Thinking about trying to ev swap one of my bikes. Don't want to break any speed records, nor do I need 100s of miles of range. But I would like to start playing around with something.
Front wheel rear wheel mid mount? Batteries? Controls? Maybe get a kit?
I do have a cordless sawzall that I don't use any more, I've had evil thoughts of converting it to assist the bike...
Rear hub motor kits are the easy way to get started down this rabbit hole. Most of the kits are in the 36-48V range, over 60V is considered high voltage and has a whole other list of complications. The batteries generally have a lot more cells than what you find in a traditional power tool battery but I have a couple friends that have taken several old batteries apart and built their own battery packs. You probably would be best off buying a kit that has a built battery. The batteries seem to be relatively standard on this cheap kits.
Start looking at stuff like this kit link
Ebikes Canada is a good resource for learning and some higher quality stuff if the ebay/amazon chinesium isn't your style. https://ebikes.ca/
This front hub conversion kit looks promising, but they are already sold out. https://www.swytchbike.com/
I went with a mid-drive Bafang kit from Luna Cycle. All in it cost me probably about $1000 and gives wayyyy more power than I'd ever need. This is on the biggest heaviest cargo bike you can imagine, and I still have no problem hitting 20 mph on a quite steep hill. I'd do that again if the kit was available - if you can replace a bottom bracket you can install a mid-drive kit.
Otherwise I'd probably just buy a built bike like the ones from REI or Radpower. Kits are usually fine but the bikes from a legit manufacturer tend to be much more refined and less finicky than a kit does. I've had no problems from mine in thousands of miles but I do know others who have had issues.
I recently learned that Specialized now offers several electric mountain bikes that are in the 50lb range. They sure look fun. Of course they start at $5k and go up to well double that...
I can second the mid-drive system from Luna Cycles. It has done well by me for the past few years being used relatively hard on a mountain bike commuting on fire roads.
Don't do any kit that involves a front hub motor, you don't get enough traction, you end up with way more inertia in your front wheel than feels comfortable for handling, etc.
750w or 1000w rear hub motors are the "cheap and easy commuter" option. Enough power to get around, easy to wire up, and normally about $300 plus battery cost. You can normally push 1500w through a 1000w motor for short periods and be fine.
Mid-drive conversions are the next step up. Uses your bike's gearing for more speed on the flats, and better climbing ability in the hills. You can normally push 1500w through a BBSHD for a while and be fine.
The next step up is 3kw or 5kw (or 8kw) rear hub motors. At this point you're well out of "just playing around" territory. Don't start here.
You can either buy a battery pack (see aliexpress or em3ev) for $500 (grab either a 48v or 52v pack), or you can buy batteries from a crashed electric car, use a spot-welder to tack them together and build your own BMS. Don't build your own battery unless you're REALLY comfortable playing with lithium batteries already. Most e-bike batteries start at about the 48v 10AH range (500 watt-hours) and go up to 52V 20AH range (1000 watt-hours). Regular power tool batteries are going to be something like 18V 4AH, which is 72 watt-hours. To get a decent battery pack from power-tool batteries, you'd need five or six of the 18V 4AH batteries all plugged into the bike at the same time.
If you want to build something, I third the Luna/Bafang mid-drive setup. I built an ebike for my wife on an old '80s steel road bike frame in spring 2020 and we both love it. I used the BBS02, which is old news nowadays, but is a nice, solid, proven setup and still a good deal for the money IMO. Combined with a 10Ah 48V pack from Amazon, the bike has a legit 30 miles of throttle-only range and a 30 MPH top speed.
It's true that for a couple hundred more, we could have had something like a Rad Power bike, which would be better-integrated with fewer wires zip-tied to the frame, but it couldn't touch the range or performance of our DIY build.
HAving been suckers into this thread via the title rather than a real interest, I have of course started clicking the links. Couple of quick Q's. The kits linked look to be to retro fit to a regular bike with a derailed etc. What about retro fits for single speed bikes with narrower rear hubs / stays / drop outs? Also, what the real world range for electric only drive in a relatively flat area? How much does a panier or trailer with groceries affect the range?
In reply to Adrian_Thompson (Forum Supporter) :
Weight doesn't affect range as much as you'd think. My bike was able to make a round trip 40 mile camping run, FULLY loaded with a ton of gear. Think 400+ pounds for gear, bike, rider all in. If you are really light on the assist without much weight I'd guess 60+ miles easy, a friend did a bike tour last year on her REI branded one and had a couple 80+ mile days without an issue.
I know these work fine on internal geared hubs - mine is one, and I think it might work on a 120mm single speed rear hub but chain line might be an issue - not sure how much it pushes out the chainline as compared to a single speed.
