BBSHD - has always seemed to have high resistance when un-powered - Suggestions?

[kiltedcelt]

So I have a BBSHD and for a while I ran it paired to an Alfine 8 internally geared hub. On a few occasions when I managed to run my battery down to the low voltage cut-off I found the bike to be very difficult to pedal, even in the lowest gearing combination that I had. It was like I was pedaling against resistance in the motor itself. I've NEVER opened this motor up and though I've owned it for something like almost 4 years, I only used it very lightly for a few months back in 2019-2020. Since then it's been uninstalled and I've periodically thrown the battery (an em3ev 52v 28.3 Ah triangle battery), on a charger to make sure it was maintaining charge. I'm building up a new recumbent trike to be my all around commuter/cargo hauler (with trailer towed behind for bulky loads), but mostly just commuter duty - approximately 120 miles per week.

I also have a Rohloff hub so I'm sticking with the mid-drive so I can continue to enjoy the use of my wonderful German-built hub. Plus, having a trike and riding in traffic, I think an internally geared drivetrain is a necessity. Being able to shift into any gear at a standstill is invaluable to me as is the all-weather performance and no fiddly chain shifting issues that I often get with derailleurs over time. Anyway, enough of that - specifics as to the BBSHD and the perceived "resistance." I've asked about this in the past and been told one of two things:
1. Mid-drives all have some resistance, that's what you're feeling (even though it seems excessive to me)
2. There's something wrong with MY mid-drive - open it up and diagnose.

So, I'm going with 2. I'm going to assume it's one of a few possible things - maybe I have overtightened the mount to the bottom bracket in the past as I have heard that can cause some feeling of resistance if you just put a "white-knuckle-death-grip" on the lock rings. I guess clutch could also be suspect. I've also read that these hubs can be woefully under-lubricated. So, before I install it on my trike, I want to buy every available possible spare and have those bits on hand before the install. Obviously I need that sort of big C-shaped gasket, but do I maybe need the inner motor housing gasket as well? What sort of grease should I buy to put in this? Should I invest in a replacement gear if I can find one in stock? I ride with PAS and I generally soft-pedal away from stops, and though I have a thumb throttle I don't use it that much except as a bit of a boost in some situations. Mostly I'm riding for exercise and just wanting to arrive a little bit quicker, and I want to make sure to get as much range out of my battery as possible. In the past, I've been able to get over 100 miles of range out of this battery when I used it with a geared hub motor, but I have no idea of what sort of range I can expect using it with the BBSHD. Since owning the BBSHD I've never ridden it long enough to get a feel for just how much range I can get out of my battery. Installing it on this trike will be the true test of range and reliablity.

Any other spares I might want to have on hand before I crack this thing open for an examination/servicing before installation? I've watched a few of the Luna videos about checking clutch and thrust bearing and such. Any other issues I should consider or videos I can watch to help diagnose this before install?

 

[fechter]

There is a freewheel clutch between the chain ring and the motor gears so there should be very little resistance when the motor is off. You can test by lifting the chain off the chain ring and just spin the pedals by hand to feel the resistance. If there actually is excessive resistance, I would guess either the freewheel clutch needs cleaning/lubing or one of the bearings is going bad. Make sure your brakes aren't dragging and the wheel bearings are spinning free too.

The grease they use is really messy stuff and not the best. Sometimes grease can get thick and gooey, but I haven't had that happen on any of my BBSHDs.

 

[kiltedcelt]

Never had any dragging brakes or issues with wheel bearings. This BBSHD has always felt like there was excessive resistance when attempting to pedal it un-powered. Shifting to the lowest gear should have theoretically made it easy to pedal, but instead it always felt like a pretty noticeable amount of force was required to turn the pedals over, even in a low gear. I'm guessing it's had a clutch issue from day one. It works fine under power, but if you turn the assist off completely or try to ride it with no power (or no battery), it does not pedal like a normal bike. I would accept a slight amount of resistance, but to feel like I had to work pretty hard to keep going forwards in the lowest gear with the motor unpowered tells me that the clutch must not be disengaging and that I'm not only trying to turn the rear wheel, but I'm also trying to turn the entire motor/gear assembly that is somehow remaining engaged and generating resistance. I would guess a new clutch (just in case), is in order along with gaskets and a higher quality grease like the red Mobile stuff that I see people using in place of the white lithium that is in the motor stock.

 

[furcifer]

Weird, I haven't noticed any resistance on any of my BBSHD builds.

