Quote Originally Posted by bedovelo View Post
Hi all

Thanks for this wonderful thread, I'm new in the form and this is my first post. Aimar, one question abut the seat tube sleeve from paragon, have you ever used them? do you braze them inside oder weld it? I have used sleeves from silva and always not sure what brazing rod to take. would prefer to use silver but if you weld on the sleeve you might burn the silver? and if you use braze I want be sure if its really brazed through. how are you doing this?
hope you do understand my english ;)
thanks
beat
Bonjour Beat

Your english is perfect to me... I'm spanish ;)

About your question, I've not used the paragon sleeve on customer frames, just a couple of test in tubes to see how it was, but it didn't appeal to me too much, and I prefer using the externally butted tubes from Columbus (either 31,7 or 28,6 ones depending on type of bike) and then bond an aluminium inner sleeve after the frame is finished, prior to painting.

But if you are looking to build using the paragon sleeve, which would be a perfectly good solution as well, you could do it tig welding the sleeve to the st, just with a nice fusion pass weld, so you have a "homemade" externally butted seat tube with your own length choice.
If going for the brazing solution, I can't really tell you much as I have not done it myself, but I assume if the brazing is placed down the st-tt-ss junction, you should be good enough when keeping good tig temperature (travel speed, heatsink, etc) as tig temp might be higher but in a much more focused area and for shorter time, rather than the bigger area affected by the flames on oa brazing, but nothing like actually having some practicing tests and see in real world if it's like that.

Cheers