We all love our Triumphs, but surely I'm not the only person frustrated by the lack of a helmet lock on our bikes. Well, I've come up with a really cheap solution. I did this on my TT600 but it should be adaptable to most Triumphs:

Find or make a hole under the seat somewhere.

Be careful where you drill! Cutting through the ECU wires would be bad.

Pick up a carabiner keyring from the checkout line at Wally World for about a dollar. I got this one "free" from my title company, so actually it wasn't all that cheap :wink:

Loop the keyring through the hole.

Snap your helmet onto the carabiner (obviously this only works if your helmet has D-rings).

Secure the seat. Your helmet is now locked!
You'll need to do some precision eyeball measuring to get the clearances right for your helmet/bike, but otherwise this should be a pretty easy mod.