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Comment by beefield | Hacker News Reader

What we really need is ebike standards for the components. You should be able to use motors, batteries and contollers from any brand interchangeably on your bike.

It is atrocious that you buy a bike worth an decent used car and you cant't expect the electric motor last more than a few thousand kilometers [1], after which you have a broken black box of an motor in you hands that you need to replace, not fix. Which, if you are out of warranty costs close to a thousand bucks. And it is a damn 250w electric motor.

[1] google shimano e7000 longevity

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That’s the reason why I built my ebike around a regular bicycle and an tsdz2 motor. It even has a FOSS firmware written by a very dedicated guy in Portugal. You can use a variety of displays with it, any battery pretty much, standard bicycle parts of course because it’s just whatever bicycle you started off with, and last I checked there was even a project to build a Garmin interface.

On the downside, it’s more work, you have to repair the motor yourself when it breaks, and it’s peak Chinese engineering where tolerances can be quite approximate along with barely good enough materials. But it’s also part of the fun (for me) and I’ve put 2700km on it in three years of (very hilly) terrain; still works well.

Do you mind providing a link with more info on how to build one?

It's incredibly simple. If you can change a crank and plug in some wires you can install one.

Buy tzd2. Undo bottom bracket. Put motor there. Screw battery on to carrier or bottle holder.

The only hard bit is finding a trustworthy local shop to buy a 36V or 48V battery.

May not be compatible with weird frame shapes, weird mountain bike frames, or proprietary nonsense from Trek or Giant.

Here: https://github.com/OpenSourceEBike/TSDZ2_wiki/wiki

You can also ask questions here: https://endless-sphere.com/sphere/threads/tsdz2-mid-drive-wi...

The gist is to get a semi recent hybrid or mountain bike (because they have standard bottom brackets) and swap it for the motor.

The battery mounts on the frame where the water bottle typically goes. To flash the firmware you’ll need to build a cable with a STM bluepill.

I wanted a quality battery that wouldn’t start a fire so I got mine from em3ev but if you like gambling it will also work with any Chinese special from aliexpress or eBay or whatever.

The 48V motor will also work with a 52V battery (that’s what I use) after flashing it to open source.

It’s not super difficult and you’ll learn how to maintain bicycles in the process. If you’ve never done it before, take your time and ask questions on the endless sphere thread. Checkout YouTube videos as well for anything you’re unsure about, you’re bound to find a good howto from channels like park tool or syd fixes bikes.

Also note that several us and Canadian cities have community bike workshops where they’ll help you do anything to your bicycle by explaining you how to do it and letting you use their tools to do it. I knew nothing about bicycles but after going there regularly to rebuild my first acoustic bike, I’m now very comfortable doing almost anything myself at home on my own (with YT or the blue book of bicycle repair as a reference)

It’s fun and very rewarding, I strongly encourage you to give it a go!

Hopefully, there will be businesses that will specialize in this, it's not difficult to guarantee spare parts.. It's a bike.

Ya gotta wonder to what degree right-to-repair laws are covering e-bikes (if at all).

Same for electric cars and err... pretty much everything for that matter. Bike parts are pretty standardized for the most part, things like tires, cables, handles and gear shifters.

But it's BiG gOvErNmEnT and some people object to that.

Bike parts are, afaik, not standardized at all. It's just that there are like two companies producing 90% of the components, so that there aren't so many different systems on the market.

> Bike parts are, afaik, not standardized at all. It's just that there are like two companies producing 90% of the components, so that there aren't so many different systems on the market.

Both of these statements aren't really true.

There are lots of bike standards (both in the XKCD sense and sometimes in a few-enough-to-be-practical sense). Not everything is made with standard parts, but the majority of parts on the majority of bikes are. This has little to do with Shimano/SRAM being the two major groupset manufacturers -- components like steerers (standard 1-1/8" at the stem), stems (made by several manufacturers, not two), handlebars (there are several standards for the clamp diameter but 31.8mm and 35mm are probably the dominant two today), bottom brackets (again, several standards, but lots of vendors in this space), etc etc. Handlebars, wheels, chains, pedals, tires are more or less all made to a handful of interchangeable standards, by many manufacturers.

