Rant: The amount of people who think a 6mm hex is a 5mm is driving me nuts

I swear, I see this at least twice a week in the shop. Someone brings in a stripped bolt on their stem or seatpost clamp, and it's always because they used a 6mm key in a 5mm bolt. The difference is only one millimeter, but it rounds out the head completely. I had a guy last Tuesday who forced it so hard he snapped the key. It's a $5 Park Tool AWS-5, not a breaker bar. How do you all handle explaining this to customers without sounding like you're talking down to them?

3 comments

3 Comments

spencerross5d ago

Could that chart also show a stripped bolt next to a good one?

daniel3915d ago

Honestly, I get why people mix them up. Those sizes are super close and the keys aren't always marked clearly, especially if they're old or dirty. Most folks aren't mechanics, they're just trying to fix their bike in a hurry. Maybe the shop should just put a big, clear chart on the wall showing the difference.

thea_bell5d ago

Right, that chart idea is solid. It needs to be dead simple, like a life-size picture you can hold your key up to. And like @spencerross said, showing a stripped bolt right next to a clean one would really drive the point home. People need to see the wreckage. Maybe even have a little display with a junked bolt and the wrong key stuck in it. A visual scare tactic beats explaining it for the hundredth time.