Bafang First ride: sheared off cassete+side cover

Well, I guess I can't recommend Bafang as I just sheared the cassette threads off in about the first 15 minutes of riding. Funny thing was, I didn't want to cook the little controller like I did my last one, so I tried pedal only up a hill and *crunch*

Ebikes+ San Franscico hills really don't mix.

Does anyone have a spare side cover/dead bafang rear they can sell to me? Or know where I can find a replacement part?
Also, I figure so long as I'm taking the side cover off, I might as well beef up the gears. I know a lot of people run 2 nylon 1 steel. Where can I find a steel gear to toss in it?

Seems like I should have called this the "Where can I find Bafang parts" thread. Any help will be greatly appreciated.

Hey Aaron,

Might be worth getting a whole new motor. That way you have an entire set of spare parts like nylon gears that go bad. They can be had cheap here:

http://www.bmsbattery.com/index.php?cPath=21_25&osCsid=b5db32185a0ebfbd23ecb9354a5d2c42

or even from ecrazyman.

I've got both, but not that model of Bafang, so not the same. Sorry.

John

TPA said:

Hey Aaron,

Might be worth getting a whole new motor. That way you have an entire set of spare parts like nylon gears that go bad. They can be had cheap here:

http://www.bmsbattery.com/index.php?cPath=21_25&osCsid=b5db32185a0ebfbd23ecb9354a5d2c42

or even from ecrazyman.

Click to expand...

I just blew ALL my money on the motor/controller/battery. If I can't find a replacement I'll have to wait until after Christmas. Can't afford the $69+$50shipping of a new motor. I was expecting to destroy this thing, but 15 minutes is a little depressing.

Can you determine if the screw action of the freewheel mounting was causing it to push against the side cover? Did that freewheel that come with the motor?

Email Keywin. I got a side cover from him for $15, same with the steel gear.

it may be hard to unscrew that side cover, would you consider JB Weld?

before you order parts, consider the whole motor from jack xie at bmsbattery. he is charging 69.99 for the rear and 79.99 for the front bafang.

if not JB Weld, using a punch or chisel to back the side plate off (unscrew it) is ok since you won't use it again so you don't have to worry about buying a fancy wrench to unscrew it.

aaronski said:

Ebikes+ San Franscico hills really don't mix.

Click to expand...

Woah there. That depends on the ebike. You wouldn't say that vehicles and off-roading don't mix based on your experiences with a Geo Metro. You just have to get an Off-Road vehicle or something designed for that.

In that spirit, there's several ebikes designed for hills. However, if you're traveling relatively long distances in hilly terrain, the battery costs might eat you alive. Batteries and motors are definitely more economical for flat terrain.

Most of the cheap hub motors, though, are definitely not designed for hills. They're often made of piss-poor aluminum that can be sheared by the forces of the granny gear on a hill, and they typically don't have the power capability to sustain hill-climbing at reasonable speeds.

.

nutsandvolts said:

TPA said:

Hey Aaron,

Might be worth getting a whole new motor. That way you have an entire set of spare parts like nylon gears that go bad. They can be had cheap here:

http://www.bmsbattery.com/index.php?cPath=21_25&osCsid=b5db32185a0ebfbd23ecb9354a5d2c42

or even from ecrazyman.

Click to expand...

They have 2000 bafang motors in stock!

Click to expand...

They say they have 2000 in stock. I'd say there's pretty good odds that they don't have even 100 in stock.

John

aaronski said:

Well, I guess I can't recommend Bafang as I just sheared the cassette threads off in about the first 15 minutes of riding. Funny thing was, I didn't want to cook the little controller like I did my last one, so I tried pedal only up a hill and *crunch*

Click to expand...

Yes you sure found the limit on that motor real quick I have however read something similar happening to a Crystalyte motor;

http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=6995&p=105628#p105565

The little Bafang is a nice assist motor but its limits are low compared to pretty much everything else on the market.
To date I've accumulated 2,109 miles on my front Bafang over hill and dale. The grades around here surely don't measure up to the famous hills of San Francisco, which I've only seen from the movies myself (gotta love "What's Up, Doc?"). Now this is just a suggestion but I thinks ya need a bigger motor...or maybe dual Bafangs

-R

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Russell said:

aaronski said:

Well, I guess I can't recommend Bafang as I just sheared the cassette threads off in about the first 15 minutes of riding. Funny thing was, I didn't want to cook the little controller like I did my last one, so I tried pedal only up a hill and *crunch*

Click to expand...

