Originally Posted by
himespau
I was wondering there was something like that that it could be. Did the holder use one or 2 bosses? Was it proud enough to get over this number holder - I'm pretty sure it's brazed on, not screwed into a second boss?
The Blackburn holder was held in place with 2 water bottle bosses (M5 thread). The pump clipped into the holder and was held more securely in place with a velcro strap. The velcro strap went around both the pump and the top tube. I believe that holder would have worked with the 2 boss arrangement on your Colnago. The number plate boss could have slipped through the holder slot and the other boss and velcro stop been enough to security hold the pump.