Smallest, lightest hub motor?

[Drunkskunk]

Reliability issues aside, I think the Tongxin motor is a pretty good compromise.

Looks like it. I tried that link you sent, its for providences in china, but i'll take a shot and email anyway. With luck, I'll catch someone who reads english.

I tried there contact page, but they want you to post into a guest book format, that anyone can read. I'm not opening my self up to international spam that way.

 

[Miles]

The top contact in that link (Diana Lin) handles overseas sales.

 

[johnrobholmes]

The RPM can be halved by using a stator/magnet combination that doubles the commutation cycle count per revolution while keeping the wind count fixed. The issue is generally finding stator laminations to suit, companies would much rather use supplies that are already being made. Also, there is a point where the stator diameter must increase to accommodate an increase in stator teeth. You have to fit wire in there somehow.

 

[Miles]

The Crystalyte motor seems a pretty optimal design, if you want direct drive...

 

[Drunkskunk]

The RPM can be halved by using a stator/magnet combination that doubles the commutation cycle count per revolution while keeping the wind count fixed. The issue is generally finding stator laminations to suit, companies would much rather use supplies that are already being made. Also, there is a point where the stator diameter must increase to accommodate an increase in stator teeth. You have to fit wire in there somehow.

Exactly. And assuming you were using all the space available for windings to begin with, to double the count, you have to increase the diameter, and that increases the mass, or, roughly, doubles the weight of the motor to halve the RPMs.

 

[jerryt]

If you have any interest, here is a discussion of the Tongxin motor (planetary rollers) compared to the Suzhou Bafang (planetary gears).

http://www.pedelecs.co.uk/forum/electric-bicycles/1215-suzhou-bafang-motor-compare-tongxin-motor.html

The Bafang is a little larger and I cannot determine if they make a smaller version. Maybe E-S esteemed member Knuckles knows.

 

[bumper]

Reliability issues aside, I think the Tongxin motor is a pretty good compromise.

Looks like it. I tried that link you sent, its for providences in china, but i'll take a shot and email anyway. With luck, I'll catch someone who reads english.

I tried there contact page, but they want you to post into a guest book format, that anyone can read. I'm not opening my self up to international spam that way.

Keep us posted if you're successful. I'm already thinking of a 2nd ebike with a small hub. Maybe a small folding bike...

 

[Reid Welch]

(snip) These motors are very cheap when purchased directly from Tongxin,
around £35 or so each, plus shipping and tax. The controllers are similarly cheap, around £15, and are sensorless, like the RC ones.

The downsides are the low power output and limited top speed (about 16 - 18mph on 36V for my recumbent).

Jeremy

Hi Jeremy, or anyone else: I may be interested in getting a Nano motor direct from Tongxin.
Is there a link to a sales page?

My new e-bike wants: uber-simple, not fast, not heavy duty.
I have a new coaster brake cheap but good all-steel cruiser bike.
Got it yesterday from a good local bike shop, Coral Way Bike Shop, Miami. Great guys there.
Well made, not crappy, steel frame, steel front fork. Coaster brake only. 22lbs, easy to ride manually.

About conversion options
I have a 36V 15Ah battery, never used, bought a couple of years ago
It weights 10 lbs.
(will it recharge, though? am trying right now to charge it up).

For my needs: just toodling about, 15 to 20mph max, with
a thumb throttle for assist when wanted. That would be ideal: simple,
plus the Nano-type of motor is stealth-looking and totally freewheeling; no magnet cogging drag.

We have no hills here. I don't need a lot of power, really.

So--where do I go to get this motor in a wheel at a reasonable price? Link?
I'm in the USA. Can't afford big buck stuff these days. To buy from China, cheap, sounds good to me.

Thanks for any advice! I know that I -should- have a front caliper brake, but....we'll see.
K.I.S.S., as they say.
This won't be a racer, but only for assist in headwinds, or for when I get tuckered out pedaling.

clickable thumbs:

 

[Miles]

Hi Reid,

Good to hear from you.

I think they're reluctant to supply single units, these days...

Check out this thread:
http://www.pedelecs.co.uk/forum/electric-bicycles/2575-tongxin-information.html

 

[Reid Welch]

Thank you, Miles and Jeremy! At this point I've only checked out Jeremy's link.
I read the thread. It does not bode well for me to buy $$$ (I don't have a pounds symbol),
from the UK. Duties on duties and markups and... ugh.

Well, meanwhile I would like to start a sort of blog thread...
I don't know if it should go here, though; is this place OK?

