swren1967

I'm thinking about buying an electric motor assisted bike for my commute. I want to be sure that the bike will last for years, though -- I don't want it to be like my electric lawn mower. I bought the mower -- used it a year, the battery stopped holding a charge, and I can not replace the battery. Now it is useless junk.

Are there electric bikes that use standard rechargeable batteries. Something that I know I can replace when I need to?

Does anybody have other advice about electric bikes?

cheg

These guys are good. The Giant LaFree Lite is a good design, though it uses a special NiMH battery pack. Don't know what bikes use "standard" batteries. It would take a lot of D calls to drive a bike. Sealed lead acid batteries are widely available in many sizes but the power to weight ration is not so good.

BTW: are you positive that no one in the world makes a battery that will work with your mower?

PS: You are probably going to get flamed for asking about electric bikes. Riles up the purists.

swren1967

> PS: You are probably going to get flamed for asking about electric bikes. Riles up the purists.

I think I can handle that. I've been a "purist" for 35 years. But to get to and from work, I'd like to have a little electric assistance.

If I lived 20 miles from work, I'd get on my road bike, and I'd plan on taking a shower when I got downtown. If I lived 3 miles from work, I'd ride my bike and not even worry about getting sweaty. As it is, I live 7 miles from work. I just barely start to build up some sweat when I get here. A little electric assistance is all I would need to make my daily commute quick and sweat-free.

So what's wrong with that? Would the purists rather that I continue to drive my 4-Runner to work?

One fewer car on the road is always good.

cheg

There is a list server for power assist bikes:

https://groups.yahoo.com/group/power-assist/

Lots of mad scientists on there.

EnigManiac

I agree. I don't ride for purists sake, myself. I don't ride to satisfy the purists perception of bicycling or commuting. I don't ride to conform to strict and narrow opinions of 'serious cycling.' I ride for me, for my economics and my health and the fact that I neither want to be jammed into a crowded bus or subway nor trapped within a car. It's very selfish, really. It's not even really about the environment; that's just a positive by-product. But if I wanted to add electric-assist to help me move my 45lb bikes, I'd do it without the slightest hesitation or concern about the scorn from 'serious bikers.' It's all about me, after all.

jeff-o

You can also get bolt-on gas engines for bikes. Great, now I'M going to get screamed at for advocating the use of gasolene. The 48cc models fall below the legal limit where you'll need a licence, but will still propel you to 30 mph on flat roads without pedalling. They cost about $150, far less than buying a whole new bike (assuming you have an old one to use for this project). You may also want to look for electric conversion kits.

theden

I have one of those 48cc motor kits on a cruiser. It cost me $177 to my door, and $60 for the bike, and took about 4 hours to install. It is a fun toy for short distances (actually a 7 mile commute may be perfect for it), but I much prefer my regular commuting bike to get to work and back. I also looked into electric bikes, but since they start around $1,000, I figured I'd go with a gas motor first (total cost around $300) and see how I liked it. So far so good, but I still am not completely sold on its reliability (only 50 miles on it so far). Check them out at www.motorizedbikes.com if this would work for you...

jeff-o

Can you pedal at the same time as the motor is running, to go even faster? How loud is it? How does the clutch/throttle (if it has one) work? How does the gear attach to the rear wheel?

jagged

Check your local laws; in many states, something is a "bicycle" only if it is propelled solely by human power. Once you strap on a motor or engine, you might lose the right to ride in bike lanes or on bike paths, and might even lose the right to weave between traffic. Think of it as a really weak motorcycle rather than a really strong bike.

I always wondered about whether the weight of the motor was worth it, but I guess that's an engineering problem that is about to be solved.

theden

Can you pedal at the same time as the motor is running, to go even faster? How loud is it? How does the clutch/throttle (if it has one) work? How does the gear attach to the rear wheel?

Yep, you can pedal it too. Sometimes I pedal little bit on the real steep hills to help it up. It is also nice to know that if it breaks down I can always pedal home. Pedaling won't help you go faster though, your speed is pretty much limited to the upper rpm range of the motor and the size of the drive sprocket.

It is a little loud I guess, but not too bad. Probably not far off from a normal motorcycle.

The throttle and clutch operate just like a motorcycle.

The drive sprocket attaches on the left side of the bike, using 9 bolts and rubber washers weaved through the rear spokes. It actually works pretty good. The higher spoke-count wheels are probably better though (36 is what I have).

As far as legality goes, it is definitely a gray area. The DMV here had no idea. Usually if I see a cop I just pedal along with the motor, just so it looks like a normal bike... I have heard though that anything under 50cc is ok. It may be licensed as a moped, if anything, but Allstate told me they can't insure something that is essentially homemade. Anyway, I know a couple people that have these and have ridden thousands of miles with no cop-trouble.

John Ridley

I have a friend who rides an electric assist bike. He's a bit of a tinkerer.

Keep in mind that there is no such thing as a non replacable battery. I regularly crack "non-servicable" battery packs for my power tools and cameras and replace the cells inside. You need to be willing to solder.

Check this place: www.batteryspace.com - they have almost everything.

My friend who has the electric assist bike bought some F cell NiMH's from there and used them to upgrade the NiCad pack that came with his bike.

I don't think any bikes are using LiIon, the discharge curve doesn't match, but if you play with them be careful, if you hook them up wrong and overcharge/overdischarge them they can explode.