Bafang 750 Watt, Integrated Wheel, Rear Hub Fat Bike Motor

[AHicks]

My thought is, that with 360 miles on the clock, you are just now starting to get the hang of riding the bike efficiently, while balancing your speed, pedaling effort/PAS level, use of the throttle, what gear you are in, etc. There's a lot going on here!

The idea of riding a 20mph may even get old after a while. Just dropping down to 15mph will make quite a difference in your range.

 

[Bravesst]

Today's ride was a bit Zen-ish in that respect. For the most part everything is flat on Long Island, so I'm basically able to stay in the top two gears, and just feather the throttle if necessary to get going. I can leave in PA 2, 3, 4 and add throttle manually, or just drop into 5 and long smooth straight aways. Yes... getting the hang of efficient riding. I can even pure throttle at lower speeds and watt usage is still incredibly low. I really do think the big chainring has made a big difference for what cadence I find comfortable.

 

[AHicks]

Just for comparison, on my most frequent rides I use the throttle just to get me moving, and across one short stretch of grass I must cross to get to the trail system in the park. From there, I'm generally pedaling along at 10-12mph in 3rd, 4th, or 5th, using PAS 1 (consuming 75-95 watts) or if I end up riding into a stiff breeze, we'll bump it up to PAS 2 (consuming about twice what I do in PAS 1). This yields a pretty easy 35 mile range with a 14.5Ah battery.

 

[harryS]

" Another possibly silly question. What does it involve building one yourself? I have a great source for 18650's and pretty good soldering skills. "

It also involves spending $200+ for a spot welder. Unless you plan to build packs for friends who sign waivers that they won't sue you, it's something to avoid.

 

[Bravesst]

@Timpo @AHicks
I've seen that one, yes, different cradle. If I want to run both batts, I have to have same cradle. Also, I will potentially have 29 amps if I carry both units. I'll make sure I get the charger.

Today's ride, about 20 miles, again flat and paved, hardly any wind. I kept PA in 2, 3, or 4 and used the throttle to avg about 18. I mixed this in with some 12 to 15 mph cruising with very little watt usage (100 ish) Used two plus bars. I do see the battery indicator drop if watt usage goes way up. It does recover. A full battery won't drop like that.

I am in gears 5,6 and 7. If I barreling along, I leave in 7, and just throttle up to speed for a few seconds after slowing down.

FYI: new controller has shipped, now I need to make that 52v battery purchase. Wife is having a fit at my new *hobby*...

 

[AHicks]

Just get her one - using a lot of input from her...... That'll cure that issue, AND give you somebody to go riding with occasionally.

My first bike was built using a 20Ah battery with the idea I could go on big all day rides. In practice, what I found is that despite my enthusiasm, my butt only had a range of 20 miles. It was at that point I figured the next bike would have a lighter battery with the BUTT's range in mind.....

 

[AHicks]

Have you considered getting a new saddle? My stock saddle was so bad so I had to get a different one..

Off topic for sure. I'm currently using the biggest Cloud 9 and a pretty decent suspension seat post set to ride about 1/3 travel with my weight on it. Nice, but it didn't increase my butt's range by 1 mile.

 

[Bravesst]

Funny, I've been looking at saddles... for my bike probably more of a motorcycle or minibike seat. I've seen some nice hump back, but hard to tell if anything but most expensive motorcycle seats (near $400) seem inferior to the one already on the bike.

Just made my 52 / 14 purchase. Thanks gentlemen for the great advice. The controller from PSW is in the mail, and this battery should be here by middle of June. I'm looking forward to more power, control, distance, and overall enjoyment. I'll keep you posted.

 

[Bravesst]

I just checked on tracking for both my new PSW controller, and AliExpress 52 / 14 battery. Nothing just yet, but I'm so looking forward to both, and doing this upgrade. I can't wait to see what this 750 watt motor can do with better programming and a bit more power.

The *butt* factor is also very important (as I'm learning). My bike comes with the mini hump saddle, actually not bad, but I ran across something on ebay that impressed me (after much searching). Seems to have lots of cushion and a little wider. Might be a bit of an improvement, and under $40. It's considered a *cafe racer* saddle, and hopefully modifying it to fit shouldn't be a problem.

