I guess anything under the recumbent banner could be considered unconventional but I think I’ll be pushing into particularly rare territory for this build. My goal is a machine that will be equally comfortable on tour or commuting to work; fun to ride, easy to maintain, impervious to weather. Fast, relatively lightweight, simple, at least externally. Here are some of the characteristics I think will get me the closest.
If you’re with me this far, I probably don’t need to evangelize riding in a rolling lawn chair. That’s been done well enough elsewhere, even by me.
For me, a tadpole trike is the perfect compromise between the quick handling but inherent instability of a short wheelbase ‘bent and the Titanic turning radius but inherent stability of a long wheelbase ‘bent. A trike is responsive and utterly stable with a relatively tight turning radius. I prefer the tadpole configuration for it’s stability and drivetrain simplicity. Plus in the high performance trike world, the delta Hase Kettweisel notwithstanding, most of the choices are tadpole.
The big rear wheel that is all the rage these days has some practical advantages: A little bit of inherent shock absorption with (perhaps) slightly less rolling resistance and, more importantly, the appropriate gear range when paired with the typical drivetrains that the recumbent minority is compelled to borrow from the upright world. But for me, none of that is worth carrying two sets of spare tubes and tires around, one of them really big. And an internally geared hub completely solves the gear range problem.
Three-wheel suspension is pretty slick. I particularly like the ICE design that uses elastomer pucks instead of conventional springs or hydraulics. I have that on my current HDQ trike (rear only) and I’ve got some time on my mom’s fully suspended ICE Adventure. Smooth. But when I hop off my mom’s trike and back onto mine, I’m not particularly bothered by the harsher ride. And it adds cost, weight, complexity, and most importantly, moving parts. Over time, on a commuting machine that sees big miles and bad weather, these moving parts start making noise. I’ll take a harsher ride over a noisier one any day, especially when I’m riding on roads. Noise has been a particular problem with my HDQ in the last couple of years. I now find I have to douse the pivot bushing with Liquid Wrench every couple of days to keep it from making some god awful noises. Granted this rear section has had a rough life and the problem is certainly solvable. But this time I just don’t want to go there. Certainly not times three.
I ride at night a lot. If it’s not also freezing cold and sleeting I rather enjoy it. Over and over again I’ve been positively giddy about the latest crazy-bright, super-small rechargeable LED gadget to come out. And then disappointed when it utterly fails for one reason or another. And even for the brief period when they’re working properly, I have to remember to keep them charged. So I keep two or three of them in rotation and still wind up riding home in the dark. Perhaps I’m revealing too much about my personality here, but I can’t stand it. The clutter! The charging! The remembering where I absentmindedly tossed my headlight! It’s almost enough to send me to the self-help aisle at the bookstore. Instead, I’m going all in. A Schmidt SON generator hub in the front married with an as-yet undetermined German headlight and taillight, permanently mounted to the trike. Have the Germans really figured this all out? I don’t know, but I’m going to find out.
If not for the generator hub I might never have taken this leap. I’m generally happy with my Sturmey Archer front drum brakes. They’re super compact, streamlined, and easy to remove and reinstall. They aren’t as powerful as disk brakes but they will easily skid my front tires or pop the rear off the ground, what use is there for any more power than that? But today, on the ICE Sprint trike, the SON generator hub is the only option for real lights, and it’s disc brake only. Incidentally Sturmey Archer told me they’ll have mirrored side-mount generator brake hubs that might be a direct replacement for my existing drum brakes in about a year but I don’t want to wait. And by forcing my hand to disc brakes, I can make the next jump to hydraulic disc brakes. The key advantage here is that the cables are a sealed system. No more contamination during a typical mid-winter that leaves me either brakeless or gearless (or both) for a couple weeks. But what about those gear cables…
Shimano (and Campagnolo) have offered electronic shift for a few years at least now. Racers seem to love them for the precise shifting that is impervious to cable stretch and the ability to put multiple controls on various parts of the bike. There’s at least one guy who has installed the Shimano Di2 system on an ICE trike. But all of this uses conventional, external front and rear derailleurs that don’t, without expensive modification, have adequate gear range for a recumbent. Recently though, Shimano introduced Di2 electronic shifting for their Alfine-11 internally geared hub. Now we’re talking. But what about contamination and freezing of the front derailleur cable…
Internally Geared Hub(s)
As I mentioned above, the Shimano Alfine-11 could solve my shifting woes for the rear hub. And a Schlumpf Speed Drive could solve it for the front crank. The Schlumpf is a planetary IGH (Internally Geared Hub) that replaces the front (usually triple) crankset. And the beauty of this thing is– no cables at all! You shift the two-speed hub by hitting buttons on each side of the bottom bracket with your heels. Sounds wacky but it works quite well. With the combination of hydraulic brakes and two IGHs I now have a machine that should brake and shift regardless how wet it was on yesterday’s commute and how cold it got overnight in my unheated garage. Of course it might be cheaper to just build a heated garage.
This is where I go off the rails a bit. Belt drives are becoming more and more common for conventional bikes. I’ve ridden with some of these guys and belt drive is awesome. Clean, light, smooth, just about maintenance-free, and utterly quiet. So why is no one offering belt drive for trikes? Well there are a number of reasons so belt drive may be fantasy for this trike. But I don’t think the problems are insurmountable. At some point I’ll work up the numbers for my HDQ which, it turns out, has some characteristics that make belt drive more feasible compared with other trike designs. Is this the next big feature, ICE?
This great Kurt. I really like your practical weighing of what makes sense. Since I built a long wheelbase 2-wheel recumbent and rode another one for 20 years before getting a short wheelbase 2-wheeler, I had to grin about your comment on the Titanic aspects of the LWB. It turns out the only place I’ve ever noticed the difference between it and anything else I’ve ridden is when I try to turn around in my driveway … ;). The practicalities of the tadpole trike intrigues me and my stubborn adherence to thinking the small aerodynmic advantage of my 2-wheelers is important is slowly crumbling.
I perceived the turning radius difference when I tried out various ‘bents a long time ago but I could totally see that it’s not a practical consideration. When I realized the weights were about the same between tadpole trike and LWB ‘bent I started leaning toward the trike for various reasons. Speed wasn’t one of them, I really don’t have a clue how much the two platforms differ on that score. Based on tire size, and 3 tracks vs one, and aerodynamics it’s probably safe to say that a two wheeled bent isn’t slower than a trike but it’s hard to quantify how much faster it might be. I cruise fast enough that I don’t feel I’m missing out on anything.
Thanks for the comment Dan!
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