Alan frame, under sized headset solution?

[stringfellow1946]

I am no expert but being dissimilar metals won't there be a chance of galvanic action / corrosion with a brass (Copper / zinc) shim?

Shaun

Its no different to fitting an Alloy Seat Post or Alloy Stem or even an Alloy Headset into a Steel frame. Apply plenty of grease if you think you want to get it out again in the 5 years time.

 

[gadgetman2000]

Sorted - Britvic tonic water can to the rescue. Glued the 'shim' to the headset races with the thinnest smear of Araldite and pressed them home before it set, with Loctite between the shim/races and head tube. Just enough of an interference fit to be solid but not too much resistance that cracking the lugs was a worry.

Thanks for everyone's suggestions. The Alan is taking shape!