EBike discussions

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ShowMaster
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EBike discussions

Post by ShowMaster »

I'm thinking of using our RC brushless motor options along with esc's and lipo's.
The cost of any kit is IMO to the moon?
Especially if you don't want to use a heavy battery.

My wife can't handle the added 30lbs it all adds. I can't handle the $ price of a ready to run or $1000 kit!

I remember in the past seeing a bike with an assist that rubbed on the back wheels tire. It used a motor, small chain drive to a rubbing drive roller pressed against the tire. Water could make it slip but it was ok on dry roads. Living in LA, we only dream about rain,
So I'm thinking, what about using a outrunner motor and press its shell against the tire? Use a large diameter low rpm one?
Make a seat post mount to spring load/press it against the tire and have a reload lever for free wheeling peddling,
Use a high amperage, high voltage ESC along with a servo driver for speed control.
Maybe 24-36-48v system. Then use lipo's from HK or others, in series or parallel.
Higher voltage lighter packs I think.
I'm just looking for a DIY simple add on boost for longer rides, especially going back home. Peddle until your tired, e-power help up a hill or back home.
I'm thinking of a top speed of 15mph, but it's more about assist on inclines or returning home.

I understand that by being a push on the front of back wheel, that automatically increases the push pressure against the wheel? Then of course, there's the front tire?
I'm thinking the motor mount would also need a bearing the normal prop drive would mount it to even and balance the shell pressure? The shell may need a rubber tire/some drive surface on it to improve the traction to the tire?
So, anyone been thinking about a light weight DIY ebike setup using RC electronics?
SM

pmullen503
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Re: EBike discussions

Post by pmullen503 »

I'd worry about torque with a typical outrunner. I suggest you look into the motor in the hub wheels. I have one and it's very nice and quiet. When the lead acid batteries go I was thinking about building a new pack from A123 cells. They are much more robust than lipos and no fire hazard. You could still use an rc car ESC and a servo tester to drive it.

I bought a kit, which had all the parts. It was worth the extra cost.
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ShowMaster
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Joined: Thu Dec 29, 2011 3:44 am
Country: -
Location: Los Angeles, CA USA

EBike discussions

Post by ShowMaster »

pmullen503 wrote:I'd worry about torque with a typical outrunner. I suggest you look into the motor in the hub wheels. I have one and it's very nice and quiet. When the lead acid batteries go I was thinking about building a new pack from A123 cells. They are much more robust than lipos and no fire hazard. You could still use an rc car ESC and a servo tester to drive it.

I bought a kit, which had all the parts. It was worth the extra cost.
The issue is that my wife is a small framed person and the lead aced batteries are heavy. So yes to lipo or any lighter better battery.
The bikes we have use shocks in the front forks. I've read that a hub drive wheel isn't recommended? For rear wheel it becomes more involved?
I have a 27" wheel bike.
The original Curie bike kit had a shaft pressing on the tire and the one I tried did well on flat ground. Very simple setup. Not wheel size dependent was the plus.
Being that I see 1/4 scale electric planes doing 3D, I thought the motors had the power and case size diameter to think about using as a rubbing system. They are 1kw or larger.
I'm ok with a front hub powered wheel setup if it's safe to use but do need to work out the battery weight issue for her.
Thanks for the ideas.
SM
In reading up more on fire driven setups I see that tire wear is a major issue. So I guess it's back to something hub driven, front or back wheel, and a battery option that's light.
More reading.
Last edited by ShowMaster on Sun Sep 06, 2015 6:23 pm, edited 1 time in total.
Reason: added text

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