This is the second story that Euan Pennington sent us and it focuses in on the Rohloff/Gates Carbon Drive he used on his fat-bike build.
Recently I created a new bike, the “Steel Donkey”, and in doing so I went looking for a reliable and long lasting drive train that could survive abuse, remote areas and adverse climatic conditions. For design inspiration I looked to motorsport, as off-road motorcycles have been around far longer than the humble mountain bike, and as a consequence have had far more money and research thrown at them. What I discovered was that motorcycles have big knobby tyres, (like mountain bikes), dual suspension, (like mountain bikes), hydraulic disk brakes, (like mountain bike), and keep all their important gears and moving parts in a little box full of oil, (like….hang on).
As I mentioned in my Reader’s Ride(s) article last week, for decades bikes have relied on exposed gears and derailleurs, (a French word that roughly translates as “expensive”), which, as systems go, is somewhat crude and unrefined; it’s just a fancy lever that forces the chain across the cogs. Is there a better way?
Enter the Rohloff internally geared hub, which can be paired with a Gates Carbon belt drive, thus removing all exposed gears as well as the chain from the drivetrain. It makes sense, but is more costly than a more conventional system, so I did some research into these components before shelling out the fun tickets. Using the Wide World of Web, I discovered that this set up was likely to be unreliable, was very reliable, was heavy, was no heavier than a more usual system, was complex, was simple, changed gear slowly, was very quick to change, was weak, was bomb proof… Hard to believe, but a quick skate of the Net showed some widely differing views, some from people who had not even ridden the components concerned, but were still clearly experts.
Eventually I bought the parts, fitted them up, and decided to write this review, to set the record straight on a few apocryphal rumors before they fester into fact. I spent my own money on this too, so there is no back slapping bias involved. So what is my version of the truth? Glad you asked.
A Rohloff hub puts 14 evenly spaced gears at your disposal, with a 526% spread – roughly the same as a 27 speed derailleur set up. It all packages in the rear hub, along with the shifting and indexing mechanisms. All that goes up to the bars is two cables running to a grip shifter that pulls one cable for up shifts, and one for down shifts. No return springs, or small plastic parts, or exposed cable inners, just robust German simplicity. The Gates Centre Track belt drive is exactly that – a belt that replaces the chain. You do need special cogs, (called pulleys), but they bolt straight on to a standard crank.
All this is slightly more tricky than setting up a normal drive train, but it’s not rocket surgery. You need a frame that is adapted to belts, with a break in the drive side seat stay, you need to know the chainstay length, the drive ratio you want, the length of belt required, and the chain line once you get the hub fitted. Sound intimidating? It certainly puts off many of the pundits on the Net, but here’s a thought. What I did was read the websites of the component manufacturers, used their online calculators to rough out what I thought would work with the frame and drive ratios I wanted, then took it to a professional cycle builder with experience in this area to build and align. Insurmountably difficult? Not really. Many problems I have read about this system stem from it not being built correctly, so do your research, read the instructions, and do it right. Take a little extra time now, and it will repay you in the long run. (Not rocket surgery).
Doing it right is important because these are not cheap parts. This set up will cost you double or more the price of a conventional drivetrain, so you don’t want to damage anything. This cost is another bug bear of the detractors, but I take a long term view. Rohloff hub maintenance requires the oil to be changed every 5000km, and … that’s all. There are Rohloffs out there with 100 000km on them. Gates belts, as best I can ascertain from the Net, if looked after, can last 10 -20 000km, and never need greasing. So a $60 chain lasts me 1000km, a $90 belt lasts ten times as long, and the hub will outlast many many clusters; that doesn’t seem expensive to me, especially taking into account the ongoing lack of maintenance. Double the cost, twenty times the endurance, on paper, this seems like a great system. It just has to work. Does it?
Fitted up, you notice the rearward weight bias. The system is roughly equivalent in weight to a mid range conventional drivetrain, so not as light as a nice shiny XTR or XO set up, but it’s not the concrete boat anchor many would have you believe. Think X7, or SLX, and that’s the ballpark, except that all the weight is in the rear hub, not spread over the front cog and shifters. Interestingly, it’s not really noticeable as you ride, just when you lift the bike over rascally logs too big to roll over. In motion, some gears are noisy, and vibrate a little, but apparently this reduces with age. It takes 1500km to run in a Rohloff, so just as your conventional drivetrain is starting to tire, this is only just warming up. Shifts are lightening fast when you get it right, but getting it right requires practice. New system, new skills. Some people don’t like this, but I’d say build a bridge, get over it. A little commitment will reap huge benefits. In addition, you can change gears standing still, and drop multiple gears in an eye blink without worrying about which chainring you are on at the time. Chain line is never an issue, nor is chain suck, nor dirty derailleur pulleys on a muddy ride. Shifts are always reliable, no questions asked.
All this has enriched my riding experience. So smooth, so simple. It has solved a problem that most of us didn’t ever really know was a problem, but life has just got better. On road, off road, rain, mud, and so far the Donkey is yet to miss a beat. To me, this should be the next frontier of cycling, getting rid of clusters and chain rings in favor of something more reliable and elegant. To me it just makes sense. Of course, as I said, there is a reeducation process if, like me, you have spent decades with Rapid Fire, but OK, just commit to learning something new. I know there are those people out there who say, “oh, but I don’t have a problem with chains and I never have problems being on the wrong chain ring and why would you bother and I’m all uptight because I wasn’t breastfed as a baby so feel compelled to be negative about everything new…”. That’s fine, if you are happy with the current way you do business. If, however, you are open to new experiences, then you may find the simplicity of this getting under your skin.
The Donkey is a fatbike, built not only as a daily driver, but with an eye to travelling through some remote terrain, and I am confidant that the Gates / Rohloff system is the right tool for the job, but I am equally sure it can enhance almost any riding experience, and the reliability and function easily offsets the slight increase in weight over a high end derailleur system. Give it a decent test ride, and I suspect you might just agree. Meanwhile, I’ll see you out there.
You can read more from Euan on his blog at http://madnotto.wordpress.com.
Do you have a fat-bike component or accessory that you are passionate about, makes your like better and that you think our readers would dig? Shoot me a note to firstname.lastname@example.org and we will check it out.