What drivetrain options are out there? Drive type list

swbluto

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Hello, I want to compile a list of possible motor configurations to the drive wheel, and I want to investigate each's pros and cons. So, can you help me? I'll update this list as I gather more information - I'll want to come back to it as I decide on my build.

So, I want to investigate this in an organized manner. So, I'm particularly interested in the following.

-Components other than the bike and motor needed, doesn't include "insignificant things" like washer, bolts, etc.
-An average cost to implement, not including the bike or motor.
-Is the motor "free-wheeling" in respect to the wheel? I.e., can regen be implemented?
-Is the motor "free-wheeling" in respect to the pedals (With a regular free-wheel bike)? I.e., could the pedals cut my legs off?
-Pictures typifying the type.
-Any notable pros and cons?
-Difficulty on a scale from 1-10. 1 is like a hub motor, whereas 10 is more like... something very difficult.

With this, I'm not particularly interested in motor placement, though if I want to make it a complete resource, that'd probably be advisable.

So here I start with my limited knowledge.
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Type: Direct drive non hub motor.
Description: The motor is placed somewhere on the bike and through a chain or belt, it's directly coupled to the wheel with a huge wheel pulley or sprocket.
Motor/Wheel Freewheel? No. Regen is thus possible. (Using a one way bearing of other arrangement, it's possible to freewheel.
Motor/Pedal Freewheel? Yes, through the freewheel on the rear cassette. No worries of legs getting chopped off.
Components needed: one motor sprocket/timing pulley, one big sprocket / wheel-pulley, one long chain or belt.
Average cost: $20 (motor sprocket) + one big sprocket/pulley $80 + one long chain or belt $30 = $150.
Max torque and power: Limited by drive-train - can be arbitrarily high. Or it can be pretty low for a wimpy belt drive system.
Difficulty: 4-6

Grin-hill's thread: http://endless-sphere.com/forums/viewtopic.php?f=28&t=9172&start=15 (Left click the image and click "show image" to expand it)
file.php


LiveForPhysic's thread: http://endless-sphere.com/forums/viewtopic.php?f=28&t=8347&start=195
p3060050.jpg



Type: Shumaker "two stage drive" or similar
Description: The motor is put into a mount that includes a 4:1 or similar reduction, and is then directly coupled to the wheel with a normal sized sprocket or, more rarely, can be connected to the cranks. (It seems this is really just a sub-type of "through the cranks" and "direct drive")
Motor/Wheel Freewheel? No. Regen is thus possible, usually. This can be changed with an extra part here or there (how?)
Motor/Pedal Freewheel? Yes, through the freewheel on the rear cassette. No worries of legs getting chopped off.
Components needed: one motor sprocket/timing pulley, one normal sprocket / wheel-pulley, one long chain or belt.
Average cost: $20 (motor sprocket) + one normal sprocket/pulley $50 + one long chain or belt $30 + one reduction mount $150 = $250.
Max torque and power: Limited by drive-train - can be arbitrarily high. Or it can be pretty low for a wimpy belt drive system.
Difficulty: 5-8

Ypedal's RC build: http://endless-sphere.com/forums/viewtopic.php?f=28&t=9342&start=345
file.php


Type: Pedal integration / "Through the cranks"
Description: The motor is mounted somewhere on the bike and attached directly to a sprocket on the pedal.
Motor/Wheel Freewheel? Yes. Regen is not possible, unless you have a coaster bike.
Motor/Pedal Freewheel? With a "free-wheeling" crank, usually yes? Unless one really wants to cut their legs off. :)
Components needed: one motor sprocket/timing pulley, one normal chain, one free-wheeling crank, possibly may want to include a "large unusable" sprocket for the motor so that you can not interfere with the drive train. I have no clue how you attach it.
Average cost: $20 (motor sprocket) + one chain $20 + one free-wheeling crank $100 + one dedicated "motor pedal sprocket" plus who knows what machining needed $150 = $290
Max Torque and Power: Limited by pedaling system, which can be pretty high. Otherwise, limited by drive-train.
Difficulty: 8

Timma's bike: http://endless-sphere.com/forums/viewtopic.php?f=28&t=12687&start=30
file.php


