bafang bbshd getting hot, excessive battery consumption

CrossRoads

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Dunno if overheating is a common issue with the bbshd. Was taking it up a steep hill to a frien'ds house i often visit, which i have done plenty of times before with this bike and this time it was feeling underpowered, and it used 20% of the battery, about twice as much as it has before to make the same climb, and also the motor was quite hot to the touch at the top, like, not smelly or smokey, but could cook an egg on it. Outside temperature was a mellow 65 degrees farenheit. Also the power was noticably sluggish.

Almost new system installed 2 months ago. I thoutht these things were supposed to be rock solid? After letting it cool down the ride later the same day it was performing as usual. It's the 52v version. Does this mean there is something wrong with the system and i should be concerned or was it just overheating a bit and i need to take it easy? Is excessive power consumption / battery drain typical with an overheated motor?
 
It is possible you were in too high of a gear while going up the hill. Do you know what gear you were in? Excessive heat is one of the worst things to happen on the motor. You definitely want to solve this one. On big hills you want to be in gears 1-3 ish. The faster you allow the motor to turn the better it is at not having heat build up.

Mine doesn't get that hot. It can get pretty warm but still touchable. I ride it on some pretty big hills
 
Thanks, that's sound advice. Generally on a climb, i'm choosing the gear to match my prefered cycling cadence, what my legs want, not as low as possible for the motor, as i would with a hub motor. It's entirely possible i was not paying much attention and choosing a gear or two higher than I do typically. I'm new to mid-drives, so not trained in using them yet. It still felt like the affect was pretty dramatic.
 
You just need to be aware that it can happen. It always helps to use those gears and leg muscles, lol. It's easy to forget about those on a BBSHD. I find myself pedaling faster cadence when I want to maintain higher speeds. If I want the hill to be more like a regular bike, I turn the PAS down to the level that is basically a little more than enough juice to compensate for the effect the motor and battery have on the bike. Having it low power doesn't allow it to heat up very much, and keeping the rpms up is better for slower heat build up at higher speeds. You can still shift to higher gears while you're going up hills as long as you're willing to pedal enough to keep it in its power-band.
 
Dunno if overheating is a common issue with the bbshd. Was taking it up a steep hill to a frien'ds house i often visit, which i have done plenty of times before with this bike and this time it was feeling underpowered, and it used 20% of the battery, about twice as much as it has before to make the same climb, and also the motor was quite hot to the touch at the top, like, not smelly or smokey, but could cook an egg on it. Outside temperature was a mellow 65 degrees farenheit. Also the power was noticably sluggish.

Almost new system installed 2 months ago. I thoutht these things were supposed to be rock solid? After letting it cool down the ride later the same day it was performing as usual. It's the 52v version. Does this mean there is something wrong with the system and i should be concerned or was it just overheating a bit and i need to take it easy? Is excessive power consumption / battery drain typical with an overheated motor?
Bracket too tight locking bearings?
 
Dunno if overheating is a common issue with the bbshd. Was taking it up a steep hill to a frien'ds house i often visit, which i have done plenty of times before with this bike and this time it was feeling underpowered, and it used 20% of the battery, about twice as much as it has before to make the same climb, and also the motor was quite hot to the touch at the top, like, not smelly or smokey, but could cook an egg on it. Outside temperature was a mellow 65 degrees farenheit. Also the power was noticably sluggish.

Almost new system installed 2 months ago. I thoutht these things were supposed to be rock solid? After letting it cool down the ride later the same day it was performing as usual. It's the 52v version. Does this mean there is something wrong with the system and i should be concerned or was it just overheating a bit and i need to take it easy? Is excessive power consumption / battery drain typical with an overheated motor?
Does your motor have an overheat shut down?

My wife's BBS02 powered bike, with adjustable Enviolo* auto trans, stopped on the big hill around Pebble Beach. It was 2-3 minutes and it started up again. She was being lazy, with a 25 r/m pedal cadence and a 3 of 5 assistance level. When it clicked back on, she upped it to 45 and took the hill again. No problem.

I'm not intricate here, but if your motor has such a safety feature, and it's not hooked up.......

*Hey, Enviolo auto trans equipper, lose the phone app for changing pedal cadence/motor speed. It's about as convenient as the 10 year old NuVinci Developers kit I use on my converted 60's era Taco mini bike. To change cadence on it I have to plug my laptop into the control box and replace the excel based control program that's in there now. I have it the way I want it, but just sayin'. So, shell out the extra few bux to go back to the old electronic twist control that my wife has. Works like a dream, instantly.
 