Yes you sure found the limit on that motor real quick I have however read something similar happening to a Crystalyte motor;

http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=6995&p=105628#p105565

The little Bafang is a nice assist motor but its limits are low compared to pretty much everything else on the market.
To date I've accumulated 2,109 miles on my front Bafang over hill and dale. The grades around here surely don't measure up to the famous hills of San Francisco, which I've only seen from the movies myself (gotta love "What's Up, Doc?"). Now this is just a suggestion but I thinks ya need a bigger motor...or maybe dual Bafangs

-R

Click to expand...

Haha, Russell, It was your posts on Fatpacks and Bafangs that led me to this setup to begin with! This is my play bike. My commute bike is a BMC 600-t@48v&30A. Plenty for my area. This build is going to be my wife's bike when it's working, and my test bench for new toys, like home built batteries and 72v controllers. I've wanted and ebike for about 10 years, then one day I realized I'm not 18 anymore, and have plenty of money/time to pursue what I am interested in. One little motor housing isn't going to stop me. I'm a little broke now, but worst case I save for a month and just buy another motor.

also ask holmes, he may buy the motor from you to put in the one he burned up so buying another new motor to get the sideplate might be more feasible, he can unscrew the sideplate for you too since he has the tools. i think.

but several have burned up a motor besides holmes and may split the cost with you to get the motor.

Aren't you the lucky one No joy from the vendor? Ship to china I presume? Bummer. Hopefully the thread will surface somebody with a new cover for you cheaper. That kind of damage is caused by the torque from the pedals isn't it? The photo looks to me like there was a bubble or something in the casting. You really ought to be getting something free from the vendor.

John in CR said:

nutsandvolts said:

TPA said:

Hey Aaron,

Might be worth getting a whole new motor. That way you have an entire set of spare parts like nylon gears that go bad. They can be had cheap here:

http://www.bmsbattery.com/index.php?cPath=21_25&osCsid=b5db32185a0ebfbd23ecb9354a5d2c42

or even from ecrazyman.

Click to expand...

They have 2000 bafang motors in stock!

Click to expand...

They say they have 2000 in stock. I'd say there's pretty good odds that they don't have even 100 in stock.

John

Click to expand...

Correct. They don't actually keep these motors in stock (at least not at this stage). Jack Xie told me to expect about 15 days for him to to get them from the factory/distributor. The consolations are (1) the price, and (2) they can supply most or all of the variants of the front and rear motors they sell. I ordered a rear 36V/200W/20" one last week.

I have parts here. Steel gears and all. Maybe I should put them up on my website? Or you can send me a PM with where you are and what you need.

Mr. Holmes added the cover and steel gears to the Holmes hobbies website. I bought them, have them at my home, and can't get the damn side cover off. I welded my own tool for removal, but it bent under the pressure. Does anyone know what the proper tool is, or where I can find something to do the job? I'm going to modify my tool and see If I can make it stronger, right now it is just a piece of angle iron with 2 bolts welded to it, I'm going to go with a rebar loop with 3 bolts welded to it, see if that works.Grr.. I don't want to spend all day welding, I want to spend it riding.
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I generally grab the lip of the cover with huge channel locks. Once it took two people to get it open, they can be very tight. One particular motor I could not get apart, and I ruined it trying.

Complete idiots guide to bafang disassembly/reassembly:

Motor is rebuilt now and I thought I would post this info while it is fresh in my head.
1. You need lock ring pliers to remove the planetery gears. Don't try it without them or you will destroy the lock rings. Lock ring pliers can be purchased for 2.99 from HarborFreight, and they work fine.Using lock ring pliers is not like trying to jimmy the lock ring off with a screwdriver, you don't try and push the lock ring open and slide past the axle, you open the lock ring a little bit and then pull it up along the axle to remove it. this saves you from stretching the lock ring.(like I did)
2. You're likely going to need a custom tool to open the hub up, a 3 prong wrench of some sort. I tried to weld my own and failed. that thing is on TIGHT, every turn you peddle locks it down further. Since mine was already trashed I ground a slot around the outer edge and hammered it open with a chisel. This worked but only because mine was already broken.
3. buy some grease before hand and add some to the gears. Especially if you're adding a new metal gear, it's going to need lubrication. I debated using butter before making another run to the store for axle grease.
4. The bearings are all pressed in pretty tight. Be careful, but it seems you can pull them out with just human force if you can get a good grip. I used a slotted screwdriver and twisted it to force the bearing out. that also worked pretty well.

I think that's it. a nice thing about it is the magnets are housed in an inner cartridge, so you don't need to worry about scraping them when you pull out the motor assembly.