I have drained the battery or broken a plug and had to pedal and it seems like there's a lot of resistance. Mainly because of going from 60km/h to 20km/h but also because I run my seat lower than I should for full out pedaling. But on the stand up in the air I don't notice any extra resistance. I've run backpack battery for a while, but even the extra weight isn't that bad.

 

[nathan89]

It's the same with the BBS02. I suspect a lot of people don't notice the resistance as they're not pedaling that often, and only use the throttle.

I swapped the nylon gear on my unit, and although it improved there's still some resistance. Maybe the added weight of the motor and battery etc doesn't help.

 

[liveforphysics]

I pedal mine with no battery pretty often, and the freewheel lets the spindle turn with minimal drag. You may have a stuck freewheel or something.

 

[kiltedcelt]

For an update - I went ahead and ordered a full set of gaskets for the various parts of the motor shell, also ordered thrust bearings (just in case - mine have side-to-side play but I don't think it's quite enough to warrant replacement), and ordered the freewheel clutch part - the one that looks like part of a cassette hub with the three pawls. I also found someone with the nylon gears in stock and ordered one of those because some of what I've read indicated that the inner clutch part of those gears might not release and can cause drag.

On a side note - I base my feelings of "heavy resistance" on the fact that before I installed the BBSHD on the cargo bike, I was able to easily ride that bike with an unplugged front geared hub motor (MAC), that was disconnected. That motor on the front was never hooked up and I ended up replacing it with the BBSHD. While I liked the greater simplicity of the wiring and installation of the BBSHD, as I mentioned, it never seemed to pedal very easily without power. It was a definite noticeable change which leads me to believe something has never been functioning properly with my motor. Somehow it's not disengaging when unpowered and is creating excessive drag when pedaled with no power.

When I get my parts I'll crack it open, and maybe just replace the nylon gear and the freewheel clutch and give it a more thorough internal lubrication as several other posts have shown. Hopefully that will improve things.

 

[docw009]

I can take the chain off the front sprocket of my BBS02, and with the power on in PAS 0, give the pedals a twist and they will spin for 4 or 5 revolutions.

I thought that was no drag til Chalo pointed out a regular BB will spin for over a minute. That's what no drag looks like, but the BBS02's drag is small,

 

[kiltedcelt]

Update: I ordered spares of gaskets, thrust bearing, an extra clutch and nylon gear, just in case there was anything funky inside my motor. TL;DR - nothing wrong. A little bit of black grease seemed to have leaked through onto the nylon gear but only a tiny amount. I cleaned everything and copiously re-lubed all bits with the red Mobile 28 grease I've seen in a few write-ups and videos for a better overall lubrication. Lubrication of white lithium grease on the nylon gear was pretty sparse. I think the most illuminating thing for me, taking the motor apart entirely, was seeing exactly how each gear works on another and ultimately realized that due to HOW the motor works, there technically is no time that gears are NOT intermeshed with each other. If you're pedaling forwards with the motor turned off or in assist level 0 you are STILL turning all of those gears against each other, right on into the motor stator which is also turning and encountering resistance against the magnets. Somehow, I'd thought that with the mention of clutches and such, that there as a total disengagement of SOMETHING within the motor and I'd wrongfully assumed that the resistance I was feeling by turning the cranks was directly related to how the motor actually works, because at no point do the clutches actually disengage anything - they only isolate the crank arms on the occasions when you engage the throttle but do no pedal.

I thought somehow that if the motor was working properly you could give a crank arm a spin and it would spin at least a few times before stopping but in this case (and in videos I've seen), it would appear that when the motor is unpowered, if you for example placed the crank arms parallel to the ground with chain disengaged, pushing one crank arm does not cause the crank arms and spindle they're attached to to spin freely - instead, it only moves as long as you push on it. As soon as you stop, the interconnected nature of all the gears in the motor and the resistance of the windings and stator insure that everything stops immediately because there's not enough spinning mass to overcome the resistance of all those intermeshed parts.

