Freyr Gunnar
> Folding bicycles definitely have an advantage when it comes to easy toting and storage, although their chain presents a design challenge – it can’t just be folded sideways along with the frame, and there’s a risk that it will transfer gunk onto the rider’s clothing as they’re carrying the bike.
Incidently, why isn't there any folding bike with a belt drive?
Because it can't fold?
I have one on my standard bike, and love it: Silent, clean, zero maintenance.
The Hoff
Nice bike design here. But Freyr is a belt more efficient than a conventional chain drive? According to Jason Smith at Friction Facts, the answer is no. By his measurements, a conventional chain drive consumes 2.92 watts on average, while the belt eats up 3.93 watts. Here's the whole article.
Does this thing have gear, because if not that's a major tick against it.
7% more efficient? Perhaps but why does it look as though the person in the demo has such an uneven pedaling motion? Amazing amount of technology has gone into this, nice work ......... if it works!
Wow! ...I really hope this actually works/comes on the general market: does somehow look a little too good to be true.
Also, they may well have to change their logo if they don't want BMW to sue them into the ground before they even get started.
Bob Stuart
A chain has no problem with a sliding, rather than folding design, so that fails as a rationale. As for the efficiency comparison, they are either lying or using a rusty chain on a broken bike to get their chain numbers, and ignoring the flex and friction in their own system. The awkwardness in the video probably comes from a very wide pedal placement. Carbon fiber can't save this turkey. That english translation in the video shows the quality standard at Bygen - only the accent is right on.
Michael Logue
Interesting concept. However, I would suspect that you would get a significant amount of flex in the "crank arms" as they are extremely long when in the forward position. I think this would result in a very mushy feel if you were peddling pretty hard. It also looks like your feet are spread quite a bit farther apart - which could put undue stress on your knees if used for extended rides.
The model weighs maybe 89 pounds? I weigh 225 and I could tear that drive system apart in 10 pumps (or less). This product is a liability that BMW will certainly try to distance itself from.
Edgar Castelo
An innovative idea. But Bob Stewart's comments are right to the point; If it slides, why not a sliding chain system? Looks like another solution looking for a problem.
Guy Lamoureux
It looks like an old locomotive engine.
@Freyr Gunnar There are many folding bikes with belt drive. Dahon, Bike Friday, Tern ...