Seeking advice for commuter e-bike setup

John Well

10 µW
Joined
Feb 10, 2021
Messages
5
Hi all,

I am a total Newbie looking for enlightened advice ;). My commute is a mix of urban paths and country roads and is 18 miles each way. I have been biking it 2-3 times a week on a normal road bike. I usually average 17-18 miles/hr. I have been contemplating upgrading to an ebike setup with the following goals in mind:

- increase ride frequency to 5 days a week without being exhausted.
- decrease commute time/increase average speed.
- I still want to pedal and get a workout.

I have an old hard tail 26" MTB to use as a donor bike. Based on my initial research, it seems like a rear hub setup would work well as I want to keep maintenance to a minimum. A couple of questions:

1. I have looked at some articles on geared vs direct drive but am still unsure as to which would be better for my situation.
2. What would be an appropriate motor/battery combo (ie, power, battery voltage and amp.hours)? Ideally I would be able to go to work and back on 1 charge although I could recharge at work.

Any advice will be much appreciated.

Thanks in advance,

John Well
 
The decision on what kind of hub motor rests on the terrain. If you have substantial but not Monster hills on the route, then a geared 500 watt motor should work well. If you have long, steep hills, then a more powerful direct drive motor would likely be better.* Only use a 500-750 watt direct drive motor if you have little in the way of hills.


* I've never had trouble with the one long (3/4 mile), steep hill I climb regularly with my 500 watt geared motor, but popular wisdom is that they tend to overheat in those circumstances.
 
Thank you for the prompt reply.

there are a couple of hills. Total elevation gain is about 800 ft:
Selection_038.png

What kind of battery would you recommend if I went with a 500W geared rear hub motor?

Is Bafang the best option or are there alternative brands I should consider?

Best,

JW
 
How much pedalling do you want to do?

Do you want regen for going down hills to regen battery power back into the battery. Direct Drive Hub Motor.

There is also regen braking, saves you from wearing down brake pads. Can almost never use pads again except for emergency braking. Direct Drive Hub Motor.

Minimal Maintenance throws out Mid Drive, so that leaves Geared Hub Motor or Direct Drive Hub Motor. Geared Motors have Freewheeling when run out of power, Direct Drive will feel like pedalling with flat tires if you run out of juice.

- I still want to pedal and get a workout.

I have an old hard tail 26" MTB to use as a donor bike. Based on my initial research, it seems like a rear hub setup would work well as I want to keep maintenance to a minimum.
 
What kind of battery would you recommend if I went with a 500W geared rear hub motor?

Is Bafang the best option or are there alternative brands I should consider?

I can't really suggest a specific battery. Just look for one from a reputable dealer or builder, that uses name brand higher grade cells. Chinese brand cells are cheaper, but won't likely hold up well. Name brand low grade cells won't do great either. A 14AH 48v pack should work well with a 500 watt geared motor. Which motor? My Das Kit motor has lots of power and has held together, but it got loud early and stayed loud. I'm in the process of replacing it. Others here can suggest the best geared hubmotors. My only other 500 watt geared motor experience is with the 8Fun on my Greenbike USA Folder, and that one's a bit anemic and balky. (It could possibly be a crappy controller...)
 
Posted this in the wrong forum yesterday. Hopefully this here is more appropriate:

Hi all,

I am a total Newbie looking for enlightened advice ;). My commute is a mix of urban paths and country roads and is 18 miles each way. I have been biking it 2-3 times a week on a normal road bike. I usually average 17-18 miles/hr.

Selection_038.png

I have been contemplating upgrading to an ebike setup with the following goals in mind:

- increase ride frequency to 5 days a week without being exhausted.
- decrease commute time/increase average speed.
- I still want to pedal and get a workout.

I have an old hard tail 26" MTB to use as a donor bike. Based on my initial research, it seems like a rear hub setup would work well as I want to keep maintenance to a minimum. A couple of questions:

1. I have looked at some articles on geared vs direct drive but am still unsure as to which would be better for my situation.
2. What would be an appropriate motor/battery combo (ie, power, battery voltage and amp.hours)? Ideally I would be able to go to work and back on 1 charge although I could recharge at work.

Any advice will be much appreciated.

Thanks in advance,

John Well
 
I had an urban commute, 13mi each way, didn't charge at work, 1.8kwh battery was comfortable, cycled it between 75% and 30% each day. Average speed 20mph. 0 pedaling. At 20mph, pedaling along would only get you about 33-50% extra range.
 
LeftieBiker said:
Mods...??? I posted several replies to this thread, and they are now vanished.


No, you posted them to his first thread, which he rudely abandoned those already helping him and started a whole new one for no reason, since he was already being helped and knew it. I merged them together, so that those helping him can see all his posts and info. Hopefully he keeps his project to this thread now. ;)


For the OP: You might want to think about it as if you were in a room talking with people, helping you out, then you just walk out of the room, go into another room, and ask the same question. You might imagine that the people that had been helping you could get a little miffed. ;)
 
Leftie,

Thanks for your previous replies. your answers didn't get deleted. I initially posted in the ES general discussion forum but then realized there was an e-bike specific general discussion forum so reposted here. My apologies if that's against forum etiquette
 
What mountain bike do you plan to use as a donor bike as there are some mountain bikes where the rear derailleur is too close to the axle will never be able to get nut on to hold the motor in place there must be enough room for a nut next to the derailleur. Plus let's look at your bike frame.
Everything must fit somewhere and figure it out before you buy the first piece.
 
