Hey all,
To start, I'd like to announce to the world my first successful ebike! In actuality I've been riding it over a month (out of necessity - it's my only means of transportation) but until recently it's been like one long beta test, fixing bugs and redesigning on the go.
I commute ~15 miles each way to school over some seriously hilly terrain (SC County, high-five LFP!) so the goal was a heavy-duty commuter, a goal this bike meets and exceeds.
The frame is from a mongoose 200 XR, a cheap but solid mountain bike sold for a time at walmart. The battery is a 48v 20Ah high-C from BMSBattery rated for 60A continuous 100max, but I'm only drawing 30A through a cheap, generic Chinese 1500W controller en route to a magic pie front hub (the front-hub weight distribution is nice with a heavy load on the rear rack but can be frustrating climbing excessively steep hills or when rapid acceleration is required, and downright sketchy in wet conditions). This setup gets me to school and back with juice left over, throttling it all the way and cruising at 25-30 mph (with a fair amount of pedal-power on my part).
The battery/controller/motor system has worked like a charm since I hooked it up (after sorting through a nightmarish tangle of unlabeled and unsorted wires from my seemingly untraceable ebay mystery controller), but getting the "bike bits" (drive, train, shifters, brakes) working smoothly has taken some serious work. My life has been a good deal easier since I bought a pair of Avid disc brakes - a good lesson that saving money on parts can cost an exorbitant amount of time.
The super-low handlebar is to emulate drop-downs while retaining the control of a twist throttle. I used to commute on a cross bike which I loved dearly until it was stolen, and since then flat-bar setups just don't feel comfortable. I'm planning on mounting a second set of brakes on the drop bars so I can drop out of the wind for long flats or descents (and to look cool passing up other bikers 8) ).
All in all I am in love with the machine - I start and end each day ripping through town and woods, singing incoherently and grinning ear-to-ear - but of course it's still a work in progress. And so, dear denizens of Endless Sphere, I turn to you.
What I have is a cheap but solid frame, an excellent and under-utilized 48v 20Ah battery, a very cheap $1500W controller, a front 1000W DD motor (which I wouldn't mind replacing for a rear), and 50+Ah of used 18650 laptop cells I'm planning on building into a long-range pack (being careful not to draw over 1 C to avoid strain). I have adequate range and torque, what I'd really like is (of course) more speed. I have some saved funds, but I'd really like to minimize spending.
I know that air resistance becomes an increasingly pressing concern at high speeds, and I've been fantasizing about kitting out a sturdy recumbent with a wind-fairing, but I haven't been able to find any suitable recumbents on Clist for under $500, and even that I'm not sure I can justify given that I have a perfectly functional upright setup. Still, if anyone has any experience with high-power high-speed eRecumbents I'd love to hear about it!
My drop bars ought to shave off some drag for high-speed descents, but my front is still pretty rough. Do you all think a wind-fairing would be a worthwhile investment?
It seems that for high-speed bikes what I really want is high-voltage, but with $500 invested in a 48v battery I'd rather not jump ship. Plus, I'm really itching to push my pack past 60A...If I were to mod the shunt in my controller what could I expect in terms of speed? From what I've read I'm guessing I won't get much on flats, but given how much relatively slow hill-climbing I do the extra amps could be nice...alternately, would you recommend just buying a high-amp lyen controller?
And finally, how about if I switched out my magic pie for a rear high-speed winding setup? What models would you recommend to get me to 40mph on a 48v setup? (if that's a worthwhile goal)
Basically, how can I optimize for speed on a budget?
Thank you all!,
Russell
To start, I'd like to announce to the world my first successful ebike! In actuality I've been riding it over a month (out of necessity - it's my only means of transportation) but until recently it's been like one long beta test, fixing bugs and redesigning on the go.
I commute ~15 miles each way to school over some seriously hilly terrain (SC County, high-five LFP!) so the goal was a heavy-duty commuter, a goal this bike meets and exceeds.
The frame is from a mongoose 200 XR, a cheap but solid mountain bike sold for a time at walmart. The battery is a 48v 20Ah high-C from BMSBattery rated for 60A continuous 100max, but I'm only drawing 30A through a cheap, generic Chinese 1500W controller en route to a magic pie front hub (the front-hub weight distribution is nice with a heavy load on the rear rack but can be frustrating climbing excessively steep hills or when rapid acceleration is required, and downright sketchy in wet conditions). This setup gets me to school and back with juice left over, throttling it all the way and cruising at 25-30 mph (with a fair amount of pedal-power on my part).
The battery/controller/motor system has worked like a charm since I hooked it up (after sorting through a nightmarish tangle of unlabeled and unsorted wires from my seemingly untraceable ebay mystery controller), but getting the "bike bits" (drive, train, shifters, brakes) working smoothly has taken some serious work. My life has been a good deal easier since I bought a pair of Avid disc brakes - a good lesson that saving money on parts can cost an exorbitant amount of time.
The super-low handlebar is to emulate drop-downs while retaining the control of a twist throttle. I used to commute on a cross bike which I loved dearly until it was stolen, and since then flat-bar setups just don't feel comfortable. I'm planning on mounting a second set of brakes on the drop bars so I can drop out of the wind for long flats or descents (and to look cool passing up other bikers 8) ).
All in all I am in love with the machine - I start and end each day ripping through town and woods, singing incoherently and grinning ear-to-ear - but of course it's still a work in progress. And so, dear denizens of Endless Sphere, I turn to you.
What I have is a cheap but solid frame, an excellent and under-utilized 48v 20Ah battery, a very cheap $1500W controller, a front 1000W DD motor (which I wouldn't mind replacing for a rear), and 50+Ah of used 18650 laptop cells I'm planning on building into a long-range pack (being careful not to draw over 1 C to avoid strain). I have adequate range and torque, what I'd really like is (of course) more speed. I have some saved funds, but I'd really like to minimize spending.
I know that air resistance becomes an increasingly pressing concern at high speeds, and I've been fantasizing about kitting out a sturdy recumbent with a wind-fairing, but I haven't been able to find any suitable recumbents on Clist for under $500, and even that I'm not sure I can justify given that I have a perfectly functional upright setup. Still, if anyone has any experience with high-power high-speed eRecumbents I'd love to hear about it!
My drop bars ought to shave off some drag for high-speed descents, but my front is still pretty rough. Do you all think a wind-fairing would be a worthwhile investment?
It seems that for high-speed bikes what I really want is high-voltage, but with $500 invested in a 48v battery I'd rather not jump ship. Plus, I'm really itching to push my pack past 60A...If I were to mod the shunt in my controller what could I expect in terms of speed? From what I've read I'm guessing I won't get much on flats, but given how much relatively slow hill-climbing I do the extra amps could be nice...alternately, would you recommend just buying a high-amp lyen controller?
And finally, how about if I switched out my magic pie for a rear high-speed winding setup? What models would you recommend to get me to 40mph on a 48v setup? (if that's a worthwhile goal)
Basically, how can I optimize for speed on a budget?
Thank you all!,
Russell
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