Slashdot Mirror
Crowd Funding For Crank Physics
BuzzSkyline writes "A new design for bicycle cranks violates basic principles of physics, but that's not stopping the inventor of Z-Torque cranks from trying to raise thousands in start-up capital through crowd funding." The picture looks intriguing for a fleeting moment before it looks silly. Covered in similar style at a site I'm glad to discover exists, the Bicycle Museum of Bad Ideas.
that it cannot be used to extract money from the gullible and hopeful -esp in America where the common man knows so much more than the engineer or the scientist...so in that sense it is a good idea just like all the weight loss and sex aid supplements you see on late night cable
-I'm just sayin'
It's possible that by moving the pedal so the cyclist's legs are in a different position during the pedal cycle
Doesn't work like that. Draw a crank like this on a piece of paper, jab a pen through the point where the crank would connect to the gear and rotate the paper: you'll quickly notice that the thing still follows the exact same circular motion as any old, regular crank does, and therefore the legs don't actually assume any different a position during cycling. If the crank was displaced from the center then there would be a difference as it would no longer follow the same path as a regular crank, but alas, that's not the case here.
An analysis, found on their webpage:
http://www.z-torque.com/Portals/6/DrHuangReport.pdf
Claims that the benefit is from two side effects of the claim:
The increased mass gives a flywheel effect, meaning the pedal goes through top dead center easier.
The long shape bends under pressure, which does slightly increase the length of the arm under pressure.
So, by going to carbon fiber (lighter, and most likely stiffer), they'll most likely negate any benefits!
> so the cyclist's legs are in a different position during the pedal cycle
Only because of the bending. If it were stiffer, position would be exactly the same.
Manual of Patent Examining Procedure; 706.03(a) Rejections under 35 USC 101 III A rejection on the ground of lack of utility is appropriate when ... (2) an assertion of specific and substantive utility for the invention is not credible. Such a rejection can include the more specific grounds of inoperativeness! Such as inventions involving perpetual motion.
You seem to regard science as some kind of dodge... or hustle.
I see a way that could make the crank behave differently compared to the classic crank: if the metal has a bit of elasticity, thanks to the z shape some force could be stored within the "spring" (crank angle) during the top-bottom push move and released at the bottom just before the other foot takes over the push.
You would think, but read this about the Interdrive crank that uses actual springs to see an explanation of why this logic doesn't work: "for energy stored in the springs, you wind up doing the work twice: once to compress the spring, then again later while you fight against the spring as it expands." I imagine material compression would similar issues.
It must have been something you assimilated. . . .