Electric Bikes - Help With Specs for Converting Electra Townie ...

I just started looking into adding a motor to my Electra Townie. Does anyone have an Electra Townie with a motor?

I was wondering because I'm not sure that the motor would fit my Townie, because the Townie is shaped a bit differently ...

Also, what is the fastest that an electric motor would take a bike, as opposed to a gas-powered motor?

http://www.light-after-darkness.org/forums/picture.php?albumid=19&pictureid=157

http://www.bikeforums.net/%5BIMG%5Dhttp://www.light-after-darkness.org/forums/picture.php?albumid=19&pictureid=157%5B/IMG%5D

Me and my roommate both have electric Electra Townies. Both of them are Townie 21's. One is driven by a front drive hub motor, the other is converted to an Xtracycle and propelled by a rear drive hub motor. Are you speaking of a frame motor? They can be dependant upon specific frame shapes, but hub motors are not.

I have also seen Townies with rear drive hub motors. Electric motors can be specified to go *extremely* fast if you so desire.

Me and my roommate both have electric Electra Townies. Both of them are Townie 21's. One is driven by a front drive hub motor, the other is converted to an Xtracycle and propelled by a rear drive hub motor. Are you speaking of a frame motor? They can be dependant upon specific frame shapes, but hub motors are not.

I have also seen Townies with rear drive hub motors. Electric motors can be specified to go *extremely* fast if you so desire.

Can you give me more specifics? I know almost nothing about motorized bicycles .... I would like to spend, if possible, no more than $500.00. I really don't care which kind of motor I have for my Electra Townie. But I would like to get something that is good quality, that will require the least maintenance and will give me the maximum life of the motor, and at least a good 30mph, or more.

When you say that electric motors can be specified to go extremely fast, just how fast are you talking about? And what is the price range for the "Extremely" fast electric bicycle motors?

Instead of max speed, a better question to ask is max range. How far do you want/need to go? What kind of terrain?

Typical electric and typical gas powered bikes have similar top speeds. Expect speeds around 20 mph without pedaling on a gearless hub motor at 36 volts. A lot depends on what kind of motor you want. The most common are:
gearless hub motors
geared hub motors
chain drive
friction drive.
Each has its own advantages and disadvantages, depending on your commute. Do you need to tackle large hills? Must it look Stealthy? Silent?


Please keep in mind that quality batteries, the kind that will get you to 30+ MPH, can easily exceed $500 all by themselves.

Yes - in many cases, you're going to spend much more on the batteries than the motor. Many can be made to go 30mph without too much trouble. I've seen videos of certain Crystalyte models being taken up to 50mph, in fact. Legally, taking your electric system past being able to do 20 classifies your bicycle as a moped, but its your responsibility to handle and understand that.

Virtually any hub motor will work on an Electra Townie. You are best to look into a rear drive model, as the Townie has a suspension fork which particularily does *not* match well with front drive.

Good quality is hard to come by under $500, I am afraid, some buyers have had luck with models like Golden Motors, but you can find some truly terrible hunks of junk out there. *Around* the $500 mark, some very acceptable performers like Crystalyte and Wilderness Energy can be purchased. A Crystalyte motor is very easy to customize to go the speeds you are seeking.

The motors around the $500 mark are higher quality Chinese models, typically. They are very acceptable for quality, and while not real works of art or polish, they're functional and reliable.

The cost of obtaining the speed you desire is going to come from purchasing the appropriate batteries and controller.

Maintenance for direct drive brushless hub motors is *zero*. Of course being a bicycle wheel, you need to do any related maintenance there, but the motor itself has no maintenance needs.

As examples for motors in your price range, a Crystalyte 408 equipped with a 36/20 controller and a 48v battery will obtain a speed of approximately 42kph, just under your goal. At 72v your goal would be greatly exceeded. Common pack sizes are 36, 48 and 72 volts, although you could easily obtain a custom pack in between 48 and 72 to hit just about the mark on what you want. The 408 is a well balanced motor.

A Crystalyte 406 is a motor with less torque output, but more speed at similar power input levels. At 48v and the same controller, it would meet your speed needs, but would accelerate slower and have inferior climbing ability to a 408.

You could likely build a lead battery system inexpensively, under $200. Lighter chemistries are considerably more expensive. The best way to really figure out your costs and define your goal is simply to shop around.

Instead of max speed, a better question to ask is max range. How far do you want/need to go? What kind of terrain?

I work different job assignments everyday. I would like to be able to accept assignments as far as 12-15 miles, so that would mean that I'd need to travel between 25-30 miles round trip. I can pedal my bike at least a few miles. But, I also need a few extra miles for running errands and shopping after work.

