Apartunis
Regular
When was the last time you went 100 to 150 km on a bicycle? People often want things in an ebike they do not really want.
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Hypothetical bike build. (Electrifying a Surly Moonlander 2.0 with Pinion Gearbox for max range)
- Thread starter Bvagu
- Start date
If I had a bicycle that would require of me to pedal with less then 100W human power and get that range on a mixed terrain, I would have done it. That is the whole point. I can tell you of plenty a times where I have gone over 150km in a day with that kind of speed on my 50cc motorcycle. If that kind of set up actually manages to get anywhere near that kind of range in the real world. I guarantee you I'll find uses for it.
Even with my cushy seat, my ass can only manage about 50 miles tops now. That's at my preferred average riding speed of ~20 mph. My usual rides are about 30 miles, or an hour and a half in the saddle, and taking a few breaks to look at stuff or getting something to eat, I'm out of the house for 3 or 4 hours. Simulator says I can go 96 miles if I had a better seat
.Full throttle, the simulator says I'd get 21 miles, and only a half hour of riding. The faster you go, the shorter the ride > Less enjoyment
.For me, the limiting factor is time in the saddle, not miles, and 100 km would 10 miles past my time in the saddle limit, unless I rode faster.
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SlowCo
Minor legend
Take a:
Q80 Bicycle Seat Frame kit for Bafang | Qulbix Performance Electric Bikes
With a BBSHD as mid drive and a hill climbing gear cassette in the rear wheel.
Then a geared hub motor without a clutch and capable of regen braking in the front wheel that can assist on the climb with its own programmable controller and left hand thumb throttle:
https://ebikes.ca/ebike-parts/hub-motor-stuff/motors/mezee250f-rg-build.html
V6 Baserunner_Z9 Controller, Stand Alone Model
Q80 Bicycle Seat Frame kit for Bafang | Qulbix Performance Electric Bikes
With a BBSHD as mid drive and a hill climbing gear cassette in the rear wheel.
Then a geared hub motor without a clutch and capable of regen braking in the front wheel that can assist on the climb with its own programmable controller and left hand thumb throttle:
https://ebikes.ca/ebike-parts/hub-motor-stuff/motors/mezee250f-rg-build.html
V6 Baserunner_Z9 Controller, Stand Alone Model
Apartunis
Regular
Yeah, my longest ever day in the saddle was about 275km but that was decades ago and I can not begin to contemplate a ride like that now.
If you fix the saddle problem you will probably find the next limitation not too many miles later. That is how it goes. If it were easy and people were moral, everybody would ride a bicycle.
I used to ride a motorcycle and I can attest that 300+ km on a motorcycle is physically challenging, but not nearly as much as the same distance on a bicycle. When people who want electric help pushing pedals also want endurance athlete type range, I am certain they do not know what they are asking for. I think almost everybody would be best served by an ebike optimized for the range and speed they are already comfortable and familiar with. For road trips it would be best to build a dedicated road trip bike. Trying to do everything with the same tool leads you stepwise to a comically humongous pickup truck which spoils things for everyone.
offGridDownUnder
Power poster
I ride a recumbent trike. Before this, I was riding a Cruzbike Q45 recumbent two-wheeler (Cruzbikes, by the way, hold many of the speed records, particularly climbing).
With deterioration in my joints, I can't manage long walks without pain - and so I don't - but I know I can ride for hours on my trike and the Cruzbike before it - because I have done so. I gave up the Cruzbike because I had to slam a foot down at slow speed when a tire caught in a seam in the footpath, and that ankle joint couldn't handle that. The trike is larger, but I mostly can't fall over. My joints will not become more resilient as I age further, but there does not seem to be much preventing me from riding until I die.
Upright bicycle frames are the problem, aggravated by the racing industry refusal to permit recumbents.
This is an easy problem to solve - it's already solved for you.
- No wrist pain.
- No neck pain.
- No shoulder pain.
- No sore butt. No numb parts.
- No sore back. No impacts slamming up my spine.
- And boy, is that view nice! I don't look at the pavement, I look at the path and the trees and the sky.
- Exercise? Sure! Strain? No.
With deterioration in my joints, I can't manage long walks without pain - and so I don't - but I know I can ride for hours on my trike and the Cruzbike before it - because I have done so. I gave up the Cruzbike because I had to slam a foot down at slow speed when a tire caught in a seam in the footpath, and that ankle joint couldn't handle that. The trike is larger, but I mostly can't fall over. My joints will not become more resilient as I age further, but there does not seem to be much preventing me from riding until I die.
Upright bicycle frames are the problem, aggravated by the racing industry refusal to permit recumbents.
This is an easy problem to solve - it's already solved for you.
