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Yes you are definitely on the right track with using a gear motor. I found a photo on Photobucket of a Schwinn Meridian bike with a 450 Watt electric gear motor attached to it.

It should be as easy as attaching the motor to the frame and sprocket to the axle and putting a chain between them.

The 36 Volt 600 Watt gear motor is more powerful than the 450 watt gear motor in the photo. It is also tougher and larger than the 450 Watt gear motor and able to dissipate more heat so it would be better for off road use than the 450 watt gear motor.

If you have a target top speed that you would like the bike to go then I could run some gear ratio calculations and let you know what size axle sprocket would be needed to achieve that speed?

As the bike travels at faster speeds the wind resistance exponentially increases so the power that is requires goes up very quickly. I ran some calculations and found that with a 600 Watt motor the top speed on flat ground is limited to around 22 miles per hour. If it was geared for a 22 MPH top speed it would have a moderate amount of torque but not a lot. At 22 MPH gearing if the bike and rider weighs 300 pounds it should be able to go up a 10 degree incline at around 6 MPH. Any steeper of an incline and the motor would run too slowly and risk overheating. For off road riding I think you might be better off with a 15 MPH top speed gear ratio. This will provide a lot more torque and the bike would be able to climb steeper inclines. The gear ratio is decided by the rear axle sprocket though so it could be changed by installing a different size axle sprocket if you are not satisfied with your first gear ratio choice.

For fatter tires and rims I recommend checking with local bicycle repair shops. If the parts are available they will be able to lace wider rims onto the wheels and install wider tires.

I can recommend, and if you want even make a pre-wired kit, out of the electrical components for this project. I can also calculate the gear ratio and let you know what size axle sprocket is needed for a certain top speed. I need to ask a few questions first in order to make these recommendations:

• Considering the information I posted above, what is your new target top speed now?
• Do you want the twist throttle to have a battery meter and key switch on it?
• How many minutes of ride time on flat ground do you want the bike to have?

Please let me know if you have any questions.

We have twist throttles with built in battery meters and key switches so everything is on one unit. Ride time is determined by the speed the bike travels at and the size of the batteries.  Faster speed equals less ride time, and larger batteries equals more ride time. You can gear the bike to go 15 MPH but ride it at say 12 MPH to get more ride time if needed, or ride it at 8 MPH to get a lot more ride time, but still have the option to go 15 MPH when needed. The size of the batteries is the biggest factor into how much ride time the bike will have. You could use three 15 Ah batteries which would provide around 10 miles of ride time on flat ground without pedaling, or three 22 Ah batteries for around 12 miles, or three 35 Ah batteries for around 20 miles. Ride time will be significantly increased with light to normal pedaling.

The MOT-36600G motor has a sprocket that works with #41 and #420 chain. Wheel sprockets for these chain sizes can be purchased at go cart and mini bike parts stores.

Depending on the size of the batteries the typical cost including batteries and battery charger for a kit like this is between $450-$700. I can build a kit and get a definite total price for the parts if you would like. For the kit I would need to know what size batteries you would like to use?

Here are photos of some of the parts I recommend and links to the pages they are on.

 

MOT-36600G ( https://www.electricscooterparts.com/motors36volt.html )

THR-110K ( https://www.electricscooterparts.com/throttles36volt.html )

SPD-CT660B9 ( https://www.electricscooterparts.com/speedcontrollers36volt.html )

15 Ah, 22Ah, and 35 Ah batteries ( https://www.electricscooterparts.com/batteries.html )

The bike will not need to be pedaled to be started - it will start on the electric motor's power alone and have good acceleration without pedaling. Gel batteries are an option but not a very good one in my opinion. Gel batteries will only provide around 80% of the ride time or mileage range that SLA batteries will for their size. So they will be heavier and bulkier. Gel batteries are also very sensitive to being overcharged and undercharged and due to that are not as reliable as SLA batteries. All electric scooter and bike companies that use lead batteries in their vehicles currently use SLA batteries.

The brake switch connector on the controller can be wired to a brake switch and will turn the motor off when the brake is applied, and then turn the motor on again when the brake is released. It is an optional connection and does not have to be used. We currently do not have any controllers rated over 500 Watts that have reverse. We do have 500 Watt controller with reverse though. If the bike used a 450 Watt gear motor then we would have a controller available for it with reverse.

I ran a gear ratio calculation with the MOT-36600G motor and assuming that the bike has 26" wheels the axle sprocket needs to have 25 teeth for a 15 MPH top speed. Here is an screenshot of the gear ratio calculation.

MOT-36600G has a 10 tooth sprocket which can be used with #41 or #420 chain so a #41 or #420 sprocket would be needed for the axle. We currently do not have axle sprockets for these chain sizes however I searched online and found many 25 tooth sprockets for #420 chain are available online.

I can definitely make a kit for your project. Before I make the kit I have a few questions I need to ask first.

• Do you want to use the 600 Watt gear motor with a forward only controller, or the 450 Watt motor with a controller that has reverse?
• Do you want to use GEL or SLA batteries?

Please let me know if you have any questions.

We carry a 25 tooth sprocket for #420 chain with a 5/8" ID for keyed axle which is parts number SPR-42025F at this link:

https://cart.electricscooterparts.com/25-tooth-5/8-bore-sprocket-for-420-chain

The only advantage to using the brake switch is that the throttle does not have to be releases when using the brakes. However since this feature does not exist on cars and motorcycles everyone is already trained to let up on the throttle when using the brakes so the power off on braking feature is not needed in my opinion. However if you want the bike to have a rear brake light then it would be needed.

The battery charger is not built into the controller. A separate battery charger needs to be used. For 35Ah batteries a battery charger with at least 4 Amps is needed in order to recharge the batteries overnight.

I made the kit for this project. Here is the link to it:

https://cart.electricscooterparts.com/36-volt-600-watt-electric-beach-wagon-power-kit

If you would like any changes made to the kit or if you have any questions please let me know.

I do not know of any websites that sell parts particularly for the Schwinn Meridian bicycle however Schwinn will sell you parts for it if they have them. Here is a link to their contact us page: 

https://www.schwinnbikes.com/en/int/support/get-help/contact-us

I just checked and the best rate for shipping KIT-149 to zip code 70446 is with FedEx at $80.55. This kit weighs around 95 pounds due to the weight of the three large batteries. Please let me know if you have any further questions.