Originally Posted by Johno59

"It's about what Scott was saying: it's the satisfaction of doing it the old way — of re-living a former age of cycling."

I apologise, it was Scott who you were quoting regards BITD. My point was clinchers have as much tradition as tubs - they just don't have, and never did have, the performance of a tub.
My 4 best bikes have tubulars and they all 1970s. It would be weird to change them to clinchers but I don't do many miles on them any more.
I do about 7 to 8 thousand miles a year and I just couldn't manage the cost using tubs. My final trip on tubs cost me 300 dollars as I punctured both my front and back. Clinchers would have reduced that cost to a dime.
Admittedly I no longer have to traverse a city center wherein there are all sorts of tub unfriendly debris on the road but I don't try and average 25 mph anymore so for me the low performing clincher makes more sense all round.
Having said that for my Colnago Supers and Eddie Merckx, what modern sealant do you recommend for a tub, how do you get it past the valve and will the sealant hold 120 psi?

Originally Posted by 63rickert

Take a close look at your valve. You will see that it is made in two pieces. Two piece valves have been around at least since the 1990s and are now almost the only kind. Find the two small wrench flats. Remove the valve core with a pair of pliers, a 4 inch adjustable wrench, a dedicated valve core tool, or sometimes it can be done with your fingers. It's a big opening. You can figure how to get the sealant in.

Panaracer Smart Seal. Orange Seal. Orange Seal Endurance. It is now cold outside. Sealant will not fix your tire while riding below 50 degrees F. Bring it inside and pump it up. In warm weather you could flat and never know it. Sealant does not last forever, it will dry out. Lasts longer inside a tube, could last a year, do not plan on more than 6 months. For bikes that spend lots of time on display and not many miles ridden, wait until you flat before using sealant.

Of course sealant holds pressure. 120 psi could be why you are flatting. If you are a large rider and need that much air in a skinny tire, replace with a wider tire. Excessive pressure was always a reason for repetitive flats. Rock hard tire slamming into sharp objects punctures more readily than a tire that flows over.

Shake well before using. 1 ounce does a skinny. Two ounces does a CX tire. One and a half ounces for 28mm tires.