Different kind of geared E-Bike...

sean

100 mW
Joined
Mar 16, 2007
Messages
43
Location
Corvallis Oregon
So I am stockpiling parts to build my first few bikes. I have quite a bit of auto fabrication experience so I am not worried about the mounting, chain tensioning, alignment, etc of the mountings.

However at the moment I am a bit wary of the controls, and I am unknowledgable about the battery types and advantages and disadvantages to each.

The plan at the moment is to use a hardtail 26" 21spd mtn bike and a independant pedalling system stoker crank. (this has it's own freewheel)
Mount the motor either under the crank hub or about where a water bottle goes and use a Kollmorgen motor to the captain gear and power through my standard 21 speed cassettes. Obviously I will have to be careful with shifts...

But I need to know more details about the Kollmorgen motor to decide on my gearing. I am going to be buying a few of those motors hopefully they perform up to par.

What RPM can I expect the peak efficiency to be at and will this change significantly with voltage?

Initially I will probably run them at 24V with the built in Controller and eventually I will be gutting at least one of them to increase to 48V at least for range and power.

What RPMs can I expect for both of those voltages?

How difficult is it to make one of the Kol motors suitable for an external controller? How difficult is it to reverse the direction (although I do intend to use them CCW currently)

Where is the best place to buy The Kol motors?

Also best place to get a gear to mount to the motor with the same chain size as the bicycle (is that 35#? or?)

I am planning on gearing down the motor drive to the hub and then of course I can use any of the 3 front or 7 rear gears to adjust torque delivery.

The beauty of this method in my eyes is that it keeps the pedals, utilizes the gears, allows you to ride under power and not pedal and has little to 0 drag from the motor.

I welcome comments, similar kits out there are the Elation:
Full%20Bike%20Right.jpg

Which mounts the gear under the bike, and uses a drive gear on the outside of the largest front gear which to me is less than ideal.

The other kit sold similar to what I plan is the Epacpower
wh_spr.jpg
which is very fine in my mind except for the 200 watt motor.

I am getting a sun independant peddling system stoker crank and then going to install a set of smaller front gears like a 20, 26 and 32. But again all of this depends on the Kol motors operating speed.

So please let me know more about the Kol motor and also let me know if you see any problems with my planned route to E-bikedom..
Thanks!!
Sean
 
Hi Sean,

I guess the only disadvantage, to taking the motor drive to the left-hand side of the crankset, is that you can't isolate the cranks. You are obliged to pedal along with the motor at all times...
 
what are your goals?
often guys build their own to get
1. high speed, exactly how high?
2. long range "
3. climb steep hills "

Your 2nd design will almost always be better due to the learning curve.
 
Miles said:
Hi Sean,

I guess the only disadvantage, to taking the motor drive to the left-hand side of the crankset, is that you can't isolate the cranks. You are obliged to pedal along with the motor at all times...
That epac looks like it has a freewheel on the left-side chain ring.
 
I'm going to be building a bike with pedals and I plan to use the "Elation" configuration. One advantage is that the torque from the motor "pulls" parallel to the rear chain. You do not get the friction of having to pass through your bottom bracket (thus improving bearing efficiency to near 100% minus the chain losses, so closer to 90% overall having two chains) and you also can run the motor without pedaling.

Stokemonkey does something similiar to the other option, which forces you to pedal.

:arrow: If you want I could probably make up a spreadsheet and model "everything" for your bike. It would take me about an hour to do, so let me know that you would be interested and I'll do it. Then you can get all kinds of charts and play all sorts of gearing "what if's" for your bike... (though since today is St Patrick's Day I won't be doing it until later) With your own "simulation spreadsheet" you will know in advance just about everything it will do... (the results I've had confirm my spreadsheets to within about 5% or better)

The chart below is an example of the kind of "what if" analysis you could do. Notice "where" the pedal power intersects with the motor's powerband. If you get that wrong your bodies powerband and the motors powerband will be incompatible. (it might be too fast, it might be too slow... you need it "just right" for it to be most effective)

I'm going to need to know your initial gearing ideas, front and rear, and your final choice of motor. From that you "begin the process" of searching for what it ideally "should be". You never know the outcome at the beginning...
 

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v_tach said:
Miles said:
Hi Sean,

I guess the only disadvantage, to taking the motor drive to the left-hand side of the crankset, is that you can't isolate the cranks. You are obliged to pedal along with the motor at all times...
That epac looks like it has a freewheel on the left-side chain ring.

To isolate the motor from the pedals, presumably.....

If the motor drives the left-hand side, it has to turn the axle, and the cranks on the IPS/Cyclone systems are attached to the axle. The freewheel is between the cranks/axle and the chainwheel, right?
 
Oh I see. On the epac, it does look like you would have to pedal with the motor. Looks like that setup just allows you to pedal without the motor turning.
 
