Is there a "best" cheapo ebike build kit?

[markz]

I'd pay $50 for the frame of an expensive oem ebike thats been stored away and battery now needs replacement.
I just love some of the bikes looks, but I know you couldnt do anything with their 500W mid drive motors, even if you could hack into them, they would probably still be only good for 1kw at max would you say? Theres got to be some lee-way, some safety factor built in to their expensive price tag.

Chalo - Whatever happened to that red Specialized ebike you got into the bike shop years ago, did you just scrap it or did you find a way to fix it?

 

[VictorNYC]

Just buy the $40 rental hubs, a $30 controller, $5 throttle and figure out your battery

Any leads on cheap rear rental hubs? I could use a coupe if anyone knows about any deals out there

Most dockless rental bikes don't use them. At their relevant power levels, there's really no advantage to a rear hub, only disadvantages. Maybe you should try front hubs and see.

That's true, and I might get one of those hubs to lace it on a fixie since I already have a baserunner Z9 I can discreetly discreetly mount behind the pack for a clean install but I use ebikes for work (Uber,GH,DD) and I find the rear hubs a little easier to control on bad weather days (snow,rain, etc) hence my interest

 

[Manbeer]

Just buy the $40 rental hubs, a $30 controller, $5 throttle and figure out your battery.

Didn't know I could get a wheel that cheaply. If this is just the hub, I don't know that it would save all that much once I buy a rim, spokes, and nipples, though. But maybe it would still. Hmm...

The surplus Jump bike hubs come built into a 26" wheel with tube, tire, disc brake rotor, and usually the brake caliper too. It's all used and its condition is variable. The rim can be a hassle to use with rim brakes.

https://jag35.com/collections/e-bike/products/26-bafang-36v-dc-electric-bike-wheel-tire-w-tektro-disk-break

https://www.batteryclearinghouse.com/products/26-bafang-dc36v-sturmey-archer-rx-rd3-electric-bike-wheel-with-tire-brake

This one is brand new, but it's a smaller hub with a Shimano roller brake spline instead of a disc mount:

https://www.ebay.com/itm/363559221130

That wheel you posted with the roller brake mount is interesting. Looks like the rim has good potential for braking but won't it be all sorts of odd because of the spacing for the roller brake? trying to figure out how it would center in the forks or if i would have to dish it almost like a rear wheel where its offset

 

[Chalo]

That wheel you posted with the roller brake mount is interesting. Looks like the rim has good potential for braking but won't it be all sorts of odd because of the spacing for the roller brake? trying to figure out how it would center in the forks or if i would have to dish it almost like a rear wheel where its offset

It has the same rim as the disc braked versions, which is difficult but not impossible to use with rim brakes. It would be better with caliper or U-brakes than with cantilever or V-brakes.

The hub has significant lateral offset, which can be mitigated somewhat by lacing all the spokes on the left side of the flange. I would do that even if were using the same spokes and rim the wheel came with. But I'd rather replace the rim with a proper rim brake compatible one, and replace the 13ga spokes with 14-15ga spokes.

https://bafang-e.com/en/oem-area/components/component/motor/fm-g320250r/

 

[Manbeer]

That wheel you posted with the roller brake mount is interesting. Looks like the rim has good potential for braking but won't it be all sorts of odd because of the spacing for the roller brake? trying to figure out how it would center in the forks or if i would have to dish it almost like a rear wheel where its offset

It has the same rim as the disc braked versions, which is difficult but not impossible to use with rim brakes. It would be better with caliper or U-brakes than with cantilever or V-brakes.

The hub has significant lateral offset, which can be mitigated somewhat by lacing all the spokes on the left side of the flange. I would do that even if were using the same spokes and rim the wheel came with. But I'd rather replace the rim with a proper rim brake compatible one, and replace the 13ga spokes with 14-15ga spokes.

https://bafang-e.com/en/oem-area/components/component/motor/fm-g320250r/

OK cool, thanks for clarifying there. Looks like I may be better off with the larger version of the motor since I would end up doing the work anyway. Actually I was just looking and I may be better off drop shipping the motors to JBI And Having them lace The wheels for my fleet bikes As the cost ends up being nothing much more than me getting the parts and doing it myself.

