Bicycle motor reviews

Tecumseh Viper - by John Davidson

In December 99, I purchased a two stroke cycle Tecumseh Viper (Island Hopper type) bike engine via an internet site in California ( Actually, I was interested in getting a folding bike but noticed the Island Hopper engine ad. Anyway, to make a long story short, I ended up ordering a Dahon folding bike and a 49cc Viper engine with 2HP and centrifugal clutch. The engine arrived first and the folding bike came much later, so, in the mean time, I put the engine on my less than $70 mountain bike. Wow! Lot's of power and lot's of fun even in cold weather. Omaha, where I live, is quite hilly. The friction drive does slip a lot in wet weather and you go up a hill a lot faster when you pedal. Nebraska requires no title or license for the bike although you need a driver's license to use a moped on the road. I always use a helmet so I never checked into the laws. A moped has to have pedals and to be less than 50cc in engine power.

Eventually, the folding bike did arrive, and I put the motor on it. Having a motor bike in the trunk of my car has proved to be a real convenience for fun opportunities at parks, etc. However, with this particular model of folding bike, I had to make a part of my own mounting bracket, which wasn't any big deal but could be aggravating to someone who doesn't to tinker.

I like the centrifugal clutch as I don't have to play with another lever while riding. The motor works as advertised: 25 to 30 mph and 35 miles per quart of fuel mixed with oil. Since I bought the engine, apparently Island Hopper in Florida, who actually sent the motor is now advertising a smaller motor at 1.6 HP. When going out at full blast on the 2HP motor, I feel I have more than enough power, so the smaller engine might be something to look into. I have pictures to send anyone who might be interested. I am at

Italian Engine Connection - by Scott H.

The product is called an Italian Engine Connection. . It is working well so far. I've had it for four months now and had no problems. It's top speed is 30mph. It's a 2stroke and the gas/oil mixture is 40:1. I use it to go to school,friends houses, stores, bascially anywhere. It has a roller that rolls on the back wheel of the bike. The version I bought can also start and go without beginning to pedal. It gets 60 miles to the liter which is roughly 200mpg. I enjoy it but it's a shame it can't be modified to go faster as a moped can be.

Power Cruiser - by Jeff Taylor (dealer)

Being a small engine enthusiast, I have found the Power Cruiser to be the standard in gasoline power assist bicycles. The american made 41cc 2 stroke power plant boasts a whopping 3 hp at max rpm, and will stretch a gallon of gasoline for 150 miles. My 26" beach cruiser will stay steady well over 30mph, and will range from 15 to 25 miles per tank. Ease of installation and quality built brackets assure you of many miles and smiles for your investment which is very affordaable, and an excellent transportation alternative. Seriously consider gas over electric when it comes to your cycling needs, for the electric bicycles in my opinion are still in their infancy, and will need a lot of refinements before they will truly be able to compete with fossil fuels. Visit my site at for a complete look at my units including the new Solex for 2000. I think you'll like it, and I thank you for your time.

ProDrive - by Scott Aikins

Before purchasing the Currie Technologies U.S. Pro-drive, I looked at most all the other offerings. I liked the instrumentation on the ill-fated EV Warrior, but not its weight and friction drive. Although every manufacturer had its advantages and disadvantages, I felt nothing was comparable to the US Prodrive. The reduction chain direct drive, brushless DC motor, its amazing torque, precise control, and a sprague clutch which allows the bike to freewheel so normal pedaling is a breeze. I use the System more as an assist to my pedaling versus an electric powered two-wheeler. After riding about 25 miles , I've never run out of battery power. This also includes heavy assist up a 6% grade for 4 miles. The bicycle they use is a Schwinn which includes decent components and nice road tires. The bike will go like crazy with no pedalling, somewhere around 18 mph..

The finest praise I can offer is the experience I had with an unforseen problem with the bike. The bike started cutting out under load. The folks at Currie Technologies had me mail them the motor so they could confirm that it met their stringent torque requirements. Then they sent me a new motor, battery pack, and charger even though the motor actually checked out fine. Then they followed up to ensure I was pleased (which I couldn't be more satisfied), then dispatched UPS to pick-up the boxes which contained the old parts and paid the shipping for both directions. They didn't even pro-rate the battery pack since they felt I shouldn't have failed. I would highly recommend Currie Technologies U.S. Prodrive System. Today, it is very difficult to find superior customer service. Currie's service is absolutely tops. The Employee's at Currie are very enthusiastic about their product, polite, sincere, and really care about Customer Satisfaction. It just doesn't get and b! etter than that!

