Electric Bikes - Seeking Advice

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View Full Version : Seeking Advice


phlewt
07-19-08, 05:57 PM
I'm hoping to get some good advice from members of this forum. I'm thinking about getting an electric bike to help me get back and forth from my home to various places I go in the nearby town. It is approximately 7 or 8 miles to town from my home. I do not currently own a bicycle, so all trips are done by car.

I've attempted to gather some info on current offerings, and here is some of what I've found:

Curry eZip -- SLA battery, 450W motor with separate chain drive, weight 72lb, claimed range is 18-25 miles, price ~ $400

Ecobike Elegance -- 36V-10Ah lithium battery, direct hub 360W motor, weight 52lb, claimed range is 25 miles, price ~ $1700.

Schwnn Continental -- 24V-10Ah lithium battery, direct hub 180W motor (pedal connected by shaft drive, so no chains), weight unknown, claimed range 40-60 miles, price ~ $2080

Bionix PL350kit on a $500 bike -- 36V-10Ah lithium battery, direct hub 350W motor, weight 50lb, claimed range is 60 miles, price ~ $2200

Obviously the eZip has the most attractive price, but I find that not all are satisfied with it. There are concerns about removing the rear wheel if one needs to replace a tire.

The bikes with the lithium batteries come in much lighter, but the price is high. Which do you think offers the best value, the eZip or one of the bikes with the lithium batteries?


JinbaIttai
07-19-08, 06:51 PM
I'd start by determining which battery is right for you, as far as voltage and type. The higher the voltage, the higher the top speed.

I am not 100% sure on the top speeds, but I think 48 volts will put your top speed in the upper 20-low-30s mph.
36 volts--low 20s.
24 volts, mid teens. 36V seems to be the most popular compromise.

As far as battery type, Will you need to lift your bike to store it? Do you live up a set of steps? You may be able to get away with using cumbersome Sealed Lead Acid. SLA batteries are a bad idea if you have to lift the bike because of their weight. At $50, 25lbs of 36V 10ah SLA will last 100-200 cycles. If you can invest more money up front, LiFePo4 batteries are the latest thing and 10lbs of them will last 1000+ cycles for around $400 at best price.

If you piece together the battery, the kit, the bike, a better rim, you should be able to keep things under $1000 with a modern battery.

Are you going to buy your bike secondhand on craigslist?

Ampedbikes.com has a great price on a front hub kit, with an upgraded rim. Goldenmotor.com has very inexpensive front and rear hub kits, but will they will need a better rim, and you will receive a beat up looking and possibly damaged package, guaranteed. For many, the price is worth the risk.
If you search for Ping's batteries on eBay, you can have a LiFePo4 battery at a greatly reduced price, but it will require some polishing up, so to speak.


7 to 8 miles to work is a suitable range for SLA and some pedaling, are there many hills on your route? Keep in mind that SLAs hate to sit in a partially discharged state and it will reduce the batteries life if you can't plug it in to charge at work as well as at home. If you go LiFePo4, no worries, charge it only once daily.

Hope this helps.

jerryt
07-19-08, 07:21 PM
The advertised range of an ebike is usually exaggerated. All claims consider that you are a lightweight athlete and will provide equal assistance by pedalling. I don't know the exact figure but guess you can cut the claimed range by 30% +.

Range (and speed) will decrease by a factor of your hilly terrain, your weight and the total weight on the bike and will increase by a combination of higher battery amps and volts and improved battery chemistry. Street tires are a plus.

My experience is with front wheel hub motors which you can start with a cheaper, SLA battery set-up and if you decide its good you can upgrade to a better chemistry like lithium (and a new charger of course).

You mentioned one kit. I started with a cheap bike and a Wilderness Energy 36v kit (roughly $500 - bushed kit $400) and it is great and can be upgraded to 48 volts and better chemistry. I weigh 240 lbs and get 18 to 20 miles on flat terrain with no pedalling.

Lots of threads here praise the eZip and it seems a good value but I don't have first hand knowledge. I believe its 24 volts.


phlewt
07-19-08, 11:32 PM
Thanks for all the information. It gives me much more to think about.

