Gear sensor installation went wrong - bbs02


New member
Local time
10:21 PM
Feb 24, 2022
Ive installed the bbs02 gear sensor as per youtube video instructions, however I did damage the cable a bit when I removing the housing, and had to remove some strands from the cable, I hoped that wouldnt matter?
And now, I can no longer use my 3 lowest gears. The bike thinks I only have 6 gears seemingly and nothing happens when i try to shift into lowest ones.
Ive no idea why that is and so dont know how to go about trying to solve it.
Any ideas? Im not sure how shifting gears work in the first place tbh..
Ive made it much worse. I tightened the cable and as a result i lost another gear, so I loosed it instead by pushing the cable back into the bike, and now ive lost all gears except the highest gear.

Pics may help.

Im guessing I need a new cable now?


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First, stop screwing with it immediately.

You may need a new cable.

You also need a bike mechanic.
Yup. Didnt expect the gear sensor install to be harder than the motor install. Ill be taking it to a mechanic sadly.
You can read or watch videos on "How to Adjust a Rear Derailleur" if you're interested in learning how to do it yourself:

Be careful though if you do it wrong the rear derailleur may get sucked into the rear spokes which will total the derailleur and could also ruin the spokes.

It sounds like you haven't had a lot of experience with fixing bikes though, so the safest bet is probably a bike mechanic as @Nelson37 has suggested.
I sprung for a Park tool cable cutter, nice, clean factory like cuts on both cable and housing. Figure i might be putting together a few e bikes and have always appreciated nice tools.
I’m about to install a gear sensor this weekend. You’ve just described my nightmare.