[email protected] wrote:
> someone sniped anonymously:
> > So which is it? Have they or have they not changed "all that much"?
> > Since I happen to think that the data supports the latter, I will
> > grant you this: they may not be the best glues to use for a spare
> > tire. That would match my experience that the contact cement method
> > of gluing tires that you recommend does not create the strongest
> > bond with VM.
>
> If they have then they won't stick again with a spare tire.
I said, "the contact cement method of gluing tires that you recommend
does not create the strongest bond with VM". I did *not* say that it
will not create any bond. And I agree with you on something else: that
inflation constriction provides a significant force to keep tires on
tubular rims. Not the best, but adequate for my riding. I have stated
before that I don't worry about it that much on a rear tire.
> You can't have it both ways.
You're constructing a false dichotomy.
> Either it's a permanent one-use glue or it is a
> tacky one that accepts resuse for changing a tire.
Or maybe something in between.
> The best glues
> were available 30 years ago just as they are today.
No, they weren't. VM was not and I don't believe Conti was either.
> Glues for new
> uses have been developed since but for reusable rim glues, there has
> been no advance.
You really have no idea, and absolutely no evidence to support this
statement. You have pulled it out of thin air.
> > I have noticed taking VM-glued tires off and only seeing the white
> > glue, but I admit that doesn't mean anything. The real question is
> > whether the degree of squirm is as great as with the old glues.
> > Some squirm would produce some oxide; a quarter as much squirm might
> > produce the same amount of oxide if the tire was used 4x as long-
> > very, very difficult to draw any meaningful conclusions from the
> > presence of aluminum oxide without a very carefully controlled test
> > procedure.
>
> Oh BS! There wasn't a wheel that was ridden in the local mountains
> that didn't have significant creep on steep, hard braking descents.
> If your tires come off lily white I doubt that you demand much from
> your glue.
OR, THEY DON'T SQUIRM THAT MUCH! (Or they weren't on that long before
they had to be pulled off.)
> What happens to your spares when they are folded?
Depends.
> Does
> the glue stick to itself and need to be pulled apart to open the tire
> for mounting? This whole picture doesn't make sense.
I already told you that I use new tires for spares sometimes. I *don't*
specifically pre-glue spares; I depend on "inflation constriction" and
rim glue to get me home, and maybe old glue on the tire.
> http://www.engr.ku.edu/~ktl/bicycle/bicycle.html
>
> Selecting one of these items that harp on tire roll-off as if that
> were the big threat, I find the temperature one most revealing in its
> lack of field experience. Here again, tire roll-off is the thrust
> rather than the more serious one of linear creep that piles the tire
> up against the stem and causes a blowout. No mention of this is made,
> indicating that these folks don't descent hard or have any idea of the
> real hazard of tubulars that has plagues them for a long time.
Force to roll off a tire is simply a way to measure bond strength. If
the glue retains as much bond strength as other glues have when cold,
it doesn't matter which direction the force is applied to measure bond
strength. It will not be able to creep anymore than it will be able to
roll off. Or, are you suggesting that these glues are directional in
their strength, like some kind of carbon fiber glue?
I think their testing is valid, and can be extrapolated to the
conditions you are worried about. You certainly have no data to the
contrary and I think your criticism is the last resort of a person who
has nothing left of substance to stand on.
> In the days if yore, when many of the major Alpine passes were
> unpaved, descending with continuous braking was the norm and caused
> major tire creep. Beyond that, they talk of 70 degC when more than
> 100 degC is common. As I have related, steam hissing out of the stem
> hole in the rim alerted me to the higher temperatures caused by
> braking, after riding in snow for a longer distance.
This is not the days of yore. Nevertheless, if their testing shows
improved bonding at 70C it is probably still stronger than your old
glues at 100C. But I will keep your advice in mind the next time I am
descending unpaved Alpine roads and make sure that my bike is equipped
with a disc brake.
> # TUBULAR TIRES: ADHESIVES AND PRACTICE
> # PART 6
> # Adhesive Performance at Higher Temperatures
> # C. S. Chip
>
> (snipped background info)
>>>>>>>>
> # Proper adhesive selection and proper
> # application are necessary to minimize the potential for roll-off.