I do not presently own a bike, so I am inclined to buy a finished unit and not piece together a kit. But after looking at the ampedbikes and goldenmotor links, it seems possible to put something together for quite a bit less with a kit.

I am retired, so my interest is more in using it for frequent trips to the grocery store, post office, etc. Obviously I would not be able to charge it up except at home, so I would need to go around 15 miles without charging the battery. I am able to pedal the bike on the straight and level, and I think that would be fun much of the time. Living in Arizona, it would be nice to have more assist on the hot summer days, however. My housing development has an entrance road that rises a couple of hundred of feet in elevation over about a one mile distance. It would therefore be nice to have assist available at the end of my trips.

Anyhow, thanks for all the help!

stokell
07-20-08, 08:45 AM
One more thing. Unless you spend the big bucks, you will get a pretty poorly made bike, with a first-generation drive. That will probably be okay for the distances you are going. It will also buy you some time to build up from a kit. All you need is a good quality bike, a kit and a few hours time.

Assuming you are going with the pre-built, keep in mind that manufacturers are very optimistic about both range and speed, even with full pedal assist. Don't let your SLA batteries go fully flat and un-recharged. You may only get a couple of hundred charges out of them at best before they become landfill.

Good luck!

crackerdog
07-20-08, 11:41 AM
As far as range with a hub motor, I think Andy at FalconEV has it about right. With LiFePO battery, it works out to be 1 mile per amp hour with little or no pedaling. With SLA it is about 3/4 of that. Since you don't have a bike now you won't be able to help as much when you first get your bike as you will be able to in 6 months.
You might also consider an inline motor like Electroportal or Cyclone (same kit). Being retired, you may consider a recumbent for comfort. I use an EZ-1 recumbent with an Ecospeed inline motor for my utility ebike. It is more money than you need to spend, I use it for hauling 8 foot long trailer filled with my construction tools. Look on Craigslist for a used recumbent, Americans don't use their bikes much so they are in great shape if you buy used. The bikeE AT (with the shock absorber under the seat) is also easy to put the E-4 kit on (Electroportal calls their recumbent kit E-4). The knock against recumbents is they don't do hills well but once it has one of the 7lb E-4 kits installed, it is great.
Hub motors are easy to install and are very quiet but are heavy and not as efficient as an inline motor. The inline motor is easiest to install on a recumbent, though Cyclone has one that goes on a diamond frame bike (haven't tried that yet) but is more complicated to install. The inline makes more noise, less than a car going by but you can hear it until you get up to 12 to 15 mph, then the wind blots it out. The Lithium Iron Phosphate (LiFePO) look like they are cheaper in the long run and the performance is much better than SLA. They are lighter and your bike is of course easier to mess with when you have less weight on it. You might consider a system that allows you to quickly remove the battery pack if you decide to go with SLA. This would allow you to lighten your bike quickly if you want to lift it up.

cerewa
07-20-08, 03:33 PM
The higher the voltage, the higher the top speed.

this is true if the motor remains the same, but the speed you'll get at a particular voltage depends on the type of e-bike motor.

With LiFePO battery, it works out to be 1 mile per amp hour
The actual amount of energy used is a better measure unless you are comparing the same voltage of battery - energy is measured in watt hours (or kilowatt hours) and at 36 volts, 1 mile per amp hour sounds about right (for no pedaling) but at 24 volts you'd need more amp hours (for the same watt hours) and at 48 volts you'd need fewer amp hours for the same watt hours. A 48v10Ah battery could easily be configured as a 24v20Ah battery by moving a couple of wires.

lynnala
07-21-08, 03:53 PM
I've got the eZip you are talking about and I am quite happy with it. I am 51 years old, female, and hadn't ridden a bike for years. The area I live in is hilly, so I use the battery assist quite often, but I also pedal constantly. I think if you are just using it for riding to the store and back, you would be fine with the eZip. If you are riding mostly flats then you won't be needing to push the battery to it's limits, and you can probably get 16-plus miles out of it. It is a heavy bike though, if you need to carry it up stairs or something, think twice! Also, I changed the rear tire by myself, once you figure it out, it really isn't too hard, you have to lift the motor off while you take off the tire, other than that, it's a pretty standard change.