Chris -
I lied, sorry

Just got home and took off the cover to my steering assembly ... went to my toolbox and my caliper is not there. I'm not sure if my neighbor borrowed it, or if a riding buddy has it. If I find it I'll be sure to let you know, but w/o the caliper I can't give you an accurate measurement, sorry. Using a tape & eye-balling it up (for whatever that's worth) it looks to be ~25mm on the steering bar but you obviously don't want to guess. I couldn't get a decent look on the pivot.
I'm hoping someone else can help you out today/tonight so you can get this done ASAP.
Edit - found out my Dad had it. Ran out to the garage and measured. By the looks of it, both "tubes" measure equal diameter ... 22mm.