mikemowbz

So, I was just reminded - when I went to pull the post - that the 1984 Mercian Professional I acquired early this year and just fished out of storage has an odd-sized binder. The bike has what I think I've heard described as a 'Dutch' binder configuration on the seat lug, where the seatpost binder bolt screws into a threaded 'ear'.

The hex fitting is between a 5mm and 6mm size, and so I was wondering:

On a British bike such as this, of the mid-1980s, would that bolt likely be a 5.5mm hex fitting, or 7/32"?

The two measurements are very close, of course, but I wanted to see what I could find out...in the interest of precision.

Any insight

howsteepisit

My late 90's mercian is a 5.5 mm hex.

bobbycorno

My King of Mercia had the same kind of binder, and took a 7/32 allen key. I'd be amazed if an older Brit bike took ANY metric key.

SP
OC, OR

mikemowbz

Indeed, though an '84 is somewhat middlingly 'older'. I understand that metrication (seriously, it's a word) made major inroads generally in the UK in the late 1970s and early 1980s (though I have no idea to what degree this influenced the finer bike builders and their preferred bolts). In the end, I might just procure both and see which appears a better fit! I have neither on hand, unfortunately...

How old is your KOM?

mikemowbz

For the sake of closure, FWIW - 7/32 key works perfectly for the binder bolt in question on the '85 Pro.