Longer Range out of the box

mbf001

Finding my (electric) wheels
Jun 14, 2014
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I'm a newcomer to this so forgive me if my thinking's still a bit out of the box.

After spending several days in cruising the web I only have the roughest idea of what is happening. What I am aiming for is long range rather than speed or style. 20 or even 15 mph would be more than enough for me if long range can be achieved. In real terms, e-bikes or pedelecs are really commuter bikes in terms of range.

For the sake of raising the bar let's just say that the target on road touring range is to be 400 miles over a theoretical level (flat/horizontal) road without hills. The question is: how is that range to be achieved? I know it sounds mad but let's go for it. because if we don't try we'll never do it.

As everyone knows, the main limiting factors are weight or mass, wind resistance, human and battery power, i.e. bigger battery = greater mass = greater energy requirement.

Real world constraints:

  • LEGALITIES: Wattage of motor, weight of bike, maximum speed, is a trailer legally permissible on an ebike or pedelec? I'd like to ignore these, probably like many others, but I value my licences too much.
  • GROSS WEIGHT of COMPLETE SETUP
  • Ah, VOLTAGE and WEIGHT of BATTERIES
  • POWER of MOTOR (let's stick with the UK legal max. of 250 watts for this exercise)
  • UPGRADED BRAKES: because of the additional towed weight of trailer and batteries the brakes would probably need to be upgraded so adding more weight (minimal).
  • FITNESS, STRENGTH & STAMINA of RIDER: Assume rider to be a fit 30 year old but one who does little or no strenuous or regular exercise.
  • SPEED -v- WIND RESISTANCE: higher speed = less miles per watt. Use 12 mph as the average speed throughout.
  • TOTAL COST: Other than style and go faster' paint jobs it seems to me that there's little performance difference between some bikes that could cost much less than £500 and those at £2,500 or much more. I've seen advertisements from one German company who offer pedelecs with a range of 200+ kilometers but I have grave misgivings about phrases in adverts like "up to" and "depending on". It's time that there was one method of unequivocally specifying performance for all ebikes and pedelecs...but that's a different subject worthy of its own thread.

There are numerous obvious trade-offs but several lateral thoughts emerge that others may have researched properly, in engineering fashion. For extended range how about:
  1. towing batteries on a trailer behind the bike. Apart from inertia in starting from 0 mph and in accelerating, most of the trailer and battery weight is a vertical downwards component, supported by the trailer wheels. Allowing for some frictional and aerodynamic losses it seems to me that in the trailer idea there's a lot of potential to substantially increase range.
  2. perhaps even with two 'standard'(?) batteries a very small small generator and charger could be carried on the trailer and run to charge one battery or more while another battery is being used to hel power the pedelec. It's a thought at least.
It would be good to hear from people who have researched these ideas or others and come up with well-researched and proven conclusions or even a final working setup.

I'm delighted to have stumbled over this forum and I look forward to learning a lot from those who beat me to it.
 

Clockwise

Esteemed Pedelecer
Jun 28, 2013
438
53
Well the longest section of the tour de france this year will be a pathetic 147.5 miles. I'd suspect that even if you can ignore speed limits and the weight issues or have some fictional iron man style mini reactor onboard then you would simply fall asleep and slump over the handlebars long before "cycling" at lets say a modest 40mph for 20hrs non stop to complete the ride...

Average fitness adult who isn't a regular cyclist could do london-brighton(60miles) without assistance and then be exhausted, many people are doing that this weekend. With an extra bit of assistance from an average ebike they could probably do 75miles(london-dover) before they are just as exhausted, sort of depends on how they used the motor as a higher top speed will burn more battery power/rider energy(candle burns the brightest).

Ideally tho most people would want to not be entirely burned out day after day and if they aren't used to cycling long distance they will probably not be eating/drinking enough so could do some damage with dehydration and things setting in on day 2. But 7-8x 50-60 miles a day with assistance, plenty of lunch stops and things can make for an enjoyable week and not riding so hard that they can get it really wrong.

I have to be honest that I can't see why anyone who rarely even exersises would suddenly want to do a 400 mile ride, it has all them desirable aspects to it like saddle sores and cramps.
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
2,671
On average, you need 6 to 15WH per mile depending on how hard you pedal. For 400 miles, that's 2400-6000WH, with the current Lithium batteries, the cheapest solution is to use 540WH, each weighs 3kgs with NCR 2900maH, costing about £350 each. So, 5 batteries at 3kgs each, 15kgs total. The bike without batteries weighs about 17kgs - it's totally legal.
You can save some weight and cash by building the battery system yourself, 10kgs in the rear carrier panier, 5kgs in a triangle pack.
With a BBS01 kit to drive the bike, total cost without the donnor bike is £330 + 5 * £350 = £2080 and will take less than a day to build. If you put the battery in trailer, it may be worthwhile considering installing solar cells on the trailer to recharge the battery. If you travel at 15mph, you use about 11WH per mile, 165W is the consumption. Assuming you put 1sqm of solar cells on the trailer, you could recover about 60W, extending the range about 20-25%. It would be cheaper if you carry a generator inverter in the trailer, the weight of the generator is about 7kgs + 4kgs petrol can, the range could be about the same 400 miles. You will need a fast charging battery system. I estimate that using a petrol generator attached to the bike will bring the cost down to about half price, £1000 but you will have to stop to recharge, flecc pointed out that it's a motobike or PHEV and will need type approval + number plate and insurance if you run the inverter while riding.
 
