'''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Originally Posted by mparker326
I'd say it was 5/32.
That's the best guess for a loose bearing (or retainer held loose balls) but I also recommend taking the old headset apart as you will need to confirm both the bearing size and the number of balls in each race.
One additional problem with a Raleigh of that vintage; the fork/headset threading is not the ISO standard used by nearly everyone else so you can't just buy an over-the-counter replacement if the old one is badly pitted. Here is Sheldon Brown's article on Raleigh threading. Scroll down to the section on headsets: