| Home > Misc topics > Recumbents > Choosing a 'bent |
There are other guides to selection online and in print; this is my take on the subject.
Study the guides cited on my links page and the manufacturers pages, and other similar resources; learn the recumbent types and the jargon. Hang onto your RTR issues and any product brochures for later reference.
Try to figure out what kind of rider you're likely to be.
Try to identify a type of bike that might suit you in theory, and maybe even try to narrow down on a particular model, if you can.
If possible, locate one or more bike dealers, close enough to visit, who have showroom recumbents available for test rides. This is getting easier all the time.
Go there, and try out all the recumbents they have. Try not to have a big audience or heavy auto traffic if you can help it. Pay attention to factors you like and don't like:
Go back to your RTR issues and other references, and re-evaluate your choice of make and model, based on what you learned in your test rides.
Lather, rinse, and repeat.
When you're comfortable with a choice, go for it.
You don't have to become a bike mechanic to buy a recumbent. In particular, you don't need to know all the geeky technical details about this year's drive-train offerings from Sachs and Shimano and Campy. But you do need to recognize basic terms like cassette, chain wheel, crank, bottom bracket, and headset when you see or hear them. This is functional jargon you will need when discussing your choices.
If you should decide to order a recumbent that's not stocked by anyone in your area, and you don't have bike mechanic skills yourself, you might want to go around and talk to mechanics at Local Bike Shops in your area, choose one that seems experienced and competent to you, and have your recumbent shipped to that bike shop for assembly. Shops that actually sell recumbents, if any, should probably be considered first for this sort of thing.
Test rides are very important. Try out all the recumbents you can, even if you have to make a day trip or two to reach a dealer with demo bikes. The Easy Racers/Sun EZ-1 line, Bacchetta, and Rans are probably the three makes you'll see most often in stores these days. If a friend will let you try their 'bent, great. Asking to ride someone's personal bike is kind of a big deal if you don't know them well, of course. If you're really out in the hinterlands and can't get any test rides, you'll just have to do the best you can from research, and be ready to sell the bike used if you have to.
When test riding short wheelbase recumbents (SWB) be aware of an issue called heel interference or heel strike. On SWB recumbents, when making a really tight turn while pedaling, it's possible for the heel of your shoe on the inside pedal to bump into the front edge of the front tire, which can result in a crash if you're not expecting it. This can only happen when making a very tight low-speed U-turn on a SWB recumbent (not LWB or CLWB). To avoid the problem, you simply stop pedaling briefly during such maneuvers.
Although I was worried about it before I got my Vision R40, heel strike isn't a big problem in practice. In normal turns, even on rather tight bike-trail S-curves, the front wheel doesn't deflect enough for heel strike to happen. Some experimenting in a big parking lot would probably be a good idea, so you get a feel for how tight you can turn before you need to stop pedaling for a moment.
Handling of long wheelbase recumbents (LWB) can be a little tricky at low speeds, as when climbing steeply or perhaps early in the season. Steering response is inherently quicker on SWB and not as quick with longer wheelbases. It's not all that hard, just requires a bit more concentration than SWB.
You may have noticed I recommend studying up on recumbents before going for test rides. By all means do it that way if you possibly can, especially if you have to road-trip to get test rides. If you inform yourself about the available configurations first, your test ride experiences will likely mean more to you.
Getting rolling, making the transition from sitting on the bike to riding, can seem a little awkward on a recumbent at first. The only real difference is the different body position, and the fact that you have to use leg muscle, rather than using your weight as you would on an upright bike.
Not all recumbent models fit neatly into these categories.
| SWB | Short wheelbase: about 33-45 inches, front wheel behind the pedals; probably the most adaptable type for different kinds of riding. Examples: ActionBent Jet Stream, Bacchetta Giro, Volae Sport, Sun Speedster, Rans V-Rex, Lightning. |
|---|---|
| MWB | Medium wheelbase: about 45-65 in. Examples: ActionBent Mustang & Tango, HP Velotechnik Speedmachine, Optima Stinger. |
| LWB | Long wheelbase: 65+ inches, front wheel ahead of the pedals. Examples: Easy Racers, Rans Stratus, Longbikes Slipstream. |
| CLWB | Compact long-wheelbase: 47-60 in. with a certain type of layout. Examples: Sun EZ-1, Cycle Genius Sparrow, Maxarya. |
| Low-racer | Mostly European performance design: ASS, low very reclined seating position, high bottom bracket & pedals |
| High-racer | American performance design: ASS, two large 26-inch or 650c wheels, relatively high reclined seat, medium to high bottom bracket & pedals. The larger wheels have lower rolling resistance and are thought to increase stability. Examples: Rans Force 5, Bacchetta Strada, ActionBent HiRacer. |
| Tandem | Two riders: "driver" and "stoker." There are upright and recumbent tandems. |
| Tadpole trike | Two steered front wheels, like a car, one rear drive wheel, lower rider position and center of gravity than delta trikes, and therefore faster cornering. Examples: Trice, Greenspeed, TerraTrike, Sun EZ-Tadpole. |
| Delta trike | One steered front wheel, two rear wheels with one or both driven. Examples: Sun EZ-3, Penninger, Lightfoot. |
Trikes are more complicated than bicycles, whether recumbent or upright. For starters, three wheels instead of two tends to lead to half again as much weight, and higher prices. Tadpole trikes with two front wheels have front-end geometry similar to a car, and front-end alignment adjustments. Delta trikes with two rear drive wheels tend to have tire-scrub problems in tight turns, just like the first cars. Choosing to connect the drivetrain to just one of the rear wheels, instead of using differential gearing like a car, is an option, but then tight right turns and tight left turns become very different in handling terms.
