E bike Gearing Why Bother

I use about two or three gears for most of my riding. I might use an fourth lower gear now and then going up some hills. I pedal at moderate effort about 90% of the time that I ride. So I use the gears mostly to help me match pedal cadence to the speed I'm going and sometimes to help the DD out when going up hills steeper than about a 10% grade.

I run in my 53T chainring (road crankset on a MTB bike) almost exclusively, but haven't removed my smaller (42T) chainring just in case I ever need to get home going uphill without e-power. The 42T not only gives me a lower gear directly, it allows me to use my largest rear sprocket as well since it frees up some chain length. But using those low gears make no sense if I have e-power.

Joecool said:

It seems most of the e bikes out these days are way to under powered. 250W - 500W why bother. Just do some more squats at the gym and there you go.

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One of the main reasons I ride an e-bike is to "flatten hills" and to increase my cruising speed to about 5mph faster than I can normally pedal. Those modest benefits are enough to transform a largely impractical 16 mile bike commute to work into a practical one. 250W - 500W is enough power for this. I happen to have about 1000W available because that was what the cheapest kits available when I jumped into this offered. And I didn't want to jump in and spend a bunch-o-money at first. My next e-bike (or two) will be lower powered. I erred on the side of more is more.

Another big reason I ride an e-bike is to avoid going to a gym to do squats and such. Yuck! Riding the bike up hills and pedaling along for 50 minutes or so on the commute is a good workout - even with the motor - if you choose to put in the effort. And you can tailor the e-power to how you feel at any given moment and customize your workout to how you feel on any time. I'm trying to arrange my life so that my regular and normal activities provide the "working out" that my body needs.

Joecool said:

Any of you guys have any recommendations for stronger hub motors at least at 3Kw or higher?

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No clue. That's more of a motorcycle than e-bike to me. But I'm sure it would be fun to ride such a motorized bike.

Damn cool about your metabolism Joe. I was just that way to about 35, then something in my liver or pancreas changed. I suspect I just stopped overproducing insulin about then. In a way it was nice, because I could go 2 hours without food and not faint, finally.

What you likely need is higher gears, not lower, for street riding. My best setup unfortunately got lost in a fire, but I loved my 56 tooth gear crank. It was neat because with a 14 rear, I could pedal to about 35 mph, with 26" rim.

Low gear still needed though, if I want to maximize range, which you do by riding slower, which means instead of 10% or less of your pedal effort goes to the total, you can get 30-50% of the total needed by pedaling slow enough.

That slow ride is still usually 15 mph, so still not in the lowest, 5 mph gears that get used with mid drives. 44-16 or so will do er.

For anyone building their first ebike, its a relative cheap and painless process. Ive since removed the gearing from the bike as well as the chain. I didnt have to connect the PAS or the speed limiter. Rides great off road and on road. Im 6'4 and 195 lbs and it tops out at about 35 mph on flat pavement. Ive also only ridden with 2 6S 10A lipos in series. The hub recommends at least 14.5A @ 48V. I have 2 more 6S 10A lipos. Ive just been to lazy to wire another harness to get 4 6s lipos in series than parallel. Once done, that will give me 6S @ 20A.
That should really make this hub have more power and run time.

Joecool said:

For anyone building their first ebike, its a relative cheap and painless process. Ive since removed the gearing from the bike as well as the chain.

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I'm thinking maybe "obviously illegal" isn't the ideal kind of first e-bike. Having working pedals is one of the statutory requirements in most places.

We're taking advantage of a very nice exception to most of the legal responsibilities of motor vehicle operators. Might as well demonstrate that we're good faith players.

Chalo said:

Having working pedals is one of the statutory requirements in most places.

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Without them, it also removes the ability to still ride it home if something goes wrong on the electric side of things.

A number of walks-of-shame people have had to do, they wouldnt have if theyd left the pedals working, and geared to at least let them ride it pedal-only.

amberwolf said:

walks

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or call a taxi
rent a car2go
call a friend or family member

Interesting reading through this thread and thinking about my personal experiences. Any hub driven e-bike, I've never really bothered pedaling much. It was always cumbersome spinning that heavy rear wheel. Mid-drives, on the other hand, I just pedal naturally. I think the pedaling on the mid-drive was a combination of relieving stress on the drivetrain as well as the bike feeling like a bike even powered down.