First of all I am not planning on using either kit I just posted them to illistrate the idea. I am using the sun IPS stoker crank which has the Captains chain (where I will hook the motor) on the left side.

To safe I don't see any reason that passing the power from one side of the crank to the other will cause any significant frictional loss.


Matt Gruber said:
what are your goals?
often guys build their own to get
1. high speed, exactly how high?
2. long range "
3. climb steep hills "

Your 2nd design will almost always be better due to the learning curve.

Ok so for your questions matt:
1) I want to go between 20-30 comfortably, I would like the top speed ultimately to be higher like 35-40 but this would be after overvolting the motor.

2) Long range I have a mostly flat 8-12 mile trip to work that I would like to be able to ride this on, I can easily plug in the bike to charge at work.

3) I want to be able to climb hills as for this bike to be usefull I need to be able to go all over without peddling much.

My short term goals for this bike are
speed: 17-25mph
Range: 15-20 miles
Hills: Climb a 10% grade without pedal assist. (can be slow)

This would all be done with the Koll motor running at 24-28volts. (hopefully)


My long term goals are:
Speed: 20-30 cruising, 35-40mph top speed.
Range: 20-30 miles
Hills: Climb a 15% grade at 15 mph.


So no one really answered any of my questions on the Kollmorgen motor, does anyone have any specs for one? Or results from a bench top test?

Any advice on reversing the rotation or setting it up for an external controller?

Thanks all!!
Sean
 
sean said:
First of all I am not planning on using either kit I just posted them to illistrate the idea. I am using the sun IPS stoker crank which has the Captains chain (where I will hook the motor) on the left side.

You'll have to explain how you can do this and use the motor without pedalling...... I don't get it :)
 
Miles said:
You'll have to explain how you can do this and use the motor without pedalling...... I don't get it :)
It's all centered on the IPS tandem stoker crank.

Think of is this way, the crank is originally intended to be for the rear rider on the tandem.
The IPS (independant peddaling system) is made so that either person on a tandem can rest their legs while the other person cranks.

So the front crank on the tandem is normal solid crank, however the stoker crank (rear crank) has two freewheels in it, one so that the chain to the rear wheels can spin independantly of the pedals, the other so that the gear to the captain can freewheel also.

Think of the captain as the motor and the rider as the stoker. The motor can be used while you leisurely ride along without peddaling. Or you can peddal and motor, or you can pedal and not motor.

The pedals will not drive the motor and the motor will not drive the pedals, this allows you to use all the gears on the bike with the motor and also pedal whenever you want.

Does that clear it up?
If not search for independant peddaling system on wiki for a description.


Now anyone with any info on the Kol or do I need to start a new thread?
 
sean said:
So no one really answered any of my questions on the Kollmorgen motor, does anyone have any specs for one? Or results from a bench top test?

Any advice on reversing the rotation or setting it up for an external controller?

Thanks all!!
Sean

So yez inner-rested in gittin a Hi-Koll(onic)? :wink:


The expert in residence is <A HREF="http://www.bobmcree.com/Kollmorgen_motors.html">This guy</A>,
<A HREF="mailto:bob@bobmcree.com"><IMG SRC="http://endless-sphere.com/forums/images/avatars/74686906845db2fc925368.jpg" ALT="bob@bobmcree.com"></A>
Bob 'Kollmorgen' McRee.



He's currently working on a project so may not be checking in too often.
A PM may be in order, look in the memberlist.
 
Miles said:
sean said:
Does that clear it up?

Not unless you're planning to use a twin co-axial bottom bracket spindle :p

See here: http://www.hostelshoppe.com/atp_archives/ips_instructions.pdf

So maybe I didn't describe it well I'll just wait till it's done and post pictures.

If you can't see how the motor would be able to drive the bike without the rider having to pedal from the IPS info you just linked then you won';t believe it till you see it.

I will e-mail bob with my questions about the Koll Motors
 
sean said:
So maybe I didn't describe it well I'll just wait till it's done and post pictures.
If you can't see how the motor would be able to drive the bike without the rider having to pedal from the IPS info you just linked then you won';t believe it till you see it.

Not with the motor drive on the left-hand side! If you can't see that from the link I posted, then you'll just have to find out for your self........ I was just trying to help - there's no cognitive deficiency on my part....
 
Hi Sean, you're on the right track. Frustrating sometimes.
Agreed, safe's hypothesis is all wrong.

There's no reason why you can't do it first class just as you plan.
I can't help with the Kollmorgen question, but Bob can.

BTW, the motor that both of the kits above use, is the Unite MY1018.
It's really rated for 250W by the maker.

Currie sells the identical motor in the US market as "450W".

It's a brushed single reduction gear motor, very simple and robust.


