hypothetical range question..

[winkinatcha]

Dude, there is no doom, only hope

Something to consider, a light geared hub motor running arround 750w max, in a vintage (1970s/1980s) style rode bike...


I've been playing around with builds like that for a couple of months now, and am personally able to get a conservative 50km with a 48v 10ah pack. (4*6s5ah LiPo), it's all road or cycleway work which helps when using a lighter motor... Oh and I am also running a 10 amp controller, so as one of my mate's says.. it sips from the batterry rather than gargling the juice down

On that bike I average around 27km/h, top speed around 32 without peddling on the flat in positive conditions, top speed clocked on the vehicle is 45 km/h but that was a descent ... Personally I am most comfortable to be peddling around 30 km/hr, using a pedal sensor rather than hand throttle and just grind the Km's down... only it's not really grinding... I pedal but I am not the fittest, nor the strongest

Though I use and endorse LiPo (when you read up and know what you are doing), at that low wattage/power output, other batterry chemistries even at a 20 ah capacity become a reasonable solution and can still fit as an inframe or rack mounted battery, or both with out too much handling and weight compromise... for a long range (100km+) machine.

C'mon Dude... it's for Love

Joe

 

[dogman dan]

It would be very nice to get there quicker, traveling for that reason. Slowing down enough to make the trip one way on 1.5kwh would eat up priceless time. Slow as I bet the bus is, I bet its faster than biking it at 30 kph.

Even at 50 kph, it would take two hours, or more because of stop signs or lights. The cost of enough battery to do this would make a small motorcycle or scooter capable of 75 kph possible. So if you could afford 2-3kwh of battery, you'd be better off with a 150 cc Chinese scooter. Hell, even 1.5 kwh of battery will cost you a pile o money.

 

[SamTexas]

ok, the real senario: my girlfriend lives about 90km away during the summer.

If you are willing to pedal lightly and don't mind a 3 hours trip, it can easily be done. Not too expensive either.

No more than 300W is needed to move at 30kph on flat ground. If you pedal along and contribute half the power (150W), then the ebike motor only has to provide 150W. So the 90km trip only needs 450Whr. A 500Whr battery should be sufficient.

150W is not hard at all. Any normal young person can do it for hours. Even a healthy senior can maintain 150W for a few hours.

 

[Tommy L]

150cc like Dogman said

If you really want to go 100km and staying with electric, time for the electric moto like a Zero.
I've built 6 electric projects thus far. Also, I've PM'd others here on their projects with high capacity
batteries for power and distances. Most end up building their own bicycle frame and have
$5,000 to $9,000 invested.

To sustain speed above 50kph, bicycle tires and rims are not what you want, that's an expense.
DOT rated tires for speed are need. Can you imagine traveling at 50kph or more on a bicycle tire
and the front blows out? It would most possibly come off the rim and possibly get caught in the
spokes and front fork and throw you down bad!
Again, speeds above 50kph, you need a reasonable wheel base and fork rake(fork angle).

Putting 3kw of batteries on a regular bicycle frame and traveling at speed above 30kph
is probably not a good idea. Cars have a GVW (gross vehicle weight) sticker on them.
Have you ever overloaded a car or mini van? They become dangerous and handling
becomes very scary as speed increases.

If you've got your heart set on an Ebike, start small, invest the minimum of 1,000-$2,000 dollars
and see from there

There is much to consider.

Tommy L sends....

 

[muffinman]

i was looking at the SYM wolf classic (essentially a honda cb150, if i recall correctly), which is $4000 brand new. insurance for a new rider on anything under 400cc was $2500. even if i could find a motorcycle for $1000 or so, its still crazy expensive. im not opposed to doing 30-35kph average speed, and im fairly confident i could maintain at least 20kph on my own for at least a couple hours.
its still just in idea phase. its easy to research ICE options, but electric choices are not well understood. this forum has an amazing pool of knowledge, and many of you are happy to advise. i appreciate it greatly.
the major downsides to the motorcycle route is license and insurance. ebikes mostly fall under the radar around here, even if doing slightly above the legal limit.

 

[SamTexas]

... im fairly confident i could maintain at least 20kph on my own for at least a couple hours.

Good. You only need a 500Whr battery to do 90km at 30kph average.

 

[dogman dan]

Then if 3 hrs to do it is quick enough, get a 700-800wh battery, 36v 20 ah, or 48v 15 ah. My personal best on one of those was 39 miles, traveling 15 mph or less. But I'm old now, not like when I was 14-25 years old, and could pedal 25 mph for a couple hours just for grins. I weighed about 60 pounds less then, btw. At 115 pounds, I could pedal uphill all day.

