Hi Ham
I have a similar dream as yours
.
Unfortunately, judging by how much spare time I have, it will remain a dream for quite some time.
However I googled quite a bit for left side drive and found a few interesting things. I started searching for large diameter chainwheel, since I hope to use a large single stage reduction.
Belt Drive:
https://www.aliexpress.com/item/1005001743328202.html?spm=a2g0o.productlist.0.0.541b3ac3unwoWY&algo_pvid=72e8cdbb-73de-4f5b-9cfc-28368deaac00&algo_exp_id=72e8cdbb-73de-4f5b-9cfc-28368deaac00-0
only item that interests me from this kit is the large rear pulley. It's HTD5M, around 120-122 teeth.
They also have a version that is mounted on the spokes but I dislike the idea. Have no idea how this one is mounted, but if directly to IS disk mount, it's nice!
However I mostly gave up on belt drive, because I'm planning on using a high RPM RC motor, and for getting the reduction I need in 1 stage, I would have to go with a very small front pulley, which has 3 disadvantages:
1) Belts aren't good with small pulleys. They deform a lot around them, resulting in high wear and bad drive efficiency.
2) I plan to have regen, and when the small pulley is the driven one, belts tend to skip much more than the other way around.
3) For such small pulleys, where a small number of teeth are engaged, belts need super high tension to avoid skipping. Which is a challenge in it's own right.
All this is what I read, mostly on this forum. (so hearsay, but from pretty good sources).
If I can find a motor with higher torque that I can use at lower RPM (and thus use a bigger front pulley) I might reconsider the belt drive.
Chain drive - 25h chain
https://www.elektromoped.at/de/25h-100z-freilauf-kettenrad-escooter.html
Problem with it is it needs an adapter.
Also, 25h is very small, so I still have some reservations on reliability with 3000+ W, but for me it will probably work fine.
A problem with 25h is that the front sprockets are very small. The smallest number of teeth I found that fits on a 12mm motor axle is 12. Which is actually OK for my needs - 8:33:1 reduction.
https://www.aliexpress.com/item/4000193274588.html?spm=a2g0o.productlist.0.0.1ae774f9XmhnEG&algo_pvid=bc63f4a7-d4be-44d6-8781-2390aa65ca11&algo_exp_id=bc63f4a7-d4be-44d6-8781-2390aa65ca11-27&pdp_ext_f=%7B%22sku_id%22%3A%2210000000721390703%22%7D
For a 14mm axle, 14t is the smallest I could find (same seller on aliexpress)
Other thoughts on this type of build:
I plan on ditching the rear brake completely. Most stopping power is on the front brake anyway, and I am aiming for a direct drive configuration with regen - which I plan to use as my primary brake.
219 chains are nice and *much* stronger than 25h, there is the option of o-ring chain, you can buy "Extron" composite chainrings up to 92t which seem to get praise on this forum, .... but I could not find a single 11t sprocket that fits on a round 12mm or 14mm axle! (anybody know where to find something like that?)
What motor are you planning on using?
Please do share, if you found any off the shelf solutions for left hand drive that bolt onto IS disk brake mount.
Br,