A way to Stabilize Bafang BBSHD motor

[AZguy]

Insurance. I ride off road a lot so there will is a lot of harsh riding. I'd be less worried if my bike was a commuter only. (plus, I like to over build things)

I ride hard off-road plenty on my hard tail fattie, often heavy loaded (I carry a ton of water) and I don't think you need to worry about it as long as your install is solid. I put a piece of hard plastic between the motor and the frame and torqued it down snug to the frame. Since the motor torque pulls it towards the frame there's no play to loosen anything.

Anyway, I'm >7000mi of hard riding on this build and haven't worried about it...

[TNC]

AZ, I haven't had mine slip either even with aggressive off road. Did mine just because belt-and-suspenders. With all the different frame shapes and designs, one can still get creative with Riv-nuts and stabilizing brackets on just about any frame...well, carbon may cause some limitations.

[AZguy]

AZ, I haven't had mine slip either even with aggressive off road. Did mine just because belt-and-suspenders. With all the different frame shapes and designs, one can still get creative with Riv-nuts and stabilizing brackets on just about any frame...well, carbon may cause some limitations.

Just my .02 but that looks like a much better approach than turnbuckles...

Still doesn't seem necessary. I guess I just figured if mine very did loosen up I'd just tighten as well as I could and limp it home loose but that's just never happened

Dang, your motor looks a heck of a lot less beat than mine!

[TNC]

LOL!...don't worry, AZ. That nice unscathed BBSHD is back in the spring shortly after installing it. Mine doesn't look yours by any means, but it will probably get there. AZ, I think some of the trails in my area may look a bit like yours...lots of cactus and mesquite trees...lots of sharp, pointy things.

[AZguy]

Interestingly enough my frame has two rivnuts already in it in the front of the downtube - I have no idea what they were thinking putting them there... I used the lower one to secure the hard plastic I put between the frame and motor... be pretty easy to install a bracket like yours using those I think... but then again I doubt I ever will....

[cwinning]

I ride hard off-road plenty on my hard tail fattie, often heavy loaded (I carry a ton of water) and I don't think you need to worry about it as long as your install is solid. I put a piece of hard plastic between the motor and the frame and torqued it down snug to the frame. Since the motor torque pulls it towards the frame there's no play to loosen anything.

Anyway, I'm >7000mi of hard riding on this build and haven't worried about it...

7000 miles is no joke, I look forward to putting on many miles on mine. I'll do everything in my power to install the motor the correct way, blue loctite too. I plan on spray painting the turnbuckle to match the bike. I'll remove it if it doesn't look or feel right. Good to know it can stay tight if done right.

[AZguy]

I think if I were going to carry "insurance" it'd just be some baling wire in my bag so that if it did come loose that would hold it up enough to get home

Insurance is like an airbag - you don't ever want to use it.... unless you need it... since reports of them coming loose are not nonexistent but apparently quite rare, I'd chalk those up to either a sub-par install or worst case from "settling in" right after the build.. and most builders worth their salt are checking torques frequently until they know what comes loose over time... anytime I throw the bike on the stand I'm checking pretty much every fastener - it's not like it takes more than a few minutes... I know after all those miles that the two bolts that hold the bracket for the thru-axle and disc brake mount to the frame will always get loose - no amount of loctite is going to stop them so they get checked more often... but I haven't touched the motor mount nut (and I didn't have room for the locking nut and only have one!) in forever...

[73Eldo]

I have one bike that mostly is on streets and its an aluminum frame. I think at this point its got 1500-2000 miles on it and I did have the BBS start creeking at one point but I tightened it with a socket instead of the $20 wrench and its been fine since. My other bike is the one I ride on the trails, fully rigid steel fat bike. That doesn't get as many miles but the ones it gets are pretty hard, lately I have been breaking spokes and that one was loose when I bought it used but I tightened it once before I had the socket and its been fine since.

At first I was concerned there was going to be issues but it just hasn't been a problem once I got them tight. Seems like you need at least one re torque which makes sense and seems reasonable. After having the socket I would not waste my money on the flat wrenches at all unless you really wanted to carry one on your bike. The socket is just so much better and easier to get em tight even for one build I would consider the socket. Flat wrench plus some sort of stabilizer that won't fit every frame cost more than the socket where I think you won't need the stabilizer.