Specific kinds of 'bents are often thought of as being naturally suited for certain kinds of riding.
Feel free to ignore the conventional wisdom if the urge strikes you. For instance, Rotator and the aluminum-frame Easy Racers Gold Rush are performance-oriented LWB bikes, and SWB recumbents get used for everything, including touring, cruising, and commuting.
Regular two-wheel recumbents use two different steering systems, and you pretty much have to pick one. It's really a matter of personal preference and comfort, rather than a functional or engineering type of choice, so try not to get too much stomach acid over it. With any luck your preference will emerge from your test rides.
In USS or under-seat steering the handlebar pivot is under the seat, and the handgrips are down at your sides. This tends to result in more-relaxed arms, and some long-distance touring enthusiasts value this, but by no means all. It certainly is a different look while riding, compared to uprights, cruising down the road feet-first, with arms and hands relaxed at the rider's sides. It sort of looks like a rotated version of an upright rider riding "no hands." Long wheelbase recumbents with USS, such as the Longbikes Slipstream, will have some type of indirect connection between the handlebars and the headset to transmit steering movements, typically a rod with pivoting connections at both ends.
ASS or above-seat steering has a riser and handlebars that resemble upright bike handlebars more, usually with a direct connection to the headset for steering. It's a lot easier to mount a computer or headlight on an ASS bike; you just put it on the handlebar. Some say the more tucked-in arm position is more aerodynamic, but it has to be a pretty small difference. ASS is a little more familiar at first when a rider is transitioning from upright bikes, but this effect is probably over with during your first day of riding.
Long wheelbase ASS bikes in which the bottom of the riser is directly connected to the headset generally have some degree of tiller effect; the handlebars move side to side when you steer. This is no big deal; normal steering movements on bikes of all types are tiny. In fact tiller effect on LWB 'bents probably contributes to stability, because it produces a self-centering effect.
Walking your bike is easier with ASS; you just put a hand on the center of the handlebars, as you would with an upright, and off you go. With a USS recumbent, often you can just hold onto the seat back and persuade the front wheel to steer a bit by leaning the bike; sometimes for precision you'll need one hand on the near-side handgrip and one on the seat back. It's just a momentary annoyance.
ASS allows you to use the very nifty Shimano RapidFire shifters, which I like to call "trigger shifters." They usually aren't practical on USS bikes, although Vision, now out of business, had a USS bar design that worked. For more about RapidFire shifters, see the section about them on my outfitting page.
Short wheelbase recumbents with ASS usually have a pivot at the bottom of the riser, that lets the riser and bars swing forward to make it easier to get on and off. For riding, the riser swings back against a stop, sometimes an adjustable stop, and the pull of your arms keeps it there.
Again, the ASS/USS choice isn't that big a deal. Test-ride both kinds, and just go with what feels good to you. USS will feel a bit odd at first, but that won't last long.
One fundamental issue in the design of recumbent bicycles is always how to provide for adjustment to fit riders with longer and shorter legs, which translates to the distance between the seat base and the bottom bracket and pedals.
The common early approach. This is a separate frame member ending in the bottom bracket, which typically slides inside the front of the rest of the frame, which has a slot and provision for bolts to clamp it around the sliding boom to fix it in position.
This is a simple system to design and build, but it has some drawbacks. Torquing down the boom bolts hard tends to be only partially effective in keeping the boom in the desired position. The boom can rotate unexpectedly, probably when you are trying to start off, and you might suddenly find your pedals and chain rings sitting sideways or at an angle, until you fix it.
Those boom bolts having to be over-torqued tends to cause them to snap about the fourth or fifth time they are tightened, which obviously can be inconvenient if it happens on the road. Some riders carry spares.
When you change the adjustment of a sliding boom, you are also changing the distance between the chain rings and the cassette. That means you have to add or remove chain links to compensate, which is annoying. Of course all this is only necessary when you adjust the bike for a different rider.
In the sliding-boom design, the seat doesn't have to move with respect to the rest of the frame, which simplifies designing its attachment. The seat can even be attached at both ends, with the base bolted to the middle of the frame, and the seat back supported by thrust braces connecting to the rear-wheel part of the frame.