The terrain where we live is mostly flat. The only hills are overpasses, and I can pedal up the passes with no problem ... But I will be carrying groceries sometimes (10-15 pounds), and a large backpack to work (another 10-15 pounds), plus my weight, around 210 pounds.

I'm also thinking seriously that I should go with an electric motor instead. I'm not sure what the legalities are in our area (Modesto, California) .... Also, I'm wondering if there would be a problem (legally) when I ride on the sidewalk? The roads are so bad where we live, and very dangerous in places, that I have no choice, but to ride on the sidewalk in many areas.

Thanks so much for your advice!!! I would be very happy if I could actually maintain 40mph on level ground!!! Around 95% of each trip, and in many case 100% of the trip, will be flat ground all the way, except for several very slight inclines (5%), for very short distances. I can easily pedal those inclines.

What is the life of these $500.00 batteries? And just how many miles/hours of use will I get before charging? And how big are the extra powerful batteries? Can I get a nice-looking case to attach to my Townie?


Yes - in many cases, you're going to spend much more on the batteries than the motor. Many can be made to go 30mph without too much trouble. I've seen videos of certain Crystalyte models being taken up to 50mph, in fact. Legally, taking your electric system past being able to do 20 classifies your bicycle as a moped, but its your responsibility to handle and understand that.

Virtually any hub motor will work on an Electra Townie. You are best to look into a rear drive model, as the Townie has a suspension fork which particularily does *not* match well with front drive.

Good quality is hard to come by under $500, I am afraid, some buyers have had luck with models like Golden Motors, but you can find some truly terrible hunks of junk out there. *Around* the $500 mark, some very acceptable performers like Crystalyte and Wilderness Energy can be purchased. A Crystalyte motor is very easy to customize to go the speeds you are seeking.

The motors around the $500 mark are higher quality Chinese models, typically. They are very acceptable for quality, and while not real works of art or polish, they're functional and reliable.

The cost of obtaining the speed you desire is going to come from purchasing the appropriate batteries and controller.

Maintenance for direct drive brushless hub motors is *zero*. Of course being a bicycle wheel, you need to do any related maintenance there, but the motor itself has no maintenance needs.

As examples for motors in your price range, a Crystalyte 408 equipped with a 36/20 controller and a 48v battery will obtain a speed of approximately 42kph, just under your goal. At 72v your goal would be greatly exceeded. Common pack sizes are 36, 48 and 72 volts, although you could easily obtain a custom pack in between 48 and 72 to hit just about the mark on what you want. The 408 is a well balanced motor.

A Crystalyte 406 is a motor with less torque output, but more speed at similar power input levels. At 48v and the same controller, it would meet your speed needs, but would accelerate slower and have inferior climbing ability to a 408.

You could likely build a lead battery system inexpensively, under $200. Lighter chemistries are considerably more expensive. The best way to really figure out your costs and define your goal is simply to shop around.

I just built a new Townie 7D w/ a WE brushed hub motor, LiFePO4 36V-20Ah, 800w-40amp controller, CA meter, lights, etc.
It does a consistent >23mph for up to 26 miles w/o pedaling. The battery cost twice as much as the bike. The motor was $300 but all the kit parts failed. The rim needed truing and accessories to protect parts and myself pushed my total to something like $1700.
I started out thinking the same way; cheap, but that wasn't realistic for my long term needs. I anticipate my battery and whole set-up will outlast the 1.5 years I need it so it amoritizes out OK.

How many years/Miles can I expect to get from an electric motor and battery? What is the maximum life I could expect for an expensive setup (and how much would it cost?) ... ???

Brushless direct drive hub motors (common variety hub motors) have no parts which suffer any real wear in them. The motor itself will last an extremely long time as a result, given that you take care of it as you would any other bike part. Geared motors require very occasional replacement of the planetary gears, brushed motors require very occasional replacement of the brushes. Their lifespans will match brushless direct drive motors if taken care of as well, however. You are likely looking at servicing these motors every 2 years with heavy use. Doing so is not difficult.

The batteries are what really have a defined lifespan. The answer to that depends on the chemistry. (Very average, based on my information) Lead batteries are likely to last roughly 200 charges, NiMH roughly 500, Lithium polymers roughly 700, Lithium Phosphates in excess of 1000, with some higher quality ones known to last 1500 or more.

Cost varies wildly depending on your needs. Anything but lead has a high initial investment, however. I spent approximately $1150 CAD on my electric motor kit and battery pack, which is a lithium polymer. For your needs, unless you are content with the high weight of sealed lead acid batteries, i'm anticipating your initial costs to be higher than that by a few hundred, it really depends on what sort of range you want to go at that speed, which determines the size of the battery - and thus, the cost.