Everything @major masingil is telling you is spot on. This sounds very much like an issue caused by gearing. Its sort of the classic mistake made on mid drives. I put this list of do's and don'ts together and its one of the more visited pages on my site:


The 'short version' of what to do is, and I quote:
Keep the motor spinning

I ride cargo bikes in an area where there are steep hills. At the bottom of a paved hill, my best practice is to go one cog *lower* than my preferred cadence. Maybe even two. Throw speed out the window as a consideration and let it go slow if necessary at some points. Then I pedal my way up at my preferred cadence on low PAS, which is my preference. As the slope changes I use my PAS selector to click assist up or down a notch at a time, which favors keeping my cadence versus my speed.

Essentially what I've done is substitute PAS selection for a derailleur shift, which has secondary benefits as shifting on a hill (regardless of whether a gear sensor is installed) with a mid drive in play is always sub-optimal. I set my gearing so it is low enough to never be an issue (bogging) at the bottom of the hill.

This would be tougher to do on a hill whose summit you can't see and/or you don't know.

Bracket to tight locking bearings?
Not an issue on a BBSHD. If anything, the tighter the better. I recommend 90 ft lbs on an installation of the inner lock ring (and use two inner rings together as a jam nut) which is WAY past the manufacturer spec but a proven good number.
 
My wife's BBS02 powered bike, with adjustable Enviolo* auto trans, stopped on the big hill around Pebble Beach.
Hah I live in the same area (not inside the gates ... I'm in PG and range from PG to Monterey, Sand City and as far out as Marina). I went out to Laguna Seca yesterday to see what was happening at Sea Otter.

We have low hills here, but they make up for that by being pretty steep in some places. Definitely could stress a BBS02. Coming up from Monterey I have a 16% grade to get over unless I take the long way around via Spanish Bay.
 
Everything @major masingil is telling you is spot on. This sounds very much like an issue caused by gearing. Its sort of the classic mistake made on mid drives. I put this list of do's and don'ts together and its one of the more visited pages on my site:


The 'short version' of what to do is, and I quote:


I ride cargo bikes in an area where there are steep hills. At the bottom of a paved hill, my best practice is to go one cog *lower* than my preferred cadence. Maybe even two. Throw speed out the window as a consideration and let it go slow if necessary at some points. Then I pedal my way up at my preferred cadence on low PAS, which is my preference. As the slope changes I use my PAS selector to click assist up or down a notch at a time, which favors keeping my cadence versus my speed.

Essentially what I've done is substitute PAS selection for a derailleur shift, which has secondary benefits as shifting on a hill (regardless of whether a gear sensor is installed) with a mid drive in play is always sub-optimal. I set my gearing so it is low enough to never be an issue (bogging) at the bottom of the hill.

This would be tougher to do on a hill whose summit you can't see and/or you don't know.


Not an issue on a BBSHD. If anything, the tighter the better. I recommend 90 ft lbs on an installation of the inner lock ring (and use two inner rings together as a jam nut) which is WAY past the manufacturer spec but a proven good number.
That is not what one tuttorial warns; too much torque on the bracket will bind on the bearings,(bafang mid-drive). use torque wrench
& do not exceed recommended torque. Apparently this is a common issue.
 
That is not what one tuttorial warns; too much torque on the bracket will bind on the bearings,(bafang mid-drive). use torque wrench
& do not exceed recommended torque. Apparently this is a common issue.

Thats not true.

Having 9 of them, all of which use 90 ft lbs (or 100) of torque to affix the motor, I can speak from some level of experience dating back to my first (bike is still in use) from 2017. Also being a member of a number of Bafang DIY groups, I have literally never heard of this problem, so no its not common.

If you understand how the attachment mechanism works, you'd be hard pressed to explain how binding is even possible. The axle assembly is not clamped on the bearings. The lock rings are simply nuts. They encircle the axle. They don't bind it down. Neither does the mounting plate.

Luna Cycle used to sell ebikes with BBSHDs pre-assembled on the bikes and they had an instructional video showing the use of an automotive torque wrench to apply 100 ft lbs of torque to their inner lock rings, stating they did that with all of their bikes to assure they never moved, along with an assertion that the threads can take it. I followed that for a few years myself although when I came up with the use of doubled inner lock rings as jam nuts, I backed that off to 90 ft lbs each and it has proven to be just fine.

The following during-assembly images come from this page, which is dedicated to pre-fitment. There is a separate installment (Assembly Day One, click on the Final Motor Assembly chapter) that you want to refer to for the actual final fitment:


You can see the threads, and...
pxl_20220317_154838755_800[1].jpg

now the mounting plate (binds as much as a washer would) and the two stacked inner lock rings (i.e. nuts) which is not using the two M6 nuts yet since this is a test fit. If you want to see whats on the other side, there are photos of that as well. This particular installation uses a 3mm polymer spacer on that side.
pxl_20220317_155321078[1].jpg


I wrote articles like this specifically to combat this sort of misinformation. Mid drives have the reputation for reliability that they do chiefly because so many people wing it, don't have a guide that explains the do's and don'ts, and fail accordingly.
 