Apartunis
Regular
That sad excuse is pushing 100 years old now and way past its expiration date. Normal bikes are normal because they work best for most people most of the time. Bents are special needs bikes.
scianiac
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I mean I feel like it's hard to say that when basically nobody has tried other shapes of two wheeled vehicle. Like — saying they work better for most people when most people have not compared them is unfair. I think normal bikes do work just fine and one is not superior — I just have to assume a lot of the low popularity of other vehicle shapes is historical, due to lack of development, being too weird for people to try, etc. I've always wanted to try a recumbent E-moto build.
Anyway back on the topic of range — and this build — do you know how long a ride is going to be before starting it? Are your rides planned or just adventures? If they are planned at least to some extent — I think a modular battery build could have some advantages. That way you can have a lighter bike which is at least somewhat more efficient to pedal sometimes — then slap on the 2nd battery for those long trips. At least that's how I would do it — I like keeping the bike efficient for the range it needs — not carrying around way more batteries than I need most of the time.
May of 2022. That was pretty much my minimum ride, for 11 years. From September of 2011 to then, I rode those two bikes 63K miles.
SlowCo
Minor legend
OlderGiantFan
Regular
Well I wouldn't try to push the envelope too far myself, nothing wrong with having a Gas powered bike for the long trips.I can tell you of plenty a times where I have gone over 150km in a day with that kind of speed on my 50cc motorcycle. If that kind of set up actually manages to get anywhere near that kind of range in the real world. I guarantee you I'll find uses for it.
I've watched this 'Lipo' technology develop for decades now, and it has serious limits across many fields of innovation. The obvious conclusion to be drawn is that for uses where the battery is light compared to the device it's great, mobile phones, torches, campervan batteries even. But scaling up introduces a lot of unwanted issues, and cost. Pedal assist is amazing but pedaling an e-bike with human power alone totally sucks! All the great mechanical efficiency goes right out the window with the extra weight. I want longer range so I add more weight in batteries and pretty soon all the nimble handling dynamics go out the window too and I'm basically riding an electric motorcycle, but one with underrated wheels, brakes and suspension
A poorly handling motorcycle prone to failure more so than a gas bike basically.
It's the same with cars, half the weight is in the batteries for the long range models, and due to cost and all the other downsides 98% of people have rejected them, rejected EVs that is. Now the whole car industry is pivoting to gasoline hybrids with small batteries and they are selling well.
Update:
I've taken into consideration all of the advises given to me and decided on the following:
I ordered today the Surly Moonlander 2.0 with the 9 speed gearbox as the base for my bike, this thing is the closest I could find in terms of ticking all of the boxes needed for what I want a bike to do.
How does this compare to what I previously had in mind?
Well my first idea was centered around full suspension frame and that is rather involved in terms of fabrication if I wanted a custom one, and it had to be a custom one since the only commercially available one is the Q140MD from Qulbix. I did reach out to them and asked if they could modify the BB of the normal frame to accept the pinion gearbox, but it was to much of a hassle for them, and I don't blame them, I really didn't expect them to accommodate my delusional ideas, so that is all good, but that kinda left me with the only option for a full suspension frame to be a custom one, and that for a first build is a no go.
How does the Moonlander 2.0 with the 9speed pinion fit in?
Well the frame is rated as an expedition-grade/all-terrain overlanding (whatever that means), and it should be plenty strong for batteries etc. It comes heavy out of the box, so after fitting motor and batteries it will be less or similar in weight to a custom frame. The difference here will be that I will have to use the hub motor in the rear wheel, but that frame is the closest to a "bolt-on" solution I could find (considering the Grin Max45) while still having a pinion gearbox before the motor. That frame also has two nice "compartments" for batteries. One is just behind the rear tire and the seat post, and the other is the middle triangle, so this way I the only "custom" part of this will be the batteries, and those two places give options for a "smaller" and a bigger battery, that way I can only carry a battery according to the adventure.
This is where we are at. I'm hoping to get the bike in a couple of weeks and start plan things. I will most likely ride the bike as is for the summer, because my summer job is at the beach, that way I'll have time to get use to this beast and contact Grin, and plan for the conversion.
Thank you guys for all of your time and comments, much appreciated. Will keep you posted on further developments.
I've taken into consideration all of the advises given to me and decided on the following:
I ordered today the Surly Moonlander 2.0 with the 9 speed gearbox as the base for my bike, this thing is the closest I could find in terms of ticking all of the boxes needed for what I want a bike to do.
How does this compare to what I previously had in mind?
Well my first idea was centered around full suspension frame and that is rather involved in terms of fabrication if I wanted a custom one, and it had to be a custom one since the only commercially available one is the Q140MD from Qulbix. I did reach out to them and asked if they could modify the BB of the normal frame to accept the pinion gearbox, but it was to much of a hassle for them, and I don't blame them, I really didn't expect them to accommodate my delusional ideas, so that is all good, but that kinda left me with the only option for a full suspension frame to be a custom one, and that for a first build is a no go.