Anyway, the size I recommended is affordable, and more importantly, is about as big as you can carry with ease on typical bikes. See how you do with that, then consider adding a few more wh with secondary packs as you can afford them.

For sure you have it made, if you could take 4 hours for the trip. Ride, charge someplace for 1 hr, then ride more. Then you'd have over 1kwh to get there.

Cost of insurance. Yeah, when I was young it was legal to ride without any. So we did. Some lived, some died. Now, with a motorcycle endorsement 35 years old, my 150cc scoot cost 200 a year to insure.

 

[Eskimo]

Just did 158km with two 48V/10Ah packs. It works when you ride with a group that cruises moderate speed. Wind resistance is lower in a group, and you don"t use WOT because you want to stay with the group. Certainly would not do it every day :wink: For daily 100km distance i would buy a motorcycle. 158km makes ones ass pretty done, just sitting hurts.
Normally when riding in a city i get around 45km out of 48V/10Ah pack. On the road with a group it can double.

 

[SamTexas]

One of my riding partners (regular bicycle) is 63 years old. We usually complete 36 miles (58 km) in 160 minutes (2hrs 40mins). If we were to it on an ebike and using the same effort we would complete it in 120 minutes and consume around 9Wh/mile.

Of course, we could also easily complete those 36 miles on ebikes in the same 2 hours and consume 20Wh/mile. I call that fake pedaling or pedal for show. That should explain why I think 500Whr is enough for the OP to complete 90km in 3 hours, while others insist on 700, 800 or even 1,000Whr.

 

[Tommy L]

Also to keep in mind when sizing your battery is to have 20% reserve as not to empty the pack. This will help in longevity of the pack.
Now one of my long workout runs is 54km and I do this on my Catrike. Man, I wouldn't want to travel 100km on a seat pole.
Recumbent s are easier on the neck, back, butt, and wrists, so consider this and the bonus is "Less Wind Resistance"

On my 54km ride I use around 330 watt hours on my catrike. SamTexas is saying the 500 would be enough. But we are in
Ontario (around 700 feet above sea level) and Colder Air which both are dense to punch through. On windy days you will need
twice the energy. On colder days too! The recumbent is the only way I know to beat it

So when I ride and pedal and maintain 35kph, I use 7 watt hours per km, so 100km will need 700 watt hours plus 20 or 30% reserve
equals 1kw pack. And this is for a recumbent!

On my Mountain bike at 50kph and pedaling, 50km with no wind/tailwind is 600 watt hours. Into a head wind, 50km is 1200 watt hours.
I average around 19 watt hours per km on this set up. Over double the recumbent. You can see that an upright Mountain Bike needs
more battery capacity. At 30kph, sure might use less than 19 watt hours per km, my guess would be at least 12-15 watt hours per km.
You are still in need of well over a 1kw pack to do the distance at our elevation/air density. It would be a drag on your first ride to
over drain your pack and kill your investment.

One of my cars is a Jetta Diesel. 1200km to the tank in the summer 800km in the winter dense air. Our elevation/air density must be
considered

Tommy L sends.....

 

[SamTexas]

When I say 500Whr I mean 500Whr usable energy. For me that's exactly 500Whr until MY LVC is reached. And my recommendation was very specific for this young OP who said he could do 20kph for at least 2 hours. I'm not giving the advice to an old geezer who can't barely produce 100W for half an hour, or to an obese individual who isn't capable of walking 1 mile without killing himself.

If we take into account of individual preference, whether it's 20% or 30% or 90% reserve or safety zone or whatchamacallit , the number becomes meaningless.

And if we take into account of countless other subjective personal matters like comfort, endurance, stamina... then we might as well not have any estimate at all. So what should be the proper answer? Well for 90km, you need anywhere from zero Whr to 10,000Whrs. I'm not sure that kind of answer really helps anyone.

 

[Tommy L]

When I say 500Whr I mean 500Whr usable energy. For me that's exactly 500Whr until MY LVC is reached. And my recommendation was very specific for this young OP who said he could do 20kph for at least 2 hours.

Hey SamTexas,

So am I understanding you correctly? Because the young OP will pedal unassisted at 20kph for 2 hours (40km travelled)
Then all he requires is 500 wh for the remainder of the trip? If so, I must have missed that part.

Also, I have no quarrel with you or any info you give here on the forum. I'm just trying to give him real world
results of my findings while I'm pedalling like a bat out of hell in this Northern Environment/elevation we
both live in.

