You know, it’s worth taking a look at the Museum of Unworkable Devices. Basically this design is kind of like an “overbalanced wheel” perpetual-motion machine, predicated on seductive but fundamentally flawed rationale. Let’s assume for a moment that the claim the company makes is true; that with these cranks, you can put more energy into each downstroke. Where did that extra energy come from? It came from the upswing; you are putting energy into the system to make it go from offset one direction to offset the other direction. The payoff is that you get to exert downward pressure sooner, but the payoff will never be more than the cost; it’s a law of thermodynamics.
I’d really like to see someone try this out for muni, I REALLY think it would help out alot, and honestly I don’t think more then 20min would be neccesary to get used to them, I dont’ see what all the fuss is about in that regards, also, if they work well, I wonder if they could be incorporated into a geared hub easily? like the one kris had at moab, I mean if your already spending 1600$ on a hub, I wouldn’t mind droping a few extra hundred for the zero ds system as well.
I stil don’t understand the advantage. Instead of paying a lot of extra money on your cranks, why not just practice being able to deal with the ds? Not only is it cheaper, you become a better rider.
People pay for pre bent cranks!?!?!
read the thread more carefully, read the descriptions more carefully, and look at the pictures more carefully. They’re not “pre-bent” cranks.
I can see where your thinking comes from, but it’s not quite right. The energy does indeed go in that cycle, however, the range where the energy for the upstroke is taken from the downstroke takes place at a slightly different point, which basically smooths out the power curve. I don’t think it necessarily adds power, but if the pedaling curve is smoother with fewer dead spots, it is definitely less exhausting.
I think it’s very unlikely that it’s less exhausting. If nothing else, there is extra friction and weight in the system that are likely to overwhelm whatever small advantage the nature of the cranks can provide.
Did you notice that in their list of winners, that none of them are more recent than 2004? And that the “Rotor News” page hasn’t been updated since February 2005? They must have run out of money to sponsor riders, so now no one is bothering with the gimmick anymore.
Re: System for eliminating deadspot
On Tue, 4 Apr 2006 14:43:53 -0500, tholub wrote:
>And there’s no way these cranks can eliminate the dead spot; the dead
>spot is biomechanical. All they can do is move it around.
Not really. You know, with any crank set (geared or not), each foot is
only effectively transmitting power during the downstroke (broadly
speaking). When the cranks of a conventional setup are vertical, both
feet are ineffective and that is called the dead spot. With these
geared cranks, the top foot is ALREADY in a position to deliver (some)
power, while the bottom foot is STILL delivering some power. So there
is no point at which both feet are ineffective, hence no dead spot.
But some positions are deader than others, I’ll give you that.
'where can i get sum of those they look so cool
You could probably make a pair for yourself, doesnt look like anything too fancy, just a right angle in the cranks, and now i wanna try the cranks, both the first ones mentioned on here, and the angled ones =p
Learners get stuck in the no-power position due to incorrect technique, not an inherent design-flaw in the unicycle.
Even if you had these on a learner-uni, the learner would still have to keep his/her weight on the seat.
Interesting link from the comments section of the original article.
Ah yes, ovalized chainrings, another bad idea that gets revived every now and then. Like most of the bad ideas people try out for bikes, it is not new; the first oval chainrings appeared in 1890. Like all of the bad ideas, it was rejected by the riding community until the next time someone tried to market an old idea as new.
I actually found idling to be nearly useless at first. I’ve been riding “hardcore” for nearly 3 years now (12 months a year in Quebec, and lots of muni) and only started idling last month Hopping is much easier
I mostly started idling because everyone else here can and I didn’t want to be alone :’(
By the time a bad idea makes it to a second place at the Olympics, I’m likely to start paying attention.
Either to the idea or to the idiot who probably could’ve had a gold medal if the idea was really as bad as it’s detractors suggest.
“…it’ll never catch on…” has been said about most products we all use on a daily basis. Most famously about the computer.
The Beatles were rejected by 11 (or 14, I can never remember) record companies.
The Colonel had his recipe for fried chicken turned down something like 53 times.
If everyone believed that you could never have a shift-on-the-fly uni, we wouldn’t have the Schlumpf. Even Harper, who must be one of the top three best-informed people in the world when it comes to geared uni-hubs, regularly said that he doubts if ‘shift-on-the-fly’ uni-hubs would ever be feasible.
Or just not good enough, yet?
There is a better mousetrap out there.
There is an improvement on the wheel out there.
Now if the father of the kid who has the idea will just stop telling him to shut up and eat his cornflakes…
Certainly, there are some good ideas which were slow to be adopted.
But there are many more ideas which are simply bad, and ovalized chainrings are one example.
Ovalized chainrings are an odd one. Whilst most people pooh-pooh them, there are a few really respected people like Sheldon Brown who like them.
My dad has ridden on some oval rings for the last 10 years apparently they’re good if you have knee problems. He does probably a couple of thousand miles a year, so I guess they work okay for him.
They seem to make sense, because even the best spinner can’t generate as much power at some points in the pedal stroke.
Hey, Im in cyberpunks Avatar!
an easy way to make a pair
go off a six foot drop with a cotterless crankset
Too bad thats not how it works, did you see the diagram of what the cranks do while you pedal?
no i didnt, but i dont want to either