I also need some good second battery storage, was considering mounting it to the down tube water bottle connector, and just not connecting it, but I would rather protect it. Any thoughts?

 

[Bravesst]

That was quick!
A package from PSW arrived today. I took a peek at the bike to see if this will be doable or not. The controller won't fit into the welded housing for the original. I can probably figure how to mount it somehow once I get it all apart.

The LCD plugs in, I can even run the bike, make changes to basic settings, but it doesn't display MPH. I'm assuming it only works with the new controller. I am able to get into a settings screen with all sorts of information. I was able to change mph / wheel dia / metric, but i'm still topping out at 21. This is all still on the 48 v battery.

Without disconnecting much, I was able to unplug a wire from the controller to try and match the wires on the new controller. I couldn't find a match, and I'm sure that's not a good sign. I'll give thorough look tomorrow. I will also take some pictures of my plugs.

Might it be possible to reprogram the old controller with the new LCD?

 

[AHicks]

Regarding the mph not reading, you're going to need a speed sensor. They're cheap and easy to install. It amounts to a magnet mounted to a spoke, and a sensor to pick up the magnet signal each time the tire turns.

You can set it up to register speed without one, but it's going to go to 0 when coasting because the motor stops turning when there's no power going to it.

Regarding reprogramming the original controller, anything is possible, but generally KT controllers and displays work only with KT equipment. Nothing saying your OEM controller isn't a rebadged KT though.....

 

[Bravesst]

@AHicks
I don't think it's a rebadged KT. It's a bit smaller, and I don't think it will fit into the welded on compartment. My concern is the plugs seem different. So if that's the case, is splicing possible?

I am going to get my shop together today. Been *collecting* tools, now I have to transition the space. I picked up one of those ceiling hoists to use as a work stand, and will mount that today. It will also function as storage for the dead of winter.

Maybe I'll even get in a ride...

Been watching some *juiced* controller upgrade videos. The juiced set up seems very similar, except the housing for the controller is screwed on vs welded.

 

[Bravesst]

Set up space in my wood shop for a bike shop. I bought one of those kayak hoists, but bike too heavy for it. I do have a kind of jack stand / tripod I use for woodworking that I built an adapter for, and even though I have to lift the 80 lb bike, it's a good working height, and pretty stable. Set the shop up pretty nice.

So the connectors seem to be different. I believe these two are battery (bottom) and possible PA.

New controller

 

[AHicks]

I hope the fact these connectors being different are no surprise? It's what I was talking about when mentioning they'd need to be matched. And don't plan on just matching the colors on each side of the connector up. If they match, fine, but you pretty much need to confirm each.

That 2 wire yellow (battery) connector is an XT 60 or 90. They're pretty popular and available from a lot of places.

The top pic is too blurred to be of much help.

 

[harryS]

Does your current controller use an IT05 harness? You would have gotten that plus the brakes, and throottle for an extra 17 bucks. The display they sell woiuld have also fit.

36V/48V 1000W 35A 12Mosfet XT60 Waterproof Sinewave ebike Electric bicycle Brushless Controller fit bafang MXUS motor - PSWPOWER.com

www.pswpower.com

If the top picture was your current 9 pin motor cable, the above kit has verbage telling you not to buy this model.

 

[Bravesst]

@AHicks No surprise, just wishful thinking.
Sorry for the blurry pics. I got the harness, brakes, throttle, display. I paid for everything they offered.

36V/48V 1000W 35A 12Mosfet XT60 Waterproof Sinewave ebike Electric bicycle Brushless Controller fit bafang MXUS motor LCD/LED:KT-LCD8H 1TO5 Cable and throttle and Brake system:1TO5 Cable and BF-thumb throttle and BF-Brake grip Lamp and PAS:with KT-QD236 and KT-V6-waterproof * Note:This is 750W sensor controller, so controller has special Big 9 pin waterproof connector. you motor must be have special Big waterproof connector,If you motor has normal 9PIN waterproof,please do not buy this controller* I guess I don't have that connector. So where do you source these connectors? And, what is the process of splicing them in?

 

[AHicks]

I'm a little confused.
Are we talking about just the motor connector? You're OK on the rest?

How many wires are on the motor? Should be 8 or 9.