I think for most people who buy a ebike, gearing /mid drives are not necessary. Brushless hub motors have come a long way as far as better efficiency. lower price , better output , better cooling/windings, etc. You can take a generic inexpensive 1000 watt rated hub motor, put some ferro fluid in it and maybe add cooling heatsink fins , and you can now run 3000 watts into that motor, without much worry, as long as you do it wisely/intermintently.

I consider the BOSCH style mid drives that have gearing options, to not only be overpriced, but only for a very small percentage of ebikers who will be riding in numerous stressful conditions...like up long mountain roads, over rough dirt trails , jumping, etc.

I have a 3kw rated generic hub motor on my ebike and it has a small amount of ferro fluid in it. I can easily run this motor at 5kw or more, without it getting hot . Top speed on my GPS was 63 mph on flat road and my Newton meters of torque output is exactly where I like it. It wont pop wheelies, but I dont want to do that . The torque is good enough that if I hammer the throttle, I feel the ebike thrust forward nicely, and I can maintain 25-30 mph, going up the steepest long roadways in my area. I think I have my phase amps set at 120 AMPS on the LYEN controller, which gives me adequate torque, but if I wanted more torque, I could easily move the pahse amps adjustment to 180 amps or more.

Mid drives, gearing, stress on drive train components ? Im not interested in those things , especially since I like simplicity , and mid drive ebikes are overpriced IMHO.

I would purchase a new mid drive ebike, as soon as the prices come down to $2000 or less , in a package that offers sleek looks, with a dependable mid drive setup, using at least 48 volt/ 20 AH battery pack , capable of at least 30 mph top speed and 80Nms of torque minimum. Im hoping someone like SONDORS will venture into the untapped, lower cost mid drive ebike niche markets that seem to currently be void of lower priced options .

rumme said:

You can take a generic inexpensive 1000 watt rated hub motor, put some ferro fluid in it and maybe add cooling heatsink fins , and you can now run 3000 watts into that motor, without much worry, as long as you do it wisely/intermintently.

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Not everybody will want to choose between getting registered/licensed/insured and running a openly illegal motor vehicle, though. Using a mid drive with variable gearing means being able to combine capable climbing and relaxed cruising in a bike that conforms to the law without hassles.

Running afoul of the law can be a lot more expensive than buying a quality e-bike. Not having to worry about it is worth something too.

Most with lower wattage systems will have use for gearing. My 500W setup maxes at 38 kph, but I can pedal downhill to 50 kph with comfortable cadance on the 48/11T combo. I leave it in the 48T front gear but constantly cycle through the highest 5 of 9 on the rear as the terrain requires.

A lot of countries have a 250w eBike limit eg. Australia where I live for example, allows 200W on throttle or 250W if you only have PAS. Most people opt for the latter, which is a drama starting on a hill without a throttle to help.

In that situation you need gearing, a 250W hub motor won't pull you up much of a gradient unless you pedal hard in the right gear.

So, 250W with a mid drive is popular, in which case it needs gears. A 3 speed hub gear is often enough with a mid drive.

Ernie said:

A lot of countries have a 250w eBike limit eg. Australia where I live for example, allows 200W on throttle or 250W if you only have PAS. Most people opt for the latter, which is a drama starting on a hill without a throttle to help.

In that situation you need gearing, a 250W hub motor won't pull you up much of a gradient unless you pedal hard in the right gear.

So, 250W with a mid drive is popular, in which case it needs gears. A 3 speed hub gear is often enough with a mid drive.

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Yep. The lower the motor power and the more varied the terrain the more important gearing becomes. That's why bikes have gears to begin with. Most human beans don't have very powerful "motors" and even small inclines can make cyclists painfully (literally) aware of that fact.

Chalo said:

rumme said:

You can take a generic inexpensive 1000 watt rated hub motor, put some ferro fluid in it and maybe add cooling heatsink fins , and you can now run 3000 watts into that motor, without much worry, as long as you do it wisely/intermintently.

