Originally Posted by NewbE-biker
that's a good link, thanks! I like the clear movies. I see how the rear wheel kits are a little more complex but surely doable as I saw in some of the other videos. The battery seems to be one of the biggest considerations, like you said 'getting what you want' out of the kit. I'm still comparing everything under the sun and just noticed that the one I was talking about before now has a
lithium polymer option: http://www.cleanrepublic.com/hill_to...rsion_kit.html
it's certainly a difference compared to the lower capacity SLA pack, so more thinking to do...
Sorry I didn't see your post with the question for me earlier. The motor on the kit you're looking at is 250W. It's probably a generic Chinese kit made for a world-wide market. The EU and parts of Asia have very strict limitations on maximum power and speed and 250W is about the legal limit. There are restrictions in North America. (For example, in the US, federal statutes require more powerful ready-made e-bikes with motors over 750W or speeds over 20 MPH to meet safety standards for mopeds/motorcycles set by the US Highway Transportation Safety Administration. Low-powered, ready-made e-bikes that have motors under 750W and speeds 20 MPH and under only have to meet the rather anemic safety standards for consumer bicycles set by the Consumer Product Safety Administration. At present, conversion kits aren't covered by these safety standards but I expect that to change as more powerful hub motors get shipped from China.)
The performance of the 250W motor may be adequate if you don't need much torque. However, if you live in a hilly area or are a larger rider, you may be unhappy with it's performance. I added the Currie kit, which as a 450W geared motor, because it has excellent torque and I live in the far norther US Rockies and my local rides are on roads with steep grades. I've been very impressed with the Currie kit. I added it to a 21-speed mountain bike so I have a slight speed advantage over the ready-made Currie bikes with the exact same motor since the Currie bikes are only 7 speeds. I normally pedal all the time and use power assist on the hills but I did check out the top speed with my kit without pedaling--it's 17 MPH on very knobby tires, if I changed out the tires, I could probably increase the top speed by 2 MPH. However, I don't really want electric assist for speed, I want it for help up the hills and I need very knobby tires to ride the unimproved gravel forest roads around me.
As far as the battery on the kit you're looking at, it may be lithium, but they don't specify that it's LIFEPO4 so I suspect it's simply a standard Li-ION battery. It's also only 8 AH, which won't give you power for very long. You could always go with a kit that offers SLA batteries and add a second LIFEPO4 battery later. Next month, I'll be building a 24V 20AH LIFEPO4 battery using Thunder Sky prismatic batteries to use as a second battery with my Currie system. The cells cost $256 at elitepowersolutions.com. I'll also be building a battery box for them that will slide into the Currie battery rack.
Before you pull the trigger on the system you're looking at, check out the following links.
I'd suggest that you check out Endless Sphere's forums. http://endless-sphere.com/forums
There's very detailed information on e-bike motors (hub and non-hub), controllers and battery technology. The more you research, the happier you'll probably be with your choice of a conversion kit. Good luck.