Allen Key Size

[105e 1]

Want to split some 1.9 front calipers to derust/,reseal, 8mm allen key is too small, 10mm too big, I bought a 9mm but that's too big as well, thank you.

[Tom Fenton 1,540]

I've a funny feeling if you look closely you'll find that they are not a regular hex socket bolt, but instead the socket is pentagon (i.e. 5 pointed). I'm not 100% on this but have a look and you'll soon see.

This is a kind of anti tamper thing to stop folk dismantling calipers.

However all is not lost, look on ebay for "pentagon brake tool" or similar and there are plenty of tools available for not much cash.

[105e 1]

Took the caliper out into the daylight and you are dead right, 5 sided, cheers (must get some better lights in my shed)