Less could be more, friction-drive

[emco5]

The logical side of my brain leans toward strong mid-drives that utilize a bike’s gear train, but the K.I.S.S. engineering principle keeps me pondering less complex ideas. Back in 2010, 'adrian_sm' posted about his Commuter Booster friction-drive idea at Endless-Sphere. From my perspective, it was a brilliantly simple way to add a bit of boost. Obviously, the small motor and wet-tire challenges are there, but the concept still has merit. Adrian_sm is no longer producing his kit but a very similar drive called "Hidden Power" is manufactured by a company in Korea. Little brushless motors, when allowed to spin and be geared down, can produce surprising torque for things like drills and saws. This Korean unit does not appear to have much gear reduction so I suspect that moderate wheel rpm is important to prevent a hot motor and ESC. Have any of you experimented with this unit? I’m really curious how efficient it is.

https://endless-sphere.com/forums/viewtopic.php?f=28&t=22187

http://www.hiddenpower.co.kr/international

 

[emco5]

FYI....
Google found data from a business in San Diego that used to sell the Hidden Power system. It appears that the motor is turned off to prevent overload when you'd need it most.... like on hills. I doubt rider safety is the concern.

"The electric speed controller cuts off power for your safety in the following events.

When you try to start the bike only with electric power.
When you try to use the power mode without pedaling after moving short distance at low speed
When you try to use the power mode when cycling uphill or when overloaded.
When you try rapid acceleration in power mode without pedaling.
At sudden start. (Even normal start may cause power-off sometimes in some unfavorable conditions.)
When the battery is empty. (Power cuts off automatically for battery protection.
In high temperature or when the kit recognizes certain conditions are unfavorable."

http://mefast.com

 

[MLB]

I think these would be perfectly adequate for MANY "real" riders (that want to peddle) , but most will never try one because they "can't make enough power" to be the self powered vehicle so many others expect.

 

[emco5]

Two other friction-drives for 2016 worth watching.

GO-E
http://go-e.bike/en/technik/
" ... it will not be possible to drive slower than 6km/h (3.7mph). So it won’t support you when you start driving uphill, you have to reach 6km/h with your own power."

ADD-E
http://www.add-e.at

 

[MLB]

On all (3) of my ebikes, I'm using "about" 25% of the available power when it's on. I'm strong and peddle all the time by choice, as these would be perfect for.
All of my setups are way overpowered, even overkill for me.