[Zerrax]

Received today the Lunacycle Stabilization bar for BBSHD, placing was easy, looks firm enough for my 1000 watt Bafang, going to test drive soon!

After test drive the metal hose clamp broke... the 160 Nm torque was too much for it.
I'm going to try a more ridged U-clamp soon..

[fixed4life]

Here is what I did for my wife's bike. Old rack strut and a bit of Aluminum bar stock. The key is to stop the sagging, The downtube will absorb the torque load. If you put in a brace that tries to hold the motor away from it, it will end in tears (these drives have some serious torque).

[caleb242]

Here is what I did for my wife's bike. Old rack strut and a bit of Aluminum bar stock. The key is to stop the sagging, The downtube will absorb the torque load. If you put in a brace that tries to hold the motor away from it, it will end in tears (these drives have some serious torque).

It looks nice. I think the similar would be done with a suitable turnbuckle, too.

I'm sharing my installation of turnbuckle, if it'll be useful for someone else. That solution works for me too. In 3 months I didn't have any problem. I tightened it about three times (it doesn't get loose by backing out, but anyway now it doesn't need any tightening).

The thing to note is I used a turnbuckle from AliExpress, which isn't the same as in the original post. With this one, it's not possible to change the angle to inside/outside. I didn't need it because I could align it easily, but with other bikes it can vary.

As I have a overly-sized downtube I drilled it, and put a nut behind (that part under battery can be opened). That part doesn't look like carrying much, it was cut for battery anyway. Probably only very little trouble was holding that many washers during install. And a broken allen key, because I tried to tighten turnbuckle too much and the hole for the key is tiny.

Sure I could paint it better and maybe properly sized washers would look better (instead of many washers).

[stts]

waste of time

[Vance]

The turnbuckle strut is a great idea. I need to hold the motor in position on my tandem bike build due to it being mounted in an eccentric BB. Unwanted upward movement tightens the chain, so I can't allow the motor to butt up against the tube and still have tension adjustment. I could just make a wedge that jams it in place, but adjustability would require making different wedges, and endless fussing with half links.

There are several reasons why the motor isn't held as rigidly as in normal builds, but they are specific to this bike model (Gary Fisher Gemini) and the type of BB axle, and the width and diameter of the BB shell. I won't elaborate here. There have been many hoops to jump through, and this should fix one of the last!

[amj289]

First post here. These are all really great ideas. I personally don't like the commercially available brace that luna and others sell. I went a similar route to a turnbuckle using items I already had at home. I didn't want to re-route my shifter cable from my lower tube so I needed a spacer that would keep the motor away from the tube while transferring the load to the tube which was difficult because of the tube and motor curves.

For the load transfer when under throttle, I ended up using a JB-Weld putty spacer (yellow arrow in pic). the putty took the shape of the motor and the bottom tube and works great to keep the motor from pinching the shifter cable.

For the sag, I used an aluminum clamp on the seat tube, with a pre-tensioned steel strap.

So far, it's rock solid.

[73Eldo]

Did you make the clamp? I suppose a seat post clamp won't work there because there is no way to get it down there? Has to be split on both ends......

[BBSHDownunder]

this is what i did https://imgur.com/a/s9hEwZC

[jaaklucas]

Mine slipped on my first take at it. I saw a post on youtube where a fellow scored the bottom bracket frame with a hacksaw to give the nubs from the tightening flange a headstart on the biting into the frame. My frame is aluminium. Wrenched it back up real tight and seems to work. If not I will rig something up to the kickstand mount . Not all bikes have that option but it seems to be the best for me from all the creative solutions here!

[Downunderebikerz]

Hi,
I also had problems with a BBSO2 motor moving in bottom bracket so I made up a better mount by by welding an extension onto the rear of the standard mount plate, then a small but strong bracket to the frame. Its adjustable and motor is positioned so torque is contained by resting against frame. This effectively locks it there, Its going nowhere now.