I first thought of a gas engine but it increases the weight more than a motor? Hence, dropped it.

Increase in weight due to fuel tank, engine etc. I like to pedal for the exercise but if weight is high, it may be difficult

 

I first thought of a gas engine but it increases the weight more than a motor? Hence, dropped it.

I have one of those gas motors, not for a bike but just the motor alone. They aren't all that heavy, I used mine for a different purpose so just bought the motor. The whole system that you will need the electric motor, batteries and the drive system, verses the gas motor system I'm betting would weigh pretty much the same amount. Plus if you batteries would go flat away from home verses running out of gas, I'll bet it is easier to find some gasoline than it would be to find someone with the right charger.

 

Thanks. Was it a 66 cc motor?

 

Thanks. Was it a 66 cc motor?

No it was I think(was a couple of years ago) it was 79cc. But they are all pretty much the same motor except for the stroke. If you look on Ebay there are quite a few to chose from. I built a gas powered winch for out in the woods. Had an electric winch that was given to me it's electric motor was burned out so I adapted the 2stroke motor to it. I was cutting fire wood so always had 2 stroke gas for the saws.

 

Back about 1967 I helped put together a pulsjet engine to drive a bike. One loud tone when it was working, and the back half of the engine glowed orange. It ran on gasoline mixed with kerosene for added impulse energy. The installation was simple, It just bolted to the rear carrier. The problem was the heat would melt the rear tire if you could ever get it stopped. Not much throttle control, it was always full power or off.

 

Thanks. My problem is that I need the exercise of pedaling so would only need motor boost on going up a slope say 10% of the time only. If I use an engine with tank etc. I won't be able to pedal on even ground as the added weight will slow or stop me. I thought of using a very small engine as in aero models - won't work. Then someone suggested a 10 - 20 cc engine but can't find them so am stuck

 

Once again, I suggest having a lower gear ratio available. At some point you should be able to pedal up most hills. With my best low gear selection the thing that stops me is the rear wheel slipping because of not enough traction. And if I put more weight on the back wheel then the front one lifts and I can not steer.

 

I won't be able to pedal on even ground as the added weight will slow or stop me.

On level ground the added weight makes very little difference to pedalling effort. The only difference I noticed when riding my power-assisted bike was balance/stability, because the centre of gravity was higher.

 

With a low enough gear you should be able to pedal up a 30% grade with no problem. Not fast, except that you would be pedaling a lot faster. On my mountain bike the biggest sprocket in back is smaller than the small front sprocket. Strictly a steep hill type of gear. But at that point you do need to have at least 5 rear sprockets and 3 on the crank end. So the setup may take a bit of effort. But still far simpler than adding a motor or engine. And it is totaly "street legal", while any engine may be challenged.

 

On level ground the added weight makes very little difference to pedalling effort.

Yea, as an avid cyclist for most of my life I'm going to have to call bull on that one.

 

Yea, as an avid cyclist for most of my life I'm going to have to call bull on that one.

Weight does matter some, no question about that. For starters, is there really such a thing as "level ground"? And weight relates directly to inertia, and that affects every speed change.

 

Yea, as an avid cyclist for most of my life I'm going to have to call bull on that one.

I was never an avid cyclist; just a kid going leisurely to and from high school. I can only report what I experienced. I accept that the extra weight would be unacceptable for sprints/racing.

 

I think TS knows that. But if TS wants to try it anyway, why not go ahead and give it a shot. It could be a valuable learning experience.

Do you agree that they are lossy?

 

It seems to me that you need to be knowledgeable and handy in a number of areas:

1) mechanical engineering - calculating power, torque, gear ratio
2) electrical power engineering - battery, motor, controller design
3) bicycle mechanics - free wheel sprockets, chains and gears
4) metal work, welding equipment and skills

If you are up to snuff with all of these and are a DIY person then go for it. Otherwise you may want to save your pennies towards an ebike conversion kit or a ready-built ebike.

