kickstand. Wowa. (Their sales materials could have been better, I didn't even know there was a kickstand, but I was super-pleased when I laid eyes on it.) IMO this right here is a huge recommendation: its a total commuter e-fatbike, period. Beyond the basics, many parts have been done very well.
There were a couple of quality issues, and I'm fortunate to have some competence dealing with them. First, the wiring for the "e" part of the bike. Whoever pulled those wires just didn't care. They were laid so that the thin inner wires were exposed to rough-cut edges on the frame, and also they were hanging out (sleeved) under the bottom bracket unnecessarily. I fixed this with some light disassembly and cable-pulling. Also I suspect the wires at the top were arranged so that rainwater could run down them into the connectors, so I squeezed in a big blob of bathroom silicone where the sleeved cables passed through the frame (internal, not visible from the outside). I literally began my ownership of the bike with disassembly and improvement, before turning the power on. The cherry on top is a doggy-bag I electric-taped to provide a rain cape over the top of the battery and/or power connector, so that the area stays a bit drier. Although the controller itself is up in the frame where it ought to be dry, the various cable connections downstream of it seem at risk of corrosion, if neglected. The next flat tire a fatbike gets around here, the failed tube is going to yield a fancy new rubber rain cape.
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| cable needlessly exposed at the bottom, as delivered |
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| the cable sleeve stops a bit early, as delivered |
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| wires in a risky configuration, as delivered |
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| cables pulled through after the rough-cut edges were sanded down |
The front hub also seems to be cheaply made. The disc rotor rubs alternatively on the inside and outside of the brake pads, at this point I assume it is because the hub isn't machined straight. This cost me one rotor, because at first I thought the rotor was bent in shipment, and I proceeded to bend it up even more. Then I bought a new one, and refrained from bending it. The current situation is that it still rubs, but the massive winter tires are so loud, nobody can hear it. Also the rubber bearing seals on the hub were awful, at least one started to squeal right away. I ended up taking out the bearings, cleaning it up, and packing lovely washout-resistant grease everywhere, also around the seals. The one bearing race looked almost a bit damaged, as it a bit corroded, who knows. I'm not a total pro on cup-and-cone bearings, but I think they had over-tightened them, as they were not smooth when turned by hand. I certainly felt very sorry for my cone wrenches trying to undo the locknuts, holy crap. There was probably sufficient grease from the factory, anyway, so thats good.
I would also rate the battery cradle as marginal quality (don't bash it around!), the seatpost seemed unusually happy to slide down after getting the customary layer of grease on it (to prevent it seizing), and the pedals are cheap (but functional). At risk of triggering OCD problems, the drive-side pedal appears to be somewhat farther from the centerline than the non-drive-side. (I don't feel the difference, and am not going to tell the lady about it.) The battery also strangely extends beyond the frame only on the non-drive-side, but it works out fine.
Proceeding past the attention-to-details problems above, there is good news. This thing ate up a 26x4.2 45Nrth Wrathlorde tire in front, a 26x4.2 45Nrth Dillinger 4 in back, huge full-coverage fenders (from Classic Cycle in Germany) and a XLC RP-R15 rack. Everything fits nicely without any risk of rubbing, although the fender and rack did compete a little for access to the frame mounts. The support for the front fender passes right by the brake without needing to be bent. The rear tire couldn't have been too much larger before meeting the frame, but the front had more space in the fork. The lights that came with it are pretty usable for commuting (and not the cheapest thing they could have found), though we added one more light front and back. We even got a Reelight SL520 front blinker light installed, which isn't always easy with fatbike-scale frames. Incidentally, the front wheel appears to be built somewhat asymmetric, making it easy to mount the Reelight generator on the drive-side front spokes. Another odd feature is that both wheels are 36 spoke, unusual for a fatbike (or MTB) but probably a great idea for a working bike. We also swapped the straight bar to a curved one for ergonomics, and put on nicer grips. Anyway, this thing is now set up a lot like a proper Danish pendler bike, just with tires that are 2.5X wider ... and knobby.
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| rear tire clearance with 26x4.2 Dillinger 4 |
The Rumble 300 has an 8-speed derailleur setup, with a substantial-looking chain on it. The screw pinching the shift cable wasn't even tight out of the box, but its just standard derailleur adjustment to get that fixed. The motor is in the rear hub, the label is Techdrive. The name is basically un-Google-able. I assume that its some label stuck on a widely-sold product from some substantial Chinese manufacturer. The axle is bolt-on, very much the opposite of "quick release", a plus for anti-theft. When ridden, it works well. There is a torque sensor that very rapidly notices when the rider wants to move, and the assist levels are pretty good. I did not notice any particular drag from the motor. The battery matches the spec published for the 2023 model rather than 2022, and it seems to have been properly handled while sitting in storage, because it delivers great range. (Does over 50km in below-freezing temperatures, on imperfect paths, running studs, soft tires, on hills, with useful assist.) Functionality overall is a huge success, I can't think of anything that could reasonably be improved. We specifically did not want a model with a center-mounted motor. Partly because that costs more, and also because it would mean more stress and failure potential on the chain, and also IMO a center motor is more exposed to water spray or just plain submersion. (The part about submersion of the motor is not only hypothetical, the e-bike that started having problems this winter had actually been taken through a flooded river this past summer. Not to be repeated.) I don't particularly like these derailleur geartrains on bikes that are supposed to be beasts of burden. Ideally you'd have a center motor with a big robust gear hub in back, but the market doesn't do that right now (short of Rohloff of Kindernay).
The range of gearing could be a limitation. It would be very unpleasant to get up our hill without assist, and even with assist, if there is heavy snow to fight through uphill, its going to heat up rider and motor both. Fatbikes BTW are not especially easy to ride in unpacked snow, because they are going to squash a big path through it. The wide tires might however make the journey possible, offering both stability and traction. Its untested as of yet, but I suspect at the lowest assist level, that the bike will avoid applying uncontrollable motor power in situations where forward progress is a challenge.
Anyway, this thing is a heck of a beast of burden. Probably summer is not its ideal season; we intend to run a cheaper skinny-tire summer e-bike instead. But this winter has offered a lot of opportunities for a fatbike to do its thing. Its snowed a good deal, its rained, its melted, its re-frozen into every conceivable shape and consistency. Surfaces which are not smooth, or which are not stable, or which are icy. Ruts and edges in ice, iced paths under water. Big tires are excellent at all that, run them a bit soft to absorb the smaller texture, to stay on top of shifting snow, and to spread out to find what grip is offered. There is a potential for the front tire to "plane" on top of snow if ridden too fast into too much semi-dense snow, which results in a loss of steering control, so the bike isn't going to enable heroic monster-trucking so much as it offers improved safety margins, and comfort, when used sensibly. Just a part of getting to work.
Thumbs up.
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| two commuter fatbikes (the Rumble 300 was still nearly stock) |