Are there just the 3 on the new controller motor plug, like you show in your pic? I ask this as the link you provided says it's a "sensor" type controller, which means it SHOULD have 8 or 9 wires!

If both sides have the right amount of wires, I would remove the plug from the old controller and splice that on to the new controller, vs. trying to find a match that's you're going to end up splicing anyway. Splice will amount to a soldered connection covered in shrink tube. That is NOT to be done until after confirming you have the wiring in order (not just matched color for color).

Notes:
I used a bunch of alligator clips to hold pairs of wires together for each "try". Wire nuts would work as a temporary holder as well.

For your wiring order "trials" just use a tiny amount of throttle to see what happens. This will prevent you from smoking any of the motor's internal sensors. If nothing happens when you apply a little throttle, your wiring is wrong. If it buzzes your wiring is wrong. If it runs backwards, you can swap any 2 phase wires (with accompanying same color sensor wires) to reverse rotation.

In addition to the 3 large phase wires, you'll have 3 much smaller matching colored sensor wires. In addition to these phase and sensor wires, you'll have a hot and a ground for the sensors. The last wire, if there is one, will be a speed sensor - that you probably won't need as you're going to need an external speed sensor (the one mentioned earlier).

If you put the blue phase wire with the blue phase wire together for a try, your sensor wires will go blue to blue. Keep those colors matched. -Al

 

[Bravesst]

There is also a wire harness, but only 4 wires come out of one end of the new controller. That's it. I'll get the bike up on the lift and take more pics of the motor. What type of wire(s) are we talking about - copper, gauge, solid, stranded? Would you use butt splice connectors as well as solder?

I have a lot to learn here, but I gotta ask the dumb questions.

Are we talking about the motor or controller?
Phase wires (3)
Sensor wires (3)
Hot (1)
Ground (1)

Isn't there a speed sensor now?

 

[harryS]

Then if you have the harness and all the extra parts, you're all set, except for the motor connector.

I only see 3 pins in the above picture, but are there six more contacts inside?

This is the typical 9 pin"water proof" motor connector, where the end with the pins comes out of the motor.

You would buy the bottom part and splice it to your controller cable. It's not a fun job. I've done it twice, and having lots of experience with exposed electrical connections outside, I worried about the brittle solder joints breaking and mechanical abrasion, etc. It's also not easy to butt solder the 14G wires together. Then there's heat shrink tubing, etc.

If you are going to do this, I recommend buying the above cable, or an extender cable. They're about $15 on ebay. Then remove the old cable from inside the controller. Just cut the wires. Run your new one inside the controller and splice there.

The wire colors should match. I've done about four or five KT controller like this. They always match. It's a lot easier to splice inside the controller. There is plenty of room for a simple twist splice.. No need for strain relief. Protected from the elements. Also, there's no need to take apart the controller as I did in this picture, but it's my clearest photo. It can be done just taking off the top plate, which gives access to all the wires.

If your motor is a geared motor and currently shows speed, and you don't see an external sensor on the wheel, then there is an internal speed sensor already wired into the motor cable. That's typical of most Bafangs. The KT controllers are also automatically wired for that. It will be the white wire inside the 9 pin cable. So when you splice all 9 wires, you're set. You do have to go into the LCD settings and enable the sensor.

If you could find the matching Big 9 connector, you could splice it to your motor cable, but I think you have to leave all the motor hardware (nut, washers, etc) on the cable as they won't go over the bigger connector. Also, now you have a non standard connector. You cannot put your old controller back in, nor will another motor fit. Finally, it's a terrible place for a splice. That's where you want a clean cable that can flex.

 

[AHicks]

The geared motors STOP when there's no power going to them - as in when coasting/decelerating. In my experience, the INTERNAL speed sensor will return to -0- at this point, until you start feeding power to the motor again. Works fine if you want to deal with that kind of thing, but it's easily avoided using an EXTERNAL speed sensor that will register speed whenever the bike is moving.

" If your motor is a geared motor and currently shows speed, and you don't see an external sensor on the wheel, then there is an internal speed sensor already wired into the motor cable. That's typical of most Bafangs. The KT controllers are also automatically wired for that. It will be the white wire inside the 9 pin cable. So when you splice all 9 wires, you're set. You do have to go into the LCD settings and enable the sensor. "