(Few months later)
I still love the bike and especially, Currie's Technical Support and Service.

ZAP power unit - by Mark Bennet

I love to ride the zap. Nearly silent, pretty fast (20mph) and rugged. Mine is mounted on an old "rifle" mountain bike. Many of the people you ride past don't know the bike is powered. The unit is two pancake 12v motors, battery, 3 speed switch and an on/off switch on handlebars. The biggest drawback: range only 8-10 miles and that's if you pedal some.

E.R.O.S. - review by Colin Lewis

I have an EROS bike motor on a cheap/heavy mountain bike with slick tires. I paid Omni Instruments an extra $30 to upgrad from the 280W motor to the 400W one.

Installation was pretty simple. A delrin (plastic) block is bolted onto the seat tube to hold the motor against the rear wheel. the battery bracket is a piece of sheet metal bent into a U shape. It bolts to the down tube using the water bottle bosses (in place of the water bottle.) brackets are included to hang the battery from the top tube if preferred.

Only one defect I noted: my roller came loose from the motor shaft! I called Omni Instruments, and they suggested I epoxy it back on. They were willing to repair it but I did not want to wait for the mail turnaround. The epoxy worked fine.

My experiences:

I have used it a few times to get me to and from work. (15 mile each way.) The batteries only help for about 3/4 of that distance, even with pedalling.

My top speed (on the flats, no pedalling) was about 14 mph.

I already can ride this route with an average of 15 mph, so the EROS doesn't help me get to work any faster. So... I modified it by adding a hard rubber caster to the existing roller so that the cruising speed is more like 25 mph. The modified roller does help my top end. At this rate I MUST pedal or the circuit breaker blows. (I am very glad that there is a circuit breaker rather than a fuse. The circuit breaker resets in a couple of minutes and I can start using the motor again.)


A nice, cheap, easy system. Useful if you often dip below 14 mph.

Omni instruments web page is:

Address is:

Omni Instruments,
POB 96,
Albion, CA

Order Line, Fax (707)937-0603

Go back to EROS summary

TSI Power Pack

I bought the Power Pack from the The Sharper Image store in St Louis Galleria. Carried the heavy box to the parking garage, condemning the inventors who still haven't come up with a practical anti-gravity device. Back in my car I opened the box only to find out that there is nothing but motor in there. That is, no way to mount it on a bike.

So, I went back to the store and politely yelled at the salesguy: "What's going on here ?!". He told me to bring the box back to the store and I said "No way, it's too heavy". He brought another box from the back, opened it - and there was no mounting hardware there as well. Then it dawned on us that the item consists of two boxes. He brought the second box, that looked even heavier than the first. "This is the end of me" - thought I, but turned out, this one was actually not heavy at all. So, I took it home.

That day was birthday, so I stopped to pick up my friends, Yury and Ann and Sasha. I told Yury about the gift I bought myself and he seemed as anxious as I was to install it and see what happens. So, it the middle of celebration, we sneaked away from other guests and went to the basement, where my Schwinn 27" touring bike stood, waiting to be motorized.

We plugged the battery to charge and sat down to watch instructional video. It made things seem easy, so soon we started assembly. We discovered that the wheels are too big and that the bicycle frame is too narrow. We used Russian know-how and mounted the motor anyway. It looked impressive. So, we left the bike stand there overnight, while battery is charging.

The next day, we installed the battery and took the bike outside for the first triumphant ride. I sat on it and started pedaling. After few seconds the electric motor came on quietly. So, I released the pedals, preparing myself for "zippy 16 mph". To my surprise, it didn't go anywhere near 16. Or 10. I'd be surprised if it was any faster than 5 mph. It did pick up speed going downhill (surprise!), but when the road went uphill, the motor quit, even though I tried to help it by pedaling like a maniac. Then it was even worse - I was trying to drag a heavy bike uphill and motor resisted my efforts. I had to get off the bike and push.

The Power Pack went back to the store that same day. So there.

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