If the bubble is on account of riding the tire unglued (or insufficiently glued), and more of a bulge than a bubble, it is a difficult repair as the casing has sort of "lost it" in that area. Typically this will be around the valve stem, and in my opinion these cases are best saved for spares.
If the bubble is on account of something else, it may not be a difficult fix. Time consuming yes, but with patience fairly simple.
Eugene Sloane has an excellent section on tubular repairs in the first several editions of "the complete book of bicycle repair." Over the past 5 years, I have used that as a guide to repairing a few dozen sew ups, some more well done than others.
Good luck with it, and get yourself a nice sharp awl . . .
- Dan Polito
cicli polito 1433 east 33rd st down rear cleveland ohio 44114 440 263 1263 ciclipolito.com
>
> Message: 6
> Date: Tue, 7 Apr 2009 13:27:18 -0700
> From: Harry Schwartzman <harryschwartzman@yahoo.com>
> Subject: [CR] Tubular repair
> To: Classic Rendezvous <classicrendezvous@bikelist.org>
> Message-ID: <247230.20740.qm@web53502.mail.re2.yahoo.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Listers,
>
> I have a relatively unused fifties tubular currently glued to a fifties
> rim. It has a bubble in it. Is it worth getting it fixed? Will it be
> durable?
>
> -Harry Schwartzman
> Long Island City, NYC