Motorized Electric BicyclesThe motorized electric bicycle is a quiet and efficient form of transportation for general commuting.
gruber assist
Discussion at Motorized Bicycle Engine Kit Forum in the Motorized Electric Bicycles forum. This is something I seen the other day it's called GruberAssist and it's a tiny 200w electric motor that slides ...
This is something I seen the other day it's called GruberAssist and it's a tiny 200w electric motor that slides down the seat tube and it's gears engage with the original internal gears of the pedal crank system and there is a small pouch that holds the battery.GRUBER ASSIST it's really revolutionary with it's stealth engineering.
I like it except it has the same problem that I would have if I hooked a conventional motor to one of the crank sprockets on a multi speed bike. The crank is going to always turn. Anytime the motor is engaged the crank is going to turn so when you go on the flat you still can't rest. Even going down small inclines the crank will probably turn some. At least that seems to be the case.
It is a good idea though. A two hundred watt motor is a good assist size I think. My 250 watt hub motor is a good assist but not good enough to do away with the pedals. The 350 watt pusher motor is good for slow riding up and down most hills. To keep the speed up I have to pedal up hill some. I am guess a 500 watt or more would be a good size to ride with minimal pedal assist.
Let me define terms here probably not what the maker would call it but. My hub motor has two different functions for me. There is pedal assist where I only use it to take some of the sting out of the pedaling. Then there is motor assist where the motor runs the bike and I rest up before the next hill or whatever. I call that motor assist.
In one the motor is helping me pedal in the other I am helping the motor maintain speed. In the case where I put a motor on my bike chain by running a chain to one of the crank sprockets. I had pedal assist which means I could turn it on to help me pedal up the hills. But if it wanted to take a break and let the motor run the bike, the crank would turn.
So this bike has only pedal assist. it can not be used to run the bike while you rest or the crank will force you to pedal anyway. I couldn't use it I don't have the wind to pedal all the time even when I am on the flat....
It is another alternative but I think that the izip is a better deal. I don't have an I zip either but it would seem like a better all around bike to me. The owner has the option to use it purely as pedal assist or to drive the bike some of the time as well.
gruber assist 
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