How does the Moonlander 2.0 with the 9speed pinion fit in?
Well the frame is rated as an expedition-grade/all-terrain overlanding (whatever that means), and it should be plenty strong for batteries etc. It comes heavy out of the box, so after fitting motor and batteries it will be less or similar in weight to a custom frame. The difference here will be that I will have to use the hub motor in the rear wheel, but that frame is the closest to a "bolt-on" solution I could find (considering the Grin Max45) while still having a pinion gearbox before the motor. That frame also has two nice "compartments" for batteries. One is just behind the rear tire and the seat post, and the other is the middle triangle, so this way I the only "custom" part of this will be the batteries, and those two places give options for a "smaller" and a bigger battery, that way I can only carry a battery according to the adventure.
This is where we are at. I'm hoping to get the bike in a couple of weeks and start plan things. I will most likely ride the bike as is for the summer, because my summer job is at the beach, that way I'll have time to get use to this beast and contact Grin, and plan for the conversion.
Thank you guys for all of your time and comments, much appreciated. Will keep you posted on further developments.
hillslayer@
Regular
The 197 dropout spacing could be a problem. Hopefully Grin can make an adapter.
I think the "normal" version rear motor with the 10speed shimano freewheel hub with integrated torque sensor comes in that specific dropout size. I'll just need to get a single speed spacer adapter with the right size sprocket and that should be all good.
I think the most amount of trouble I will have is in terms of rims + tires. The "normal" 24inch 6inch wide tires are certainly not rated for any sort of electric power assist. I haven't yet looked up the specs of those rims + tires, but I recon if I just put a hub motor on them, as they come from the box, the rim will spin off the tire immediately. I'll like to keep the original rim+tire set as the non-assisted version and build a different set for the powered version.
scianiac
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The factory rim and tire will be just fine unless the tire pressure is super low maybe but at some point spinning tires on rims seems pretty rare. I've only had it happen with extreme amounts of torque, very low tire pressure and very old tires where the rubber on the bead was partially rubbed through, I ended up fixing it with bead locks though as I like my low tire pressure. I think though those tires will suck up a fair amount of battery.
Technically a triplet.
Apartunis
Regular
I do not think that is true. Any tire over 3 inches/75mm wide that you can buy will cost you a lot of range. Since that is the most difficult criterion you have, you undermine you own goals by using a knobby fat tire. Knobby might be important for mountain climbing, but fat tires will need a lot more battery to get the same range.
I thought of a way to widen your power delivery speed range. If you have two batteries of the same voltage and two controllers, you could switch between half voltage and double current or double voltage and half current. You could use a big multipole switch to change batteries between series and parallel and to switch between one controller and the other. If the motor is rated to take the higher current then you would have a mountain climbing speed range and a faster but lower torque operating range for roads and less steep terrain.
scianiac
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That's not really how electric motors work, switching the battery voltage while keeping the motor the same will do basically nothing. Technically there is probably some very very slight change due to switching losses or something. To change electrical "gears" you have to change the motor winding and even then the advantages are slight unless your operating speed range is massive. This isn't unheard of, that is having two sets of windings that you can switch into parallel or series but it's pretty rare and again only works if the speed range is quite large, which based on his conservative top speed isn't the case.
Thinking about ways to make a bike adapt to increase range, with fat tires an automated tire inflation system would be interesting. You could use two of those tiny battery pumps mounted to the hubs. To make it really automated though you would need a system to release pressure to a set pressure, which could also be done. Central inflation would be pretty neat, too bad I only ride my fatbikes in areas where low pressure is always needed or it would be a cool project.
Apartunis
Regular
What I was suggesting was having for example a 48V 25A controller alongside a 24V 50A controller that get switched over when the batteries are changed from series to parallel. With any given single motor winding, the motor will find a lower efficient speed at lower voltage, even if the higher voltage controller can serve up the same maximum current from a stop. Which it probably can not.
The low voltage configuration will most likely give more torque at low speed, but definitely will deliver better efficiency and less heat at low speed.
It depends on what you're looking for. Higher peak current is higher peak torque (or percieved power), but that's applies to peak of the torque curve, that is at stall on an electric motor. For my ebike riding, that peak isn't of much use, but for a wheelchair trying to get up a curb, it might be. Raising the voltage shifts the torque curve so there is a much greater torque advantage at ebike speeds. This is why, given a choice between the two, as long as the peak torque of the higher voltage system is adequate, I'd choose higher voltage, and just keep it that way rather than switching back and forth.
