How do I tell if I have tubulars on my rim? There is no identifacation on the existing tires. They are 700 x 20's, about the size of your thumb! and are holding air real good. I intend to replace them with 700 x 28's. The alloy rims have nipple inserts. Yeah I know , take 'em off and see!!! Then the question do I have to stick with tubulars. Thanks guys

If the current wheelset is built for tubulars, then yes, you have to stick with tubulars (or get a different wheelset). Taking the air out of the tires and pushing on the bead should tell you pretty quick which you're working with.

and do the pushing around the valve hole, alot of times there is no glue
applied there anyhow.
before you do that, if you look at the tire is it shaped like an O cross section or an upside down U ?

O would be tubular, U would be clincher.
As Cuda said, if they are tubular rims clinchers will not work on them.
marty

Here's an illustration I put together a while back that may help. The top photos show a tubular rim and a tubular tire glued to it. Notice that the surface of the rim where the tire sits is nothing more than a concave curve. The glue, which is clearly visible in the photo, is the only thing (besides air pressure in the tire) that keeps the tire from simply rolling off the rim.

The bottom photos show a clincher rim with hooks on the both edges to grab the bead of the clincher tire.

Whew! I let the air out of a tire and to my good luck, it's a regular tire. I was pretty sure it was a regular tire after using the sight method, ie round or like an inverted u.Thanks guys!!

Make sure you have enough frame clearance for the size tires you want. Also, note that not all 700Cx28s are equal in width; my Continental Ultra 2000s are about the size of 700Cx25s from Specialized.

I'll let you in on a secret: Having tubulars is not a disadvantage. Actually they're slightly better than 700c clinchers, and well worth the time and trouble to learn the methodology necessary to use them. I'm currently running five wheelsets between four bikes - one set is clinchers. The next two wheel building projects are also tubular.

You really appreciate them when you get a puncture 35 miles from home . . . .

That's like being relieved your classic vintage bike is made of gas pipe, not Reynolds or Columbus tubing.

Seriously, it's easy to tell the difference. If you look at the pictures Scooper posted, you'll see the edge of the base tape on the tubular. Often it's peeling back and has loose hanging threads when it gets older. The sidewalls also look messy after a while with smears of glue. You won't see a brand new bike with tubulars in a bike shop these days, but the tires would look flat all the way around when there's no air in them, which would be about a week after they've been inflated. Nevertheless, tubulars must still hold a slight performance edge over the lightest and fastest clinchers, because many racers still use them.

After Oldyelers comment about base tape showing and getting sorta hairy, I checked the tires again and lo and behold tape was showing just above the rim edge. Yikes said I and proceded to let the air out and check again. Not really a clincher rim, straight sides. The tire did have tape on the sides just above the bead. Why I don't know. The tires are not tubular anyway. After much surfing the pros and cons of tubulars, I understand the reasoning for traditionists to prefer tubulars. For once in a while riders, clinchers are fine!!!!
Thanks again guys.

Well, if they are clinchers, you should be able to push the bead inwards when deflated and expose the tube. A tubular will take a lot more pushing to break the glue and roll the tire off the rim and you won't see the tube.

Why would a tubular be used in a rim that is not concave to fit the contour of the tubular tire? My rims look sorta like l l cross section. Gad zooks! I did expose about 3 inches of the tire and saw the bead but
\____/
no tube. When all the air is out, flat on the bottom, the rest of the tire retains a round shape. Tomorrow I'll see if I can lift the bead and see a tube. No evidence of glue on the inside of the rim. I can say one thing, you just can't "roll" the tire off the rim, I'll have to use tire tools!

l l
\___/ Cross section.

I hope you get the cross section idea!!!

a few rims were made for both.Also tufo makes tubulars for chencher rims.

Everything is cool! Changed a tire today. The rims are definately clinchers. The tire I took off was glued in several places and had tape on the side walls. Weird. I learned a lot from this experience, know a lot more about tubulars. Oh, yes, I did repack the bearings!!! Good riding, Frank