Speed vs Range

[DrkAngel]

Everyone likes more speed!
Well ... most everyone.

What most don't realize is the cost of more speed.
Pulled from the ebikes.ca simulator, I noted the various ranges supplied at different speeds.

Generic Mountain bike - motor only.
665w peak output motor w/48V 10ah battery = similar to a 24V 450w peak output eZip motor - pushed to 36V 675w peak output motor.

Anyway
10mph = 46 miles range
15mph = 30 miles range
20mph = 20 miles range
25mph = 13 miles range
30mph = 8 miles range

Wow! ... calculator click click click ... Every 5mph increase in speed decreases range by 33%!

Most are shocked at the affect wind resistance plays.
Wind resistance is the major factor, but road load, tires, drive train etc. also contribute.

Makes me reconsider a lot!
Do I need 30mph capability? Nice to have it but ... don't need to use it! - OK! - Still a go.
Road Style bike with high pressure tires and crouched position? - Working on one!
Motor only, crouched behind an Aerodynamic fairing? Sounds almost essential - for sustained 30mph! - Battery pack mounted between bars and fork is a partial fairing. I'm sure I could easily enhance that!

Fortunately, I tend to cruise at 15mph, commute at 20mph with only very limited bursts nearing 30mph.

I'm even considering not upgrading (choke) my latest eZip Trailz LS.
OEM configuration is limited to 15mph in TAG (Twist And Go) mode and ~10mph in PAS (Pedal Assist System) mode.
Well, not upgrading, till after I run a range trial with my prototype 22.2V 40Ah pack.
I will add high pressure 1.75" tires for less rolling resistance and comfort seat and suspension post ... <15mph range trial might mean 5+ hours in the saddle!

 

[Richard H.]

Good summation of the facts and IMO really not a problem since a sustained 30 mph is too fast for most bicycles unless custom made for it. By that I mean running the gamut from cheap dept store bikes to mid level LBS bikes. 15 to 20 mph is more realistic on several fronts from component durability, brakes systems not to mention legal compliance. Want more speed than that, get a motorcycle.

 

[schulze 123]

Hi Guys,
Here's another interesting observation for you in that once you start opening the throttle on your E Bike above the 2/3 mark, just watch those amps start to climb. If you can gear your set up (bit hard with hub motors) so that you can achieve your desired cruise speed between 1/2 and 2/3 throttle, you will get the best range and torque.

Cheers BJ

 

[bromoto]

Great job DA,

After seeing those numbers and the decrease in range at 33%, also makes me wonder if I should re-enforce my build to handle two batteries or If I don't getting 8miles at 30Mph......

 

[wheelbender6]

It looks like for commuting to work, 15mph is a good compromise between speed and range. That is about the speed you would go on human power alone. The electric kit allows you to do 15mph without having to change out of sweaty clothes when you arrive. You can further increase range by pedalling along with the electric boost.

 

[Sidewinder Jerry]

Hybrids are getting very popular with systems which recharge while using gas only.

 

[rawly old]

Anyway you look at it, it would take forever going coast to coast on
electric alone.

 

[Sidewinder Jerry]

People have done it on peddle power alone.

 

[rawly old]

Quite true,
when I was a young man, I'd pedal as much as 140 mi. in a day,(60 uphill &
80 down). Now I'm a fat old man whose had "major' traumatic injuries to both
legs. I could still make 140 a day with the Tanaka if my hind quarters held up.

 

[darwin]

Back in the day I'd walk 7 miles to school in a blizzard with no shoes on and then run 26 mi marathon in PE class. You whipper snappers are spoiled today.