BBSHD mounting bolts don't fit?

[flyingpylon]

I recently received my BBSHD kit and have started putting things together to see how they fit. Unfortunately I seem to have run into an issue right off the bat.

I have a 68mm BB and ordered the 68-73mm kit. The drive I received has a sticker that says 68mm.

1. Either I am doing something incredibly boneheaded, or the two mounting bolts do not fit into the holes provided on the drive. When I say they don't fit, I mean that they literally will not go into the holes, not that they are too long or too short. They seem slightly too wide. I can just barely get them started, but they immediately get very tight and it feels like I will strip the threads on either the bolts or the drive if I start to crank on it. The kit came with additional bolts and spacers in a bag marked 73 but they don't fit either and I assume those are intended for a 73mm BB anyway. I have watched a few installation videos and the bolts seem to go right in with no issues.

2. Did I get an "old" drive? I thought I read that newer drives are marked 73mm or 68-73mm and only the older drives are marked 68mm.

I will open a ticket with Luna support if needed but since it's the weekend I was hoping maybe someone else could provide some guidance.

[Galroc]

I assume you are using the provided spacers for those two bolts? The issue I ran into was the walls on those two spacers are too thick which causes those bolts to be out of alignment with the holes. I ground down one side of the spacers to give more clearance. Also, I seem to recall there is a bit of paint in the threads and it was a very tight fit for those two screws. Just work the screws in and out slowly to clear the paint out.

[flyingpylon]

Thanks for the reply. No spacers in the equation just yet, I was test-fitting things to see if the spacers were required. The bolts just won't go into the holes. I wondered about the possibility of paint in the threaded holes too and have tried working the bolts in and out multiple times, but it's really at the point where it feels like I'm going to damage something. At this point I assume I will need the spacers since the holes appear to be very shallow as well.

[M 2.0]

With two of the Kits I ordered, a 68mm and 100mm I had to re-tap the holes to get the bolts threaded correctly. If I remember it was a 6mm tap in case you want to do the same.

[Hladeky]

Hello
I had the same problem.
Bolts and holes are too much coloured. Just carefuly little by little screw and unscrew, put some oil and go on until the end. I then installed without problems.

[marjamar]

The powder coating was in the threads on the 2 kits Andy and I installed on our bikes. Andy's was the hardest to get started, mine was less tight so they went in easier. All we did was tighten and loosen a little at a time until the bolts were past where the powder coating was in the threads. If Andy's was much worse, we would have chased the threads out with a tap.

[flyingpylon]

Thanks for the replies. Sounds like I may need to try a little harder to clean out the threads. Based on some additional info, I should do that with a thread chaser, not a tap. A tap is designed to remove metal, and I am very reluctant to do something like that for fear of screwing it up and being left with an unusable drive (I suppose it would just be the housing that would need to be replaced, but it's still not something I'd want to deal with).

[marjamar]

Maybe a chaser, but all I have ever used over the years is a tap. Just be careful to start it at the same point as the original threads is all.

[marjamar]

Actually I guess I should mention I have very often made a thread chaser if I didn't have a tap on hand. I would just use one of the bolts (or if find an extra one) and use a dremel cut-off wheel and cut a vertical line across the threads at least 5 threads long. Cut it maybe double the thread depth or so. Just start the bold as normal and every 1/4 turn or so back it out. It will clean any burs (or in this case powder coat) from the threads as you step it down.

[flyingpylon]

Okay, problem solved. I made my own thread chaser and added a small drop of oil. Within a few turns everything was cleared out and the bolts go right in. I feel kinda stupid, perhaps I was just being overly cautious. But I learned something so that's worthwhile. Hopefully someone else will find this thread useful and be spared the time, trouble and embarrassment. Thanks for everyone's help!

[marjamar]

Good, never ever bad to learn good things.

[Arboh]

I experienced the same bracket to motor hole mismatch and reported it through a ticket to Luna Cycle. I explained that if this problem exists on mine, it very likely exists on others as well. Not sure if any action was taken, or how may units are in the supply chain, but I am confident that this issue will continue until somebody works with Bafang to figure our what changed and why.

[g725s]

Bafang should do better, as it is not that hard to check powder coat in the threads or eliminate it to begin with.
They are charging a pretty penny for these units for what they are, in this day and age anyway.
Hoping other quality control is better....

[marjamar]

It's a coating prep issue. We do all types of technical coatings and surface prep, including sandblasting. What has happened is someone either forgot or did not understand any threaded surfaces must be protected during any abrasive prep process and any coating process. Had they done this, there would not have been any issues with bolts not fitting.

[Eric Luna]

yes thanks for this we have recently got word of this problem and are now opening every drive and checking the threading before shipment....

Sorry you went through this..... and thanks everyone for assisting us in pinpointing this problem.

[Arboh]

Eric... This issue may have more than one facet... Could be thread problems.. but at least on my HD (I turned in a ticket on this about a week ago) the holes in the mounting bracket just do not align with the holes in the HD motor housing. I had to oversize one of the small holes in the mounting bracket to allow the allen bolt to thread into the motor at 90 degrees. If I had tried to thread in the bolt without enlarging the hole size, it would have cross threaded.

[Eric Luna]

yeah we have seen some of the triangle mounting brackets have slightly smaller holes than the bolts....this is an easy fix ....the holes just need to be drilled out a bit.