a new gadget for the new year

BennyMul

http://www.rockthepost.com/posts/view/1847/ZTorque-Bicycle-Cranks

Will this take off ?

Kurt Godel

BennyMul wrote: »

http://www.rockthepost.com/posts/view/1847/ZTorque-Bicycle-Cranks

Will this take off ?

Not a hope. Anyone with a basic understanding of vectors will notice the fundamental design flaw. This crank is a "free energy" concept, it can't work as proposed.

BennyMul

but the man said

Kurt Godel

Their proposal is to take a lever (the crank), and lengthen it, to get greater torque (Archimedes' law of the lever). However, for this to have effect on a standard bike, the cranks would be too long, and would hit the ground. So they fold the cranks up in a "z" shape to counteract this. At the same time counteracting any perceived lengthening advantage. You couldn't make it up:D

RayCun

... but ... but .... I paid a fortune for that set of z-shaped spanners :eek:

sconhome

http://www.kickstarter.com/projects/1202837765/z-torque-bicycle-cranks-ride-faster-longer-easier/comments

Tried to raise funding for it and failed before. Some really interesting pieces of opinion in the comments including a very detailed piece by an engineer- Terence.

Also the smack down & pin re his idea not being new as a similar ideal was launched in 1981 http://www.classicrendezvous.com/Italy/PMP_crk_ad.htm and died a slow painful death judging by the timeline.

Guy is probably up to his hock in development costs he doesn't want to listen to the advice but as the saying goes, when in a hole stop digging.

Oryx

Kurt Godel wrote: »

Their proposal is to take a lever (the crank), and lengthen it, to get greater torque (Archimedes' law of the lever). However, for this to have effect on a standard bike, the cranks would be too long, and would hit the ground. So they fold the cranks up in a "z" shape to counteract this. At the same time counteracting any perceived lengthening advantage. You couldn't make it up:D

So their perception of an easier ride was
a) placebo effect?
b) makey uppey market speak?
c) glenn proving he is clever but with no cop on?

Kurt Godel

Oryx wrote: »

So their perception of an easier ride was
a) placebo effect?
b) makey uppey market speak?
c) glenn proving he is clever but with no cop on?

I don't know what their perception was based on, but the physics is the same as in the example Amphibkingwest gave. The whole object of the crank is to turn the sprocket, and it doesn't matter where this energy comes from. The vector forces V1+V2 below are equal in magnitude to V3... if only there was some simple device to connect the pedal and sprocket along V3...:D

[IMG]https://lh4.googleusercontent.com/--ek7WTX7GL4/UO7IA9fOx_I/AAAAAAAAAzs/4y483F6R_zo/s800/CrankVectors.jpg" height="389" width="619"[/IMG]

BennyMul

lets be honest the main problem with this is it lack a power meter,

peter kern

thats a long enough crank me thinks

Kurt Godel wrote: »

Their proposal is to take a lever (the crank), and lengthen it, to get greater torque (Archimedes' law of the lever). However, for this to have effect on a standard bike, the cranks would be too long, and would hit the ground. So they fold the cranks up in a "z" shape to counteract this. At the same time counteracting any perceived lengthening advantage. You couldn't make it up:D

hardCopy

peter kern wrote: »

thats a long enough crank me thinks

That bike would be very handy for having a shave while commuting.