Doug Landau said:Quoted message said:Quoted message said:IIRC you put your patched tubes in your seatbag. What is your
patch success rate?
Quoted message said:Quoted message said:100%. What is it that goes wrong with your patches?
http://www.sheldonbrown.com/brandt/patching.html
Quoted message said:I am not sure, perhaps using them too soon. I will stop using them
right away and see if it helps. I am not sure what you are saying
is the problem with that. you write:
# Assuming a patch was properly installed, it may still leak after a few
# miles, if used immediately after patching. Because tubes are generally
# smaller than the inside of the tire to prevent wrinkles on
# installation, they stretch on inflation, as does the patch. The
# stretched tube under the patch wants to shrink away from the patch, and
# because there is no holding force from inflation pressure at the hole,
# the tube can gradually peel away from the patch starting at the hole,
# while the tube under the remainder of the patch is pressed against it
# by air pressure.
# ---
Quoted message said:Why is this only a problem with patches which are used immediately?
Because the bond between patch and tube is uncured. As I mentioned,
if you make a mistake putting a patch on (nearly missing the hole) you
can pull it off again easily. You cannot do that tomorrow.
I had an interesting discussion with the REMA representative at
InterBike. I talked to him about the items I explain in that FAQ and
discovered that he was unaware of the reason for sanding off the skin
of the rubber (mold release) and was equally unaware that a fresh
patch could be removed easily. He proceeded to put a patch on a
sample tube and was certain that the patch could not be pulled off.
When he had completed his ritual, he handed me the tube and I pulled
the patch of with no trace on the tube of it having been there except
a clean spot. He seemed stunned.
The part about old patch removal in the FAQ is not there without
cause. Most who have tried to remove a cured parch have failed to do
so. That is why patch heating is essential. The same goes for the
BIC shaver for removing mold flash ridges, especially if the
perforation is on or near such a ridge.
I don't expect REMA to update their instructions in spite of the
demonstration and attempted education. Hey! Who knows more about
tire patching...? However, REMA makes excellent patches. I wish I
could convince the patch glue folks to not merely crimp the ends of
their glue tubes but to make a hermetic seal. We experience dried out
glue tubes far to often. They were aware of a screw cap leaking and
now have the cap end metal sealed, but the other end of the tube
breathes was well, right past the crimp. At least they use metal
tubes.
You may have noticed that imported sparkling water comes in glass
bottles. That's because plastic bottles leak CO2 and go flat before
they reach the shelf. Don't buy Club Soda at a store that has little
turnover. It has no fuzz.
Jobst Brandt