> # Given the temperature rise due to braking during descents, the
> # subsequent lateral stress placed on the adhesive bonds in corners
> # and slides and the potential for serious injury to the rider, it is
> # important for the mechanic to know how the adhesive will perform. <<<<<<<<
Exactly. So don't use your old glues, use VM. It is the only logical
choice for someone who has found tire creep to be an issue in their
descending.
> >>> Unlike you, I have ridden tubulars almost exclusively for the last
> >>> 30+ years.
>
> >> Oh? How do you know how many years I rode tubulars?
>
> > I made no reference to how long you rode tubulars, I don't know how
> > many years you rode them, and I don't care. What I *do* know is
> > that you haven't ridden them with any regularity for about thirty
> > years, and I know this because you have told us this over and over
> > here on this NG.
>
> You seem to gloss over your words "Unlike you..."
No, that was a comment on our relative experience with tubulars during
the period in which these new glues were introduced. Your experience
with the old glues is irrelevant.
> I am sure I have
> ridden at least as many tubulars in more conditions than you, judging
> from your claims.
Irrelevant experience, because it is not contemporary. In fact, worse
than irrelvant, because you think you are experienced, but your
experience is obsolete.
> Besides, the articles in the above web site should
> mainly convince readers that they do not want to partake in these
> arcane and time consuming rituals. I sense that they are trying to
> say something useful while covering their liability, the latter being
> the main thrust.
The papers appear to me to be academic in nature.
> OH? Please let me know what isn't up to date?
A. The glues referenced.
B. The gluing method.
> What has changes in
> tubulars other than that some of them have no stitching and others use
> adhesives that make them unrepairable.
It's not the tires, it's the glues.
> I see you believe in the one-flat-per-ride theory... which is mainly
> theoretical.
It's not a question of theory, it's one of probability.
> When riding alone we always carries two spares on any
> ride farther than we wanted to walk.
For the once-every-fifteen-years probability, I will deal with it when
it happens rather than try to strap on an extra tubular for that long
shot (unless I win the lottery in which case I gotta figure something
about my luck is changing).
> > I have spare wheels; they don't have tires mounted on them. That
> > hasn't really been a need since I last raced years ago.
>
> You mean... since I last rode actively... Racing has nothing to do
> with this.
Hell, I rode 165 miles in the last week. And, of course racing has
something to do with this- you train on different wheel/tire sets from
those on which you race. Now there is no race, so no special wheelsets.
> > Given that VM is a relatively new glue, and proven that at high rim
> > temperatures is retains more strength than the old glues did at
> > optimal temperatures, it is clear that it *has* changed.
>
> As long as it is a pressure sensitive glue it is also thermo plastic
> and will creep on hot braking descents.
So all thermo plastic materials have the exact same temperature
sensitivity and exhibit that plasticity at the same temperature?
> As I have described, I used
> thick cotton webbing soaked in epoxy as heat barriers on my rims to
> prevent this. Just the same, insulation has only so much resistance
> and in time heat comes through. I rode with heat barriers for many
> years and still have two sets of these wheels gathering dust.
Gathering dust is probably a good use for them.
> I don't think you've tried. If the tire is changeable on the road
> when flat then it can be pushed off the rim with thumb pressure.
As I have said before here, it is not really changeable on the road
after a flat without some kind of tool to pry the tire off the rim, at
least enough to get your hand under it. I have used I small allen
wrench which a was able to work under the tire and then use it to pry
up more of the tire.
So, yes, I have tried. If I can get it off with my hands, I did not do
a good job of gluing the tire.
> Stop creating straw men!
You first! That story about tubular glue resisting the heat of braking
on unpaved Alpine roads in the 60s is a strawman if I ever heard of
one.
> I would like to hear some factual data that supports your view of
> tubular tire adhesion and replacement.
The data is in the studies I referenced.
> It seems that you are only
> willing to say my perspective is all wrong and old fashioned. It is
> the tubular that is old fashioned.
It apparently, nevertheless, still presents the best weight and rolling
resistance available, despite your testing with Avocet.
> I think you know not of what you speak. You don't understand the
> difference between "like" and "as".
I think you don't understand the difference between colloquial and
"proper" English. Actually, no, I don't think that. I think that you're
making this pointless criticism because you got nothin' else.
