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Speed vs Range
- Thread starter DrkAngel
- Start date
DrkAngel
Member
20mph "Legal" Limit (USA)
I have multiple "compliant" eBikes:
Comfort Cruiser
2009 eZip Trailz LS (Low Step)
No pretenses, 20mph limit on a big tired, big low slung suspension seat, full upright position.
Typically I "cruise" at 15mph and "meander" even slower.
Designed for motor only, but I do apply some assist getting up to speed and on hills ...
Dumped the 24V 10Ah SLA batteries and packed 25.9V 25.92Ah LiPo into the oem eZip battery case.
The battery upgrade, combined with the 16T upgrade provides a reasonable ~20mph.
The Commuter
2008 eZip Trailz
Designed to commute at a sustained 20mph.
29.6V 31.2Ah homemade Li-ion battery pack.
16T upgraded drive gear.
Smaller, higher pressure, Kevlar belted, low RR tires.
Proper pedaling position seat.
Designed for continuous pedal assist, motor only 20mph+, reasonable pedal assist provides better range or a comfortable 25mph.
Safety gear includes reflective tires, strobe headlight tail and turn signals, (mirror is mounted on helmet).
Snow Beast
2008 eZip Mountain Trailz
Winter only, designed to mush through slush, snow and ice.
OEM 20T gearing but upgraded from 24V SLA to 33.3V 31.2Ah Li-ion for a ~20mph capability with a substantial torque increase. (1st upgrade 37V 20.8Ah Li-ion battery replaced for better durability and 20mph legality)
Homemade studded tires ... front tire swaps between mountain tread and sheet metal screwed mountain tire, dependent on road conditions. Rear tire is a used carbide studded tire, drive wheel wears steel studs too quickly. Home made studded provides better traction than the carbide.
I do assist for extra umph, when needed,
When really icy-nasty ... I lower seat and ski my feet.
Might have gone overboard with this one ...
Then I went way too far ...
So 20mph is OK by me ... though I might push the limits.
By tuning motor wattage, amperage and gearing, I can limit motor only speed to the "legal" 20mph, but provide substantial motor assist above 20 mph.
Even modest pedal assist might provide 25mph+ speed and some assist is available right through 30 mph!
I do have a Haro 700C 24speed I intend on gearing for 22.2V 43.2Ah battery that provides 20mph capability ... might be a switch that "TURBOs" to 44.4V 21.6Ah (providing 30mph+ capability), 48-11T sprockets allow 30mph+ pedal assist at 90rpm.
The 20mph USA "legal" eBike speed begins to look more "reasonable" than it did originally?
I have multiple "compliant" eBikes:
Comfort Cruiser
2009 eZip Trailz LS (Low Step)
No pretenses, 20mph limit on a big tired, big low slung suspension seat, full upright position.
Typically I "cruise" at 15mph and "meander" even slower.
Designed for motor only, but I do apply some assist getting up to speed and on hills ...
Dumped the 24V 10Ah SLA batteries and packed 25.9V 25.92Ah LiPo into the oem eZip battery case.
The battery upgrade, combined with the 16T upgrade provides a reasonable ~20mph.
The Commuter
2008 eZip Trailz
Designed to commute at a sustained 20mph.
29.6V 31.2Ah homemade Li-ion battery pack.
16T upgraded drive gear.
Smaller, higher pressure, Kevlar belted, low RR tires.
Proper pedaling position seat.
Designed for continuous pedal assist, motor only 20mph+, reasonable pedal assist provides better range or a comfortable 25mph.
Safety gear includes reflective tires, strobe headlight tail and turn signals, (mirror is mounted on helmet).
Snow Beast
2008 eZip Mountain Trailz
Winter only, designed to mush through slush, snow and ice.
OEM 20T gearing but upgraded from 24V SLA to 33.3V 31.2Ah Li-ion for a ~20mph capability with a substantial torque increase. (1st upgrade 37V 20.8Ah Li-ion battery replaced for better durability and 20mph legality)
Homemade studded tires ... front tire swaps between mountain tread and sheet metal screwed mountain tire, dependent on road conditions. Rear tire is a used carbide studded tire, drive wheel wears steel studs too quickly. Home made studded provides better traction than the carbide.
I do assist for extra umph, when needed,
When really icy-nasty ... I lower seat and ski my feet.
Might have gone overboard with this one ...
Then I went way too far ...
So 20mph is OK by me ... though I might push the limits.
By tuning motor wattage, amperage and gearing, I can limit motor only speed to the "legal" 20mph, but provide substantial motor assist above 20 mph.
