The only other downside is price...
The large one will handle more current better, but how much current do you
expect to need? It still might not be up to the task. I have run mine at a 14
to 41 ratio which is about 3 to 1. IIRC you are in the 1 to 1 range. It takes
at least 100 amps just to get me rolling, and most of my riding is spent in the
100 to 200 amp range. I guess yours will likely take 3 times as much. Mine
only has 4 brushes, and while you are correct that more brush area is better
for higher amps, I think even a 4 brush one will handle your amp requirements
fine. The biggest problem you will have is the heat. This style motor
utilizes an internal fan to keep it cool and at low RPMs this fan does not move
enough air. I have this problem when I drag my kids around in the snow. I am
running at very low speeds, with lots of extra drag which heats my motor up
quickly. The solution is that at the end of each ride the kid gets to scoop up
a big armful of snow and pack it on the end of the motor.
A motors ability to deal with heat does have a lot to do with how much copper
is in it, so the 80 lbs motor will likely be able to deal with about 30% more
heat than the 60 lbs motor. I think even at this, if you are pulling 100s of
amps at less than 1000 rpms you will have heating issues. If most of your
riding is going to be done around 2000 rpms your probably fine with the larger
motor directly coupled to the shaft. One thing to remember about the motor is
that it is not going to lose any value, so if you try it and it doesn't work
out, you should easily be able to resale it.
On my truck I get away with a smaller motor (about the size of the one you
want) because I force extra air through it with a blower. I also have a
transmission. It works great, but trying to fit a blower on a motorcycle is
not much better than trying to fit a transmission on it.
It is unlikely that there is a perfect solution, but I still think finding a
way to let the motor spin faster is the best compromise. Perhaps you can fit
smaller wheels, or even find rim with a sprocket to swap in the back. I know I
have a couple of motorcycle junkyards around me that make that kind of change
pretty easy. If you take a look at most fixed gear ratios on electrics I think
you will see that they are usually somewhere in the 3 or 4 to 1 range.
I first bought my motorcycle from a local add. I had no idea what I was doing
but wanted to do something. While I think I made a decent choice, when I
started looking for parts I found the motorcycle junkyards. Once I found
those, I couldn't help but think this is the place where I should have started.
They had a selection of rolling chasis I could have compared to each other and
chosen from.
damon> Date: Wed, 26 Mar 2008 13:29:49 -0500> From: [EMAIL PROTECTED]> To:
[email protected]> Subject: Re: [ElectricMotorcycles] Hi-Torque
Motors for sale> > The smaller ones are about the size of what I have now, but
I imagine > they have a lot more pull. I really would like to connect directly
to > the driveshaft, but that means pretty low RPMs at low speed and hence >
lots of current. The motor I have now doesn't like that. I'm thinking a >
larger motor, esp. with 8 brushes, would deal with that a lot better. > And
since I would need less than 2500 RPM max or so, I don't need to > overvoltage
it. What is the downside of a larger motor ( other than > weight and size)?> >
- SteveS> > > > damon henry wrote:> > It will be great at lower volts. It
likely has spent it's life up > > until now running at 36 or 48 volts. When Jim
says he has advanced it > > to run at 72 to 120 volts what he means is that he
has drilled and > > tapped new holes and rotated the brush cap so to tune it to
the higher > > voltage. It's just a matter of setting the cap back to it's
original > > position to optimize it for lower voltages and Jim would happlily
take > > care of that little detail for you :-)> > > > That particular motor is
as big as the one I have in my Datsun Truck. > > It's definitely more than you
need for a motorcycle. I have been > > riding for years on a motor the size of
the smaller ones he has listed > > with no problems. As long as your motorcycle
is not super heavy you > > should just snatch one of those up. > > > > Of
course you will still have to work out the shaft drive thing. > > Perhaps you
can just work up some kind of jack shaft with sprockets > > so you can try
different gear ratios. It should take up less room > > than a transmission and
you will have more options as to where to > > mount it.
http://www.surpluscenter.com has a nice selection of > > bearings, shafts,
chains, and gears at very low prices. It makes > > experimenting quite
affordable.> > > > damon> >> > > Date: Wed, 26 Mar 2008 12:42:02 -0500> > >
From: [EMAIL PROTECTED]> > > To: [email protected]> > > Subject:
Re: [ElectricMotorcycles] Hi-Torque Motors for sale> > >> > > Yeah, I've been
drooling over them. Prices are much better than I> > > thought they might be!>
> >> > > The first one (DSCN2032) might be what I need for the BMW conversion.>
> > Right now I'm in the middle of adding a transmission to it so I can run> >
> more tests with my present motor, but the tranny really screws up the> > >
layout and I really don't want it in the final setup. I wonder how that> > >
motor would be at lower volts?> > >> > > - SteveS> > >> > >> > > Damon henry
wrote:> > > > If you are in need of a good motor take a look at Jim's latest> >
> > offerings. Take my advice, don't screw around with one of those easy> > > >
to melt pancake motors, get yourself one of these forklift rebuilds> > > >
instead. Jim makes them bulletproof. They just soak up whatever> > > > amps you
throw at them and keep pushing you down the road.> > > >> > > > > >
http://hitorqueelectric.com/gallery/v/MOTORS+FOR+SALE/rebuilt+modified/> > > >>
> > > damon> > > >> > > > > >
------------------------------------------------------------------------> > > >
In a rush? Get real-time answers with Windows Live Messenger.> > > > > >
<http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refresh_realtime_042008>
> >> > > >> > > > > >
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>> > > > No virus found in this incoming message.> > > > Checked by AVG.> > > >
Version: 7.5.519 / Virus Database: 269.22.0/1344 - Release Date: > > 3/26/2008
8:52 AM> > > >> > >> > >> >> >> >
------------------------------------------------------------------------> > In
a rush? Get real-time answers with Windows Live Messenger. > >
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>
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