C
Hmmm . . . it may be a bad idea to ooze downhill dragging the rear
brake just to chat with a visiting friend.
Jobst has mentioned blowing a tire off surprisingly quickly that way:
"My latest experience with that was descending Grosse Scheidegg to
Grindelwald with some of the most famous mountains and glaciers
arrayed in front of me. My friend stopped to take pictures so I
waited for him riding the rear brake over the lever hood at less than
10mph when BAM! the tire that I had previously ridden over steep
curving descents blew off."
http://groups.google.com/group/rec.bicycles.tech/msg/840cb236d153481e
And I run stretchy Kevlar bead tires, while Jobst probably uses tires
with tight steel beads.
Plus I run 120 psi, while Jobst sensibly runs lower pressures--and
weighs less than I do.
So let go of the brake, tuck in, and start coasting . . .
What's that odd thump-thump-thump?
Better slow down and look at my tire--
Better not use the rear brake to slow down, idiot!
Look, the rear tire's just about to come off the rim there, right by
the valve stem!
If I can get the cap off the Presta valve in time--
Bang-splat!
http://server5.theimagehosting.com/image.php?img=269bsplat.jpg
or http://tinyurl.com/yy7hgm
My friend took the picture of what happens when a Slime tube goes bang
just as you're reaching for the Presta valve.
And here's what the Slime tube and Kevlar-bead tire look like:
http://server5.theimagehosting.com/image.php?img=279asplat.jpg
or http://tinyurl.com/yxewwh
The black blob holding the Kevlar bead away from the ripped tire is
just a handy cyclocomputer, while a spoke helps the split Slime tube
to pose à la Goya's Maja.
I was surprised that the bead ripped out of the tire. A moment before
the bang-splat, he tire edge was clearly visible and undamaged as it
crept up out of the rim well toward freedom.
But memories of a few similar disasters years ago on wire-bead 27-inch
tires remind me that the tire usually rips away from the bead when it
creeps comes off rim, though I'm damned if I know why.
I don't count this as a goathead flat.
On an unrelated matter, these aren't goatheads, either:
http://server5.theimagehosting.com/image.php?img=270btumbleweeds.jpg
or http://tinyurl.com/trz6g
There were so many tumbleweeds blowing briskly across the highway that
I had time to stop and take a picture.
They weren't bad tumbleweeds, since they were rolling on the ground
instead of kicking up at head-height and flying across the road.
But they're still a good example of local variation. I gather that
some posters will use snow to make snowmen at Christmas instead of
spray-painting stacked tumbleweeds white.
Cheers,
Carl Fogel
brake just to chat with a visiting friend.
Jobst has mentioned blowing a tire off surprisingly quickly that way:
"My latest experience with that was descending Grosse Scheidegg to
Grindelwald with some of the most famous mountains and glaciers
arrayed in front of me. My friend stopped to take pictures so I
waited for him riding the rear brake over the lever hood at less than
10mph when BAM! the tire that I had previously ridden over steep
curving descents blew off."
http://groups.google.com/group/rec.bicycles.tech/msg/840cb236d153481e
And I run stretchy Kevlar bead tires, while Jobst probably uses tires
with tight steel beads.
Plus I run 120 psi, while Jobst sensibly runs lower pressures--and
weighs less than I do.
So let go of the brake, tuck in, and start coasting . . .
What's that odd thump-thump-thump?
Better slow down and look at my tire--
Better not use the rear brake to slow down, idiot!
Look, the rear tire's just about to come off the rim there, right by
the valve stem!
If I can get the cap off the Presta valve in time--
Bang-splat!
http://server5.theimagehosting.com/image.php?img=269bsplat.jpg
or http://tinyurl.com/yy7hgm
My friend took the picture of what happens when a Slime tube goes bang
just as you're reaching for the Presta valve.
And here's what the Slime tube and Kevlar-bead tire look like:
http://server5.theimagehosting.com/image.php?img=279asplat.jpg
or http://tinyurl.com/yxewwh
The black blob holding the Kevlar bead away from the ripped tire is
just a handy cyclocomputer, while a spoke helps the split Slime tube
to pose à la Goya's Maja.
I was surprised that the bead ripped out of the tire. A moment before
the bang-splat, he tire edge was clearly visible and undamaged as it
crept up out of the rim well toward freedom.
But memories of a few similar disasters years ago on wire-bead 27-inch
tires remind me that the tire usually rips away from the bead when it
creeps comes off rim, though I'm damned if I know why.
I don't count this as a goathead flat.
On an unrelated matter, these aren't goatheads, either:
http://server5.theimagehosting.com/image.php?img=270btumbleweeds.jpg
or http://tinyurl.com/trz6g
There were so many tumbleweeds blowing briskly across the highway that
I had time to stop and take a picture.
They weren't bad tumbleweeds, since they were rolling on the ground
instead of kicking up at head-height and flying across the road.
But they're still a good example of local variation. I gather that
some posters will use snow to make snowmen at Christmas instead of
spray-painting stacked tumbleweeds white.
Cheers,
Carl Fogel