What size is the handlebar bolt?

[No H2O]

I could have sworn I measured this at 34mm but when I finally did locate a 34mm socket it was too small by a hair. I think a 35mm would be too loose. According to my calculations 34.5mm would be 1-23/64 which isn't an available size. Perhaps it's a 1-3/8 or a 1-11/32?
This is on a 2004 Ridgeback. Can anyone confirm or provide the correct size?

 

[Mr. Wright]

I use a 1 3/8'' socket, and put masking tape on it, to protect the chrome.

 

[Mr. Wright]

Like this

 

[No H2O]

Thanks!