Lets dispel this binding notion fully by looking at all the parts and explaining how each works. First of all, below is the mounting plate. its upside down to show the ridges that will face the bottom bracket. This plate goes between the frame and the mounting rings as a sort of washer. The visible ridges will dig into the bottom bracket metal - from the clamping force provided by the lock rings. It is these teeth that do the work of fixing the motor, but only in conjunction with the two M6 bolts which attach the mounting ring to the motor.
img_20191008_174717_800[1].jpg


Here is the final assembly, with the mounting bolts attached to the mounting plate. These mounting bolts mate the mounting plate/washer to the motor, so if the washer can't move, the motor can't move either. Those two M6 bolts and the dug-in steel ridges are what keeps the motor from rotating/moving. This pic also shows a separate additional clamping mechanism (the hose clamps) that is a precautionary measure for motors subject to extreme use (i.e. singletrack drops). Not relevant here.

pxl_20220327_195532730-edited[1].jpg

You can see the non drive side bearing around the squared-off spindle above. The lock ring is not clamping that bearing. The same goes for the drive side, where the secondary housing is what is taking the force independent of the spindle or the spindle's bearings (there's one inside, not on the outer edge and its sort of free-spinning and not subject to clamping. You can find pics of this on web sites that sell spare spindles/axles).
 
Thats not true.

Having 9 of them, all of which use 90 ft lbs (or 100) of torque to affix the motor, I can speak from some level of experience dating back to my first (bike is still in use) from 2017. Also being a member of a number of Bafang DIY groups, I have literally never heard of this problem, so no its not common.

If you understand how the attachment mechanism works, you'd be hard pressed to explain how binding is even possible. The axle assembly is not clamped on the bearings. The lock rings are simply nuts. They encircle the axle. They don't bind it down. Neither does the mounting plate.

Luna Cycle used to sell ebikes with BBSHDs pre-assembled on the bikes and they had an instructional video showing the use of an automotive torque wrench to apply 100 ft lbs of torque to their inner lock rings, stating they did that with all of their bikes to assure they never moved, along with an assertion that the threads can take it. I followed that for a few years myself although when I came up with the use of doubled inner lock rings as jam nuts, I backed that off to 90 ft lbs each and it has proven to be just fine.

The following during-assembly images come from this page, which is dedicated to pre-fitment. There is a separate installment (Assembly Day One, click on the Final Motor Assembly chapter) that you want to refer to for the actual final fitment:


You can see the threads, and...
View attachment 14239
now the mounting plate (binds as much as a washer would) and the two stacked inner lock rings (i.e. nuts) which is not using the two M6 nuts yet since this is a test fit. If you want to see whats on the other side, there are photos of that as well. This particular installation uses a 3mm polymer spacer on that side.
View attachment 14240

I wrote articles like this specifically to combat this sort of misinformation. Mid drives have the reputation for reliability that they do chiefly because so many people wing it, don't have a guide that explains the do's and don'ts, and fail accordingly.
 
Fine, I watched it; the tutorial exists. I didn't make it up; I'm not a liar. It's obvious you know everything there is to know.
Nobody said you were lying, its just misinformation being passed along. There are lots of videos on YouTube giving bad information. Do you own or have you ever put one of these together? There is no way for the lock rings on the outside no matter how tight to affect the bearings on the inside.
 
A question for @m@Robertson

I have just used the steel thick lock ring and then the second aluminum lock ring that came with the BBSHD but I see you are using two of the thick steel rings, which is good if you have enough threads for it. I just used the tool that came with the BBSHD to tighten them down by hitting the end of the wrench with a mallet to get it good and tight. What tool/tools are you using that lets you put a torque wrench on it? And is there one for the Bafang outer aluminum lock ring as well? I have several professional torque wrenches and would always prefer to use them whenever possible instead of guessing.
 
@munirider The inner lock ring takes a special m33 socket. I have the Wheels Manufacturing, link below. There is also a socket for the outer ring but it is about same price as the inner socket and, imo, is not worth it. Lekkie is another brand that offers sockets. You may find cheaper ones on aliexpress.
Wheels Manufacturing Ebike Lockring Socket - Bafang Inner, M33 https://a.co/d/1T6jYOJ

I will add that I had mine torqued to 50 ft-lbs and that was sufficient on hard surfaces through 100 miles. Last Friday I did my first off-roading on a very bumpy rutted service road. Not only did my left side crank bolt loosen and fall off, but the motor bracket lock ring loosened as well. I had about 1/8” play. I re-torqued to 60 ft-lbs and will go up from there as needed. The crank bolts I had re-torqued to 25 ft-lbs two weeks ago, but I did not apply new thread locker. I come to find out the left side crank bolt is known to loosen. I threw on another crank bolt with blue thread locker and torqued to 30 ft-lbs. I will put red thread locker if it loosens again.
 