 

[Chalo]

Looks like I may be better off with the larger version of the motor since I would end up doing the work anyway. Actually I was just looking and I may be better off drop shipping the motors to JBI And Having them lace The wheels for my fleet bikes

Note that the hub holes are oversized, so JBI would either have to add spoke head washers, or else use 13ga spokes (if they have appropriate lengths). In either case that might cost you extra. If it's thick spokes, it will continue to cost the fleet operator more in maintenance.

 

[Electric Earth]

Thanks everyone for the conversation. I’m still reading along.
As mentioned by someone else, I’m interested in the rear drive mostly due to the weather. The last thing I want is a front drive wheel spinning out in the snow mid-turn.
I need to read up more to confirm, but it seems like I can run 52v battery on a 48v 1,000 watt kit and get at least 30mph with decent acceleration.

…a store bought "oem" ebike, or an online ready to ride ebike. But really, suggest it once and move on, really. :wink:

Especially when the OP asked about doing a build, and then specifically (nicely ) turned down the OEM idea. Maybe let the thread continue with kits rather than push to derail it. I’m interested in doing a build, which I’ll enjoy, and will get a better result for my ~$550 vs. a cheap, crappy, sub$1,000 OEM bike with less power.

 

[ebike4healthandfitness]

Especially when the OP asked about doing a build, and then specifically (nicely ) turned down the OEM idea.

You originally turned down the OEM bike idea because you thought it would cost $1200 on sale. Furthermore you never mentioned ( until the post above this one) you wanted at least 30 mph and 1000+ watts.

P.S. I would not cheap out on the battery pack. It would also be wise to choose a pack.with decent continous amp headroom over what the controller in the 1000 watt kit is rated at. (The 1500 watt kit comes with a 35 amp controller, not sure what the 1000 watt kit comes with). Otherwise this moped you are building (it's a moped you are creating, not an ebike) may not be safe.

 

[Chalo]

As mentioned by someone else, I’m interested in the rear drive mostly due to the weather. The last thing I want is a front drive wheel spinning out in the snow mid-turn.

Keep in mind that a skidding unpowered front wheel goes sideways, but a spinning powered front wheel still pulls in the direction you point it. As a lifelong cyclist, front spinouts scared the crap out of me at first, but I soon figured out they were no big deal. I have yet to fall due to a powered front wheel losing traction. I'm on my third front hub motor bike.

 

[99t4]

I use ebikes for work (Uber,GH,DD) and I find the rear hubs a little easier to control on bad weather days (snow,rain, etc) hence my interest

I thought all you NYC guys ran Arrows? No? :?

 

[ebike4healthandfitness]

I use ebikes for work (Uber,GH,DD) and I find the rear hubs a little easier to control on bad weather days (snow,rain, etc) hence my interest

I thought all you NYC guys ran Arrows? No? :?

All the Arrows I have seen in pictures have rear hub motors.

 

[dogman dan]

I found front hub traction problems were only a big problem if you are on steep hills. On the flat, front hub power skids are fun in dirt. You do have to ride with some sense of course, like not applying full throttle in a corner on snow, wet leaves, mud puddle.

But I also digress from the intended discussion here. Buy the cheapo rear hub 48v 1000w kit that is in stock, and ships from the USA. No particular cheapo kit that is better than the other. They all use cheap controllers, and crappy rims and spokes.

Tune the wheel before you ride it, then tune it again after you ride a few miles, and again after 50 miles or so. Then the crap spokes have a good chance to survive unless you weigh a lot more than 250. If the cheapo controller blows in 6 months, cheapo controllers are cheap. You can keep a cheapo wheel going for an incredibly long time, if you don't just go beat it to death riding around with loose and broken spokes.

 

[markz]

Ride the laced wheel until it starts breaking then relace into quality spokes and a good rim.

I love front hubs, only because I get far less flats and spoke breakage, and I can roll with a front hub with 4 missing spokes, and wobble and had been doing so for months. Do that on a rear, for me, days it will take, days.

Front hubs, rain and puddles, ice, frost and dirt gotta be careful and more so if your using ebrakes/regen braking.

Its always nice to give options out there, oem has their place [deleted]
Good to give people options who might not otherwise surf the other threads, but mention it and move on as I said in my post.