I thought somehow that because my front geared hub motor allegedly had a clutch and free wheeled when unpowered, that I was not feeling resistance with it, when in fact there was probably some resistance in that motor as well, but since I wasn't directly cranking it but instead pushing it and the wheel it was installed in with the rest of the drivetrain, I wasn't feeling "resistance." What I'm feeling with the BBSHD is just the nature of the design of these motors. That, and I suspect since I was using the BBSHD before with an Alfine 8 speed, it's entirely possible that my selected chainring on the BBSHD and the cog on the Alfine were insufficient to give a good transfer of power when the motor was unpowered. Maybe I didn't have a low enough gear available and so when the system was unpowered I was pushing to big of a gear just to maintain a low speed. Or, I got so damn lazy from only having e-assist for several months or even a couple years prior that I was just not in as good a shape as I used to be. At any rate, I think from what I've found that my BBSHD must be operating normally and what I'm experiencing is just a natural amount of resistance. I wonder if there's a mid-drive that actually does completely disengage all gearing in the motor and completely isolates the chainring/crank arms from the motor in unpowered pedaling? I suspect whatever that system would be like would have a traditional clutch and pressure plate type of system like in the transmission for something like a car, and simply wouldn't be the rudimentary "clutch" that simply keeps crank arms from spinning when you're on throttle-only.

 

[amberwolf]

I thought somehow that because my front geared hub motor allegedly had a clutch and free wheeled when unpowered, that I was not feeling resistance with it, when in fact there was probably some resistance in that motor as well, but since I wasn't directly cranking it but instead pushing it and the wheel it was installed in with the rest of the drivetrain, I wasn't feeling "resistance."

I don't know the BBSxx designs well enough to say, but there are threads discussing the clutches and how they work and failure modes and whatnot if you need to know for sure.

However, on geared hubmotors, the clutch there does actually prevent (or at least is intended to, when it is working correctly) spinning the motor inside by just spinning the wheel (casing). It only engages when the motor is spinning faster than clutch, driving the rollers up the ramps to grab the clutch.

 

[kiltedcelt]

Amberwolf - that's pretty much how I thought the geared hub clutch type system worked. However, in the BBSHD, it's clear that all of the various gears are enmeshed all the time which means when the motor is unpowered you're essentially turning all those gears against the inherent resistance of the rotor/stator. I suspect this is an equivalent resistance to what is mentioned when people are discussing the resistance of pedaling an unpowered direct drive motor. I guess I'm less concerned about it now that I have a better idea of exactly how everything goes together inside the motor and heck, it means I've also thoroughly greased the whole inside and also eliminated the black grease which apparently sometimes infiltrates into the housing with the nylon gear. Reassembled, this thing should be good for several thousand miles or more. I guess the only other puzzle piece will be figuring the best chainring/Rohloff cog combo that will allow for lower effort unpowered pedaling but will also give a good selection of gearing to work with the BBSHD since it should be powered all the time. The only time when it won't be powered will be if I forget to charge the battery.

 

[MacGuyver_Season1]

Amberwolf - that's pretty much how I thought the geared hub clutch type system worked. However, in the BBSHD, it's clear that all of the various gears are enmeshed all the time which means when the motor is unpowered you're essentially turning all those gears against the inherent resistance of the rotor/stator. I suspect this is an equivalent resistance to what is mentioned when people are discussing the resistance of pedaling an unpowered direct drive motor. I guess I'm less concerned about it now that I have a better idea of exactly how everything goes together inside the motor and heck, it means I've also thoroughly greased the whole inside and also eliminated the black grease which apparently sometimes infiltrates into the housing with the nylon gear. Reassembled, this thing should be good for several thousand miles or more. I guess the only other puzzle piece will be figuring the best chainring/Rohloff cog combo that will allow for lower effort unpowered pedaling but will also give a good selection of gearing to work with the BBSHD since it should be powered all the time. The only time when it won't be powered will be if I forget to charge the battery.

I opened up my BBSHD to work on the controller but also noticed how much resistance/friction there was in the gears with no power. I thought the issue was the original old/bad grease, so I took apart more. The actual large bearing around the large steel gear on the chainring side has a very high resistance. Same with axle running through the spindle bearing. This is WITHOUT factoring in the pinion gear (with resistance from magnets) and nylon reduction gear. Do these bearings need to be lubricated? The freewheel is fine and smaller bearing next to that on axle as well as nylon gear spins freely, so very strange.

 

[uhmwpolyethylene]

Speaking of, do any of you think it's necessary to upgrade to the PEEK ceramic gear over stock nylon?

 

[sysrq]

I opened up my BBSHD to work on the controller but also noticed how much resistance/friction there was in the gears with no power. I thought the issue was the original old/bad grease, so I took apart more. The actual large bearing around the large steel gear on the chainring side has a very high resistance. Same with axle running through the spindle bearing. This is WITHOUT factoring in the pinion gear (with resistance from magnets) and nylon reduction gear. Do these bearings need to be lubricated? The freewheel is fine and smaller bearing next to that on axle as well as nylon gear spins freely, so very strange.

