Bicycles

Novel recumbent bike features a folding shaft drive

Novel recumbent bike features a folding shaft drive
The Speed Bent is presently on Kickstarter
The Speed Bent is presently on Kickstarter
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The Speed Bent, all folded up
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The Speed Bent, all folded up
The Speed Bent is presently on Kickstarter
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The Speed Bent is presently on Kickstarter
Rider height for the Speed Bent ranges from 5'3" (1,600 mm) to 6'3" (1,905 mm)
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Rider height for the Speed Bent ranges from 5'3" (1,600 mm) to 6'3" (1,905 mm)
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With their laidback seating, recumbent bikes are typically more comfortable than uprights, although they're also longer and thus more awkward to store and carry. The Speed Bent addresses that problem by folding, and utilizing a shaft-drive drivetrain.

Developed by Los Angeles-based fluid dynamics engineer Aram Samvelian, the Speed Bent features a folding frame made almost entirely of aerospace-grade 6061 t9 aluminum alloy.

Running inside of that frame, from the pedals to the rear wheel, is the custom shaft drive. Unlike a chain, it doesn't require lubrication, nor will it leave grease stains on the rider's clothing. Additionally, utilizing an integrated universal joint, it actually folds along with the frame.

The Speed Bent, all folded up
The Speed Bent, all folded up

The current version of the Speed Bent just has a single gear, with a ratio of 3.75:1. That said, Samvelian tells us that a multi-gear rear hub transmission is in the works.

The whole bike measures a little over 57 inches long (precisely 1,451 mm) when in "riding" mode, or 28.25 inches (718 mm) when folded. It weighs a claimed 24 lb (10.9 kg), and can accommodate riders weighing up to 240 lb (109 kg).

Rider height for the Speed Bent ranges from 5'3" (1,600 mm) to 6'3" (1,905 mm)
Rider height for the Speed Bent ranges from 5'3" (1,600 mm) to 6'3" (1,905 mm)

Some of its other features include an adjustable-angle seat and backrest, 12.5-inch aluminum wheels, a single mechanical rear disc brake, and an optional adjustable-angle handlebar stem.

Should you be interested, the Speed Bent is currently the subject of a Kickstarter campaign. A pledge of US$460 will get you one, when and if they reach production. The planned retail price runs from $625 to $735, depending on the options selected.

You can see it in action, in the video below.

Sources: Kickstarter, Speed Bent Bikes

The Speed Bent is a cross between a go-kart and a bike.

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7 comments
7 comments
Michael son of Lester
I like the idea of this bike but there are two things that concern me. First is the size of the wheels. At 12 inch I don't know how well they would mitigate vibration. The second thing that comes to mind is nowhere in the description can I find out if these are single speed bikes or if not then how many speeds they have.

If I could find out the answer to the single-speed question I might even order one of these. The idea of driving into the city, parking the car and biking the last few blocks to my destination is appealing.
MarylandUSA
A folding recumbent ... and one that's ultralight. Will wonders never cease. Its looks remind me of the Bickerton, a 22-pound British aluminum folder that I rode from 1980 to 1982.
Michael son of Lester
I was curious if the bike was single speed or multi-speed so I contacted Aram who is the inventer. His answer was that it's a single-speed with a 3.75: 1 gear ratio. Considering the distances I would be riding and the hilly terrain around here, I'll pass. But, if you live in the city and only have to go a few blocks to travel this might well be worth it.
Douglas Rogers
Nice, convenient seating position. I am working on a thee wheel lean-to-turn with this seating position. If I am going more than a couple of miles I would want narrow, large, high pressure tires. This bike will safely roll down a hill at 40 mph, unlike many portables.
HaroldBalsac
I really like the idea of shaft-drive for bicycles and would like to own one someday. This bike is a good start, but not ready for prime time in my opinion. Having owned a couple of ‘bents and being familiar with their riding characteristics, equipping them with multiple gears is essential. With a one-speed ‘bent you’d find yourself laboring up hills and probably walking the bike in most cases. You’d also find yourself pedaling at a ridiculous pace just to maintain a decent speed on flat stretches. I don’t believe that you can find a one gear solution to satisfactorily address these two recumbent bike issues. Also, the small size of the wheels will produce very nervous and twitchy handling. I wouldn’t recommend this bike as an entry-level recumbent and would personally prefer something with larger wheels. I’d send it back to the drawing board to incorporate wheels with a minimum 14” diameter, (16” would be better), and equip it with that multi-speed, rear hub. If you could do all that and make it light and foldable, then you might have a winner.
The deerhunter
Looks great but all the other comments are valid and I raise two more. Uphill, the lack of use of body weight for leverage would be a disadvantage and how does one start off one of these? One foot on the ground and one on a pedal? It would be a bit trickier than staring on a conventional bike. However, a battery & motor would answer both those problems, at the expense of cost and weight. Also,like Micheal, I too am very nervous of small wheels. They are hard riding and offer no centifugal assistance for balance. Most importantly, much smaller things like edges of manhole covers can become a big deal and throw you off in an extreme case. For that reason I would never buy a scooter with tiny wheels for road use.
Develocon
All the shots of the bike folding or even being wheeled along (1:31) don't show the seat.
that's pretty misleading about how small this thing is.

otherwise, I like the drive system.