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D8ve

Esteemed Pedelecer
Jan 30, 2013
2,142
1,294
Bristol
One factor not considered is the bike.
A recumbent will have a lower wind resistance and hence use less watts per mile. Going for a velomobile is the pricy but queen of this class.
Combined with the comfortable seating they are a serious contender for Randonnering or Audaxing.

At 15mph you can do 360 miles in 24 hours.
You need to eat and excrete as well or you won't last.
So your hypothetical cyclist with a generous 16 hour day would do 240 miles.

Looking at trex's figures. You would need 6 watts per mile(Bents are very efficient ) or about 3 power packs. Circa 10kg.

Get strong with training and you can do this without power as well.
Classic Audaxing has guide speeds of 10 to 18mph.
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
2,671
+1 for long range recumbent trikes
 
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Deleted member 4366

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Bicycles get you from A to B, but you have to provide all the energy, which makes your legs ache.

Motorcycles get you from A to B, and provide all the energy, so you don't get tired at all

Electric assist bicycles fill the gap in between. By selecting the appropriate system, you can have one anywhere on the scale of proportions of energy supplied from very little to nearly all, so you can choose how much your legs will ache.

Got it now?
 
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D8ve

Esteemed Pedelecer
Jan 30, 2013
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1,294
Bristol
A fuel cell is commercially available and will produce electricity for a small weight. It's a mini generator that can run on alcohol.
But then a number of contributors here can run directly on alcohol :-0
 

mbf001

Finding my (electric) wheels
Jun 14, 2014
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Great replies. Many thanks.

Trex - the cost and energy breakdowns are very useful. Thinking about the generator, as I'm just beginning this mission, I have no idea about the weight of a generator but my intuition says that surely there must be a lighter weight available but maybe not. I'll do some poking around. The solar cell option is a bit ify where I am in Scotland. 1) We see the sun about 5 minutes a year - if we are lucky; 2) The winds up here would probably blow me, the bike and the trailer up into Norway...now there's a thought.

D8ve - ditto. The fuel cell alternative has got me thinking even more. I'd like to explore that much further. Can you advise me on any good reference sources/websites? Gotta adtmit that alcohol gets some people a long way :eek:) By the way, what's a "Bent"?

Clockwise - I'm into positive mode of thought in this exercise. At this time I'm exploring the theory. Getting up and doing it will come later. The 400 mile target for 'Sedentary Man' was purely arbitrary - put there just to stretch the theoretical boundaries and explore options. Y'never know, y'know!

I'm in Glasgow, a few miles south east of Loch Lomond and there are many great open places to go to up here.

I'm not attracted to cycling everywhere at high speed or for too many hours in the saddle. Slow and steady will do for me. The story of the tortoise and the hare come to mind.
 

D8ve

Esteemed Pedelecer
Jan 30, 2013
2,142
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Bristol
Mbf001,
Try mccraw.co.uk for an introduction to Scottish recumBENT cycling.
Long distance touring is one of his things.
If it is touring then 1kw of battery should last all day on a legal bike.
And recharge in the b&b overnight.
Lots to learn from there. And laid back cycles in Edinburgh could also help.
 

Artstu

Esteemed Pedelecer
Aug 2, 2009
2,420
925
I'm not attracted to cycling everywhere at high speed or for too many hours in the saddle. Slow and steady will do for me. The story of the tortoise and the hare come to mind.
I don't understand the point of this thread? it sounds like you just need to ride an ordinary bike.
 
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Deleted member 4366

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The lightest generators that you can buy are about 9kg. A 20aH 36v battery will take you about 50 miles towing a trailer, so you'd need a spare and 6 x 5-hour charges to do 400 miles, which means about 12 litres of fuel, so you can say that you need to tow the trailer plus spare battery (5kg), generator (9kg), charger (1kg) and fuel (11kg) = 26kg.

I'd be surprised if anybody would bother you if you had the generator running to charge a battery if nothing on the trailer is connected (electrically) to the bike.

Some people built smaller generators using a R/C 4-stroke motor driving a R/C brushless motor. You need some complicated electronics to manage the charging/voltage control. You can find them on Youtube.

