The Toecutter
100 kW
- Joined
- Feb 8, 2015
- Messages
- 1,312
Today I met a friend who had ordered two front-suspension electric fatbikes. They used Bafang hub motors and cadence sensors, with a twist throttle that had a switch that allows one to choose PAS or throttle operation. I was told the system was 750W. The battery is 48V 13AH. It was a 7 speed in the rear with a single sprocket up front, and I do not know the ratios. The throttle had a setting of 1 to 5, and I tried it on 5.
I rode one of them and found that the brakes were a bit squishy and the gears didn't shift right, so I was extra careful. They are said to be able to reach 28 mph on throttle only, but I didn't take it above 23 mph because the brakes weren't set right. Acceleration wasn't all that great.
I'm every bit as fast on my unmotorized 39" wide KMX trike with front suspension and 50 km/h rated E-bike tires with heavy double wall rims, lugging 15 lbs of tools around, and with the aerodynamic body shell currently removed. Without the body, I could top out at 28-29 mph lugging my homemade toolbox around(30 without the toolbox), and 35 mph when I had the first body shell on it, all without anything but pedal input. I have a baseline for what 750W feels like now having ridden a vehicle of similar weight to my trike, and the acceleration resultant from my pedal output on the trike at max effort feels similar to using the fatbike on a "5" setting with throttle-only at full throttle, at least for a few seconds at a time(the fatbike motor/controller doesn't get tired in a few seconds at that kind of wattage like I do, as I cannot maintain top speed on my KMX once I reach it).
That said, because the brakes on the fatbike did not work quite right, it was a bit scary on a setting of 5, even though it wasn't very fast. This applied to both throttle-only and PAS modes. I was a LOT more comfortable on my trike, which when I had the first body shell on it, I've been more than 50 mph downhill and it was stable and safe making lane changes over an imperfect road. I really loved the PAS mode on this fatbike though and regret that I do not have the funds to electrify my trike at this time.
I also tried this fatbike with the motor turned off. I did not find it to be much more lossy than my trike, although since the gears and brakes weren't working right, I wasn't able to test my capabilities on it with the motor turned off.
After riding this electric fatbike, I had no problem using the tools I carried on board my trike to adjust the rear derailleur and front/rear disc brake cables/calipers. Now the bike is stopping and shifting great, although I didn't get to play with it on the "5" throttle setting while everything was well adjusted. Maybe next time I get a chance to ride it I'll push it to its limits on the max setting.
I'm looking forward to finally getting my build electrified. I just need to find an income stream first. I recently applied to a bicycle courier job, which with my level of fitness, and a new body shell about to go on my trike, said job would be a great match. Should I get it, it would allow me to upgrade my trike and make it able to move like a car, without the expense of a car, with no range anxiety due to the aerodynamic body shell and the ability to pedal it faster than a normal upright bike. I'd also become a faster rider, as I currently cover 100-150 miles a week in my trike as is, unmotorized, and use it for transportation. The next body shell is going to be significantly more aero than the last one, possibly allowing me to exceed 40 mph on flat ground pedaling it with no motor and cruise all day at 25+ mph as long as the ground is flat, and will seal the chainline up to prevent dust from reaching the chain, as well as keep me dry in the rain, warm in the cold, and the sun off me during the summer. Add an electric drive system to that and all kinds of wonderful things would happen.
And I'm not going to settle for 750W, either. I'm planning on a Leafbike motor with a 3T wind running at 4 kW to start with, a custom built 72V pack of Tesla Model 3 cells, a torque sensor feeding info to a Sabvoton Sinewave controller with PAS, and a Cycle Analyst computer. The goal is to keep the entire bike under 100 lbs, and for it to be able to be pedaled almost as fast as a normal velomobile with the drive system turned completely off. I'm also looking at the possibility of needing to add rear suspension, build up DOT moped rims, install low rolling resistance solar race car tires, and add hydraulic brake calipers. As I work out the bugs and shortcomings, the motor will be upgraded, perhaps to over 6 kW, and replaced when something lighter with better peak power enters the market.