Am now swapping front wheels from the old Currie Mongoose,
which I had fitted with super-easy-riding-low rolling resistance
"giant" slick balloon tires, to the new bike.
Oh, they are like velvet-action road shock absorbers, and still practically new.
So, will get these on the new bike and show pictures!

Click!




I'll add some more pictures to this posting as I go along.
And I will check Miles' link....EDIT: the Nano-Tongxin does not look so attractive any more!

Nevertheless, I must go with the flow, one step at a time... and re-use what I can,
salvaging from the bin-bits, such parts of the old Currie Mongoose as can be re-applied:
the blue-cased Brain Drain that Justin made for me back then, for instance,
and the sweet Bontrager tires.

front against rear for size comparisons:


Here, the Currie front rim-with Bontrager-tire, is ready to be dropped into the new Sun bike.
It is wider and taller. I'll get an actual measurement for you all soon....as I take a first test ride.
I know it will ride even sweeter.

Front done, and next goes on the rear Bontrager....but first I go for a test ride!
Click!


-----
Slide show showing the first day of the new bike:
mounting fat tires (the pictures above, in autoplay form)
http://tinyurl.com/6xt23b

 

[gregben1]

Let's hear a bit more about your battery.
Is this a SLA (Sealed Lead-Acid) battery?
If so, have you been keeping it charged? If not, better charge it.
Also, if SLA, 10Lbs is too light weight for 36V, 15AH. It should be closer to 30Lbs.

 

[vanilla ice]

Nice looking cruiser Reid. Like those tires too, got me wanting a pair. Bat is Lipo!

 

[Reid Welch]

Let's hear a bit more about your battery.
Is this a SLA (Sealed Lead-Acid) battery?
If so, have you been keeping it charged? If not, better charge it.
Also, if SLA, 10Lbs is too light weight for 36V, 15AH. It should be closer to 30Lbs.

Yes sir, that battery is NOS LiPo,
(two years ago new, never used....Knoxie helped me to get it from the Texas folks who were selling them.

It is ten pounds of 36/15Ah nomina LiPo with battery management.
However, it seems dead: it is not taking a charge. The long-down time of non-use may
have spoiled the battery (it was, like $700!).

I will get a mulitmeter and check cell voltages, and I will need some hand-holding from Knoxie
or others here to see if this costly unit can be brought back to life.

As of this writing, I have not measured voltages of the pack nor of the cells.
I should have been topping it a bit from time to time and keeping in in the refrigerator.....
Off to Radio Shack now for a needed set of meter leads.

----

What now for a front hub motor? (rhetorical question). the "Nano" model seems to be out of the question
due to reliability issues. So I need to read, read, reid and catch up on what's what today. Miles' links lead me that other direction,
away from the Nano-type. Though, maybe a Nano-type -would- serve my light duty needs. I'm not gonna be racing too much.

I've been out of this hobby/nirvana/hell for so long that I forget where to begin again.
But this WILL become a casual-use, minimalist, e-bike in time on LiPo or similar,
and never ever again on lead acid...been there, done that.

Nice looking cruiser Reid. Like those tires too, got me wanting a pair. Bat is Lipo!

Thanks! And you sure did peg the battery type!

Of course, the Sun branded bike is just a cheapie, yet, it is straight and strong and it will make a good bike for runs to the store and back.
And it's going to get me back into aerobic shape, needed, 'cause SLE kept me out of action, totally sedentary for so long.
NOW I am in complete remission, a remission that will last. No terrible drugs, either. I found my own magic pill,
and, believe it or not: "valium" (generic) turns off my body's "self allergy", which is what SLE is about.
I'm delighted to be able to get out and about again, make things and do things.
It got old, being a slug for lo these many, many months!

Cheers,

determined r.

 

[Reid Welch]

Let's hear a bit more about your battery.
Is this a SLA (Sealed Lead-Acid) battery?
If so, have you been keeping it charged? If not, better charge it.
Also, if SLA, 10Lbs is too light weight for 36V, 15AH. It should be closer to 30Lbs.

Hi, Greg! I found a higher, better, usage for lead acid.
---had three 12V/18Ah bricks, never used, date coded 11/05.
Have put two of them (24V) in to external-tethered service to power a Back-UPS, to power this computer
when the power so frequently goes off, usually while I am trying to upload a video.
Now I get 2.5 hours of computer/monitor/dsl modem run time.
Here's how I did the trick, in slide show form: http://tinyurl.com/6z4dpy
extract from this wordy-wordy thread of mine at the APC forums:
http://www.apc-forums.com/thread.jspa?threadID=2567&tstart=0