I can run my cruiser bike (currie) at 25mph plus using that little motor,
if it is force cooled.

Kollmorgen will be better I suppose. It's certainly more efficent.
However, you can get much more than 200W power from the Unite;
enough for 20MPH operation on the level.


The EPAC kit's design is truly superior looking.
http://epacpower.com.au/
Motor is up out of the filth,
the right side is preserved for regular pedal drive gearings.
The EPAC is mechanically correct, surely better than the Cyclone kit.

Just now studying the ratings and claims:


Epac Specifications
* Recharge time 5 hours
* Range up to 25km
* Consistent maintainable top speed 35km per hour
* Motor 200 watts
* Battery 24 volt 12 amp hour
* Charger 24 volt 1.8 amp
* Weight 9 kilos

That's all right. Nothing puffed, no lies-except for "200W", which is a downrating in number only to meet AU's national limit for ebike outputs.


Gee, the cost of the entire kit (but who needs those SLA batteries?)
is only $565US. If I were making another ebike---I think I would get the epac motor mount and crankset, order the Unite from TNC , use my own batteries, and drive an internally geared hub with it.

Like (dream on) a Rohloff or a Nuvinci!

yay!






UNITE MY1018---"the little motor that can"
 
sean said:
To safe I don't see any reason that passing the power from one side of the crank to the other will cause any significant frictional loss.

If you plan to be able to ride without the pedals moving then you have to isolate the two. If you are content to always pedal then the friction would always be there anyway, so it won't matter.

I've got a transaxle setup on mine and it doesn't add much friction, but it does add a little. So it's no "big deal" but why force yourself to pedal all the time? There will be times when you just want a simple cruise ride and not want to "have to" pedal. (or like in my case I'm doing the "road racer" thing and need to be in tight tuck for wind resistance reasons) If you are running an upright mountain bike setup you won't be going faster than probably 25 mph anyway because the wind will prevent forward progress.
 
:?: :?: :?:

What's not to understand? You guys are lost, I'm quite sure.

The EPAC, for example, is perfectly independent and mutual:

motor only, pedal only, or both,

-the pedals are not spun by the motor-

and this is true also with Sean's plan, and with the Cyclone kit, and with the eLation kit.


---see? understand now?

Or am I the confused person here?
 
Miles said:
How can a L-H motor drive turn the bottom bracket spindle, without turning the cranks? The freewheel is between the crank and the chainwheel.

I second the question... how do they do it?

Maybe if they had a double crank spindle with the inside being the crank part and the outside being the motor axle part. Outside both of those you would have the actual bottom bracket bearings. This would be complicated and I don't think very efficient.
 
safe said:
Maybe if they had a double crank spindle with the inside being the crank part and the outside being the motor axle part. Outside both of those you would have the actual bottom bracket bearings. This would be complicated and I don't think very efficient.

This was my twin co-axial spindle joke, further back in the thread :)
 
Miles and Safe:

The IPS system available now, the Sun bicycles one has the captains gear on the left side of the crank. It is MADE to transfer power to the gears on the cassette side of the crank WITHOUT the pedals moving.

Safe,
the crank is ISOLATED from the gears with freewheels so you can sit there without pedaling and motor along.

Reid,
Nice to see someone who understands the mechanical properties of all the components I am listing, I have looked at the kit but since I will be using a different motor using the Epac system woulden't be cost effective, I would only be using the crank and I can get the crank with extended Bottom bracket to install the stoker crank locally for like $150.
I am also going to be initially working with another different setup so I will be trying two different setups.


Look into the ONLY available IPS system, the Sun and you will find what I am saying about the gear on the left side and the required bottom bracket part.

Anyway I will probably have this together in the next month and you will all get to see pics then.
 
full_21930.jpg


http://www.bikepartsusa.com/product_info.asp?f_q=stem&cp=8&p=01-98473

Wow, you learn something new every day! 8)

Road Front Silver
39x1.75
Forged Alloy Arms
Fits Square Bottom Bracket
Stoker Crank Arm Set
Will Allow Captain or Stoker to Coast or Pedal with Complete Crank Independence

Your price: $106.48 / ea
 
Ooops! Might have just learned something that is not true... (you still need a right side chain coming from the motor for these)

"IPS rear 170 mm crank: 110 mm BCD on timing CR (39t cheapo CR included) and 130/74 mm BCD for drive CRs (not included) $150.00

Replacing the stoker's crankset on you tandem with an IPS lets the stoker coast while the captain is pedaling. Note that the IPS puts the timing chain on the right side of the tandem, which may require you to replace the RH captain's crank with one that has a chainring spider on it.

Drivetrain: crank IPS rear 170mm — $150.00 each, qty:"


http://www.easystreetrecumbents.com/stuff/drivetrain.html

IPS.jpg
 
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