Looking for a trustworthy front hub motor

[khorse]

Hello there.

At the moment I've got a Cyclone 3000 mid drive that i've always been happy with, but circumstances mean I have to step down to something a bit more discreet. However, I still want to reuse my battery pack from the Cyclone build. It's 52V nominal, 58V fully charged.

The bike I'm looking to convert this time has a very narrow rear triangle with a full chain case on it, so I can't go with a rear hub or a mid drive. In fact the bottom bracket is nonstandard anyway, so I couldn't if I wanted. It also has rim brakes, and a nonstandard wheel diameter of 650A, so I'll be lacing up the wheel myself.

So, I'm looking for a front hub motor, 36 spoke, fits in 100mm dropouts, and not going to melt at 60V. Targeting a maximum speed of 20mph.

Anyone have any recommendations for a motor and a controller?

 

[JackFlorey]

Anyone have any recommendations for a motor and a controller?

For those specs the Grin solution (All-Axle motor, Phaserunner and Cycle Analyst) would work well. The All-Axle is a bit lighter than most direct drive hub motors out there for the power they put out.

 

[Chalo]

I can't think of a hub motor other than a special winding Leaf motor that would top out at 20 mph at 52V in a 26x1-3/8" wheel.

The 201 RPM version of the Q128 front hub would likely get you closest to that natural speed.

https://bmsbattery.com/motor/301-15723-q128-36v400w-500w-front-driving-v-brake-hub-motor-ebike-kit.html#/213-rpm-201

If you get a somewhat faster motor, like the Bafang front hub from JAG35 or Battery Clearing House, you can use a configurable controller and display to electronically limit the top speed. Those are designed to go about 20 mph on 36V.

It isn't voltage, but current that will cook your motor. Respect its limits and you'll be fine.

 

[MadRhino]

What makes a front wheel build trustworthy, is how good you fit and tune it. Most any motor will do, for you need to tune it low power enough so that your front wheel doesn’t risk loosing traction and wash you out. The fit must be strong and secured. Choose a robust fork.

Light weight low kv motor with matching programable controller. Lace with bicycle spokes. Use a sticky tire.

 

[khorse]

I should clarify. When I say "trustworthy", I mean not made of junk. I've come across people complaining that eg the Q128 has cheese grade gears, or such and such hub is has waterproofing issues... That's what I'm trying to avoid.

The Grin All-axle looks very impressive, but it's also $600 before controller, misc costs, and shipping to europe. Very indulgent for what is supposed to be a "just enough power" build.

I'm trying to find that sweet spot in pricing where I avoid something that will break, but don't pay for 1500+W capability i'll never use.

20mph is "i would like to reach this", not "i must never go faster than this", although a programmable controller would be nice - i've never bought one, so would like to hear a model recommendation.

 

[dogman dan]

Since you won't be using the crappy rim and spokes that come with them, any of the 1000w 48v kits have a motor you can count on. But don't get hung up on spoke number. Go with what the motor comes with. Should be 32 I think.

These are 500w rated DD motors, that can take 1500w with ease, or 3000w for 45 min. Used to be called 9 continent type, since they sold that particular brand in the US and CA a lot back in 2010. The kit will come with a controller you can use, but cheap enough to toss aside to use something better.

Yes, it can ingest some water vapor if you live where it rains almost daily. Then it can accumulate over time. If so, drill a few 1/8 inch holes in the cover. They will let in water but not much, which won't matter much because every time you run it the water vapor can get back out. Cooks dry every longer run. It will rust in a few years, but still run fine rusty as hell. If you like, tape over the holes, and just open them up for a good ride monthly.

In 26" wheel, they go 30 mph with the wind they typically use. (6t) Same type motor can be bought for more money, and more quality, but you should get many years from the cheap ass version too. You are just looking for 28 mm stator, DD motor.

Re brakes, most bikes like you have will have a steel fork, and the motors come with a disc mount. So you can very easily weld a disk caliper mount to the fork. With just coaster brakes, I do advise keeping it under 20 mph as much as possible.

 

[khorse]

Has to be 36 spokes, need to use westrick rims. Getting a 32 spoke rim would mean importing a 60 year old bike from england.

Looking at those 48V kits, they're all 260 euros, and I'd be paying for a tyre, rim, spokes, brake levers, and god knows what else I don't want, and they're all promising delivery times of 1 month, even though they're supposedly only in germany.

The ones listed as 500W 36V are much cheaper. Some as cheap as 170 euros. Is it ususally the same motor, but just with a different controller?

 

[Mclewis1]

So, I'm looking for a front hub motor, 36 spoke, fits in 100mm dropouts, and not going to melt at 60V. Targeting a maximum speed of 20mph. Anyone have any recommendations for a motor and a controller?