 

[ebike4healthandfitness]

If these kits come with zinc plated carbon steel spokes (and probably some less than ideal nipple material (i.e. not brass) I think it would be better not to buy the ebay kit and instead make your own kit......since you are so absolutely determined to build a bike from a kit. (In your home built kit use stainless steel spokes for strength and corrosion resistance, buy a better controller, etc).

These cheap kits are a bad idea for moped level power.....especially moped level power in the snow (where corrosion will be an issue).

I am concerned about your safety.

 

[markz]

Mind you Austin Texas is hot year round, no ice, no snow, no frost, no problems..... other then thorns if I am not mistaken.
Just water, mud and loose materials (gravel, sand)
I to love front hub motors as I get less flats.
If I may ask, why do you go front hub motor. If my memory serves me right, you do cargo bikes so front hub is easy to install. Have you ever done rear hub?

Keep in mind that a skidding unpowered front wheel goes sideways, but a spinning powered front wheel still pulls in the direction you point it. As a lifelong cyclist, front spinouts scared the crap out of me at first, but I soon figured out they were no big deal. I have yet to fall due to a powered front wheel losing traction. I'm on my third front hub motor bike.

 

[LewTwo]

Mind you Austin Texas is hot year round, no ice, no snow, no frost, no problems ....

Most years ... Texas had a bit of an exception this year

 

[markz]

Yeah well even Mexico gets snow once in a blue moon.
https://www.buzzfeed.com/aliciabarron/a-mexican-city-was-covered-in-several-feet-of-ice-after-a
I wasnt thinking 2019, was thinking more like 80's or something, mexico city.
1967 and 1940 Google says for Mex City.

Mind you Austin Texas is hot year round, no ice, no snow, no frost, no problems ....

Most years ... Texas had a bit of an exception this year

 

[dogman dan]

I don't think anybody is suggesting a front hub would be great for riding where its snowy and icy on the road for 6 months of the year. But it can be done. You just aren't power sliding through corners in those conditions with front or rear hub. But if you live where studded tires are required, its not ruling out front hubs.

On dry pavement corners, or at least not too wet and muddy or slushy, having the front hub pulling, pedaling to push with the rear, is a good feeling, 2wd. But again, with only enough push on both ends to make traction, not break it. Not saying go power slide an icy corner. Lots of folks farther north love a tadpole trike for winter. Makes some sense.

Its riding up curbs, staircases, steep rocky trails, where rear hub gets easier to ride. But any street bike can be ridden fine with front hub. I just saw my front tires wear out a bit faster, because of spin on loose sand at stop signs.

 

[VictorNYC]

I use ebikes for work (Uber,GH,DD) and I find the rear hubs a little easier to control on bad weather days (snow,rain, etc) hence my interest

I thought all you NYC guys ran Arrows? No? :?

They are basically black holes that only became popular due to how easy it is to find parts and service for them, but they are not worth it, to give you an example let's focus on the controller: Most Asian bike shops will charge you about $60 dollars (36v) $75 dollars (48v) + Service for a super cheap, non weather proofed basic controller (around $5) that's gonna die out on you 2/3 times a year. Batteries? Silverfish Chinese cells sold as Samsung. CA? Same. Motor? They all buy whatever it's cheaper regardless of brand sooo not much better, their business model it's keeping you in the shop spending, and since most users cant even replace their own break pads it's a consistent base, the bikes are not necessarily cheap anymore (around $1,500) so at that point you are better off with Rad bikes or anything similar that will give you slightly better and upgradable parts (but not designed for work) The only upside it's being able to get your bike fixed and up and running in a couple of hours but.... After a while you learn that nothing beats diy

 

[ben2401]

I'm about to build another ebike. I figure a cheapo kit where I can take the battery off and leave the bike in the bike shed is my best bet. I can't bring the bike into my new apartment, and I just want something to jump on, push a throttle, and be to work in 10 minutes a couple miles away when it's shitty, windy, and bitter cold(WI) and I don't feel like really riding. I could build on a 26" bike that I can likely source for free, or a 650b wheeled Schwinn "mountain bike" from a box store that I found next to a dumpster this past summer.

Will one of the cheapo kits survive the cold of staying in a small bike shed for the winter? Will wiring, throttle, or LCD likely be an issue?

