Sinclair Zeta for this century?

[pdarnett]

http://www.gizmag.com/shareroller-electrify-bicycle-share/30918/

Looks like someone is re visiting Sir Clive's old idea again. I may have a go at a friction drive this year again.

 

[trex]

good on paper but.. consider that the weight on the tyres usually exceeds 30kg and sometimes they lose friction - you can't expect much from about 5 kgs of pressure with a friction motor. Small battery, gutless motor, it's not good.
Fuel cell powering conventional e-bikes is the way to go.

 

[Deleted member 4366]

If the box is rigidly mounted, you could get the necessary friction force. I think it works like the Kepler Commuter Booster. Once it gives power, the friction drags it further round to give a servo effect, and when you free-wheel, the direction of the wheel pushes it back out. The Kepler one is very simple and clever. It totally disengages during free-wheeling, and uses the motor torque to bring it back in contact and then self-servo into full drive position.

it looks like a lot of development has gone into this one, so I'd be surprised if it doesn't do what's claimed, especially as the claims seem conservative and realistic: 18 mph and 12 miles.

I guess you need the right tyres for it to work properly, especially in the rain.

 

[trex]

it's a bike sharing scheme, the host bike still needs the mounting adapter for the motor box.
Would you like to lug around your 6kgs motor box or a 150g hydrogen cartridge?

 

[Deleted member 4366]

it's a bike sharing scheme, the host bike still needs the mounting adapter for the motor box.
Would you like to lug around your 6kgs motor box or a 150g hydrogen cartridge?

It says 2.7kg or 3.2kg in the article, I guess 3.2kg is for the larger battery. that's not too bad, is it?

 

[trex]

it seems a bit light. They claim motor output of 700W.
You have already the (steel?) casing, the controller, motor, pinch roller mechanism, that's probably 2.5kgs already, does not leave much for the battery. May be motor or battery is made with papier-mâché.

 

[pdarnett]

And no room in the case for your lunch

 

[Deleted member 4366]

it seems a bit light. They claim motor output of 700W.
You have already the (steel?) casing, the controller, motor, pinch roller mechanism, that's probably 2.5kgs already, does not leave much for the battery. May be motor or battery is made with papier-mâché.

Have a look at Kepler's Commuter Booster. It's capable of massive power for a tiny weight. hiscan pump out 2kW from a 1kg motor. These R/C motors are exceptional when it comes to power to weight ratios.

http://www.commuterbooster.com/home

 

[flecc]

These R/C motors are exceptional when it comes to power to weight ratios.

And noise!

 

[Geebee]

And has issues in the wet, looked into it.