E-bikers-
PREFACE: Thanks in advance for any recommendations you can provide! I'm an experienced mechanical engineer so I've got a good handle on the technical interrelationships between volts/amps/watts/etc and direct drive vs. geared, etc. Relatively new to cycling/commuting and e-biking in general (about a year) so I'll probably get most of the tech jargon but may still have the occasional noob follow-up question to ask.
BACKGROUND: I do a 6 mile one-way (12 mile round trip) mostly-flat commute through a mostly suburban/small town area with some open stretches of road w/ vehicular speed limits of up to 40 mph. I started commuting last year on a 26" 24-speed mountain bike, then added an electric iMortor 250W front hub motor w/ built-in battery and controller so that I could ride to work in work clothes vs. sweating my arse off and having to shower/change upon arrival (I do pedal more aggressively on the way home to get a bit of a workout... who cares what happens to the work clothes then). I like the exercise and the environmental friendliness of bike commuting, but I'm really doing it to save TIME and gain PREDICTABILITY. The vehicular traffic (Boston metro area) varies wildly based on time of departure, weather, day of week, whether Mercury is in retrograde, or who TF knows what else... one way can take as few as 14 minutes or as long as 35-40. I can do it on the bike in 21-25 minutes no matter what time of day or no matter how much traffic. I could shave that considerably if I could reach a higher speed on the flats once I'm outside of town. Plus, in a few years, we're moving a couple miles down the road to a new HQ that will make those long, high-speed flats even longer. That's even more time I'd be leaving on the table on a heavy (~60lb) underpowered bike that can only do about 20 mph on the level, with me pedaling to help.
NEW BIKE: For Christmas, I decided to upgrade to an All Go Carbon from M2Sbikes.com (imported Alienozo from China). 36v 350W Bofeili crank drive, Lishui controller, APT 800 display, all CF frame, 650b (27.5") wheels, 20-speed gearset. It weighs about 40 lbs with the pannier rack and lights/tools/water bottle/fender I added. I figured that dropping 20 lbs and gaining 100W would be a recipe for top speed improvement, but so far it's been a lackluster experience (although the whole package is a lot more maneuverable and more fun as a "bike"... and it's also GORGEOUS). CAVEAT - I purchased the bike "open box" from M2Sbikes, knowing that there was some damage to the wiring (the controller/motor had been pulled out and caused some breaks in the harness). I re-wired it over the holidays and got everything working properly, EXCEPT the pedal-assist. I added a manual throttle and that seemed to take care of that, but it's possible that there's something messed up with the torque/hall sensors and that might be keeping the motor from putting out full power? Throttle will get no-load speed well over 30mph, so it "seems" that the motor is functioning properly, but a road test is obviously very different conditions than a bench test.
GOAL: I figure that I'll need about a combined 1000w of power for 30mph pedal-assisted cruise. Mass state law limits unregistered e-bikes to 20mph throttle-only and 750W max, so I am okay with "fudging" my numbers a little bit but do NOT want to attract attention by passing cars on a 3kw hot rod! The bike already has a 36v 10.5AH battery with integrated BMS (which I can charge at work) so at 1000w that should give me the 25 minutes of 1000w I would need to complete a one-way trip. That 36V limit is the "long pole in the tent," unfortunately... I wish it was 48V but it doesn't make sense for me to re-do the battery and the existing motor controller in order to up that if I can achieve my goals with a 36v system. TO THAT END... what are your thoughts on the best rear hub motor to help me get up to around that 30+mph pedal-assisted mark? I can't go much larger than the 27.5" overall diameter wheels, either, as the clearance is somewhat tight on the bottom bracket area. I would assume brushless, but should I go geared or gearless? What is out there with the best gearing/windings for 36v high speed?
I suppose for simplicity's sake a Golden Motor Magic Pie Edge would be the easiest solution since they offer 36v options and have built-in controllers. The MP5 is rated at 750W for 36v, I think, and the MPE is only 500W for 36v, unfortunately... otherwise it would accept the 10-speed cassette I already have on the bike, making it the solution that would involve the least amount of work/additional parts to implement. I also couldn't find a datasheet on the edge, so I have no idea what it's torque or RPM ratings are. I know it doesn't matter if I've got TEN motors on the bike... if they all top out at 20-25 MPH, I'm never cruising at 30-35.
Okay, enough rambling... hopefully this is enough info to make it clear what I'm trying to determine, but not too much to the point where you stop reading or won't reply!
Thanks much, and I hope you're all enjoying the spring weather as much as I am!
