How To Attach a Water Bottle Cage to a Bike Frame without Braze-On Fittings

I have several steel frame bikes that do not have braze-on fittings on the seat tube or down tube for the attachment of water bottles.  I have used the "push-close clamping hangers" from the McMaster-Carr mail order catalogue to securely attach the water bottle cages to the frame.  In my case, two of my bikes had 27.2 mm diameter frames (1 and 1/16 inch) so I used the 30075T4 clamp.  Along with each clamp, you need to get the "threaded rod adapters" that slip into the clamp and allow you to attach the cage using a 1/4" diameter, 20 thread per inch, 1/2 inch long machine screw.  Another of my bikes had a larger seat tube, and I used the 30075T5 clamp hanger.  I've used these clamps for a few years now, and they hold the water bottles quite securely.  Here is a picture from the McMaster-Carr catalogue page of the clamps:
 


Here is a link to the catalogue page:http://www.mcmaster.com/#catalog/117/1502/=ckmqie

The clamps are available in a variety of sizes, so you really need to measure the diameter of the frame tube you are attaching it to.