The bearing in a Lekkie Pro HD cover has even more resistance than the original. All the videos and Lekkie manual not advising to use a press for gear insertion but a rubber mallet doesn't help either. Tightening the cover bolts over 2Nm also significantly increases preloaded on a thrust bearing which isn't talked about anywhere. Pinion sprag clutch also has uneven resistance and sound compared to TSDZ2 for example.

 

[MacGuyver_Season1]

The bearing in a Lekkie Pro HD cover has even more resistance than the original. All the videos and Lekkie manual not advising to use a press for gear insertion but a rubber mallet doesn't help either. Tightening the cover bolts over 2Nm also significantly increases preloaded on a thrust bearing which isn't talked about anywhere. Pinion sprag clutch also has uneven resistance and sound compared to TSDZ2 for example.

Argh!!! I actually have one of those on order, was hoping the Lekkie had a better bearing. But interesting, need to break out my torque wrench and see where I’m at.

 

[MacGuyver_Season1]

Speaking of, do any of you think it's necessary to upgrade to the PEEK ceramic gear over stock nylon?

I have one on the shelf, plan to install. I think a lot of people do just fine with nylon gear if you don’t abuse it. I’m trying to run more power through mine and believe it is the heat that causes nylon to fail. I don’t think it is ceramic FYI (not completely ceramic at least). I think it is some type of plastic composite that is stronger/handles heat better than nylon.

 

[uhmwpolyethylene]

I have one on the shelf, plan to install. I think a lot of people do just fine with nylon gear if you don’t abuse it. I’m trying to run more power through mine and believe it is the heat that causes nylon to fail. I don’t think it is ceramic FYI (not completely ceramic at least). I think it is some type of plastic composite that is stronger/handles heat better than nylon.

I had seen some call it ceramic but yeah idk. I bet aramid would work also, very high heat tolerance, but maybe too hard compared to nylon idk

 

[uhmwpolyethylene]

Hey guys I need quick serious advice, a guy wants to sell me a build practically at cost or less to make room but it has the BBSHD which is technically illegal as an ebike, is the bbs02 really truly inferior with overheating issues or whatever even if adding say heat sinks, and how much weight would that add. The 02 and HD seem like the only game in town right now . I'm worried even if I etch off the HD 1000w engraving it's still visually different, and could even be recognized by ai image camera search . I think I could get away with the 1200w? Peak of 02 vs 1600? Peak of HD. Does the 02 just have really bad structural problems with heat dissipation or anything else in comparison? And what is torque on 02 like vs HD with 52v

 

[MacGuyver_Season1]

Hey guys I need quick serious advice, a guy wants to sell me a build practically at cost or less to make room but it has the BBSHD which is technically illegal as an ebike, is the bbs02 really truly inferior with overheating issues or whatever even if adding say heat sinks, and how much weight would that add. The 02 and HD seem like the only game in town right now . I'm worried even if I etch off the HD 1000w engraving it's still visually different, and could even be recognized by ai image camera search . I think I could get away with the 1200w? Peak of 02 vs 1600? Peak of HD. Does the 02 just have really bad structural problems with heat dissipation or anything else in comparison? And what is torque on 02 like vs HD with 52v

Not sure how strict rules are where you are. Could always use a big Nalgene water bottle holder to cover up. I don’t have experience with anything other than the HD, so can’t give an opinion there. The newer HDs are made very well, just bought a motor core after having one since 2016.

 

[MacGuyver_Season1]

 

[Chuy]

… it has the BBSHD which is technically illegal as an ebike …

No eBike is illegal, unless specified by law. How and where you use it, is what is restricted. The federal law of 750 watts is to define a “low speed electric bicycle” for use on federal lands/parks/property. And the federal law actually states the ebike must be UNDER 750 watts. See 15CFR2085. A Federal Registry entry by NPS clarifies the law, and there may be other entries.
Federal Register :: Request Access

States and cities are free to mandate ebike usage and definition as they see fit. Six states allow 1000 watt ebikes wherever bikes are allowed - GA, KS, MN, OK, OR, and VA. Two states have no limit - FL and MS. As of press date of this article:
Class 3 eBike Laws, US Electric Bike Regulations | Quietkat USA