Marin 700C Hybrid Bicycle Coverted to 48V E-bike

I wanted a bike that could go faster and farther that the typical converted e-bike. The key was to go for large wheels and with low rolling resistance, good road tires, and more power! On a level riding surface, high air pressure in tires, and ideal riding conditions such as cool temperatures, no wind, partly cloudy, etc. You can easily get 50 miles on a full charge at 20 MPH average speed.

I've also done a more "real world" test with hills and obstacles such as people to slow down, speed up, etc. Under these conditions, the bike can still achieve a good 36+ miles of range without any pedaling.

Thanks for posting the pictures and video of your bike. It's interesting to me because it's similar to mine; I have a WE BL36 running at 48V, on a hybrid (Al frame, steel forks) with 80 psi tires on 700C wheels. I also have NiMH batteries I got from Batteryspace (mine are the 10AH, though), and I even have the same Schwinn speedometer.

Your seems to be faster than mine; my no-load speed with the wheel in the air is only about 32 mph. Is yours still assisting at 35, or are you just pedaling hard? Just curious, since for me it makes little difference; I rarely break 25 mph anyway. I probably have more voltage sag with the smaller batteries.

Jay

If you have the tire diameter measured down to the millimeter, it should be a much faster speed closer to this one. When batteries are fully charged on mine, they push out about 56 volts. I also replaced all the wiring to the motor and batteries with a heavier gauge wire to carry as much current as possible. Also, that speed is under ideal conditions such as perfectly flat road, no head wind, myself crouched down on the bike wearing my "cyclist" pants and shirt to reduce wind drag. If it was a typical day with me wearing blue jeans and a loose shirt, speeds are closer to 30 MPH then. I would have to put in some extra effort to get it to 35 MPH then just because of all the wind drag and me just sitting up the entire ride. I think you may be right, the extra amps does tweak out the speed a little higher.

Thanks for the reply. My speedometer seems to be calibrated OK(checked with GPS), and my batt's are at about 56V right off the charger also (a couple V lower after they sit for a while). I think we have the same controller too (pedal-first from WE). If I was more curious I'd hook up my Watt's Up meter and check the voltage sag, but I mostly limit myself to 25 mph anyway. That's as fast as I want to go on a bike, due to, well, cowardice!

BTW, are you using the small blue "smart chargers" from Batteryspace?

I like your bike - it looks efficient enough to still be fun to ride with the motor off.

Jay

Jay said:

BTW, are you using the small blue "smart chargers" from Batteryspace?

I like your bike - it looks efficient enough to still be fun to ride with the motor off.

Jay

Click to expand...

It's one of the old "large" solid black chargers from back in 2004 they sold. They have the magno-temp sensor and standard plug in. I have two so I can charge both packs at the same time instead of one after the other. If the NiMH packs are dead, takes about 6 hours to give them a full charge.

Yeah, the bike, despite it's weight, it's really not that difficult to pedal at all on level and slight grade surfaces. Once you hit a good grade though, that weight is really noticeable then.

Knightmb,

I took the cover off my stock 20 amp controller and looked inside. It seems that they ran 10 guage wire from batteries to the controller, but the 3 wires that go from the controller to the motor are about 1/3 the diameter of 10 guage. Its only a 2 ft section, not sure if the small gain would be worth the effort to replace them. But........ How difficult was it to replace the wires that go to the motor? Was it a tight fit getting heavier guage wire out of the motor? Did you solder or crimp the wires inside motor? Did you have to use a larger wire harness? Is your controller 20 amps? Any pictures? etc.........

D-Man said:

Knightmb,

I took the cover off my stock 20 amp controller and looked inside. It seems that they ran 10 guage wire from batteries to the controller, but the 3 wires that go from the controller to the motor are about 1/3 the diameter of 10 guage. Its only a 2 ft section, not sure if the small gain would be worth the effort to replace them. But........ How difficult was it to replace the wires that go to the motor? Was it a tight fit getting heavier guage wire out of the motor? Did you solder or crimp the wires inside motor? Did you have to use a larger wire harness? Is your controller 20 amps? Any pictures? etc.........

Click to expand...

If I remember correctly, the motor had a 6' foot 14 guage wire running to it. I shorten it and changed the guage to 12 all the way to the motor where I had to remove the "plastic" case that was around the original wires and get those 3 wires to fit through the hole. Wires were soldered in just like the original wires. Afterwards I used electrical tape to wind outside of the motor and protect the wires. Also had to buy a slightly bigger 3 wire case for the wires because they wouldn't fit down the original. So from the outside it doesn't look like much of a change, but every little bit helps. Shorter length and more wire means more current can flow through. It's the standard pedal-first controller from WE (back from 2004, not sure how many amps that was then). It might be the 20 amp controller, but since the motor will max at 800 watts and with 48 volts, using 20 amps would push it close to 960 watts, so the 20 amp is probably what is being used then because the motor never did melt (or the controller fry).

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I recently found out that my pedal first controller is actually a 35 amp controller instead of 20 amp that I posted earlier. Just an FYI. :wink: