Joined: Apr 2008
Posts: 2,638
Likes: 14
From: Maidstone, Kent, England
Bikes: 1970 Holdsworth Mistral, Vitus 979, Colnago Primavera, Corratec Hydracarbon, Massi MegaTeam, 1935 Claud Butler Super Velo, Carrera Virtuoso, Viner, 1953 Claud Butler Silver Jubilee, 1954 Holdsworth Typhoon, 1966 Claud Butler Olympic Road, 1982 Claud
Unusual for an LBS not to have a 7mm allen key? Ask a car mechanic to try a 7mm size in your bolt head. If that's not the right size, it might just be in one of the old "Imperial" sizes - measured in fractions of an inch, not in millimetres. They really are a different size to metric. The good news is that you can buy sets of both Imperial and Metric in good quality steel quite cheaply. Having said that, all of my TTT stem bolts are all 6mm, but they are from the 1970's and the size might have changed.