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Not everybody will want to choose between getting registered/licensed/insured and running a openly illegal motor vehicle, though. Using a mid drive with variable gearing means being able to combine capable climbing and relaxed cruising in a bike that conforms to the law without hassles.

Running afoul of the law can be a lot more expensive than buying a quality e-bike. Not having to worry about it is worth something too.

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Here in AMERICA , law enforcement still seems to ignore ebikers and the " loose" ebike regulations.

I understand that having a 1000 watt hub motor and running 3000 watts thru it, can be deemed illegal here in the U.S....but 99.9999% of police officers do not even know the ebike laws, and even if they did, all you have to do is put a sticker on your hub motor tha says " 500 watts " and now they really cant prove you have the ability you run 3000 watts to that hub motor , unless they catch you on radar doing 40 mph on a flat roadway.

I do agree with you, that any ebiker that uses a ebike capable of 30 mph or more, for regular commutting on roadways, should get insured/ licensed , but most of us in the U.S. do not use ebikes for that.

In practice, I agree it often doesn't matter whether an e-bike meets applicable technical limitations or not. But if you do have a bike that is within legal spec (such as those which major manufacturers are likely to produce), it will do more things better if it sends motor power through variable gearing. And if it's within legal spec, then the power it makes won't be especially destructive to its drive components.

These things remain true for most of the different local formulas that define e-bikes.

I met a guy with an expensive commercial ebike, I think it was a Kalkhoff. He was having shifting problems and trying to fix it by adjusting the derailleur, which was not working. He had about 700 miles on it.

Even legal commercial high quality ebikes wear their drivetrains, rather rapidly in many cases. His friend with a geared hubmotor had no such problems.

Alan B said:

I met a guy with an expensive commercial ebike, I think it was a Kalkhoff. He was having shifting problems and trying to fix it by adjusting the derailleur, which was not working. He had about 700 mile on it.

Even legal commercial high quality ebikes wear their drivetrains, rather rapidly in many cases. His friend with a geared hubmotor had no such problems.

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I have to agree for the most part. Mid drives have more wear and tear on the drivetrain components of bottom bracket, chain , gears, etc. Hub motors have come such a long way from just 5-10 years ago, that they are mostly a no brainer and the best choice for most ebikers . In recent years, they have become lighter in weight , improved efficiency , have more options for speed or torque , more dependable and costs have come much lower then mid drive systems. Then, add in the ability to use inexpensive modifications like ferro fluid or heat sinks, and its easily possible and safe to run 3000 watts thru a hub motor rated 1500 watts.

Im using a generic 3kw hub motor, and it has a small amount of ferro fluid in it. Ive ran it with 5800 watts of power for 20 second bursts, and the motor has never gotten hot ! I doubt ANY mid drive ebike that has a motor rated for 1000 watts of power, can keep up with my inexpensive generic 3kw hub motor .

Over amping a hub motor is certainly safer and less stressful on the ebike then trying to over amp a mid drive.
If a ebike that has a mid drive motor is rated for 1000 watts , I doubt that mid drive motor could handle 2000 watts nor could the drivetrain components handle it for any length of time. But, you can take a 1000 watt hub motor that costs $149 , and make a few simple and inexpensive modfications and be able to pump 3000 watts thru it without much worry.

Two great reasons to have rear gears ( cassette ) on a e-bike

1) Different people have different amounts of power they can input , it is a bike remember, the more rear gears you have the better you can match your leg cadence to the speed and power that the hub motor is pushing you down the road.
This is , Very , important to anyone who has some inflammation / arthritis in their knees . The more gears for us that are aging the better we can go on a ride with less knee pain at the end of the ride .

2 ) Someday a wire is going to come loose, or melt, or the battery will be so low , etc. so you will need to peddle home.
The more gears you have on the rear the better since you are now going to be peddling a bike that weighs twice or more that a non motor bike. see above for explanation about your knees .