I'm not sure that's practical, but I think there are certain regulatory things one could do. Like requiring that especially ebike motors can be repaired, that parts are available and fairly priced, that any software needed to service bikes is made available to repair shops at decent prices etc.

I don't think you really want heavily standardized components across brands since it limits innovation and forces lowest common denominator solutions. You want repairability.

I choose cars, motorcycles, ebikes based on whether there is a decent repair shop nearby. Because stuff will wear out and break. You will have to get work done. And when that happens you want someone who makes an honest effort rather than some junior mechanic who will just follow the standard repair procedure no matter what. (Don't get me started on how poorly qualified brand-affiliated car workshops often are)

> You should be able to use motors, batteries and contollers from any brand interchangeably on your bike.

There is no way this (one standard for everything) will happen, because it doesn't work like this either in the car industry or in the bike industry. That said, the number of standards in bike industry is somehow manageable I think, and for some bike types (like road bikes) you can build a completely standard bike with every component easily interchangeable. However this is not the case for the motors and batteries. The price of the components is a different issue still.

> because it doesn't work like this either in the car industry or in the bike industry

This is... not entirely true, there's heaps of standardized components in both industries. Think batteries, brake pads / brakes, springs, all the nuts and bolts, the OBD port, tires/wheels, airbags / seatbelts, and on the bike side, think cables, saddles (saddle pins), tires/wheels again, gears, pedals, etc etc.

While you probably can't fully repair one car with the other, there's plenty that has been standardized by the industry and legislation.

Yeah but there are several standards for each component. Like for bikes (which I understand more) there are the 622mm wheels (700c - 28" but also 29" which is confusingly the same rim diameter but wider rim), 635mm wheels, and then 26", 27.5", 24", 20" and some smaller ones. Not sure what size wheels are used on fat bikes... And then you have QR axles and thru-axles in 100mm, 130mm, 135mm, 142mm and 148mm sizes and some other and usually 15mm or 12mm diameters (except the QRs that are 5 or 9mm). Equipped with either rim or disc brakes, for each brake type the rear (and sometimes front too) axle size will probably be different. Then the rear wheel has a freewheel on which the cassette is fastened unless you use a internal gear hub (like Rohloff).. so the freewheel is one of I think 2-3 different Sram types, 2-3 Shimano ones, 1-2 Campagnolo and maybe some other. And so on. So there are certainly standards. Lots of them.

Many standards would be fine (and to be clear, very much needed). They just would need to be open so that a third party manufacturer can build a motor or a battery that they can just plug in to the system.

Yes that would be great, but instead what is happenning is that with each new electronic component the system is closed down further. With the increasing popularity of wireless shifting (Di2/eTap) and e-bikes this will only get worse I'm afraid. I don't even know if we can realistically hope for some sensible regulation.

We don't need every part to work in every bike, but we do need a few parts like the small-block Chevy V8: reliable, well-built, and reasonably easy to kludge into just about any donor vehicle.

Are Bafang kits still a good deal for bike conversions?

Wheel and bottom-bracket mount mid drive motors are quite standard.

Companies like Bafang and Tongsheng (not just these) sell motors that can go on any normal frame or in any normal (sufficiently strong) wheel and are compatible with standard drivetrain components. They accept and 36V or 48V (or anything 24-56V with some software tweaking and possibly lower power) power source.

It is not too late to have standards here, we just have to stop buying the shimano, bosch and yamaha nonsense (even if they are technically a little better right now).

I did google that. Seems like a few people complaining about lemons or not realizing a bike needs maintainance (chain/cassette swaps etc) and otherwise basically fine? In any case that's an eMTB part so you'd expect more trouble than something regular, just like how MTBs are way higher maintainance than road in every way.

Your general point is good but it sounds like you had a bad experience and are generalizing. And how would you already be out of warranty after a few thousand km, doesn't add up.

Shimano warranty is 2 years. I'm close to a small rental operation, and they had 3 out of eight motors blown within the first 2 years. 1500-6000 km on the odo.

Absolutely not. There has been so much innovation and improvement in batteries and motors in the past 5 years. Some kind of interoperability regulation would have completely wrecked that.

Coyld you elaborate what development happened in the last 5 years that would not have happened if it was required that your battery/motor fits into one of handful standard brackets and talks (at least) standard messages?

for this reason I converted a bike myself - much more repairble

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