I have a set of crash bars on my bike in case Matilda decides to take a nap. They protect the engine from having a sudden coming together with terra firma.

They work great and I’ve certainly tested them a few times. This is about the fastener choice.

Last time I was changing the oil and checking the valves I had to take off the left side crash bars to access the cylinder head. When reinstalling it I managed to strip out the socket from the longer of the bolts above. I figured I was just applying too much torque or something.

Today I was going to get a replacement so in case I need to perform a roadside repair I would have an intact bolt to play with.

I went down and checked on my bolt size gauge.

6mm? Nope.

8mm? Nope.

1/4″? Yep.1/4-20 3/4″ bolt.

1/4-20 3/4″ bolt.

This set has three metric fasteners on each side and a single imperial one. Who does this? I can see using one or the other standard for any given part. Knowing that this was going to fit a BMW matric would be the obvious choice.

Then throw in a 1/4″ bolt just to spice things up.


I’m honestly tempted to drill and tap in an 8mm bolt to replace it.