ConquistaThor said:
That motor was salt water submerged and is seized solid.
Yeah, then you'll have to replace it.
I am pretty certain I want to tackle this with a hub motor conversion, and change the front drive pedal sprocket to much smaller one to provide some ability to pedal the unit for emergency use or repositioning.
Presumably the hubmotor wil replace the Nuvinci IGH that is in the rear wheel?
If the motor will be the only thing running it most of the time, and you won't ever need to pedal at more than one very low speed, you can use a very large rear sprocket and a very small front sprocket, and no shiftable gearing between them, to get high torque but low speed.
I do something like this on my SB Cruiser trike. Though I do have a 3speed IGH in the chainline in the frame between pedals and wheel, it stays in the lowest gear 99% of the time. For me, pedalling is used to control the motor system, and the motor provides all the actual power, because my body is pretty worn out in all the wrong places, and I have to save what ability I do have for the other things I have to do that I can't replace with motors.
If you think you'll need more than one gear, I'd go ahead and put an IGH in the chainline like it probably originally had (if it is like the site I linked), so you don't have to deal with derailers/etc. A simple 3-speed IGH would likely do for most things, with a low gear, a 1:1 gear, and a high gear. Different ratios are available, or you can use an IGH with more gears (typically less gears mean they're wider inside and thus a little stronger and wear out less quickly), or even a NuVinci for continously variable gearing. If you don't have the mounting brackets for that, you can use the ones for the motor instead.
https://www.sheldonbrown.com/internal-gears.html
http://john-s-allen.com/gears/hubratios.htm
I did find a a spare sprocket which I think did fit on the disk break side of the rear axle to provide input power from the original motor.
FWIW, I don't see a disc caliper mount or caliper on that rear wheel area. Is there one that is just not visible? (if there isn't one, then no need to even have the disc mounted; leaves space for the sprocket if you do want to do it as below
If you are doing a hubmotor in the wheel conversion, and are using an IGH inline with the pedal chainline, then you can use that same sprocket on the hubmotor's disk brake mount to accept the pedal chain output from the IGH, pretty much just like the original design probably was. I would put the IGH as close to the rear wheel as possible, so that the always-spinning chain you'll have from it to the wheel is as short as possible.
If you don't have an IGH or some other freewheeling device between that sprocket and the pedals (assuming the pedal chainrings are used on the left side to line up with it in this use case), then the entire chainline and pedals will be forced to spin all the time the ELF is in motion, either forwards or backwards.
Alternately you can run a regular freewheeling sprocket on the right side of the hubmotor in the wheel, and keep a single chain from the pedals to the rear, and the chain and pedals will only move when you are pedalling. If you install a derailer on the rear as well as a multisprocket cluster on the wheel, then you can shift gears too.
Keep in mind that the longer the chain is, the more important it is to keep proper tension on it, or else it can bounce on bumps/holes while pedalling so that the chain comes off the top of the pedal chainring and jams up (doesn't usually happen if the chain isn't being pulled, so if you stop pedalling before each bump or hole, and only resume after the chain isn't bouncing, that works too).
Ghost rings (unattached chainrings stuck between the top and bottom runs of chain along the length of a long chainline) can help keep this from happening, if they are large enough to push the runs apart and keep them tensioned, but if a bump does separate the runs because of insufficient tension, the ghost rings will fall out.
I have been looking at the ebikes.ca site which had a ton of helpful information. If I cannot find anything domestic I'll contact them, as they have one of the best sites out there.
Yes, Grin Tech (ebikes.ca) is one of the most complete places to get information and ebike stuff; they are also inventors and developers of various things (they don't just buy various chinese/etc things and have their stickers put on them like most places do; they do sell some stuff like that, but the products that carry their name are actually theirs). They're not perfect, and sometimes they are so busy it is hard to get hold of them, but I haven't found any other place that is consistently any better at that part.
They actually keep this forum alive, too, having rescued it some years back from it's originator who was selling it off.
They also have something else useful for determining what system might work best for a particular bike and situation: http://ebikes.ca/tools/simulator.html
Why would I want to change the rim and spokes if I can find one ready to go - saw a video on how to do it, but, what is forcing me to swap the rims around?
If you are going for a hubmotor in the wheel rather than redoing the original hubmotor as a middrive, then there is no reason to remove the rim and spokes from the motor; you just order the hubmotor with the correct diameter rim for your frame (same as the original that you are replacing, presumably the rear), and the correct width rim for the tires you wish to use on it (taht will still fit within the frame).
Some advantages of a hubmotor in the wheel system:
--simple; less things in the chainline to align and tension during setup
--only the pedal drive uses the chain, less wear on the chaindrive system
Some disadvantages:
--weaker wheel (shorter spokes, different angles, etc)
--heavier wheel and more hardware to attach it (harder to fix flats, etc)
--dropouts not typically designed to deal with hubmotor axle torque, so special hardware has to be installed and secured to do that
--motor has to directly do all the work to the wheel, no gearing changes are possible for it (just for pedals); motor (and controller/battery) may need to be more powerful to do the same work under some conditions
The only reason to remove the rim and spokes from the hubmotor is if you are going to use the drive the same way it was originally built, by placing the hubmotor in the frame and running the pedal chain thru / past it to the rear wheel, so they both use the same drivetrain to run it.
Some advantages of a hubmotor as middrive:
--Stronger wheel (longer spokes, etc)
--lighter wheel, easier to fix flats, etc (can also easily carry whole spare wheels if necessary to speed flat fixes)
--no special dropout hardware needed
--if gearshifting device (IGH, etc) is after motor in chainline, then motor gets advantages of being able to shift gears just like the pedals (and your legs) do; may need less motor (and controller/battery) to do the same work under some conditions
Some disadvantages:
--more complex, more things to align and tension in chainline
--chaindrive system wears faster