No experience with 2 wheels but I have done two three wheel conversions. same kit just different rim laced on. I do not like the mid drive, while it is more balanced it is putting all the force through the chain which is not as strong as it used to be with 8-9 speed hubs. Never broke a chain with a 5-6 speed hub in my 30s, but in my 50s I broke 2 relatively new chains. A hub drive will guarantee you get home.
Even though some have issues with a hand throttle instead of assist when pedalling only I love it. On assist, make sure you have at least 5 levels. First controller only had 3 and none of them met my needs. Now I have 9 and have never gone above 7. On power I would say 500 watt min, we have a 350 and it is fine for helping up the hills but the 650 watt hub is just too much fun. It will smoke the tire on loose surfaces and has a top end of just over 25. I would recommend electric bike kit dot com, their hardware and support was excellent.
OK, bringing this up again. I was planning on doing a lot of reading and research last week while off for Thanksgiving, and order a kit of some kind today, Cyber Monday. Unfortunately life, or more specifically COVID had other plans, and I've been wiped out for a week, including a brief trip to hospital for dehydration and muscle cramps. Fun stuff. Anyway, I'd still like to make the jump today if possible while I assume (hope?) there are some genuine deals out there.
The want. This is actually for my wife, we both have decent bikes that we're basically happy with, but my wife would like an e-bike for up North. When we finally retire up North we will certainly buy two new e-bikes, but for now we don't want to make that kind of financial outlay. Back in September while up North we rented an e-bike for her so we could make the 20 mile round trip from our place to the next village and back. The exact use case we want. She rented a Retrospec rear mount bike which had I think a 36V / 360W battery and motor, although it may have been the 48V/500W. That seemed perfect. Three levels of pedal assist, or simply press and go. I'd like to replicate that on her old bike.
Her old bike is an early 90's MIYATA Road Runner, a bit of a tank, but a really really nice bike to ride. Because it's kind of heavy already I've added front and rear baskets, and if we go out with (the small) dog we take him in the front basket, with a second rear basket for water, food, etc. Here's an old pic with no baskets, yes the tire is flat! The distance between the rear drop outs is approx 130mm, although that's estimated as I didn't remove the rear wheel to check exactly.
So, any recommendations for a specific kit, or kits to avoid, and what other Q's do I need to ask and get answered before buying. Anyone aware of any good deals right now?
Depends on how far and fast you think she is going to want to go.
For short distances, a minimalist Swytch kit with maybe an extra battery would be a simple easy way to go. These are small kits meant to go 15 miles or so on a charge.
For longer distance you could get either a rear hub drive or a mid-drive kit from Bafang, like the one Luna sells. Probably overkill, even the smaller BBS02 motor has enough power to run my cargo bike with me and two kids on board for 20-30 miles.
Everything seems to be backordered, especially batteries.
But honestly once you put in the $1200 towards a nice mid drive and battery, you're much of the way to a new eBike - which is the easy button really.
I considered doing a kit but wound up buying a Radrunner about a year ago. I have enough car and house (and other bike!) projects going where the appeal of a finished, integrated bike was paramount. We use it downtown for errands, going out to eat, whatever.. my wife can sit on the back (it has a padded seat on the rack and fold down foot pegs) and it has a front basket for cargo.
I was riding it to work one-way quite a bit, a 20 mile ride. I plug it in at my office and then ride it home the next day. Ironically the past 3-4 months we've been training on the tandem heavily so I haven't ridden the e-bike much at all. This winter will probably see more use, as it has great lights for riding after dark, including a brake light.
In reply to Erich :
Thanks Eric, I was hoping you'd chime in.
Well this is nuts. The only people that (claim) to have BAFANG kits in stock seems to be Amazon. The thing is for a 26" wheel, they only seem to offer 48V 500W, but the kit including a rear mount battery is $774. The bike we rented with 48V 500W is only $899 ready to roll. I honestly expected to buy the kit and battery for $4-500. It's just not worth it for this cost. The SWYTCH you mentioned doesn't seem to be on sale yet, and very unimpressive for it's projected price of $499, especially being FWD which just seems like a nightmare for a bicycle. I guess it must be back to the drawing board on presents!
Yeah my advice lately has been just find an eBike off the shelf you like and buy that. Don't pay too much attention to the watts etc - wattage can be equal but torque is often not. Only convert something if you can't find an equivalent eBike or if the equivalent eBike would be wayyy more expensive.
My wife and I bought a somewhat expensive Tern HSD for around town and shopping use, and it's fantastic. It immediately converted her into looking for a reason to ride places, rather than an excuse not to ride. We're actually putting studded tires on it for this winter.