I've been using a Shengyi SX-1 (standard wind geared front hub) from Grin with a BaseRunner controller and a 52v battery for over a year and it's been bulletproof. It's on a steel frame Surly Bridge Club with 27.5" wheels (Grin built 36 spoke wheel) that is used as an all weather around town grocery getter/commuter. All in weight (me, bike with fenders, rack, panniers, etc.) is around 125kg.

The Cycle Analyst monitors the motor's internal temps (and I've never seen over 90°C) so I can climb hard (or run to 45kph on the flats) using up to 1000w for shorter periods of time. The motor axle fits very well in my steel front dropouts (I check their condition every month). After about 5000km the motor internals basically still look pristine.

 

[dogman dan]

I must be confused about spoke count. I thought most non racing bikes, like cruisers and mtb's are 32 spoke. Getting older and stupider day by day.

Whatever the common spoke count is for ordinary cheap motors is,, that's the rim you use. Don't get hung up on the rim for no good reason. Just select a good rim and spoke set, such as you can get from grin.

 

[khorse]

I must be confused about spoke count. I thought most non racing bikes, like cruisers and mtb's are 32 spoke. Getting older and stupider day by day.

Whatever the common spoke count is for ordinary cheap motors is,, that's the rim you use. Don't get hung up on the rim for no good reason. Just select a good rim and spoke set, such as you can get from grin.

Nah 36 is the normal amount, less than that is a weird choice. I counted the cheap kits, they're also 36 spoke.

as I said earlier, the bike is 650A. Rims of this size do not come in spoke counts other than 36 unless you take them from a bike more than half a century old. It's impossible to budge on this matter at all.

Luckily 36 seems to be standard for front hub motors. I was originally worried people would be doing 40 spoke or something.

 

[amberwolf]

There's a few options listed in this search
https://www.google.com/search?q=650A+32+hole+rims+-650B+-650C
though I don't know if they have them in stock or not. Or perhaps they all have the wrong size listed and they're not really 650A, if they're ones you've already found and tried.

Or I might be completely blind and reading the found pages all wrong--it's happened before.


However, regarding the hubmotors, virtually all of them I've seen are 36-hole. There have been some 32's posted about over the years, but I've never personally held one in my hands. So if you already have a 36hole rim for it (or are getting one, then you should be all set.

 

[khorse]

I actually wasn't aware the CR-18 came in 32 holes. Last time I looked I couldn't find them, in fact finding anyone selling aluminium rims this size was very difficult.

Anyway, I think I'm going to take a chance with the Q128. But what controller to use with a 52V battery? bmsbattery are selling a lot of very cheaply looking 36/48v controllers with absolutely no details about connector pinout or anything.

 

[Chalo]

I actually wasn't aware the CR-18 came in 32 holes. Last time I looked I couldn't find them, in fact finding anyone selling aluminium rims this size was very difficult.

If you're building your own wheel, that's a great opportunity to let go of the obsolete ISO 590 wheel size in favor of a much better supported size like 559 (MTB 26") or 584 (650B, 27.5", 26x1-1/2"). The latter option probably wouldn't even affect your brakes, except for needing to adjust the pads.

 

[khorse]

If I go to the shops here I can easily get a few different models of 650A street tyres. Cheap ones and also a couple different models of Shwalbes with good puncture protection. Tubes too. If I go to the same shops and look for 650B tyres, most of them don't have any. I can go to a shop that sells 650B mountain bikes, but then they want to sell me knobbly mountain bike tyres. If we go online then there are 650B street choices but 559 has less of everything every year.

So as far as I'm concerned 650B is obsolete for city riding and 650A is still the raining champion.

But really, enough talk about rims, tyre sizes, spoke counts, whatever. it's settled. What's actually important is what motor controller to choose for a Q128 and a 52V nominal (58V fully charged) battery. Let us please talk about that instead.

 

[Bigwheel]

Check out KT controllers and displays they seem to be popular and some will handle 52v and as you say 58v @ full charge.

 

[amberwolf]

Most stuff has no (or wrong) info about wiring/connectors, at best it's in a really bad translation of Chinese to English. Many people have posted threads over the years here to figure out how to connect stuff (even stuff that came as a "kit").

If you can get a "kit" of everything you need from the same place, especially if it has those Higo (or Julet) waterproof connectors, then it's very likely it will all just plug together and "work" (once any settings are setup in the controller, for those that have that sort of thing).

If you already have controls or wiring on the bike you'd rather reuse, you could still use the controllers that use these connectors, even if you have to cut them off, because those are typically standard wirings on the connectors, and thus easier to determine which connector does what and with which wires. (you shouldn't have to buy the kit of stuff to get just the controller (and display if needed)).


For a small motor like the Q128, you won't need a big controller. My guess is a 10A 6FET ore smaller would work for this; at 52v that's about 500w. If you want less, you'd get a lower current (A) controller.

