Hypermiling - settings to modify to get extreme range

[Mr. Coffee]

It is a heresy!
It makes more sense to me to carry as many fully charged lithium-ion batteries as one is able to afford and carry, then ride the long distance with no worries Sounds like a joke Mr. Coffee but if I rode an acoustic that would be at some 8 mph and I would give up after 40 miles...Taking the train back home!

What's so wrong with just going slower and shorter distances? I'm personally not in a very large hurry most of the time. And also taking the train is much easier with an acoustic bike than an e-bike.

Sometimes a non-electric bike is just more appropriate technology.

 

[Stefan Mikes]

What's so wrong with just going slower and shorter distances? I'm personally not in a very large hurry most of the time. And also taking the train is much easier with an acoustic bike than an e-bike.

Sometimes a non-electric bike is just more appropriate technology.

Wasn't you the man carrying three batteries on his e-bike and making long trips in the Cascades?

 

[Mr. Coffee]

Wasn't you the man carrying three batteries on his e-bike and making long trips in the Cascades?

The problem is that I have trips in mind where four or five batteries might well be necessary. Or where there is more than a bit of hike-a-bike required, and I'd rather push a much lighter and much more lightly loaded bike.

Also for me, this is about having fun and seeing and experiencing the world, not necessarily covering the ground at a rapid rate.

 

[Stefan Mikes]

Also for me, this is about having fun and seeing and experiencing the world, not necessarily covering the ground at a rapid rate.

I know you are all for bike-packing and camping. Your trips are far from civilization, too. It is therefore understandable you need to be independent of the electric assistance. I look with envy at my younger, healthy and strong gravel riding mates: they often participate in ultramarathons, meaning 300+miles to be covered in limited time. The ultramarathon rules often require self-sufficiency from the riders (for instance, they are forbidden to book any hotel in advance). I wish I could be one of them but that's not possible.

The longest day in Poland, Jun 21st has 17 hours of daylight; most of the days are shorter than that. For me, assisted pedalling for the Imperial Century means over 7 hours net. My latest 170 km ride took me twelve and half hours gross. I need speed not to get anywhere fast; it is to be able to complete a ride such as a Double Metric Century within the daylight. My medical condition makes unassisted rides impossible for me, either.

A fast ride? I love seeing landscapes changing fast

It is obvious a traditional bike has the range only limited by the rider's "internal battery". We are, however, discussing hypermiling on e-bikes here.

 

[mschwett]

Wind resistance is roughly based on the square of your speed, so double your speed, quadruple the wind resistance.

but the power it takes is actually closer to the cube. takes 200 watts to go 20, and over 1,400 to go 40… because not only is the instantaneous resistance squared …. you’re going twice as fast, encountering twice as much of it per unit of time.

"Note that the power needed to push an object through a fluid increases as the cube of the velocity. A car cruising on a highway at 50 mph (80 km/h) may require only 10 horsepower (7.5 kW) to overcome aerodynamic drag, but that same car at 100 mph (160 km/h) requires 80 hp (60 kW).[16] With a doubling of speed the drag (force) quadruples per the formula. Exerting 4 times the force over a fixed distance produces 4 times as much work. At twice the speed the work (resulting in displacement over a fixed distance) is done twice as fast. Since power is the rate of doing work, 4 times the work done in half the time requires 8 times the power."

here are the ways to really increase range

1) go slow
2) reduce your drag. get down low on the bike, wear smooth and tightly fitted clothes, a tapered and smooth helmet, a bike with narrow and deep section wheels, streamlined frame, no junk on the bars or your back etc etc etc. most of the drag comes from the rider, so the most important part is that the shape of the bike allows the rider to get as aero a profile as possible
3) keep your speed steady. don’t use the brakes unless absolutely necessary, especially going downhill. you built up a huge amount of potential energy going up, don’t waste it to heat!
4) minimize rolling resistance. no integrated gear hubs, motors must be disengaged when not under power, supple tubeless tires with smooth or no tread, well lubricated and maintained drivetrain, etc.
5) use the motor only when you need it (hills and wind!) and, if it’s a mid drive, make sure you are pedaling with a cadence that allows it to operate where it’s most efficient. motor efficiency falls off a cliff at very low or very high RPM.

basically, you want to do all the things people who want to go far fast on a regular bike do. they’ve done them for decades, much has been learned.

the longest ride i’ve done on my e-bike is about 118 miles with about 6,700 feet of climbing. winds were fierce in spots so it wasn’t a super efficient ride. i used 26% of the bike’s battery (83 watt hours) and contributed about 1,300wh of human power, for about 11.7wh/mile at an average speed of 15mph. it ought to be possible to get that number down to around 7.5wh/mile at the same speed with a steadier pace, less hills, wind, and better aerodynamics.

at 12mph, it should be possible to get down to 5wh/mile. if the rider supplies half (almost no work at all!) and the motor the other half, a 700wh battery would go 200+ miles. but that’s no fun!

