Marc,
I'm not a frame builder and I don't play one on Television either, but after 25 years of looking at tubing spec's, "4/10" used in connection with a name of tubing sounds like the thickness dimension of the tubing wall to me.
Also, again I'm not an engineer, but 4/10 of a millimeter would be as thin as you'd ever want to go on a tube set. Actually probably thinner than you'd want to go if you're over 100 lbs soaking wet ;)
Just guessing here, but I bet that Eddy Merckx's hour record bike was 4/10 Record and not the 5/10 Record listed in the Columbus tubing catalog. It only needed to last one hour before "beer canning" a top tube ;)
Chuck Schmidt South Pasadena, California
Marc Boral wrote:
>
> Chuck and Richard seem to be of the opinion that "4/10 Record" refers to the
> guage/thickness. However I do not see the logic. Record tubes are 0.5 mm. for
> triangle tubes and all stays, and 0.8 for the head tube. How do you derive at the "4"
> in "4/10" pertaining to thickness? I was also told by Colnago that Record tubing was
> specked in only certain tubes on the frame, not throughout. So this is why I believe
> that "4/10" refers to how many Record tubes were used. Please submit your input,
> because I certainly do not want to share incorrect info.
>
> Marc Boral