Single speed 26" conversion suggestions

[Ian Lasrado]

Hi Guys,

I'm a cyclist from Mumbai and want to convert my spare bike to an e bike.

I am rather poor regarding specs so I'm sharing the bike link so that youl can guide me better.

City Cycle Btwin My Bike - Steel Frame, Single Speed, V-Brakes, Aluminium Rims

A single speed, simple cycle suited best for urban commuting. Frame and wheels designed for tarmac roads and countryside trails. A value for money cycle which can be used for daily commute and trails. A cycle with a wide seat, raised handle bars for better posture.

www.decathlon.in

I understand i need a hub motor as it's a single speed, and i think rear is better for stability.

What i need help with is power and batter size. I keep reading 250w is too less so I'm thinking 350w and i would ideally want a 40 kms pedal assist range. Also getting good manufacturer's cells in the battery is a priority.

Based on these requirements something rather economical as it's my first project.

If i can get links for recommended kits with my requirements in AliExpress or another site that ships to India would be awesome.

Also feel free to suggest me anything u feel would go well with the bike.

Thanks guys,
Ian

 

[indianajo]

First off, your proposed converted bike has rim brakes. In extremely rural environments with no other traffic or pedestrians, this might be safe. If you ever have to stop quickly in the rain, with rim brakes, you could wish you had stayed below 5 kph where this is safe. That bike has no suspension, and 55 mm or smaller tire cross section. This indicates speed should be below 15 kph unless pavement is truly excellent.
Em3ev in Hong Kong has a good reputation in the Eastern Hemisphere. I suggest you check their catalog. How often you stop and go, what gross weight you will be carrying, and how steep are the hills you climb, all go into what wattage you need, and whether you need a geared hub, direct drive hub, or mid drive bike with multi-speed rear . Much of India is reputed to be very flat, but if you are climbing near Darjeeling, you may need DD (which doesn't overheat much) or mid drive.
I get about 50 km range with a 17 AH 48 v battery, but I climb a number of hills at full throttle with a 1200 w motor. I average 13 kph over 3.5 hours. Flat trips with no stops and only PAS1 assistance can get that far with 10 or 12 AH.
Be aware with a conversion, you need to pull the pedal crank off to install the magnet ring for the PAS pickup. That often requires a special tool. You also need a drill motor, drills, hacksaw & a vise to fabricate various brackets to hang controller, battery, and display. Use safety glasses when using power tools. Torque arms sometimes can be bought, but with the above you can also fabricate them out of scrap steel as I did. Hub motor axles are sometimes too thick to fit in bike forks, so you need a grind wheel mandrel & ~12 cm wheel to open up the slot a little. If your kit requires extension wires to connect the battery to the controller (1.4 mm or fatter) you'll need a quality crimp tool to install ring terminals for a screw terminal block or .157" bullet terminals for the red/black wires on other kits. I get good results from terminals made in Taiwan or USA. Crimp terminals of ***** have the tendency to melt when subjected to 30 amp loads.
If there is a problem you may need a DVM to diagnose it. I do not recommend building a battery, connections can be hard to make reliable even in allegedly experienced shops.
Best of luck.

 

[Ian Lasrado]

Thanks for the response,

I agree the brakes are especially poor during rains, and it does rain a lot in Mumbai. But prefer not venturing too much during rains. I will consider upgrading the brakes n tires.

I do intend using the bike in the city which is mostly flat and include stop n go traffic. I weigh 62kg and even if i do get panniers it would be a combined weight of <75kg.

I was hoping a rear hub would eliminate the need for special tools, but i would need pedal assist. On checking the em3ev site they do have hub motor kits, but unable to determine the configuration.

Also you put a lot of factors into consideration i am unaware of, once i can determine the kit i got to pick up i can educate myself on how to get it assembled.

 

[tomjasz]

Hello and welcome. A Cutler MAC is a very good choice. I especially like the versatility. Pretty good at riding up hill and I really like the idea of using a battery from 24V to 60V. The newest controllers that are programable and fit into the base plate of a Hailong(shark) pack helps the build look nice and simple. Clean if you will.

Controller fits in a Hailong case!

https://www.aliexpress.com/item/32967236787.html?spm=a2g0o.store_home.productList_14542667.pic_6 Ebikes.ca has an even nicer version, albeit more expensive. They call it a Baserunner.

electricbikereview.com

most don’t realize MAC is very well known in the kit world. It’s a very simple and a much improved motor, but even the older versions are just tough reliable motors. Repairable and with lots of support.

ebikes.ca has the coolest Baserunner Hailong case mount controller, again with great support and features.

next, if you have a steel front fork a nice nine-continent or clone front hub motor makes for a nice one speed. With the right controller and display you’ll have a sweet engine braking motor. I have. MXUS 1000w and love the ones speed with front wheel drive and braking. i think front drives get blown off and that’s a shame. They’re so simple. I really like the braking not being affected by rain, and front drives ability to pull me out of a skid. Super on snow but any braking on snow is pretty easy for you!