Tommy L sends.....

 

[muffinman]

ok, ill be honest, i never thought about reserves.

 

[muffinman]

my battery knowledge is still severely lacking. still reading old posts, gleaning what i can here and there. i think i have amphours, watthours, watts, and volts down pat. havent ruled out controllers as tech from the future...
im not overly concerned about the length of time it takes to get there. id like to keep it at or under 3 hours travelling time. might stop for a rest a few times on top of that. the main thing is that the bus only runs one trip, wednesday, friday and sunday. unless im free between those specific times, i cant go. a transportation option that increases flexibility would be nice. this thread was just to determine if that was possible, and how difficult. thanks to some fantastic input, i have a much better understanding. all that being said, this may not be needed, or it may be a bad idea for other reasons.

 

[SamTexas]

It never hurts to ask specific questions, one at a time. But don't forget to also ask for on-topic, relevant answer to the question.

 

[muffinman]

It never hurts to ask specific questions, one at a time. But don't forget to also ask for on-topic, relevant answer to the question.

nonsense! lol

 

[SamTexas]

Huh?

 

[swbluto]

I got my recumbent for $400 on ebay, rear-suspension to boot, and can bike upto 200 miles on 1000wh. At 30mph, I'd probably be looking at 50 miles.

Not a trike, just a regular two wheeled recumbent. Look for ones that are laid back and keep your legs in front of you if you want maximum range.

 

[swbluto]

Huh?

Sarcasm? lol

 

[SamTexas]

I got my recumbent for $400 on ebay, rear-suspension to boot, and can bike upto 200 miles on 1000wh.

What was your overall moving average speed?

I have a 1.4Kwh (exact capacity from 4.2 to 3.0V per cell) battery on my mountain bike (with street tires). I can do 140 miles at an overall moving average speed of 18mph (top speed up to 26mph). Of course, I was always pedaling, using the exact same effort as if I was riding a regular bike at around 13mph. So the additional 10Wh/mile gives me a 5mph boost. I can do 18mph on my own power too, but never more than 20 continuous minutes.

 

[swbluto]

I got my recumbent for $400 on ebay, rear-suspension to boot, and can bike upto 200 miles on 1000wh.

What was your overall moving average speed?

I have a 1.4Kwh (exact capacity from 4.2 to 3.0V per cell) battery on my mountain bike (with street tires). I can do 140 miles at an overall moving average speed of 18mph (top speed up to 26mph). Of course, I was always pedaling, using the exact same effort as if I was riding a regular bike at around 13mph. So the additional 10Wh/mile gives me a 5mph boost. I can do 18mph on my own power too, but never more than 20 continuous minutes.

Well, I'm getting a new derailleur as my old derailleur couldn't use the fast gears, so my top speed was 15 mph continuously.

Anyway, that's when I'm pedaling "comfortably" (Contributing about 50-70 watts). I can maintain that pace all day long and not get tired.

I also installed a new primo comet low-rolling resistance tire on the back which reduced the average power consumption by 20-30 watts, so I'm eager to see what efficiency I can get when I get my new derailleur installed. (The bike is currently busted - out of commission derailleur. But getting some extremely promising figures on the new tires.)

 

[muffinman]

Huh?

sorry, sarcasm. im prone to using it often.

 

[SamTexas]

I also installed a new primo low-rolling resistance tire on the back which reduced the average power consumption by 20-30 watts...

That sounds too optimistic. I don't believe it until I see the actual test data. I would be extremely happy if a low-rolling tire gives me a 10 watts saving.

 

[swbluto]

I also installed a new primo low-rolling resistance tire on the back which reduced the average power consumption by 20-30 watts...

That sounds too optimistic. I don't believe it until I see the actual test data. I would be extremely happy if a low-rolling tire gives me a 10 watts saving.

The test data was simply a controlled two-way experiment at 12mph, *my* standard test speed.

The difference is a 40psi knobby compared to a 100psi ultra-low-rolling resistance primo tire.

An airshock for the rear suspension makes the high PSI tire not so noticeable in terms of harshness of ride quality, though there was a difference, not a big difference though. Still pretty comfortable.

Here's the data I used to choose the tire. http://www.discoveryride.com/human/rolling.html

 

[SamTexas]

The difference is a 40psi knobby compared to a 100psi ultra-low-rolling resistance primo tire.

Ah. That's not a fair comparison, but I see what you mean now. I thought you were comparing it to a street tire.

Going from a 40psi knobby to a 65psi street can easily give you 10 watts difference.