Maybe I should chime in a little.
This has been discussed and very good detailed essays have been posted and
are lodged somewhere in the Library at/of Alexandria.
I have for over 60 years been prestretching sew-ups.
This does several things:
Make the tire easier to mount onto the glued, prepared rim.
Sees if they hold air.
Are they straight to ride?
This makes it posssible to return to distibutor for exchange. Once it has
glue you eat it. Dealers?, how's your client PR when you tell him sorry no
refund or credit? Or your own pissed off attitude when refused by your
rep/supplier? NO THANKS!
When mounting the tire to the rim after proper prep, I always put enough air
in to round out the tire so I can grab and stretch around rim and "pop over"
at the opposite side.
I start at top with valve, rim on floor, pull down the tire, push heel of
hand to keep tire from backsliding, stretch tire with fingers and with nice
prestretched tire can pop over with no gooo on sidewalls.
While stretching I check the valve and pull accordingly with R/L hand to
keep valve straight.
Then I put about 40/50# in to give firm body to tie and move it straight
into the well/bed of rim and straighten out the strip to run straight and
center as posible.
If you place the tire into the well as you are stretching, this exercise
will be much less work.
Putting full pressure into the tire immediatly after mounting sometimes
squeezes too much glue out the sides.
I put enough in to firm the tire so the cross section/volume of the tire is
full and firm, ooooh, and then when it's left overnite to dry, then fully
inflated the glue squeezeout should be minimal or nonexistent.
Cleanup should be very cosmetically simple and not what the hell do I do now
type exclamation.
Everyone who rides tubulars should have several tires for backup on clean
rims/wheels for the aforementioned points and to "age/cure" the tires for
best longevity and performance.
I suppose I could write Ted's Epistle to the Mechanichalonians but trust
you can fill in the gaps as good discyclists and go and do likewise.
Ted Ernst
Palos Verdes Estates
CA USA
<iamnofred@aol.com> Sent: Friday, April 17, 2009 6:37 PM Subject: Re: [CR] Squeaky tubular--remount?
As this subject continues to be discussed my guess (with over 25 yrs. Of riding tubulars and gluing all of them myself) is that the tire need to be aligned with the rim a little better. If the tubular is not flush with the concave surface on the rim there will be a small area of the rim where the tire will not have a tight contact which may cause a popping noise on each revolution. This can be done by putting about 20-30 in the tires after it is mounted. Spin the wheel and fined the wobbles. Grip the tire and by rotating/twisting the tire it will straighten out. Then air the tire up to 130-140 psi and let it sit overnight. I rarely prestretch my tires. I think that to glue well it is more about technique over strength. - the Conti Sprinter is a good enough tire that there is rarely a Sprinter with a wobble built into it. There is a very good chance that the seam tape if fine. Conti makes a very good tire (I prefer Vittoria , Torelli and a few others). On older tubulars this separation was a issue. Not with modern tubulars.
Gary Smith TLC4Bikes Raleigh NC ------Original Message------ From: Charlotte Bronte Sender: classicrendezvous-bounces@bikelist.org To: classicrendezvous@bikelist.org ReplyTo: j1847e@yahoo.com Sent: 17 Apr 2009 14:55 Subject: [CR] Squeaky tubular--remount?
I just returned from a gloriously beautiful spring ride here in southern On tario, marred only by a squeaky front tubular. It's a Contintental Sprin ter, which I recently mounted on a newly built Fiamme Ergal rim. It was a chore getting the last bit over the rim--it appears I didn't pre-stretch it well enough. So there is a bit of a wobble.
Is this what is causing the squeak, or a problem with the gluing, or other?
Any help appreciated.
Robert Aguirre Windsor, ON =0A=0A=0A
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