On top of that Thilde and I have released our Kickstarter campaign for The Unwanted photobook that we have been working on for the last 4 years. Every time I watch the video for the project, I actually cry. I’m not sure if it’s because of my sad improv piano playing in the background or if it’s from the stress of remembering the 6 months of living on the road in a car together and photographing the homeless all over America. The reality is that the hardship we endured with this project is nothing compared to the daily struggle that millions of homeless Americans have to deal with every single day. Please consider supporting our project and help spread the word.
This article is not about learning to drive bulldozer by watching Youtube videos or how bad you smell when you live out of your car for months on end, it is about my struggle to find a freehub that doesn’t destruct when you regularly feed 2500 Watts through your bicycle drivetrain. This article is about why normal aluminum freehubs fail, and how to find rear hubs that will hold up to high power mid-drive motors over 1000W without self-destructing.
I am by no means an expert on Freehubs, I’m just a guy who has destroyed at least 5 of them in the last 5 years by running them under extreme load with a 60 Amp Ludicrous BBSHD through deep snow. There are several issues I will describe in this article.
When you have an aluminum freehub body and use a cassette that does not link the rings together this is what your freehub body will look like after using a high power mid drive
If you can get a bike with a steel freehub, you can pretty much skip this entire article. The easiest way to tell if a freehub is steel or aluminum is to bring a magnet to the bike store and try to stick it to the hub. If it sticks, you are in business, if not you will probably eventually have issues if you put a high power mid-drive on it. Only the cheapest bikes (under $500) generally have steel freehubs and I want to be clear, I have never had a single steel freehub fail in the last 5 years, only aluminum ones.
I first started noticing problems with my hubs when it came time to service the cassettes and I could not get them off the bikes. The problem is that the aluminum hubs don’t work well with cassettes that are not a single solid piece. If the cogs are separate then all the stress from the motor is localized on a very small area and the cogs end up eating into the aluminum hubs. Usually, with a bit of working it back and forth, I can get the cassette cogs off one at a time, but it’s a royal pain. The best solution I’ve found for this problem is not to worry about using an aluminum hub (almost all of them are aluminum) but rather to focus on buying a steel cassette that has pins that hold it all together in one piece. I’ve reviewed several great cassettes including steel 11-36T ones, 10Sp 11-42T and 11sp 11-42T cassettes. It doesn’t matter that much what brand of cassette you use as long as its one piece (some are mostly one piece with only the 11T road gear separate) and they are made of steel.
This is a great image of Pawl destruction on the Freehub, the steel pawls push into the Aluminum over time until they start to skip
Most freehubs have 3 or 4 pawls that lock into the hub. These pawls are the only contact points when the wheel is turning and a tremendous amount of torque is placed on them. Think about how a socket wrench works as a large lever. You wheel is really just a 2-foot long socket wrench and when the motor turns the back wheel all the torque going to your wheel is carried by these tiny steel pawls. The force is amplified because it is so close to the center of the wheel. Over time these steel pawls eat into the soft aluminum and will start to skip. Eventually, they will get so bad that they will either fall out of the freehub or just stop catching on the hub teeth altogether. Since the average rider can’t put out more than about 300 watts of power they are just not designed for running with 2500+ watt motors.
If you can get steel freehubs and hubs, that is always the best way to go. Most bikes will not have that as an option, only the cheaper bikes will have them. I’ve found that the brand name hubs (like Novatec) seem to work longer than the no-name Chinese aluminum ones which are really poor quality. If you are running a no-name hub it is also likely that you will not be able to buy a replacement freehub, you will end up having to replace the whole hub and lacing up wheels is a royal Pain In The Ass. If you do have to replace a hub make sure you get one that has about the same size and whole spacing so you can reuse the spokes. It usually takes me about an hour to relace and true a wheel, longer if you haven’t had a lot of practice.
Forrest Carver from Carver bikes/Bikeman is a great guy to get information out of for what kind of gear holds up in the snow and what doesn’t. I sent him an email in 2016 about hubs destructing and he told me that the 350 was the hub that he had been using for pedal bikes that seem to really hold up well to the stress of riding fatties through the snow. The price was steep at $320 (available at Bikeman here) which was a hard justification for a bike I paid $699 for the complete pedal bike (no motor or batteries). I’ve been trashing on the Big Ride 350 for over a year now in the worst sort of conditions and the hub has been really solid, so it’s nice to go out riding with one less component that you are worried about will break. This has been a tough season for me as I’ve melted 3 Nylon gears on 3 different bikes. I sure wish someone would make a stronger nylon gear for the BBSHD, I bet they would sell a lot of them.
The ratchet system is the two large circles in the center that push into each other and lock with many different teeth
The ratcheting mechanism on the 350 is totally different from anything I have ever seen and is quite ingenious. Two metal ratching plates are pushed together with a spring and there are many different contact points when the wheel is turned (instead of just 3 or 4). The Freehub body is still aluminum, but it is made of much stronger aluminum than what you usually see come on cheap Chinese bikes.
It’s not cheap, but the 350 Big Fat Ride can take a lot of punishment that high power mid drives can dish out. If you want to ride singletrack and have the best experience you can, then mid drives are the way to go. The only problems with middrives are how quickly they wear out the drivetrain and components. It’s a small price to pay to not have to ride with a giant hub motor on the rear wheel, so I’ll take it. If you take care of your drive train and hubs, then they won’t let you down and leave you stranded in the woods (like I seem to every other ride or so).
Just a private heads up on the dirt work: be very careful with your local county pukes, as in sneaky. They can and probably do require all kinds of permits to do what you did. Even here in very rural Idaho, they are big on crap like that, even potential runoff into water ways is a big issue. Last year I cut in a 1/4 mile of trail on my property using a mini excavator and my tractor, and got away with it, with no permits, but I did it as fast as I could and was paranoid the entire time! It being your ground doesn’t matter, they can still jack you around. I live on a mountainside so i savvy the swales and ponds/catchments, they are all around me, just keep in mind you may be a lawbreaker. HA HA HA! Like me…. Don’t worry about it, your committed now, just keep it in mind.
BTW: I’m building, done next week, a Surly Wednesday with a Rohloff XL, and the BBSHD (tweaked) off my last fatbike, the Rohloff Montague ride I carry in my plane ruined me for derailleurs, I have no patience for their quirks anymore, and their wonked out chain lines, and Luna had them pretty cheap “only” 1400 bucks.
There is a steel version of that freehub body available. Jenson USA has them. I expected my alloy body to fail so I bought a couple cheap on Fleabay (got lucky and paid $35 each… they usually cost around $90+). But the original alloy is still going strong, like yours.
$35 is a good deal. Ebay is great for cheap bike parts, but a lot of them come out of China and take a long time to get here.
I’ve been following your blog for years and have often wondered why not get good parts and build them into a purpose built bike (I’ve been a bike mechanic for 25 years, so sorry if I sound judgemental.) If you ever want to pick my brain I’d love to chat. Davis Carver is a solid dude BTW. I live in Maine just like Carver.
The Unwanted is a really tremendous project – I was a big fan of The Canaries as well. Looking forward to seeing the book when it comes out. Gerry Badger is quite a get for the text!
Looks nice, but pricey. I’d just as soon go with a cheap heavy steel hub that was an extra lb or two than all that fancy stuff. I’ve had poor luck with aluminum anything when you’re talking over 1500W drive train. Just build it out of steel and be done with it.
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