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Thanks, that one is less than the Lekkie one here from California-ebike https://california-ebike.com/products/lekkie-four-42-socket

I guess I'll have to bite the bullet and get one or the other of these, Leikkie is expensive but their tools are really nice but it looks like the other tool is also nice. I hate buying everything on Amazon but after shipping the Leikkie would end up twice the price as the one on Amazon.

I have hammered mine down as tight as I could and haven't had any of them come loose so far on either bike but I would like to be able to properly torque them.
 
@munirider I hear you. I am not a fan of the hammer method either,for the inner ring, the outer, maybe. It baffles me that Bafang shows a torque setting but gives you a cheap tool for the lock ring, and they don't even sell the socket. They could be making some extra $$ selling a cheap steel socket.

I am now seeing a cheap socket on aliexpress, but only for the outer ring. $11,43 plus $4 shipping; keyword: Bafang Mid-Mounted Motorr Installation Tool M500 M600 M620 BBS0102/HD Crankshaft Nut Bolt Installation Tool. [sic]
 
Fine, I watched it; the tutorial exists. I didn't make it up; I'm not a liar. It's obvious you know everything there is to know.
Nobody said you were lying, its just misinformation being passed along. There are lots of videos on YouTube giving bad information. Do you own or have you ever put one of these together? There is no way for the lock rings on the outside no matter how tight to affect the bearings on the inside.
Exactly this. @Rawly Old the information you referred to is wrong, and I didn't just say its wrong, I took the time to illustrate in detail why. There's no need to blindly follow what I say because you were given specifics, with pictures, so you can use your brain for yourself and figure out what the the correct answer has to be (or rather that it cannot be what the tutorial you reference describes).
 
A question for @m@Robertson

I have just used the steel thick lock ring and then the second aluminum lock ring that came with the BBSHD but I see you are using two of the thick steel rings, which is good if you have enough threads for it.
I have found that, surprisingly, there doesn't seem to be any more threads required to do two inner lock rings versus the factory default inner+outer. Actually I have not done a proper analysis. I've just eyeballed it one vs. the other during an installation and it looked to be about the same. Thats not what I expected as it LOOKS like the inner would need more threads vs. the outer by quite a bit.

The best solution to a lack of threads is a Lekkie OneNut. Amazingly they are now available on Amazon for only $22:

More on the tool you need for that below.
I just used the tool that came with the BBSHD to tighten them down by hitting the end of the wrench with a mallet to get it good and tight.
Ugh. You and a whole lot of other people. FWIW if you must use one of those knuckle-buster mini wrenches, try and get a steel one. The alloy ones self-destruct pretty quickly.
What tool/tools are you using that lets you put a torque wrench on it? And is there one for the Bafang outer aluminum lock ring as well? I have several professional torque wrenches and would always prefer to use them whenever possible instead of guessing.
My preferred tools are no longer commercially available. Luna Cycle sold a set of inner and outer sockets that worked directly with 1/2" automotive torque wrenches. They cost me about $50. I bought a set during their briefly available time on the market, and have been using them ever since. They look a little weird but they are super heavy duty.
luna_torque_wrench__65269.1516220927[1].jpg


Which does you no good at all, right? Here are some alternatives. First of all, Bafang has an official set of sockets that can be very difficult to find. Empowered Cycles has them fairly reliably. $50 for the pair. Take note that the outer ring tool is 16-notch. More on that below.


The Bafang tools are set up to use a 1/2" wrench.

Lekkie sells analogs to the Bafang versions. Beautiful and expensive. Here is the inner tool. US$55 just for this.

And here is the outer. Another US$55.

But here's the thing about that outer socket... its a standard 16-notch bottom bracket tool, with an extension inside to account for the axle sticking out. Regular bottom bracket tools won't work because of that axle/spindle. So to get around that, you remove the secondary housing on the other side, and then just pull the axle assembly out. Problem solved and now you can use a standard (cheap) 16-notch bottom bracket tool that you can find pretty much anywhere to affix a Lekkie OneNut.

But wait there's more :) ... the market is evolving and now there are more out there. Wheels Manufacturing now makes a Bafang inner and outer socket. Here it is for about US$36. You can see the companion outer lock ring tool linked on the same page. I did a little digging and the Wheels tools are made to work with 1/2" torque wrenches, unlike the Lekkie stuff.
 
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