The Forgotten / Hidden Bolt That Ruined My eMTB Shifting (and How I Fixed It!)

Ever had your shifting feel “just a little off” and couldn’t figure out why? On my Niner eMTB, I ran into a weird problem—everything looked fine but the gears just wouldn’t shift right. After a full teardown, I found the real culprit: a loose derailleur hanger bolt hidden deep in the frame.

In this video, I’ll walk through the symptoms, my troubleshooting process, the obscure cause, and how to prevent it from happening on your own mountain bike or eMTB.

This fix applies to most modern full-suspension bikes (Niner, Specialized, Trek, Santa Cruz, etc.) and especially to Shimano and SRAM derailleur setups where shifting precision is key.

Chapters / Timestamps:
00:00 Intro – Strange shifting on the Niner eMTB
00:42 The first clues: sloppy shifting on the trail
01:32 Usual suspect check – derailleur bolt & hanger alignment
02:41 Temporary fixes and trail-side testing
03:58 Back at camp: minor improvements but still not perfect
05:10 The breakthrough – finding the real problem
06:24 What a loose hanger bolt does to your shifting
07:30 Secondary issue: how it loosened the rear axle
08:45 The final fix – Loctite and torque check
09:25 Preventing future shifting problems
10:02 Wrap-up & key takeaway

Key terms for search:
eMTB shifting fix, mountain bike shifting problem, derailleur hanger bolt loose, e-bike maintenance, Niner eMTB troubleshooting, Shimano derailleur indexing issue, loose axle wobble, MTB repair tips

Gear Mentioned:
Niner eMTB
Shimano drivetrain
Derailleur hanger alignment tool
Loctite (blue 243)