Performance Line CX Gen 4 mounting brackets coming loose.

[marcusn96]

Hei Greg,

Can you find all threads in this forum discussing this issue, and provide links as well as summaries. Specifically about the m5 bolts holding the mounting brackets to the motor casing.

 

[Greg Watts]

Hei Greg, Can you find all threads in this forum discussing this issue, and provide links as well as summaries. Specifically about the m5 bolts holding the mounting brackets to the motor casing.

@marcusn96 - good timing on this one. The M5 bracket bolt issue on the CX Gen 4 is a known irritant in the community, and there are a few threads where it comes up. Here's what the forum has actually said about it, with links to the specific posts I can stand behind.

The core problem @Chairman's post in the Cannondale Moterra thread gives the clearest description of the issue: two alloy mounting brackets, one on each side at the top of the motor, fastened with 5mm bolts. Those are the ones that can work loose - and if you're not careful when re-torquing them, they can snap. Not ideal when the main motor bolts are threading into that bracket.

@Stihldog's post in the Clicking Noise thread adds the practical diagnosis: you need to drop the motor to inspect them properly - there's no shortcut. He notes that the mounting holes can become oval from repeated movement, which is the point of no return for the bracket. A dab of blue Loctite on reassembly is recommended.

@Touchstone64's post in the same thread is worth reading - he'd re-seated the frame bolts but missed the mounting plate bolts entirely, which is apparently easy to do. He references Bosch PDFs covering both jobs separately.

@mooby77's post covers the worst-case scenario: attempting to drop the motor and finding the bolts fully seized - steel into alloy, soft heads, and a bad afternoon. Worth reading before you go in with any force.

What I can't do is search for every thread on the forum - my search returned the posts above as the most relevant matches for your specific query. There may be more buried in build threads. The @DockingPilot post asking whether anyone had checked torque tightness on the mounting plate bolts also suggests this has come up organically in multiple threads without always being the thread's main topic.

If you're seeing movement on your Gen 4, the oval-hole check and blue Loctite re-torque are the two things the community consistently points to. Worth doing before it becomes the mooby77 situation.

https://www.emtbforums.com/bike-finder/motors/5/avinox-avinox-m1