Concerning #2-Although I removed the frt. deraileur, I left the smaller chain wheel on the bike(I actually use it for mounting the PAS disc.)so in the event I would have to pedal without power I can fit the chain to the lower gear by hand. That's plenty of low gears, but I haven't had to do that yet.

motomech said:

Concerning #2-Although I removed the frt. deraileur, I left the smaller chain wheel on the bike(I actually use it for mounting the PAS disc.)so in the event I would have to pedal without power I can fit the chain to the lower gear by hand. That's plenty of low gears, but I haven't had to do that yet.

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I was thinking about doing something like that, I only have a single 34 tooth front chain ring and it makes it hard to keep up with the speed the motor wants to do during PAS. Changing to a two cog ring sounds like a good idea, but I heard the chain might come off unless you have a front derailleur to keep it in place. Something to do with shorter teeth and little ramps or bumps they add to front chain rings to make them shift easier. The point being if you are going to do so, you might need to get two sprockets that were designed for single speed "fixie" style bikes to stop them coming off.

My two donor mountain bikes came w/ 44T and 46T big chain rings and I replaced those w/ 48T and 50T respectively. W/ the same chain, there is more tension which helps to keep the chain from coming off.
On the 50T big gear, I fitted a plastic "chain guard", which not only keeps my pant's leg from getting caught, but also prevents the chain from coming off;

On my other bike, a guard won't work and every now and then the chain comes off. But not from bumps, but if I try and shift while spinning the pedals w/ no load on the chain. I'm getting used to it now and sort of "short shift" and I don't think it's going to be a prob. from here on out.

34T is very sm. and I wouldn't think you could pedal along over, say, 15 MPH.
On my bikes, it works out like this;
11T X 48T, normal crank arm length and 26" wheel- pedal up to 20 mph.
11T X 50T, short crank arms and 24" wheel-pedal up to 23 mph.

Cadence is a matter of preference. Personally, I find a cadence of 80-90 RPM the most comfortable and efficient, and I consider myself a bit of a masher. Here, this nets me between 28 and 32 mph with my current setup with 48T/11T. For that reason, I typically use the next cassette cog up on flat terrain.

From http://www.bikecalc.com/speed_at_cadence

All my bikes use 9 gear systems, most of them 3x9 gears and I use the whole range.

I even try to optimze gears, i.e. in my speed pedelec I prefer low increments between gears.

This is the planned setup with a modified 26-38-48 chainring and a 11-12-13-14-16-18-21-24-28 cassette.

85rpm cadenze, 40-622 tires (28")



I like to use my e-bikes like efficient bicycles with motor _assistance_, not as electric motorcycles with some fake pedaling

Wow, you guys have charts and data, excellent. Ferro fluid, never heard of that before for over volting a motor, thats awesome! Thats why I love and post on forms like this, I always learn something. As I stated earlier, I got rid of the derailleur and chain all together. Im 6'4 and about 195 lbs. With my smart phone gps I do about 30 MPH on level pavement. Off road not very good really. Since this is my first hub motor build there is a learning curve to what the hub motor likes and dislikes. It has a mellow or low torque acceleration as it picks up speed. For 200 bucks Im not complaining. Im more used to a stepper brushless motor where you can change the gearing. I generally use a T8F 9tooth motor sprocket and a T8f 74tooth wheel sprocket. On my go kart and push scooter I can wheelie from a stand still. They have massive amounts of torque since the gear ratio is 8.2 gear ratio. My range is about 20 Miles using 4 6s 10A lipos wired in series then parallel for a total of 48V @ 20A. Some of you guys need to toughen up. If you want exercise, the walk of shame is where its at. On my scooter build I was jumping curbs at 20 Mph and popping wheelies and broke my chain a few months ago. I had to walk with my head down back home about 3.2 miles away. Thats how I learned how to correct the problem, from my mistakes. Granted, you could say, just dont jump curbes, but thats no fun is it. Im specking another e bike build as we speak, I need, want more powa! Something in the 3-5kw range. Granted, this will me more off road then on. More of an electric dirt bike I guess. Any recommendations on the motor? Also might try my hand at using some 18650 cells also, never used them before so I kind of want to try them out instead of my lipos. I use lipos currently on all my e builds simply because I do a lot of RC like fpv mini drones, Traxxas erevo trucks, etc.