The other approach is to use a sliding seat, and make the frame in one piece including the bottom bracket. There's no sliding/rotating boom, and no overstressed boom bolts. A well-designed sliding-seat recumbent can be adjusted for a different rider in seconds, and no fiddling with chain links is required.
On the minus side, you have to come up with some way for the seat to adjust fore and aft, and still be able to clamp solidly after adjustment, and thrust braces can be problematic. If your sliding base is the only point of attachment of the seat, that means it will be highly stressed and may tend to flex or squeak. Another potential minus is that moving a sliding seat changes the rider/bike center of gravity (CG) and weight distribution relative to the front and rear wheels, more so than sliding boom adjustments do. This tends to be more of an issue with riders on the tall/short ends of the fit range, of course.
As with anything else, results depend as much on quality of execution as on which system is used. Either system provides a certain range of adjustment. Some manufacturers further extend the fit range of a design by offering different sizes, either of the entire frame or in some cases just the sliding boom.
| Advantages | Disadvantages | |
|---|---|---|
| Sliding boom | Simple design Seat can be attached front and back |
Boom can rotate unexpectedly Overtorqued boom bolts can break Adjustment requires adding/removing chain links |
| Sliding seat | One-piece frame No chain-links hassle when adjusting |
Seat base design is a challenge, can squeak or flex Thrust braces can be problematic CG & weight distribution changes more |
Recumbents have a lot of chain, because the pedals are at the very front of a recumbent, and the drive wheel is usually still at the rear.
Conventional recumbents with a single long chain often have one or more idlers which constrain and control the motion of the chain. Idlers are small wheels or cogs that the chain passes over or under on its way between the cranks and the cassette. Some idlers look like pulleys, some are more like the small cogs that are part of a normal rear derailleur. In some designs with highly stressed plastic idlers, the idlers wear rapidly enough that they have to be replaced yearly. Many pulley-style idlers are now being made from super-tough solid urethane plastic, like skate wheels, which helps lots. TerraTrike is now using Delrin® thermoplastic in their power-side idlers.
The cheaper and maybe less elegant way to control chain motion is with chain tubes. These are just one or two lengths of plastic tubing attached to the frame; one or both sides of the chain pass through. Chain tubes have more bearing surface than idlers and perhaps less wear potential, but also tend to make more noise.
Idlers and chain tubes both tend to add noise and some small percentage of mechanical loss due to added friction.
Any bicycle chain has an upper power side, moving forward, and a lower return side, moving to the rear. The power side is under significant tension, because it is actually transferring your pedal power from the front chain wheels to the rear cassette. The only tension on the return side of the chain is that applied by the spring in the rear derailleur. Because of this difference in tension force, idlers or chain tubes on the power side of the chain make a lot more noise and difference than idlers or chain tubes on the return side.
It also makes a difference how much angle the chain makes as it passes over an idler or through a chain tube; the straighter the chain is, the less lateral force the idler or tube is applying to the chain and the less noise and loss there will be. Recumbent tadpole trikes that are built low for faster cornering necessarily have large idler angles, because the rider's keister is down between the front and rear cogs, and the chain has to go around.
A mid-drive recumbent bike has two separate chains, and three sets of cogs on three bearings instead of two. I've never yet seen a recumbent design with a mid-drive that I didn't think was a mistake, with the possible exception of Rotator.
In the simple form of a mid-drive design, the cranks drive a single smallish chain wheel up front, which connects via a short chain to a single cog coaxial with a set of three chain wheels, mounted in an extra bearing in the bottom middle of the bike, with a conventional front derailleur and chain rings. A second short chain then connects those chain rings to a conventional cassette and rear derailleur at the rear axle. It's like an ordinary upright bike drivetrain, remotely driven by that extra chain in front. This provides great chain management but adds weight and cost.
There are mid-drives that use some combination of three derailleurs and three shifters, which always seems to me over-complicated and more needless expense. We already know many people have trouble managing the usual two shifters.
A peculiar effect called pogo can occur on suspension recumbents only. This typically comes up when the power side of the long recumbent chain ends up making a significant angle with the rear suspension swing-arm. Every time the rider pushes on a pedal, this causes the chain to pull against the swing-arm and make it flex more. As you watch the rider climb a hill, his head bobs up and down every time he pushes on the pedals, hence the name.
This not only looks goofy, but some of the rider's energy is being wasted on making the suspension flex. The way to avoid pogo is to pay attention in design to the relative geometry of the chain power side and the suspension.
Look at the bike when someone of average size is sitting on it with a foot on a pedal, holding the chain tight; the rider's weight will also put the suspension in its loaded position. If the power side of the chain passes close to the axis of the suspension pivot, or at least the line of the chain power side is roughly parallel to the suspension-pivot/rear-axle line, then pogo is unlikely to be a problem, unless you are a purist. Or you could just ride it and see.
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