Also, I can't remember the website I ordered the battery from last time. Any thoughts on where to look for a cheap battery pack?

Best worthwhile entry level brand new kit? CSC on Aliexpress builds nice kits at great prices with KT controllers and displays (best entry level controllers and displays with a wealth of troubleshooting info because they are widely used and easy to set up, also have an open source firmware project with a 200 page thread here). Their higher power kits use the “leafbike” 1500W/1000W motors with 28mm/35mm stators and 0.35mm laminations. They offer a very strong SunRingle MTX rim for not much more. It’s a nice wheel (wish they used 14 gauge Sapim spokes but fine otherwise).

The leaf bike kits look nice too with the Mavic rim.

There are cheaper deals out there if you’re willing to search for them and be creative as others have posted. Below the level of KT controllers you mostly have unreliable junk with no documentation. Some may be fine but good luck finding a schematic or info on how to fix them or set them up.

 

[ebike4healthandfitness]

What do people suggest for a safe battery?

I am assuming the 1000 watt kit will come with at least a 25 amp controller.

And yet he only needs to ride 4 miles per day ( 2 miles each way to and from work).

So he needs a battery with high discharge cells not capacity cells.

 

[ben2401]

What do people suggest for a safe battery?

I am assuming the 1000 watt kit will come with at least a 25 amp controller.

And yet he only needs to ride 4 miles per day ( 2 miles each way to and from work).

So he needs a battery with high discharge cells not capacity cells.

Bare minimum a 13s3p if using higher quality cells. I ran my 1500W (actually ~2000W because 45A x 48V is 2160W) at 50% max current (lowest setting) with a generic 13s3p Aliexpress 7.8Ah/2600mAh cell pack at first before I bought a second identical pack to run at full current in parallel. Had about 15-20km range if taking it easy. I run my other bike at 50% current (1000W) with a 13s4p 12Ah/3000mAh cell pack. About 30km. Get the best pack you can afford basically. Most cells if you have the space (for current discharge capacity) and better quality if not or you want to keep the bike light.

 

[LewTwo]

What do people suggest for a safe battery?

LiFePO4

 

[99t4]

I use ebikes for work (Uber,GH,DD) and I find the rear hubs a little easier to control on bad weather days (snow,rain, etc) hence my interest

I thought all you NYC guys ran Arrows? No? :?

They are basically black holes that only became popular due to how easy it is to find parts and service for them, but they are not worth it, to give you an example let's focus on the controller: Most Asian bike shops will charge you about $60 dollars (36v) $75 dollars (48v) + Service for a super cheap, non weather proofed basic controller (around $5) that's gonna die out on you 2/3 times a year. Batteries? Silverfish Chinese cells sold as Samsung. CA? Same. Motor? They all buy whatever it's cheaper regardless of brand sooo not much better, their business model it's keeping you in the shop spending, and since most users cant even replace their own break pads it's a consistent base, the bikes are not necessarily cheap anymore (around $1,500) so at that point you are better off with Rad bikes or anything similar that will give you slightly better and upgradable parts (but not designed for work) The only upside it's being able to get your bike fixed and up and running in a couple of hours but.... After a while you learn that nothing beats diy

Thanks for your helpful description. I had figured they had reached a critical mass to support a local specialized support system (many local shops stocking spare parts, and ability to offer while-you-wait repairs) but did not realize the extreme fragility of the batteries and controllers.

Main reason I was curious is because one of my kids (starting out living independently) is currently living NYC adjacent and wants an ebike for transportation. I had found $1200 Arrow-type bike for pickup in Brooklyn on ebay and thought at least the local repair infrastructure would be a benefit for when problems arise, but upon learning about the crappy controller and battery and business practice plan of nickle-and-dime you to death are not very appealing.

 

[VictorNYC]

Don't pay 1200 dollars for it, you don't see many of those used by regular ppl, meaning that battery pack is probably depleted, and those packs are not the safest to begin with, I had one literally melt a few years ago, for much less you can build him something very similar with a much safer new battery, or something much nicer for about the same (depending on what kinda frame you get) and it's winter now, bikes and parts get a little more frequent and cheaper in NYC, with a little luck you two could build something very nice for just a little more.