P
Paul Knudsen
I was wondering about this, too. If I had to get a new tire, would it
be possible to have the tread ground down to match the others?
Wasteful, sure, but not as much as buying four tires.
I was wondering about this, too. If I had to get a new tire, would it
be possible to have the tread ground down to match the others?
Wasteful, sure, but not as much as buying four tires.
T
Tom Reingold
y_p_w said:
I patched many tubular tires in my days. It takes forever to sew them
back up. I always glued patches to the tubes. I heard that the technique
you describe is possible in theory, but the trick is to get the patch in
the right place. I never knew anyone not to use glue. And once the tire
is deflated, I would expect the patch to shift to the wrong place. No
harm in using glue. But you are right that pressure is the real secret
to a patch, not glue. The claim that the glue vulcanized the patch on
was exaggerated.
Tom
Y
y_p_w
Tom said:
I've never ridden on a tubular tire/rim setup before. Always wanted
to try, and I bought a couple (incl a Mavic GL330) but never fully
built the wheels.
I think the key is that there has to be some sort of pressure keeping
the patch on. After patching several bike inner tubes, I've tried
inflating them w/o a tire. The patch would expand, and I'm guessing
that if I left it like that long enough, the cement bond might be
compromised. What really helps is that (when inflated in the tire),
the patch is pressed against the casing. What helps with a patch
inside a car tire is that the pressure presses the patch against the
wall of the tire. What I worry about with plug-only repairs is that
there's nothing holding the plug in except the glue. Even a patch
that isn't fully secured with glue will be forced against the tire
wall by the pressure.
BTW - I never liked the fancy patch kits from Rema, etc. I'd go
to Toys-R-Us and get a simple kit using generic rubber repair glue
and simple rubber patches.
T
Tom Reingold
y_p_w said:
It's really not worth the trouble any more, though it is a lighter
setup. I have some old tubular tires in my closet if you're interested,
though. Never been used. In my youth, I though they were "too nice" to
use, so I saved them and rode on cheap tires.
That's right. A tube would expand a long way without a tire, and the
patch falls off. But inside a tire, the patch stays just fine.
Interesting.
Many years ago, the bible on bike repair was called Glenn's. It showed
some archaic techniques that I never tried, including hot patching. A
few months ago, I started to patch a bike tube and noticed my glue had
run dry, so I tried hot patching, by pressing the inner tube hard onto
my stove's electric burner. It worked!
Tom
Y
y_p_w
Tom said:
Going back to Rema and the like, I was curious and looked up their
catalog. I think their bike business is just an aside, and their
automotive/truck division seems to be their biggest business. I
checked their catalog:
<http://www.rematiptop.com/Rema Site New/Passenger and Light Truck Tire Nail Hole Repair Catalog.htm>
Their "mushroom" patch is called the "Minicombi". They also have
flat "Universal" patches, but recommend they be used with their
"Rema Stems" as a two piece repair. They've also got "special blue
cement" along with carbide cutters for preparing the hole for the
stems.
Apparently a cutter is important to clear the sharp steel tread
fragments from damaging the repair, and to allow the plug to fill
the area well.
<http://www.chemco.ca/Products/Tire_Repair/Goodyear/gdy_carbide_cut.htm>
This is a lot harder than I thought.
R
Rick Courtright
y_p_w said:
At one time they were big in conveyor belt manufacturing, for big mining
equipment and such! Probably still are. Quite a spread from there down
to their ultra-light bicycle patches!
This is a lot harder than I thought.
Yeah, I think that might explain why just plain patching is so common
(at least in my "neighborhood")--I'd venture at least half our tire guys
around here didn't do so well in school, so teaching them the
intricacies of a two piece patching system might be a real job! They'd
probably ruin more tires than they fixed... with attendant liability
problems...
Rick
Y
y_p_w
Rick said:
Doesn't really seem all that complicated for someone who knows how to
mount and balance a tire, just not as simple as I'd hope it would be.
A proper two piece repair seems to be:
1) Remove the tire, pull out the debris, and check the hole for
further damage. Mark the area with a grease pencil.
2) Drill out the hole with a carbide cutter, to the next largest
size bit. This will help the plug fit better and will smooth
out any frayed fragements of the damaged steel belt.
3) Cement and pull in a stem/plug and cut off the excess.
4) Buff the area to be patched. Cement the area, let it dry a
bit and apply the patch. Let it completely dry before
remounting.
5) Mount and balance the tire.
Now that I think of it, $30 was dowright reasonable. OTOH - I
believe the place I bought my tire from will repair a tire for
free if you bought it there, I know they do free balancing.
One time I found a screw embedded in a tire. I took it to a
service station that patched it for $15. No rebalance though.
The guy seemed to be doing a competent job although he was
smoking in the back of a gas station. :-0