-Jon
PREFACE: Thanks in advance for any recommendations you can provide! I'm an experienced mechanical engineer so I've got a good handle on the technical interrelationships between volts/amps/watts/etc and direct drive vs. geared, etc. Relatively new to cycling/commuting and e-biking in general (about a year) so I'll probably get most of the tech jargon but may still have the occasional noob follow-up question to ask.
BACKGROUND: I do a 6 mile one-way (12 mile round trip) mostly-flat commute through a mostly suburban/small town area with some open stretches of road w/ vehicular speed limits of up to 40 mph. I started commuting last year on a 26" 24-speed mountain bike, then added an electric iMortor 250W front hub motor w/ built-in battery and controller so that I could ride to work in work clothes vs. sweating my arse off and having to shower/change upon arrival (I do pedal more aggressively on the way home to get a bit of a workout... who cares what happens to the work clothes then). I like the exercise and the environmental friendliness of bike commuting, but I'm really doing it to save TIME and gain PREDICTABILITY. The vehicular traffic (Boston metro area) varies wildly based on time of departure, weather, day of week, whether Mercury is in retrograde, or who TF knows what else... one way can take as few as 14 minutes or as long as 35-40. I can do it on the bike in 21-25 minutes no matter what time of day or no matter how much traffic. I could shave that considerably if I could reach a higher speed on the flats once I'm outside of town. Plus, in a few years, we're moving a couple miles down the road to a new HQ that will make those long, high-speed flats even longer. That's even more time I'd be leaving on the table on a heavy (~60lb) underpowered bike that can only do about 20 mph on the level, with me pedaling to help.
NEW BIKE: For Christmas, I decided to upgrade to an All Go Carbon from M2Sbikes.com (imported Alienozo from China). 36v 350W Bofeili crank drive, Lishui controller, APT 800 display, all CF frame, 650b (27.5") wheels, 20-speed gearset. It weighs about 40 lbs with the pannier rack and lights/tools/water bottle/fender I added. I figured that dropping 20 lbs and gaining 100W would be a recipe for top speed improvement, but so far it's been a lackluster experience (although the whole package is a lot more maneuverable and more fun as a "bike"... and it's also GORGEOUS). CAVEAT - I purchased the bike "open box" from M2Sbikes, knowing that there was some damage to the wiring (the controller/motor had been pulled out and caused some breaks in the harness). I re-wired it over the holidays and got everything working properly, EXCEPT the pedal-assist. I added a manual throttle and that seemed to take care of that, but it's possible that there's something messed up with the torque/hall sensors and that might be keeping the motor from putting out full power? Throttle will get no-load speed well over 30mph, so it "seems" that the motor is functioning properly, but a road test is obviously very different conditions than a bench test.
GOAL: I figure that I'll need about a combined 1000w of power for 30mph pedal-assisted cruise. Mass state law limits unregistered e-bikes to 20mph throttle-only and 750W max, so I am okay with "fudging" my numbers a little bit but do NOT want to attract attention by passing cars on a 3kw hot rod! The bike already has a 36v 10.5AH battery with integrated BMS (which I can charge at work) so at 1000w that should give me the 25 minutes of 1000w I would need to complete a one-way trip. That 36V limit is the "long pole in the tent," unfortunately... I wish it was 48V but it doesn't make sense for me to re-do the battery and the existing motor controller in order to up that if I can achieve my goals with a 36v system. TO THAT END... what are your thoughts on the best rear hub motor to help me get up to around that 30+mph pedal-assisted mark? I can't go much larger than the 27.5" overall diameter wheels, either, as the clearance is somewhat tight on the bottom bracket area. I would assume brushless, but should I go geared or gearless? What is out there with the best gearing/windings for 36v high speed?
I suppose for simplicity's sake a Golden Motor Magic Pie Edge would be the easiest solution since they offer 36v options and have built-in controllers. The MP5 is rated at 750W for 36v, I think, and the MPE is only 500W for 36v, unfortunately... otherwise it would accept the 10-speed cassette I already have on the bike, making it the solution that would involve the least amount of work/additional parts to implement. I also couldn't find a datasheet on the edge, so I have no idea what it's torque or RPM ratings are. I know it doesn't matter if I've got TEN motors on the bike... if they all top out at 20-25 MPH, I'm never cruising at 30-35.
Okay, enough rambling... hopefully this is enough info to make it clear what I'm trying to determine, but not too much to the point where you stop reading or won't reply!
Thanks much, and I hope you're all enjoying the spring weather as much as I am!
-Jon