Here's a trailer I built for the same purpose. It towed quite easily with a Bafang BPM motor:



 

john h

Esteemed Pedelecer
Nov 22, 2012
510
147
murthly castle estate
mbfoo1 Ilived in glasgow for a lot of years, my run was from glasgow to the bonny banks on sundays along the clyde to partic then on the old rail track to clydebank then the canal bank to alexandra then bolling and on, it was a great run (still miss it)
the right bike will take you far, lots of good cycling open places to explore there as you said,
 

mbf001

Finding my (electric) wheels
Jun 14, 2014
5
0
73
mbfoo1 Ilived in glasgow for a lot of years, my run was from glasgow to the bonny banks on sundays along the clyde to partic then on the old rail track to clydebank then the canal bank to alexandra then bolling and on, it was a great run (still miss it)
the right bike will take you far, lots of good cycling open places to explore there as you said,
Yep johnh - I'm in Westerton at the southern point of Bearsden. Agreed, the canal path and onwards is a great route.
 

mbf001

Finding my (electric) wheels
Jun 14, 2014
5
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73
mbfoo1 Ilived in glasgow for a lot of years, my run was from glasgow to the bonny banks on sundays along the clyde to partic then on the old rail track to clydebank then the canal bank to alexandra then bolling and on, it was a great run (still miss it)
the right bike will take you far, lots of good cycling open places to explore there as you said,
The lightest generators that you can buy are about 9kg. A 20aH 36v battery will take you about 50 miles towing a trailer, so you'd need a spare and 6 x 5-hour charges to do 400 miles, which means about 12 litres of fuel, so you can say that you need to tow the trailer plus spare battery (5kg), generator (9kg), charger (1kg) and fuel (11kg) = 26kg.

I'd be surprised if anybody would bother you if you had the generator running to charge a battery if nothing on the trailer is connected (electrically) to the bike.

Some people built smaller generators using a R/C 4-stroke motor driving a R/C brushless motor. You need some complicated electronics to manage the charging/voltage control. You can find them on Youtube.

Here's a trailer I built for the same purpose. It towed quite easily with a Bafang BPM motor:



D8veh
Your trailer looks great to me but you must have legs like tree trunks to haul it around. I'd be leaning to the lighter side of trailer construction and/or maybe a helium balloon to take some of the weight ;-)

Because weight is a huge factor the RC brushless 4 stroke motor sounds worthy of some investigation, even if my electronics skills aren't up to par.

Tricycles, especially the recumbents aren't things I've thought of before so again, food for thought.

Thanks for your tips.
 
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Deleted member 4366

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I don't need strong legs. The motor does all the hard work.
 

D8ve

Esteemed Pedelecer
Jan 30, 2013
2,142
1,294
Bristol
Two wheeled recumbents are fine with good weight capacity. The trikes are good for learning but heavier and slower on corners?
5 months on a bent now and I am doing 25kph on the flat in a relaxed cruse mode.
The run to Lomond side should be easy perhaps head wind but really flat.

Only the rest to worry about in Argile
 

mbf001

Finding my (electric) wheels
Jun 14, 2014
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D8ve,
Gorrit. Trikes are also a bit more susceptible to cars and trucks with 'mow 'em down' proclivities.

Has anyone done a bike trailer with one wheel? I haven't seen one. If set up with equal weight distribution on both sides it could yield benefits....errmmm, perhaps, maybe.
 

Geebee

Esteemed Pedelecer
Mar 26, 2010
1,256
227
Australia
Two wheeled recumbents are fine with good weight capacity. The trikes are good for learning but heavier and slower on corners?
5 months on a bent now and I am doing 25kph on the flat in a relaxed cruse mode.
The run to Lomond side should be easy perhaps head wind but really flat.

Only the rest to worry about in Argile
A good recumbent trike (with a practise rider) will out corner a 2 wheeler upright or 'bent, also out brake either by a large margin.
As to getting run over, drivers tend to give them a LOT more room and if you do get a minor hit you wont be thrown off.
 

twinkle

E-Triker
May 14, 2013
249
93
Peacehaven nr Brighton
Hi Guys

Towing a running generator that is charging the batteries that are your propulsion source as you ride is Illegal in the UK , The bicycle become a motor powered bike .
Solar charging is legal as such and I don't believe that has been challenged yet in court ,
My recumbent trikes will out corner most things and due to the reduced wind resistance it is easier to ride , and most motorist tend to give trikes a wide berth , mine will happily tow about 1 cwt in a twin wheel trailer and that could either extend the range or carry enough camping equipment for 2 people. My trailer tows from a cars track rod end mounted on a towing iron fitted under the ns rear wheel spindle .
Remember that due to a quirk in British law the trailer must carry rear lights and a warning triangle even if the bike has no lights !!!!!!!!!!!!!
A friend of mine started a touring holiday around Holland with a mono wheel trailer with panniers on his trike, the twisting force are different on a trike to a bike and the trailer frame luckily broke before twisting the rear end of the trike .
All my trikes are home built and equipped with front discs that will out perform
most bikes for stopping the rear brake unless the trike is heavily loaded will lock up as the weight is transferred to the front under heavy braking, again 3 braked wheels is a legal requirement to electric trikes .

regards emma