Removing bottom bracket - wrong size tool?

[gmaz]

I'm pretty new to bike maintenance, but am attempting to convert a bike into an ebike.

I need to add a pedal sensor to the bottom bracket but the tool I bought doesn't seem to fit my Diamondback Sorrento (about 20 years old). It looks very close to the right size but cannot be tapped in. What tool/size do I need to undo the slotted lockring/bearing cup(?)

Thanks

[gazza285]

Bigger hammer?

[Justin S]

Take out the alloy/ steel drive side first. The plastic non drive is there to keep it aligned and will split and break if you try to take it out first.

[gmaz]

Justin S said:

Take out the alloy/ steel drive side first. The plastic non drive is there to keep it aligned and will split and break if you try to take it out first.

Hmm.. am I likely to lose all the ball bearings? I just need to get the plastic ring out to fit the sensor behind it.

It looks like this.

[Whalespin]

Hey gmaz,

That’s definitely the right tool to remove the bottom bracket, it just doesn’t always go in all the way (or at least it doesn’t on my bike!).

However, if you just need to fit a pedal sensor then it doesn’t look like you’d need to remove the bottom bracket. Just use the crank extractor on the drive side and the pedal + chainring should come off so you can add the sensor.

Also worth mentioning that in this case the actual bottom bracket is a sealed unit so there’s no risk of any ball bearings falling out.

Hope this helps!