That fat bike ride really taught me a lot with regard to what I can expect with an EV drive system on what would normally be a pedal powered vehicle. Damn I'm hooked. I had more fun when I drove my incomplete/not yet legal electric Triumph GT6 conversion, but it was much faster than the fatbike, and I'd like to replicate that sensation with my trike.
I rode one of them and found that the brakes were a bit squishy and the gears didn't shift right, so I was extra careful. They are said to be able to reach 28 mph on throttle only, but I didn't take it above 23 mph because the brakes weren't set right. Acceleration wasn't all that great.
I'm every bit as fast on my unmotorized 39" wide KMX trike with front suspension and 50 km/h rated E-bike tires with heavy double wall rims, lugging 15 lbs of tools around, and with the aerodynamic body shell currently removed. Without the body, I could top out at 28-29 mph lugging my homemade toolbox around(30 without the toolbox), and 35 mph when I had the first body shell on it, all without anything but pedal input. I have a baseline for what 750W feels like now having ridden a vehicle of similar weight to my trike, and the acceleration resultant from my pedal output on the trike at max effort feels similar to using the fatbike on a "5" setting with throttle-only at full throttle, at least for a few seconds at a time(the fatbike motor/controller doesn't get tired in a few seconds at that kind of wattage like I do, as I cannot maintain top speed on my KMX once I reach it).
That said, because the brakes on the fatbike did not work quite right, it was a bit scary on a setting of 5, even though it wasn't very fast. This applied to both throttle-only and PAS modes. I was a LOT more comfortable on my trike, which when I had the first body shell on it, I've been more than 50 mph downhill and it was stable and safe making lane changes over an imperfect road. I really loved the PAS mode on this fatbike though and regret that I do not have the funds to electrify my trike at this time.
I also tried this fatbike with the motor turned off. I did not find it to be much more lossy than my trike, although since the gears and brakes weren't working right, I wasn't able to test my capabilities on it with the motor turned off.
After riding this electric fatbike, I had no problem using the tools I carried on board my trike to adjust the rear derailleur and front/rear disc brake cables/calipers. Now the bike is stopping and shifting great, although I didn't get to play with it on the "5" throttle setting while everything was well adjusted. Maybe next time I get a chance to ride it I'll push it to its limits on the max setting.
I'm looking forward to finally getting my build electrified. I just need to find an income stream first. I recently applied to a bicycle courier job, which with my level of fitness, and a new body shell about to go on my trike, said job would be a great match. Should I get it, it would allow me to upgrade my trike and make it able to move like a car, without the expense of a car, with no range anxiety due to the aerodynamic body shell and the ability to pedal it faster than a normal upright bike. I'd also become a faster rider, as I currently cover 100-150 miles a week in my trike as is, unmotorized, and use it for transportation. The next body shell is going to be significantly more aero than the last one, possibly allowing me to exceed 40 mph on flat ground pedaling it with no motor and cruise all day at 25+ mph as long as the ground is flat, and will seal the chainline up to prevent dust from reaching the chain, as well as keep me dry in the rain, warm in the cold, and the sun off me during the summer. Add an electric drive system to that and all kinds of wonderful things would happen.
And I'm not going to settle for 750W, either. I'm planning on a Leafbike motor with a 3T wind running at 4 kW to start with, a custom built 72V pack of Tesla Model 3 cells, a torque sensor feeding info to a Sabvoton Sinewave controller with PAS, and a Cycle Analyst computer. The goal is to keep the entire bike under 100 lbs, and for it to be able to be pedaled almost as fast as a normal velomobile with the drive system turned completely off. I'm also looking at the possibility of needing to add rear suspension, build up DOT moped rims, install low rolling resistance solar race car tires, and add hydraulic brake calipers. As I work out the bugs and shortcomings, the motor will be upgraded, perhaps to over 6 kW, and replaced when something lighter with better peak power enters the market.
That fat bike ride really taught me a lot with regard to what I can expect with an EV drive system on what would normally be a pedal powered vehicle. Damn I'm hooked. I had more fun when I drove my incomplete/not yet legal electric Triumph GT6 conversion, but it was much faster than the fatbike, and I'd like to replicate that sensation with my trike.