Given the typically low C rates of NiMH batteries, you probably won't want to look into those for a high demand system. Your best choices for a high power drain operation are either SLA or Lithium Phosphate (LiFePO4). The Phosphate pack will have a high initial investment, but an extremely long service life, light weight, and excellent characteristics for high drain operations. The Lead will be a pig, and short lived, but cheap.

You have to think of an e-bike in terms of long term savings over alternatives.

Brushless direct drive hub motors have no parts which suffer any real wear in them. The motor itself will last an extremely long time as a result, given that you take care of it as you would any other bike part.

The batteries are what really have a defined lifespan. The answer to that depends on the chemistry. Lead batteries are likely to last roughly 200 charges, NiMH roughly 500, Lithium polymers roughly 700, Lithium Phosphates in excess of 1000, with some higher quality ones known to last 1500 or more.

Cost varies wildly depending on your needs. Anything but lead has a high initial investment, however. I spent approximately $1150 on my electric motor kit and battery pack, which is a lithium polymer. You have to think of an e-bike in terms of long term savings over alternatives.

This is all new to me, and I'm not a mechanic ... Which type of electric motor setup will give the longest life? Somebody mentioned the different types -- chain, belt, gear ... I really don't know anything about the different types, and which would last longer, or give better performance ... ???

I agree ... long terms savings are important ... and that is what I'm looking into for a serious investment. I need to have an electric motor and highest quality battery, so I can depend on getting to work and back. I've invested in the Bontrager hard case tires, with heavy-duty inner tubes and liners. I have the same tires, tubes and liners on my 18-speed Mongoose Switchback, and haven't had a flat yet!!!


Brushless direct drive hub motors have no parts which suffer any real wear in them. The motor itself will last an extremely long time as a result, given that you take care of it as you would any other bike part.

The batteries are what really have a defined lifespan. The answer to that depends on the chemistry. Lead batteries are likely to last roughly 200 charges, NiMH roughly 500, Lithium polymers roughly 700, Lithium Phosphates in excess of 1000, with some higher quality ones known to last 1500 or more.

Cost varies wildly depending on your needs. Anything but lead has a high initial investment, however. I spent approximately $1150 on my electric motor kit and battery pack, which is a lithium polymer. You have to think of an e-bike in terms of long term savings over alternatives.

This is all new to me, and I'm not a mechanic ... Which type of electric motor setup will give the longest life? Somebody mentioned the different types -- chain, belt, gear ... I really don't know anything about the different types, and which would last longer, or give better performance ... ???

Any system which goes through your bicycle's drivetrain and uses its gearing will provide the best efficiency and performance per watt, by far, as the motor is capable of using variable ratios using this method (think about having a car with a 5 speed transmission, then think about one which was stuck in one gear. Whats better?). These types of motors mount on the frame itself, and drive your chain directly. However, your Townie has a fairly non-standard frame and may be difficult to work with a frame mount motor. You would have to research that.

Secondly, geared hub motors or axle drive motors are fairly efficient and powerful. They don't use multiple speeds like the frame motors do, but due to their design the electric motor itself spins at very high RPM's and is then reduced through a transmission to a lower speed at the wheel. Electric motors are much more efficient and capable of outputting much higher torque at high speeds, and geared hub/axle motors are fairly good as a result.

Direct drive hub motors are the least efficient. They use no variable gearing, nor do they spin at the high speeds of the geared style motors. They will be the heaviest and least efficient motors by far. These can still be made into very powerful units, but they are overweight and extremely power intensive compared to their geared brethren.

Any system which goes through your bicycle's drivetrain and uses its gearing will provide the best efficiency and performance per watt, by far, as the motor is capable of using variable ratios using this method (think about having a car with a 5 speed transmission, then think about one which was stuck in one gear. Whats better?).

What types of motor systems would use my bicycle's drivetrain and gears? Wouldn't that tend to wear out the chain on my bicycle much quicker?


These types of motors mount on the frame itself, and drive your chain directly. However, your Townie has a fairly non-standard frame and may be difficult to work with a frame mount motor. You would have to research that.

Secondly, geared hub motors or axle drive motors are fairly efficient and powerful. They don't use multiple speeds like the frame motors do, but due to their design the electric motor itself spins at very high RPM's and is then reduced through a transmission to a lower speed at the wheel. Electric motors are much more efficient and capable of outputting much higher torque at high speeds, and geared hub/axle motors are fairly good as a result.

I definitely want something that is highly effecient ... with the least amount of wear and tear. I'd also like to have a lighter motor. I was looking at something (I think it was a direct hub drive) that weighed 35 pounds!


Direct drive hub motors are the least efficient. They use no variable gearing, nor do they spin at the high speeds of the geared style motors. They will be the heaviest and least efficient motors by far. These can still be made into very powerful units, but they are overweight and extremely power intensive compared to their geared brethren.