For connectorizing/wiring, is the Q128 you're looking at one that comes with the Julet 9-pin waterproof connector? If so, then if you look for controllers that have the same one, they're probably already pin-compatible (and can be made so if they're not, with a little rewiring at the controller end where waterproofing is easier).

Do you need torque sensing? Or cadence PAS? Or just throttle control? (if it's in the thread I missed it, and if so I apologize).


One suggestion:

KT (KunTeng) controllers and LS (LiShui) controllers can usually use a display to set them up (and change functions while riding), and come in some very small sizes (almost as small as a hefty pack of cigarettes, in some cases, not counting the wiring/connectors). They also have open-source firmware projects here on the forums that can give them much more capability / features than stock, and some of them may come preprogrammed with versions of that but most won't and would have to be setup by you.

 

[khorse]

It's just going to be a thumb throttle for now, and maybe I'll think about PAS later down the line. I don't really like PAS as the bikes we use at work have a lot of lag and are very jumpy with it.

https://bmsbattery.com/motor/397-15947-q128-48v400w-500w-front-driving-v-brake-hub-motor-ebike-kit.html#/213-rpm-201

I think that's the 9 pin connector you mention. The photos have it covered with a protective cap though.

 

[amberwolf]

PAS operation has many ways it can operate, it's dependent on the hardware used and the way that hardware is setup in some cases. There's typical cheap PAS, and then there's good PAS (which can be cadence or torque based, but even cadence-only can be almost as good as a great torque setup).


All the common cheap stuff I've seen typically takes a significant amount of crank rotation to begin operation, and the same time (or longer!) to stop after ceasing pedalling. Also, it can't control the amount of assist, it just turns it on and off, at the level the hardware is set for (or what the user chose on the controls).

But there are other ways--some systems actually let you control the power with the pedalling, not just on/off, even with just cadence-style PAS (not torque sensing).

Or you can use the Cycle Analyst v3.x to add cadence (or torque) PAS to any controller that has a throttle input that does not also require it's own PAS control to operate (some do). This is how I operate the SB Cruiser trike, with cadence-PAS control.



This is the common Julet motor connector; I see this on a lot of small motors:

 

[999zip999]

Maybe you should start with a different bike with steel front fork and a 559 tire. Bikes here in the USA are good used chrome-moly steel bikes from $50 to 100usd all day long.. This may make it easier to start with.

 

[khorse]

Maybe you should start with a different bike with steel front fork and a 559 tire. Bikes here in the USA are good used chrome-moly steel bikes from $50 to 100usd all day long.. This may make it easier to start with.

I already have a cromoly mountain bike with 559 rims and a cyclone motor. Why would I want to build a second, identical bike?

I have this nice Raleigh Superbe which I enjoy very much and would like to be able to ride long distances without getting tired. There are no kits for it's wheel size, so I asked what hub motors and controllers people think are reliable.

At no point did I ask anyone if I should switch to mountain bikes, or their opinion on wheel sizes, or anything else.

 

[999zip999]

I understand your love for this particular bike but it does not match up with any kits on the market for easy installation you're causing yourself a lot of extra work and money by being stuck on this bike.By the time you get custom spokes a separate controller than a throttle than a display. Lot's of time and trouble. Unless you need a indoor hobby for the winter. and can wait to spring to ride it. As I build three wheels with motors and it takes a learning curve for that
I was just trying to let you know there are easier ways to your madness.

 

[khorse]

You have a strong opinion on the difficulty I'll face with this project, despite the fact that you

1) know nothing about the bike.
2) know nothing about the things I can do.
3) have made no attempt to rectify 1 and 2.

Why form strong opinions about things you know nothing? It has caused you to come into a thread about building a bike I want, and start telling me to build a bike that I don't want, but that you do. It's just not relevant to the thread or interesting to me what kind of bike you want, or that you personally struggle to build wheels, or whatever.

In the words of a famous chinese leader:

"When you have not probed into a problem, into the present facts and its past history, and know nothing of its essentials, whatever you say about it will undoubtedly be nonsense."

 

[999zip999]

Good luck and let us know when you start and when you finish.

 

[electric_nz]

Bafang geared hubs are OEM on a lot of factory ebikes and are very conservatively rated- generally perfectly happy at double nameplate watts. I’m running an old bpm 500w front hub at 52V with a KT 20A sensorless controller at 1000W and it barely gets warm.

 

[BKGuy]

Battery clearing house dot com does have a bafamg geared hub 36 spoke for $23 . I got the one in the wheel .. same one as jag but I got from bch and I run a 52v 22 amp controller on it. Top speed is 25 mph. So far no troubles and I do take it easy because if I don't it spins the front tire and pulls 1800 watts. I do use 2 torque arms. I have another hooked up to a kt36-72 controller 11 amps. Have not put on a bike only on a clamp on the bench but it works fine and the smallet controller should make it more tame.

For 23 bucks how can you go wrong. Bafang. All metal enclosure.
Did I mention its 23 bucks?