PS. I didn't adjust the internal resistance of the pack to reflect the serial vs parallel arrangement, but I doubt it matters much. I used 2x battery current for the phase current limit.
scianiac
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I understood exactly what you meant, it's just not correct. The same motor, at the same speed and phase current will be basically identically efficiency wise if you change the controller input voltage in this range (yes if you like change it from 2V to 300V or something you are going to start to get some weird very extreme switching and inductive losses). The lower voltage config will give exactly the same torque if the phase current is the same and the efficiency will be basically the same.
If you want to make a motor run very efficiency you need all of the losses and you match those will the load and you select a winding that fits the speeds and torques you need. Many many of these ideas of, oh the motor is more efficient when XYZ have basically nothing to do with those factors and are just because those mean the motor ends up operating in a more efficient range as a side effect of the voltage, current, and windings being well matched. Put simply you run a motor too fast with too little load, it's inefficient, you run it too slow with too much load it's inefficient.
For example:
Note something important here, I've turned on the auto throttle and set the speed to the same. So same motor, same speed, same torque to maintain that speed. IDK does that theoretical 1.7% increase in efficiency seem worth it? Pretty sure the weight of the controller, switches, etc, could be used for a few more batteries. And note I did adjust the battery resistance.
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lnanek
Power poster
I think Rivian does have several patents on throwing switches to reconfigure the voltage of batteries. E.g.:
www.teslarati.com
No idea if they found it valuable enough to put in a production system, but they did seem to find it valuable enough to pay the patent fees
Rivian patent application hints at 900V fast charging capabilities
A recently published Rivian patent application titled “Configurable Battery Pack for Fast Charge” describes a method of switching between battery pack connection types to allow for both 450V and 900V fast charging without the need for specialized components. The invention was filed in both the...
www.teslarati.com
No idea if they found it valuable enough to put in a production system, but they did seem to find it valuable enough to pay the patent fees
scianiac
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Many EVs do this, has nothing to do with the motor, they change the battery pack from series to parallel for charging depending on the charging infrastructure available. I mean it says it right there in the article, has nothing to do with motor efficiency.I think Rivian does have several patents on throwing switches to reconfigure the voltage of batteries. E.g.:
Rivian patent application hints at 900V fast charging capabilities
A recently published Rivian patent application titled “Configurable Battery Pack for Fast Charge” describes a method of switching between battery pack connection types to allow for both 450V and 900V fast charging without the need for specialized components. The invention was filed in both the...
No idea if they found it valuable enough to put in a production system, but they did seem to find it valuable enough to pay the patent fees
Like I said there are some EVs that do reconfigure motors on the fly, I don't recall who, saw it in a munro video a little while back.
lnanek
Power poster
I wrote patents, plural, with an s. Some of them cover discharge as well:
There are useful characteristics of higher voltage used with the same winding motor, namely re top speed. Changing to higher voltage has saved bikes that were too slow for me otherwise, even ones that supported field weakening. Field weakening is very inefficient.
It's very difficult to get the motor simulator to claim top speed would be the same for double the voltage:
Even with auto throttle giving an unfair advantage to the lower voltage configuration (I always run full throttle anyway in actual practice, unless at the speed limit), the baserunner controller I use still ends up running faster at higher voltage:
Yes, the other person said power and not speed, but it's not useful to attack every idea like this compared to strong manning arguments to enable a more productive conversation.
US20140368041A1 - Reconfigurable hybrid energy storage system for electrified vehicles - Google Patents
The embodiments described herein relate to a reconfigurable energy storage system. In one embodiment, the reconfigurable energy storage system comprises a first energy storage system, a second energy storage system and a power converter. The power converter determines a first power level, a...
patents.google.com
There are useful characteristics of higher voltage used with the same winding motor, namely re top speed. Changing to higher voltage has saved bikes that were too slow for me otherwise, even ones that supported field weakening. Field weakening is very inefficient.
It's very difficult to get the motor simulator to claim top speed would be the same for double the voltage:
Even with auto throttle giving an unfair advantage to the lower voltage configuration (I always run full throttle anyway in actual practice, unless at the speed limit), the baserunner controller I use still ends up running faster at higher voltage:
Yes, the other person said power and not speed, but it's not useful to attack every idea like this compared to strong manning arguments to enable a more productive conversation.
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Apartunis
Regular
Controllers do not have unlimited ability to step up battery current. Most will double it and some will triple it in the right conditions. Do you think a 48V 25A rated controller will deliver as much maximum current as a 24V 50A controller? If so, explain.
Also every controller has a most efficient range above 3/4 of its free speed. How can a 48V controller running at 3/8 of its free speed compete efficiency wise with a 24V controller running at 3/4 of its free speed on the same slope?
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