Even modest pedal assist might provide 25mph+ speed and some assist is available right through 30 mph!
I do have a Haro 700C 24speed I intend on gearing for 22.2V 43.2Ah battery that provides 20mph capability ... might be a switch that "TURBOs" to 44.4V 21.6Ah (providing 30mph+ capability), 48-11T sprockets allow 30mph+ pedal assist at 90rpm.
Last edited:
DrkAngel
Member
30mph w/assist from a 20mph "legal" eBike?
30mph or run down ...
I live in a small city with every street within several miles limited to 30mph.
Most anywhere there are multiple routes available ... most everywhere ...
In particular, there is one ~5 block stretch of 4 lane, no shoulder, that I must traverse on a daily basis.
Usually I hop on from a side street at their red light and hump it up to 25mph+ to stay ahead of them.
Sadly, motor assist declines from about 12mph and is nothing at 25mph.
Ideally, I could fine tune a bike for motor only 20mph but supplies substantial pedal assist to 30mph.
With the proper voltage and amperage "fine tuning" this is possible.
Using the ebike.ca simulator I "built" this example ...
Overvolting, while reducing amps, provides less assist below 20mph but gives substantial assist past 30mph.
Ideal for the cyclist looking for a sustainable "keep up with traffic" speed.
Even moderate drafting should greatly reduce required assist effort.
Added benefits are:
Higher efficiency, especially at lower speeds
Less overheat potential in spite of the higher voltage
A perfect alternative as an eaBike as opposed to an eBike
Find a truck or van for substantial drafting
Find a car of proper height for good overall visibility, use it for moderate drafting, and as a "blocker"
(Drafting, especially with larger vehicles, does not require being dangerously close)
Graph is for a Mountain Bike, Road or Race bike should benefit even more!
3 shunt Controller "switchable" by cutting and adding switch to one or more shunts?
1 shunt - 11.7Amp - 350w - 20mph motor only = legal
+ shunt - 23.4Amp - 620w - 28mph motor only
+ shunt - 35.0Amp - 820w - 28mph motor only = full power! (Substantial acceleration increase)
30mph or run down ...
I live in a small city with every street within several miles limited to 30mph.
Most anywhere there are multiple routes available ... most everywhere ...
In particular, there is one ~5 block stretch of 4 lane, no shoulder, that I must traverse on a daily basis.
Usually I hop on from a side street at their red light and hump it up to 25mph+ to stay ahead of them.
Sadly, motor assist declines from about 12mph and is nothing at 25mph.
Ideally, I could fine tune a bike for motor only 20mph but supplies substantial pedal assist to 30mph.
With the proper voltage and amperage "fine tuning" this is possible.
Using the ebike.ca simulator I "built" this example ...
Overvolting, while reducing amps, provides less assist below 20mph but gives substantial assist past 30mph.
Ideal for the cyclist looking for a sustainable "keep up with traffic" speed.
Even moderate drafting should greatly reduce required assist effort.
Added benefits are:
Higher efficiency, especially at lower speeds
Less overheat potential in spite of the higher voltage
A perfect alternative as an eaBike as opposed to an eBike
Find a truck or van for substantial drafting
Find a car of proper height for good overall visibility, use it for moderate drafting, and as a "blocker"
(Drafting, especially with larger vehicles, does not require being dangerously close)
Graph is for a Mountain Bike, Road or Race bike should benefit even more!
3 shunt Controller "switchable" by cutting and adding switch to one or more shunts?
1 shunt - 11.7Amp - 350w - 20mph motor only = legal
+ shunt - 23.4Amp - 620w - 28mph motor only
+ shunt - 35.0Amp - 820w - 28mph motor only = full power! (Substantial acceleration increase)
rawly old
Active Member
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I'm sure as technology progresses, we'll be seeing electric bikes with
greater range for extended travel in spite being hobbled by wattage
limits. I can't only hope they become more affordable as well.
As it stands now, 150 mpg with my 35cc honda on a $15 bike is still
the most practical option for me, but then I'm a dirt poor old man.
I like the notion of an electric bike, but I suffer from 'range anxiety',
and am skeptical since, to my knowledge, those expensive batteries
seldom if ever survive to the touted 2000 charges.
greater range for extended travel in spite being hobbled by wattage
limits. I can't only hope they become more affordable as well.
As it stands now, 150 mpg with my 35cc honda on a $15 bike is still
the most practical option for me, but then I'm a dirt poor old man.
I like the notion of an electric bike, but I suffer from 'range anxiety',
and am skeptical since, to my knowledge, those expensive batteries
seldom if ever survive to the touted 2000 charges.