In reply to Adrian_Thompson (Forum Supporter) :
FWD ain't bad. 48v at 500 watts is likely as aggressive as you'd want to go, but that way if you run out of power you still ride with little additional weight.
But you're hitting the real snag- at the costs for a good kit (i'd suggest Grin Tech at ebikes.ca) you're at a price where you could buy a brand new, ground-up designed eBike.
If you are looking for hillclimbing prowess, this is my setup. I used a mid drive 52volt bafang bbshd 20ah battery pack coupled with a 33 tooth front chainring and a 11-44t rear cassette.
It will almost climb anything... That being said, I am going to be switching to a larger rear cassette (or an internaly geared hub more on that later) to make sure it can climb anything.
It is more akin to an electric dirt bike now rather than a mountain bike. Max speed I have achieved on the flats is 41mph.
One caveat with mid drives especially ones like mine, you must use quality parts, and carry spares and tools!
I break chains and dereulers alot. Use an old chain and learn how to turn it into a single speed just in case you break a dereuler just before dark. Or you may end up walking along way home.Or spring for a quality internally geared hub. I can't remember which brand but one brand allows for throttle on shifting.
Oh and for night riding the cheapest way to get lots of light is to install some 12 volt led lights and tiny Lifepo battery. I get about 4hours out of the battery and the trails are lit up like the Mulsanne at 2am! I found that setup to be much cheaper than lights dedicated to riding. 
What did the bike weigh before you converted it ?
and how heavy now ?
Thanks...
PS: just asking as I heard some conversions are pretty heavy and difficult to lift onto the bike rack.....
All I got is... careful with them batteries.
(not my trike)
In reply to californiamilleghia :
I stupidly didn't weight it before I did the conversion. But it started life as a DiamondBack Motown if that helps. My quick search didn't reveal the base weight of the bike though.
It weights 69 pounds with the 20ah battery pack the lights and the 12v Lifepo battery to power them, although the Lifepo is less than a pound.
Personally I have never had an issue getting it on my hitch mount bike rack, or the maintenance stand. But most batteries are easily removable for transport.
BTW speaking of batteries, get bigger rather than smaller you won't regret having too much capacity. I started out with a 13ah battery and was disappointed. I was pleased with the 20ah.
Oh one other thing, make sure the battery will fit within the frame before choosing a bike or battery combination. Most but not all hardtails will fit the 20ah triangular battery I ended up settling on.
drsmooth said:If you are looking for hillclimbing prowess, this is my setup. I used a mid drive 52volt bafang bbshd 20ah battery pack coupled with a 33 tooth front chainring and a 11-44t rear cassette.
It will almost climb anything... That being said, I am going to be switching to a larger rear cassette (or an internaly geared hub more on that later) to make sure it can climb anything.
Uh, Sturmey-Archer 3 speed I think is what you're talking. I think it's the only hub set that can handle the torquing. If You want one, you can snag one from Battery Clearing House here for $26 + Shipping. I've gotten two from them.
One caveat with mid drives especially ones like mine, you must use quality parts, and carry spares and tools!
I break chains and dereulers alot. Use an old chain and learn how to turn it into a single speed just in case you break a dereuler just before dark. Or you may end up walking along way home.Or spring for a quality internally geared hub. I can't remember which brand but one brand allows for throttle on shifting.
Oh and for night riding the cheapest way to get lots of light is to install some 12 volt led lights and tiny Lifepo battery. I get about 4hours out of the battery and the trails are lit up like the Mulsanne at 2am! I found that setup to be much cheaper than lights dedicated to riding.
That's the big problem with mid-drives like the BBSHD- above ~350 watts of power they just RIP through bike parts, because normal bike stuff is built for human ~120 watts max power levels. These damn things are sweet but they churn out 10 times that, so when you realize that you see why hub motors are such a big deal and why Grintech focuses on them.
Great point on the lights! Everyone wants something different, but keeping it separate can also keep the battery wiring from getting to complex AND allows you to potentially use automotive lights.
In reply to GIRTHQUAKE :
Thanks for the link I am going to pick a few if those rims up!
I was actually thinking of switching to a belt drive and an 8 speed internally geared hub just to cut down on the maintenance and parts cost.
But these Hubs are so reasonably priced with the rim no less, that I may just change my plans!
With the hubs you linked I may try a chain drive with a rear tensioner and or dereuler.
Along with a two or 3 Speed front chainring and front dereuler. This setup should work provided I can get the proper chain alignment..
I just want to have more options for hillclimbing and low speed crusing... Those motors barely use any power on the flats when cruising at high revs in low gear.
You'll need to log in to post.
