Electric 3-wheel adult bike.....

[Shari]

I need a little help with an electric bike we have for hubby's use. We bought this a couple of years ago and found it just didn't have enough 'power' for his taste.

Has anyone ever worked on an electric bike that could give us guidance as to what size motor we need to move my 210# hubby up a slight uphill (10% max) grade over 500 feet using only electric power?

 

[lukem]

To size the HP rating of the motor, one needs to know how fast said husband desires to travel up the grade.

 

[Shari]

To size the HP rating of the motor, one needs to know how fast said husband desires to travel up the grade.

"A fast walk" would be fine. Anything faster would not be good.

 

[lukem]

You'll have to convert watts to HP, but this should work well for you. Then size the DC motor's HP rating or wattage to to fit. I come up with about 1/2 HP.

1 watt =
0.00134102209 hp

http://bikecalculator.com/examples.html

 

[SlyFerret]

I have a feeling that the battery is going to be your biggest challenge, not the motor. Post pics and other info as you keep working on your design. THis sounds like a very interesting project!

-SF

 

[Shari]

I have a feeling that the battery is going to be your biggest challenge, not the motor. Post pics and other info as you keep working on your design. THis sounds like a very interesting project!

-SF

I don't know much about anything electric (hey, I took secretarial courses in high school but he's got a really large cargo basket on the rear of the bike which would probably fit 3-4 riding mower sized batteries or 2 deep cell marine batteries but then we would have to account for the weight of the batteries.

We aren't starting from scratch as the bike was built as an electric so we have a motor, etc. but just found it undersized for his weight. This is not to say we will probably have to do some major mods to get it where hubby wants it.

Let me look around for my camera and, if found, will post some pictures.

 

[lukem]

Batteries will impact duration. Higher HP motor will impact speed and "zippiness". If the RPMs are the same should be as simple as hooking up a new motor using existing gearing and wiring. Got to be careful the new motor doesn't draw more amperage than your wiring can handle though.

 

[Backwoods Savage]

I need a little help with an electric bike we have for hubby's use. We bought this a couple of years ago and found it just didn't have enough 'power' for his taste.

Has anyone ever worked on an electric bike that could give us guidance as to what size motor we need to move my 210# hubby up a slight uphill (10% max) grade over 500 feet using only electric power?

Shari, although they don't sell electric bikes (I don't think so anyway) I'd still call the Hostel Shoppe there in WI. 800-233-4340

In the meantime I'll contact a couple other places to see if they can help. I know a couple really good people who own bike shops.

 

[semipro]

Is the motor one built into the wheel hub (hub motor)? If so I'm guessing one rear wheel has a motor? If a hub motor, what size wheel is it?
Many hub motors are around 250 watts but range in size up to more than 3 times that. You may just be able to buy a new wheel with motor and then add batteries in parallel to provide more capacity.

 

[Shari]

Guys, Thanks for all the replies. Let me locate my camera and I will post pictures which (hopefully) will answer questions posed.

 

[begreen]

This one is designed for up to 500#:
http://dingbikes.com/electric-trikes/glide-special/

 

[semipro]

This one is designed for up to 500#:
http://dingbikes.com/electric-trikes/glide-special/

Its hard to imagine how a front wheel drive trike with most weight on the rear wheels would make a 10% grade.

 

[begreen]

Lower gearing?

 

[semipro]

Lower gearing?

I was thinking that traction between the front wheel and ground might be an issue.

Edit:hub motors aren't geared. They're direct drive.

 

[begreen]

I hear ya. The unit I posted said it was a 3-speed, but I think that is for the pedal power assist. The other alternative would be reverse, but I don't see that option.

 

[Shari]

Well, the search for the camera has been in vain...... but I did get some info on his bike.

The model name is "Lightning Trike".

Here's one link: http://www.walmart.com/ip/Worksman-Lightning-Trike-Electric-Tricycle/5691453

and another: http://fubike.blogspot.com/2013/06/worksman-adult-port-o-trike-lightning.html

The above links say it is now manufactured by "Worksman" whereas ours says "Electric Mobility Corp." - but then again I think ours is the 1989 version.

There appears to be at least appearance changes: Our switch is different - ours contains on/off for a headlight and a horn. There is a somewhat similar front hub like in the links above and a motor is mounted behind the pedals. Battery power is simply a deep cell marine battery. New models fold for storage, ours does not.

Ours is a 3-speed shift like a regular bike w/electric as an option - which I think is different from the above links. Max weight limit is 300#.

Numbers on our motor are: 478487 12v 2033427MO3O6M.

We had (unsuccessful) "help" when we were having problems with the switch and it hasn't been looked at in at least a year.

 

[begreen]

A 12V motor is going to be wimpy. Most modern units are 36-48v including the modern Workman that you posted the link to.

 

[Shari]

A 12V motor is going to be wimpy. Most modern units are 36-48v including the modern Workman that you posted the link to.

Yes - therein lies our current problem. I'm thinking a whole new electrical kit is what I should be looking for but I know zip about what to look for.

I found a Schwinn electrical kit - but it goes up to around 14 mph and I think that is too fast for hubby to handle.

 

[begreen]

I don't think he'll be going 14 mph uphill!

 

[Shari]

I don't think he'll be going 14 mph uphill!

Probably not - but where there is an uphill there is also a downhill. Seriously though, I know he'd like to go on a fairly long bike ride and considering I would pedaling (non-electric) next to him I'd rather an electrical unit that one can set various speeds on. I'm not sure but I think a twist grip style might be a variable speed so I think that's what I'm looking for. The one he has now is 'full speed ahead', only on or off and I'd like to get away from that style.

 

[Backwoods Savage]

Shari, sorry but my other contacts were not of any help.

 

[semipro]

You can upgrade the bike by replacing the front wheel and controls and adding a 4th 12 volt battery with a kit like this:
(broken link removed to http://www.ebay.com/itm/2013-New-48V-1000W-Front-Wheel-Electric-Bicycle-Conversion-Kits-LCD-Display-/231009265827#vi-content)
Power would be increased from 600 to 1000 watts. The wheel should be a bolt-in repacement.
I'm not recommending this specific kit.

 

[Shari]

Semipro - Thanks for the link. I read through it and a lot sounded greek to me but I am learning a little. I did notice no batteries are included. The charger is rated for lead-acid batteris (I think I am leaning toward Lithium batteries) and then I read this "We offer one year warranty period due to quality problem" which kind of turned me off on the item.

 

[semipro]

Semipro - Thanks for the link. I read through it and a lot sounded greek to me but I am learning a little. I did notice no batteries are included. The charger is rated for lead-acid batteris (I think I am leaning toward Lithium batteries) and then I read this "We offer one year warranty period due to quality problem" which kind of turned me off on the item.

Lithium batteries are nice for energy density (weight versus stored energy) but they'll cost you. They'll also require a new charger.
You can definitely buy better quality kits than the one at the link above but you'll pay for quality. Bionix makes quality stuff. I've been eying one of their conversion systems for a while. http://www.bionxinternational.com/na-en/products/

 

[basod]

If you're just looking for a boost up grade the "easiest" mod would be to add a starter motor with friction drive to one or both of the rear wheels.
Would require some welding&wiring but the parts are fairly cheap