Apollo owners - Check your wire grommets for sharp edges!


Well-Known Member
I've got two Apollos, which have been good bikes for us these past couple/few years. However, just recently, one of the bikes began having problems, which I eventually (as in too late) tracked down to the little black wire grommets that cover the holes in the carbon fiber frame through which wiring and hydraulics are passed.

Here's a shot of the damaged wires in place, with the grommet removed:

Here's a wider angle showing the hole with new wires in place:

Here's a shot of the grommet:

The left hold is for the attachment bolt, the center hole could be for a mechanical cable or hydraulic hose, and the notch is where the Bafang wiring harness wires go though.

Now, note that my two Apollos were setup slightly differently by Luna. The Bafang Ultra wiring harness has a big cylinder near one end, out of which come the individual wires for display, throttle, and 2 braking connections. On this bike, that big cylinder is inside the frame and so just the individual wires come out. On the other (older) bike, the big cylinder is outside the frame.

The back of this grommet is flat, so the hole and notch come to a sharp edge. I've taken to filing that edge to be somewhat rounded so that this damage won't happen in the future:

With the older bike, I actually zip-tied the big cylinder to the frame, which turned out to be a good thing since it prevented any rubbing back and forth against the sharp edge, as well as having the larger outer jacket at the edge, which is somewhat more protective. On the bike with the damage, the individual wires came out but were not secured, so every time the handlebars moved, the wires moved against that sharp edge. Over the course of 2-3 years that cut through enough to get to bare wire.

This eventually caused damage to two display units and the motor's controller. So, every expensive to fix.

I recommend checking all the wires coming out your black metal grommets for damage, and even proactively removing the grommets from the frame (if the center hole is used they won't go far) and seeing if any edges are sharp, and if so dealing with it (file/tape over, etc.).

Here's the thread where I'm debugging the damage done: https://electricbikereview.com/foru...ng-0-mph-with-bafang-m620-860c-display.51957/