New crank design on Kickstarter - RRAD

[C R]

I did physics at Genocide College [(c) Jeremy Hardy] and TBH we usually didn't venture into the Mech Eng slums. They were pits of crime, disease and empirically derived equations <shudder>.

Urgh, empirically derived equations, I am going to have nightmares for a week now.

 

[Alan O]

On a more serious note it *might* have some utility for a very few riders who have a limited range of knee movement, but it'd be pretty niche.

He needs to hit his funding target of ~75k by the end of the month and has managed to get 5k so far. I'd be surprised if he hit the target.

I'm surprised he's managed 5k. His video pitch is devoid of meaningful content - just "Trust me" and some vague handwavery about muscles and how pedaling is inefficient, which it isn't.

A mechanism needed to turn pump action into rotary action? Pedaling is already a rotary action! Legs with knees in them are very good at turning pumping action by the thighs into rotary action at the feet.

And did anyone notice how many cuts there are in the vid? It's close to every sentence being a separate take, with jerky joins between them.

 

[Pale Rider]

The claims seem extravagant, but as mentioned 'treadle' action bicycles seem to work.

I've never tried an Elliptigo but there was a small squad of them on the last but one London Edinburgh London audax.

If I recall, a couple conked out/ran out of time, but one guy may have finished.

Similar results to what might have been expected had the same riders used traditional bicycles, which in turn suggests the Elliptigo has similar efficiency.

 

[Randy Butternubs]

On reflection I think I may have been a bit over-skeptical. Treadles still have the same 'dead zone' that normal cranks do so this is actually quite different. While each leg individually still has inactive time, together you have constant down stroke.

'Dead zone' is a bit of a misnomer though. With the cranks close to vertical you have, effectively, high gearing rather than wasted movement. Even that assumes that legs operate like pistons, pumping straight up and down without significant sweeping movement, which doesn't seem like a given.

His video only shows single-speed bikes so I've got to wonder if it's a solution to stalling on hills. If so, it seems like having multiple gears would be a simpler solution.

 

[Alan O]

From Wikipedia... "From a mechanical viewpoint, up to 99% of the energy delivered by the rider into the pedals is transmitted to the wheels..." (with reductions for various kinds of gearing).

So with the 50% improvement in efficiency, we'll now get up to 148.5%?

 

[Alan O]

Looking at this a bit more, I don't think I understand the finances of the thing.

It looks to me like he's selling a water bottle for $25, a plastic road version of the device for $250, or a metal version of it for $499 - but with no guarantee that you'll actually get what you pay for. Or you can just give him less than $25 and get nothing in return.

Have I understood that? And if so, how is that a good deal?

Oh, and I also see that for $999 you can get "Digital blue prints of the RRAD kit designs - including the off-road version - with a personal, experimental and non-commercial license so you can make your own version of the device. Perfect for e-bike manufacturers!" How is a personal, experimental and non-commercial license perfect for e-bike manufacturers?

 

[Bollo]

Looking at this a bit more, I don't think I understand the finances of the thing.

It looks to me like he's selling a water bottle for $25, a plastic road version of the device for $250, or a metal version of it for $499 - but with no guarantee that you'll actually get what you pay for. Or you can just give him less than $25 and get nothing in return.

Have I understood that? And if so, how is that a good deal?

Oh, and I also see that for $999 you can get "Digital blue prints of the RRAD kit designs - including the off-road version - with a personal, experimental and non-commercial license so you can make your own version of the device. Perfect for e-bike manufacturers!" How is a personal, experimental and non-commercial license perfect for e-bike manufacturers?

Welcome to Crowdfunding!

And remember Kickstarter is at the reputable end of the spectrum. For the full monorail experience, Indiegogo is the place to go. Check out the Limits power meter debacle on here, DC Rainmaker and the Indiegogo project.

 

[nickyboy]

I love these crowdfunding idiots.

He's not considered basic physiology. Regardless of whether you can increase the possibility to apply force to the pedal, you're going to be limited by the thing applying the force...the CV system

If you're on the limit climbing with a conventional bike, that's what will stop you going faster, not how the cranks work

 

[keithmac]

Welcome to Crowdfunding!

And remember Kickstarter is at the reputable end of the spectrum. For the full monorail experience, Indiegogo is the place to go. Check out the Limits power meter debacle on here, DC Rainmaker and the Indiegogo project.

The Simpsons monorail?..

 

[T4tomo]

On a more serious note it *might* have some utility for a very few riders who have a limited range of knee movement, but it'd be pretty niche.

He needs to hit his funding target of ~75k by the end of the month and has managed to get 5k so far. I'd be surprised if he hit the target.

I’m surprised he’s got 5k to be honest.

 

[Bollo]

I’m surprised he’s got 5k to be honest.

There's a bit of me that admires the chutzpah of asking for the money.

 

[keithmac]

Look like when you were 8 years old and just getting into fixing bikes with tools.

Who hasn't put both cranks in the same postion and ridden up and down the street?, only when you're 8 you realise it's a stupid idea and put them back to normal; not try and raise £75k..

 

[keithmac]

I was going to mention the hinged crank arms and what a daft idea they were until I watched the video on this page.

Take it all back they look like and excellent idea..

https://www.sportwheels.ca/products/custom-hinged-crank-arm

 

[PaulSB]

I backed a Kickstarter project once. It was a device to make a quick release more secure from wheel theft. It cost me £20. It was rubbish. The project wasn’t fulfilled and it quickly became apparent the people who made the most noise received the product.

Personally I wouldn’t go near Kickstarter again.