 

[bobf]

Some posts have said to use maximum tire pressure, but that might not be the best. Check out the discussion at

Tire Pressure Calculator

Finally a tire pressure calculator based on real-road rolling resistance measurements. On real roads—rather than on a steel drum in the lab—supple high-performance tires work best at considerably lower pressures than most cyclists are used to. Lower pressures roll as fast or faster, while...

www.renehersecycles.com

I would definitely agree that supple tires make the riding more fun.

 

[Asher]

I recall seeing a bikebiz or similar article about a company that makes a machine to test ebike fuel efficiency under standardized conditions, for manufacturers. I wish someone would obtain and publish these results, like a publicly funded lab like the EPA does with cars. Set a standard rider, say, 170 lb on flat ground, with a mix of slopes, with ~100w pedal input, and calculate both mileage and voltage sag.

 

[Tbill]

I'm interested in trying some e-bike "hypermiling" (a term I hear e-cars owners using for when they're trying to get max range on a charge). I have a bike where I can modify top speed, assist percentage, max torque, and max wattage, and I'm curious for feedback on the best way to do that.

I think the most obvious way to do it is to reduce the top speed down to 25 km/h (the lowest I can adjust to). That's fine for a touring pace for me. Back in the day my solo touring pace on a muscle bike typically averaged 18-19 km/h when (for example) doing an 8 hour solo ride on a hilly-ish route.

However, out of reducing the max torque, the assist percentage, and the max wattage, which is likely to be the most effective at further extending range? Or is it six of one, half a dozen for each of the others?

My supposition is that reducing the assist percentage would do the most to extend range on a mostly flat ride, and that reducing max wattage and/or max torque would do the most to extend range on a mostly hilly ride. But I've been wrong before!

I'm particularly curious about reducing max wattage, and whether there're any good reasons to do this or to not do this. All comments on any of the above appreciated, though!

I would depend on a lot of things. Terrain. The amount of stop signs and lights? Posted speed limits.
With automobiles, you try to use potential energy so if you are going down a decline, you stop as high up as you can so gravity will assist you in getting back up to speed. You can also coast to the stop sign so you don't reach it at full speed and waste all of that energy when you brake. You can also try to time the lights so you reach the intersection when the light is green rather than red.
You can also assume the position. Reducing wind resistance will save a lot of energy.
These are obvious answers but some people may not have thought of one of them.

 

[PSm]

Some posts have said to use maximum tire pressure, but that might not be the best. Check out the discussion at

Tire Pressure Calculator

Finally a tire pressure calculator based on real-road rolling resistance measurements. On real roads—rather than on a steel drum in the lab—supple high-performance tires work best at considerably lower pressures than most cyclists are used to. Lower pressures roll as fast or faster, while...

www.renehersecycles.com

I would definitely agree that supple tires make the riding more fun.

+1. The general guideline from bikerollingresistance.com is to inflate to 85% of maximum pressure. Provides a balance of lower rolling resistance and comfort. I’ve now settled on that, after trying both higher and lower pressures.

 

[PSm]

I would depend on a lot of things. Terrain. The amount of stop signs and lights? Posted speed limits.
With automobiles, you try to use potential energy so if you are going down a decline, you stop as high up as you can so gravity will assist you in getting back up to speed. You can also coast to the stop sign so you don't reach it at full speed and waste all of that energy when you break. You can also try to time the lights so you reach the intersection when the light is green rather than red.
You can also assume the position. Reducing wind resistance will save a lot of energy.
These are obvious answers but some people may not have thought of one of them.

+1. For my e-bike, analog traditional bike, and plug-in cars, many of the similar rules apply. Coasting as much as possible downhills, reduce wind resistance (for bikes, aero body positions; for cars, no roof racks, keep windows closed), minimize rolling resistance with the right tires and tire pressures, minimize power usage (for bikes, low or no assist; for cars, smooth and gradual acceleration, plan for stopping with good regen braking when approaching stop lights), and good cornering techniques to keep speed up and efficiently make turns.

 

[Tbill]

Of course another one is to look to see if there are any cops around and if not, treat stop signs as yield signs.
In Paris, there are no stop signs, apparently. People just defer to the person to the right of them, presumably. What if all four reach the intersection at the same time? Well, light up a cigarette and wait until someone moves.

 

[Jeremy McCreary]

Of course another one is to look to see if there are any cops around and if not, treat stop signs as yield signs.
In Paris, there are no stop signs, apparently. People just defer to the person to the right of them, presumably. What if all four reach the intersection at the same time? Well, light up a cigarette and wait until someone moves.

When I visited Paris in 2019, the city traffic was total Brownian motion everywhere. Why they bothered to paint lines on the streets is beyond me. In big jams, the sidewalks became fair game.

Wasn't paying attention to bike infrastructure then, but can't imagine that any separating line or rumble strip or bump would help. A 1 meter wall or force field, maybe.