I noticed that on the Trek hybrid with 700c, but its still doable, its more the fault of Leaf 1500W axle being to short.

999zip999 said:
What mountain bike do you plan to use as a donor bike as there are some mountain bikes where the rear derailleur is too close to the axle will never be able to get not on do hold the motor in place there must be enough room for a nut next to the derailleur. Plus let's look at your bike frame.
Everything must fit somewhere and figure it out before you buy the first piece.
 
An 800 ft rise on the commute suggests to me your best choice is a BBSHD. I have ridden many dozens of ebikes, and I have owned several. The one I have kept riding for five years is the BBSHD.

You could save a few dollars and a few ounces by getting the BBS02, or possibly the even smaller TSDZ2. BUT...a BBSHD will handle that without ever getting hot.

On flat land or mild hills, there are several advantages to a hubmotor, but the only way to find out if one of them would be adequate is to buy and try. If you are not the experimantal type, a BBSHD will work for that commute.

Do not get a 36V system. Make sure to get 48V or 52V.
 
The axis scaling is deceiving on your graph, but calculating the steepest portion of the commute near the peak, it looks like that comes to under 3%, so no problem with assist.

Direct drive, with some cooling, controller with regen and 52V 20Ah battery should do it. Basically you're using power climbing about half the distance each way, so need around 18 total miles worth of assist/battery capacity. Or, you can have a smaller battery and assume recouping a portion of the energy during the descent.

Assuming a 5% average grade to be conservative, and 20 mph speed, and 150W and 75W human power scenarios, it looks like no issues with overheating and you can easily meet the range requirement. If you have regen, you have even more of a buffer:

https://ebikes.ca/tools/simulator.html?motor=M2706_SA&hp=150&grade=5&axis=mph&batt=B5220_GA&cont=C35&cont_b=C35&motor_b=M2706_SA&batt_b=B5220_GA&hp_b=75&grade_b=5&bopen=true&throt=63&throt_b=64.9

You could even ride 10% indefinitely without overheating if you throttle back slightly and provide 75W of pedaling, but your range would be limited:
https://ebikes.ca/tools/simulator.html?motor=M2706_SA&hp=75&grade=10&axis=mph&batt=B5220_GA&cont=C35&cont_b=C35&motor_b=M2706_SA&batt_b=B5220_GA&hp_b=75&grade_b=10&throt=68&throt_b=68
 
E-HP said:
Direct drive, with some cooling, controller with regen and 52V 20Ah battery should do it. Basically you're using power climbing about half the distance each way, so need around 18 total miles worth of assist/battery capacity. Or, you can have a smaller battery and assume recouping a portion of the energy during the descent.

Would you really cut it that close? My limited experience with batteries suggests you'll be lucky to have 2/3 the advertised amp-hours - maybe my experience is uniquely terrible, but everyone got the full advertised amp-hours in their boxes? I doubt it. And then there's the decline in capacity over time.

Taking 20Ah at face value, it would allow up to an average 28 Wh/mile, which seems more than enough for that speed? I wonder if it would be possible to use the ebikes.ca trip simulator on a case like this. I haven't used it before, and a quick fiddle with it left me somewhat in the dark, but it looks like it's intended to answer just this kind of question.
 
No, you posted them to his first thread, which he rudely abandoned those already helping him and started a whole new one for no reason, since he was already being helped and knew it. I merged them together, so that those helping him can see all his posts and info. Hopefully he keeps his project to this thread now. ;)

Got it, thanks. Since 800 foot elevation changes aren't in my experience (my Big Hill is roughly 1/4 that or less) I'm dropping out of this thread. One last comment: I agree that you don't want to have just enough battery, because in two years it will likely become not enough battery.
 
donn said:
Would you really cut it that close? My limited experience with batteries suggests you'll be lucky to have 2/3 the advertised amp-hours - maybe my experience is uniquely terrible, but everyone got the full advertised amp-hours in their boxes? I doubt it. And then there's the decline in capacity over time.

Taking 20Ah at face value, it would allow up to an average 28 Wh/mile, which seems more than enough for that speed? I wonder if it would be possible to use the ebikes.ca trip simulator on a case like this. I haven't used it before, and a quick fiddle with it left me somewhat in the dark, but it looks like it's intended to answer just this kind of question.

I'm just using my original bike configuration and riding conditions as a data point. When I used my 20Ah generic cell battery, I could ride until my butt couldn't take it any more, which happens around 50 miles, and still have about 30-40% left getting home. A typical ride is around 35 miles with a variety of hills up to 20%. I use regen and on average my hills are closer to 10%, but I recapture some with regen. If he's pedaling with 3% or less, I'm guessing it will be ample.-
 
Thank you all very much for the replies! That's a wealth of info that I need to process...

