I spoke with Tomo at Reynolds: Thomson stems ARE compatible with Reynolds carbon steer tube forks. I was wrong.
This is why: Tomo told me, that in the strictest interpretation of the line drawings that accompnay the forks the Thomson stem (according to the drawing) IS NOT compatible. However, Tomo went on to say that the tolerances of the clamping mechanism, the materials and finish used and other factors unique to the Thomson stem make it compatible with Reynold Carbon steer tube forks.
Tomo did say that other pinch bolt stems, such as the ITM Big One and Deda Zero (with the exception of the 2 bolt clamp style, which IS compatible) are NOT approved for use with the Reynolds carbon steer tube forks.
Also, Litespeed makes a titanium stem that has pinch-bolt configuration that Tomo at REynolds told me is compatible with their carbon steer tube forks.
Confused? yup, me too.... We are taking the safe way and the easy way and will be phoning Reynolds with questions ab0ut the stems we use with forks- maybe everytime we build one- until we know exactly what the standards are. I'd be lying if I said I'm not still a little confused. It is getting clearer though. The bottom line at this point is the Thomson stems do work, and I erroeously reported that they do not. My mistake. I was wrong. Again, the forum has done its job... The sacred tribunal of multisport knowledge.
The Tri Shop.com