 

It seems to me that you need to be knowledgeable and handy in a number of areas:

1) mechanical engineering - calculating power, torque, gear ratio
2) electrical power engineering - battery, motor, controller design
3) bicycle mechanics - free wheel sprockets, chains and gears
4) metal work, welding equipment and skills

If you are up to snuff with all of these and are a DIY person then go for it. Otherwise you may want to save your pennies towards an ebike conversion kit or a ready-built ebike.

Thanks. Think a kit would be best, but would like a friction rear-wheel drive kit. Don't see any!

 

Darn. I just gave away one of my ebikes to a reseller a few weeks ago.

The only friction drives I can find are sold from China. They are pricey. C$400 and up.

Here is a side mount drive.
Seller location is confusing. It says item is located in Ontario, Canada. Yet seller is in China.
Caveat emptor - I cannot vouch or make any recommendations on this or any product. You have to judge your own ability to install this product. It does look complex.

C$118.85
https://www.ebay.ca/itm/24V-250W-El...805827?hash=item2ad9638a83:g:-vsAAOSwhU5fD~ts

YaeGoo 24V 250W Electric Bicycle Motor Kit, Easy to DIY E-Bike Economic E-Bike Conversion Kit Electric Bike Side Mounted Motor Design

Buyers need to know:

This kit is not suitable for any bike, contact us before you purchase it.
please see the pictures carefully, or contact us before you purchase the kit. you can send the pictures of your rear wheel to us,
both left side and right side, we can give you some suggestions.
All the buyers should have experience to install it. If not, please do not buy it.

This kit includes:

1). 1pcs DC 250w 24v motor
2). 1pcs motor controller
3). 1pcs chain
4). 1pcs freewheel
5). 1pcs freewheel adapter
6). 1pcs mounting plate with bolts
7). 1pcs throttle handle & brake lever
8). 1pcs headlight
9). 1pcs switch & key
10).1pcs 18cm axis

Note:
This kit suitable for 22"-28" bicycle.
This kit without battery, battery charger and battery box.

 

What type of bicycle do you have? Road bike or mountain bike?

This friction drive is advertised for a mountain bike.
https://www.aliexpress.com/i/33004527515.html?spm=2114.12057483.0.0.76a64cfbLhLI5Y

Dimensions are pictured here:
https://www.banggood.com/200W-24V-Bicycle-Bike-Booster-160+120+80mm-Durable-For-E-Bike-Electric-Mountain-Bike-Bicycle-Cycling-Accessories-New-Arrival-2019-p-1521039.html

 

Road bike

 

Darn. I just gave away one of my ebikes to a reseller a few weeks ago.

The only friction drives I can find are sold from China. They are pricey. C$400 and up.

Here is a side mount drive.
Seller location is confusing. It says item is located in Ontario, Canada. Yet seller is in China.
Caveat emptor - I cannot vouch or make any recommendations on this or any product. You have to judge your own ability to install this product. It does look complex.

C$118.85
https://www.ebay.ca/itm/24V-250W-El...805827?hash=item2ad9638a83:g:-vsAAOSwhU5fD~ts

YaeGoo 24V 250W Electric Bicycle Motor Kit, Easy to DIY E-Bike Economic E-Bike Conversion Kit Electric Bike Side Mounted Motor Design

Buyers need to know:

This kit is not suitable for any bike, contact us before you purchase it.
please see the pictures carefully, or contact us before you purchase the kit. you can send the pictures of your rear wheel to us,
both left side and right side, we can give you some suggestions.
All the buyers should have experience to install it. If not, please do not buy it.

This kit includes:

1). 1pcs DC 250w 24v motor
2). 1pcs motor controller
3). 1pcs chain
4). 1pcs freewheel
5). 1pcs freewheel adapter
6). 1pcs mounting plate with bolts
7). 1pcs throttle handle & brake lever
8). 1pcs headlight
9). 1pcs switch & key
10).1pcs 18cm axis

Note:
This kit suitable for 22"-28" bicycle.
This kit without battery, battery charger and battery box.

This looks good. It says may not suit all bikes, contact us. I clicked contact us but no luck.

 

This looks good. It says may not suit all bikes, contact us. I clicked contact us but no luck.

Is there any way I can contact them? May be you had better luck?