Tommm: Can I ask what motor you used? Also 1.8kWh seems like a sizeable battery, what combination voltage and aH did you use?

999zip999: It's a fairly generic MTB from the late nineties I built using an aluminium frame from Nashbar:IMG_20210213_073159.jpgIMG_20210213_073216.jpg

Spinningmagnets: the BBSHD looks really nice indeed. My main concern is maintenance/reliability as I'd like to use the bike on a daily basis as much as possible. From what I have read so far, my impression is that mid drives are very hard on drivetrains. How many miles did you ride on the BBSHD in those 5 years and how many chains/cassettes... did you go through?

E-HP: THanks for the link to the simulator. I will need to spend some time figuring out how to use it and make sense of the results :wink: . Also I started reading through your build thread and it is really nice and inspiring. I think something similar to what you did would work well for my situation. Do you have any recommendations for a motor and controller (or a kit) if I went with a 52V/20aH battery? Also do you have any experience with geared rear hubs or should I not even consider them?
 
John Well said:
Also do you have any experience with geared rear hubs or should I not even consider them?

For trips like that, practically anything will work, so unfortunately you have to consider them all. I'm kind of prejudiced against crank drives, but people seem to get along with them OK and after all, it seems to be practically the rule in factory bicycles. A small geared motor with a freewheel is probably the best for ordinary bicyclist action, because it interferes the least with normal human powered mode. [ And I should add, for myself I use a direct drive rear hub, so that's really the best. ]
 
You would be happy with a mid Drive don't shift under power. Yes try make an interrupt for shifting. And a throttle.
52v 15ah or more of quality name and important part model number #. As each and every cell brand and model number are made for a different purpose
Or don't buy a no name generic Chinese pack.
Plus koolstop brake pads and lights. What part of the country do you live ?
What is your budget ?
if your bark last two to three years you'll make up for it and gasoline car maintenance etc. Plus +
 
I commuted 30 miles a day by e bike for 5 years, then had to retire early for illness. Went through a lot of brake pads, tires, batteries.

Since you are so used to pedaling hard, its not going to matter so much which type or brand of motor you use. Lots of appeal to a good mid drive, but really, with that much leg going into the effort, any 500w rated hub motor will do, if given up to 1000w of power into it. ( FWIW, the typical 1000w 48v cheapo kit is a 500w rated direct drive motor).

You will like the way a geared motor coasts better, so if you go hub motor get a geared one.

To increase your speed any, you will need to go 48v, AND modify the bike a bit. Put as big a front chain ring on that bike as will fit without rubbing the frame. Likely 52 t wont fit, but at least replace a 44t with a 48.

Figure on charging at work. A 48 or 52v 15 ah will be enough for one way. Enough for both ways will be damn heavy to carry. Cargo bikes for carrying 2 kw of battery is best. Maybe that later.

Its a long ride, but you might find that a 20 mph cruise is best depending on the actual road. 30 mph cruise is quite possible, but bone rattling on some roads with crap pavement, and way to fast for safety on any kind of shared path with walkers or lots of bike traffic. You can slow down where you need, but then haul ass at 30 mph where conditions permit. At 30 mph, it will take a full 1000w, and a 52 tooth front ring, to pedal hard. Another reason to figure on a bit slower, like 20-25 mph most of your ride. Clown pedaling (spinning with the motor doing the work) is not the goal when on the way to work. might run faster home though.

Spend your money on the battery!!! No cheap bargain batteries. Charge whatever you get outside.
 
John Well said:
Thank you all very much for the replies! That's a wealth of info that I need to process...

Tommm: Can I ask what motor you used? Also 1.8kWh seems like a sizeable battery, what combination voltage and aH did you use?

999zip999: It's a fairly generic MTB from the late nineties I built using an aluminium frame from Nashbar:IMG_20210213_073159.jpgIMG_20210213_073216.jpg

Spinningmagnets: the BBSHD looks really nice indeed. My main concern is maintenance/reliability as I'd like to use the bike on a daily basis as much as possible. From what I have read so far, my impression is that mid drives are very hard on drivetrains. How many miles did you ride on the BBSHD in those 5 years and how many chains/cassettes... did you go through?

E-HP: THanks for the link to the simulator. I will need to spend some time figuring out how to use it and make sense of the results :wink: . Also I started reading through your build thread and it is really nice and inspiring. I think something similar to what you did would work well for my situation. Do you have any recommendations for a motor and controller (or a kit) if I went with a 52V/20aH battery? Also do you have any experience with geared rear hubs or should I not even consider them?

I have the cyclone coaxial bike, the battery is 20s8p panasonic PF (2900mah), comes in at 10kg. Running 80A peak in summer, 60A in winter. Obviously it is not a great cell choice today, I would get lg mj1 (3500mah) and have either a 8kg pack with 1.8kwh, or a 10kg pack with with 2.3kwh. The pack is from UPP, the bms died/refused to balance so I had it replaced with a bluetooth one. Bluetooth bms is a must have as it lets you depower the bike completely without wearing out any connectors.

https://endless-sphere.com/forums/viewtopic.php?f=28&t=88921&start=175#p1545519
 
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