Type:Friction Drive
Description: The motor is planted right next to the tire, usually the rear, and either rolls the tire using friction with an outrunner's case or using a knurled roller.
Motor/Wheel Freewheel? Not usually, though possible with an auto-retracting or self-engaging mechanism.
Motor/Pedal Freewheel? Yes. No need to worry about getting your legs cut off (Unless using a coaster bike)
Components needed: bracket and possibly a roller.
Average cost: bracket $20 + roller $40 = $60.
Max Torque and Power: Max torque depends on the friction / pressure on the tire. Power can be high enough to get upto 50+ mph.
Difficulty: 4 - 8 (Close to 8 if you do something like making an auto-retracting type)
Cons: Limited use in wet weather due to slipping on the tire.

Triton's build: http://endless-sphere.com/forums/viewtopic.php?f=28&t=17076&start=15
file.php


Others? If you feel there's other distinct types out there, you can copy and paste the below to describe or just explain it. Add more fields if you think they're needed or highly desired.
Code:
[b]Type:[/b]
[b]Description:[/b]
[b]Motor/Wheel Freewheel? [/b]
[b]Motor/Pedal Freewheel?[/b]  
[b]Components needed: [/b]
[b]Average cost: [/b]
[b]Max Torque and Power: [/b]
[b]Difficulty:[/b]
Also, if there's something wrong with the above figures, let me know. I haven't actually built any of the above, so I'd expect I got at least a few things wrong.
 
That is actually a pretty good list. I like the difficulty rating. This is a good thread especially for those who are not decided on what they want to do. Actually, depending on how this thread goes, this may make a good sticky to point people to who ask these type of questions.

I would say hubs are the obvious easy installation. They are innexpensive (for the most part) and relatively reliable.

The oposite extreme would be a scratch built drive of most any kind. And the most difficult of those would be a through the crank drive.

As for cost, I would say RC stuff ranks up there if you are using a Plettenberg or large Astro motor. The difficult is high as well as is the required knowledge not only to install, but to service the unit.

I think a good overall price range for a completed system of the various types would be good to add to this thread as well.

Matt
 
recumpence said:
I think a good overall price range for a completed system of the various types would be good to add to this thread as well.

Matt

It'd be handy information, but it's pretty variable. One can go with a $60 HXT motor and that's been a fine motor for me for upto 2 kW (Hub territory) or one can go with a 12 kw colossus for some price (Likely somewhere in the 400 to 700 price range depending on how the deal finally settles), or one can go with a high quality astro 3220 for something like $600.

Moving onto bikes, there's walmart bikes, quality bikes, full suspension types, etc.

Moving onto batteries, one can go with lipo, lifepo4 or SLA, which varies significantly depending on desired power, cycle life and so on.

Then, with each part, there's a selection of cheap and expensive high quality parts, some of which are optional.

So, to get a total combination price would involve a lot of possible combinations. If anyone wants to add a realistic "total system" price for their build, I'll probably add it.
 
You can add the type I made even tho it's not really on the bike...treadmill motor+SCR+inverter. I've only got a few test runs on it so far and it's not got the capacity I want, but it's working ok otherwise. I think I rambled enough in my thread that you could nail the pros/cons if you want..or ask there and I'll get to it as I can.

I like it..good idea, this thread! :)
 
Muds BMX RC-drive is similar to a Currie rear axle unit, but a big improvement over Currie. It could bolt onto the 6-hole rear disc brake flange on the left side of a rear wheel. I'll dig up a pic from my files as soon as I can. edit: pic found...
 

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For the "Pedal integration / "Through the cranks"" section, there are several ways to implement that, including a jackshaft method as I have done on CrazyBIke2 (which will be modified to add motor and pedal freewheels, with Thud's new jackshaft design for it).

This method doesn't lend itself well to a standard bike, but almost any recumbent or semi-recumbent could already have the jackshaft points on there to do this, depending on how the chains are run. Some nearly regular bikes in more of a cruiser configuration, low-rear seat and higher-forward cranks would allow a jackshaft to be installed where normally there'd be a BB at the base of the seatpost, and feed pedal chain and motor chain to the left side of it, and standard bike drivetrain front bits on the right, including a shiftable triple if desired.
 
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