Quoted message said:
Ozark Bicycle said:Quoted message said:Hi All,
After many thousands of kilometers, I finally got a flat. Too bad (for
me) I was cocky and didn't have a spare tube or pump or anyting else
with me. Luckily I was "only" 5km from home so the walk in 4C rain
wasn't that long. I didn't feel like ruining my cleats, so I decided to
walk in just my socks. The bike path is strewn with gravel which made
this too unpleasant, so I opted to walk in the grass along the edge of
the path. Wrong! That's reserved for dog-do! In the old days with
tubulars, I would have just ridden home on the flat. Anyway, enough of
that.
When I refitted the tire, the bead does not seat where it should in one
place, and this creates a very noticeable flat-spot. I tried
man-handling it into place with high and low pressures, as well as just
plain old 150psi to see if it would pop into place. No luck. Does
anyone have some handy tips on how to get this bead to come out where
it should be? These tires are not particularly tight, I had no problems
getting them on the rims with just my thumbs.
Was the result of an impact ("pinch flat"😉? Did you check the rim for
any possible damage?
Nope. It was a sharp little stone that worked it's way through. The
rims are fine, as far as I know. I tried rotating the tire around the
rim a bit, and flipped it the other way too. No dice.
Joseph
Dear Joseph,
I don't believe a word of it! As has been discussed, sharp little
stones do not cause flats in bicycle tires because otherwise car tires
would go flat, too. I sense UK myth and lore about flin--
Er, never mind. You ride where such things happen.
Is the spot that won't pop out opposite a spot on the tire where the
tire pops out a little too far, possibly where it was damaged?
That is, does the tire pop out a little further at Y, half-way around
the rim from the flat spot at X?
X--bead won't pop out axle Y-bead pops out a little far?
maybe where tire is damaged?
A damaged area can creep out further on the rim than usual, pulling
the opposite but undamaged side inward on the rim.
Other seating tricks include cleaning the offending spot on the
sidewall (leaving a little water and even soap on it), inflating to
10~20 psi and pressing with both thumbs, and even using tools like
this:
http://www.parktool.com/products/detail.asp?cat=17&item=PTS%2D1
After I made my own beadseater pliers from $6 Harbor Freight pipe
pliers, my tires began cringing and behaving themselves, but I leave
the pliers out in plain sight on a workbench just to remind the tires
that I'm no longer willing to put up with any nonsense:
http://groups.google.com/group/rec.bicycles.tech/msg/3b0dc8537b36f39a
You've already tried seating the tire at different spots on the same
rim without any success, so trying to mount the tire on another rim
(or a different tire on that rim) would be a somewhat pointless way to
check things.
But sometimes pointless cross-checks expose unlikely culprits.
Cheers,
F. Flintstone