Continual punctures
03-28-20 | 06:02 PM
#26
Thread Starter
Senior Member
Joined: Dec 2005
Posts: 4,429
Likes: 257
From: Ashland, VA
Bikes: The keepers: 1969 Magneet Sprint, 1971 Gitane Tour de France, 1973 Raleigh Twenty, 3 - 1986 Rossins.
Zooming in on the rim, it looks like it has a fairly narrow central ridge where the nipple holes are. Sometimes when you have a rim profile that’s deep and narrow, the tube won’t fill the trench evenly. It’ll get hung up on the edges and then only the material earlier spanning the trench will stretch to the bottom of the trench. Whether it’s the localized stretch as such that pops the tube, or the thinness that makes it more sensitivite, I don’t know.
You have a couple of options if you want to research this route:
1) make sure to use the widest tube possible
2) inflate slowly, giving the tube time to creep into the crevasse
3) use some talcum powder, corn starch etc on the inside of the rim to encourage creep
4) if you don’t need the trench to get the tire on, fill it. I’ve got an old Dutch bike with a similar rim profile that had a length of rope as filler. Not a great choice of material b/c of water retention and long-term survival of the rim, but sound in principle. If I ever find a less rusty replacement rim I’d probably use a length of transparent fuel hose of the right size instead.
5) or deck it over. I’d probably use something sold as a tape rather than something sold as a rim strip. Duct tape with a long-lasting adhesive cut down to width for example.
You have a couple of options if you want to research this route:
1) make sure to use the widest tube possible
2) inflate slowly, giving the tube time to creep into the crevasse
3) use some talcum powder, corn starch etc on the inside of the rim to encourage creep
4) if you don’t need the trench to get the tire on, fill it. I’ve got an old Dutch bike with a similar rim profile that had a length of rope as filler. Not a great choice of material b/c of water retention and long-term survival of the rim, but sound in principle. If I ever find a less rusty replacement rim I’d probably use a length of transparent fuel hose of the right size instead.
5) or deck it over. I’d probably use something sold as a tape rather than something sold as a rim strip. Duct tape with a long-lasting adhesive cut down to width for example.
Then again, this doesn't necessarily guarantee everything works to perfection. Getting back from the first 5 mile ride today, I check out the tire and discover that the bead had slipped off the left side of the tire at the valve stem and going about two inches on either side. Happily, the Chinese tires had stiff enough sidewalls that it held the tube in place (50 yards? 4.9 miles?) during the ride and got me home safely. Immediately depressurized the tire, shoved the bead back in place, held it down with an old toe strap wrapped around the tire/rim and went back thru my inflating ritual. Held just fine second ride.
Going to take it out over the next couple of days on my usual five mile rides, only going further away from the house as I start to trust the bike.
__________________
Syke
“No one in this world, so far as I know — and I have searched the records for years, and employed agents to help me — has ever lost money by underestimating the intelligence of the great masses of the plain people. Nor has anyone ever lost public office thereby.”
H.L. Mencken, (1926)
Syke
“No one in this world, so far as I know — and I have searched the records for years, and employed agents to help me — has ever lost money by underestimating the intelligence of the great masses of the plain people. Nor has anyone ever lost public office thereby.”
H.L. Mencken, (1926)
03-28-20 | 06:05 PM
#27
Thread Starter
Senior Member
Joined: Dec 2005
Posts: 4,429
Likes: 257
From: Ashland, VA
Bikes: The keepers: 1969 Magneet Sprint, 1971 Gitane Tour de France, 1973 Raleigh Twenty, 3 - 1986 Rossins.
Ride with the same tube and patch it. This will give you a running record of where tie issue(s) is. (Remember, the cut is "n" spokes from theeh valve but can be in either direction.) My guess is that you will see the patches falling in near the same place (or directly beside each other if you hold the valve and pull the tube away from it). Now you know the issue is. Knowing exactly where to look makes finding an unknown much easier.
I patch tubes for routine flats whenever possible. For very small punctures, it tells me where to be looikng for that nearly invisible tire wire or tiny piece of glass or broken thorn, all of which can be entirely inside the casing waiting to cause the next flat.
Ben
I patch tubes for routine flats whenever possible. For very small punctures, it tells me where to be looikng for that nearly invisible tire wire or tiny piece of glass or broken thorn, all of which can be entirely inside the casing waiting to cause the next flat.
Ben
__________________
Syke
“No one in this world, so far as I know — and I have searched the records for years, and employed agents to help me — has ever lost money by underestimating the intelligence of the great masses of the plain people. Nor has anyone ever lost public office thereby.”
H.L. Mencken, (1926)
Syke
“No one in this world, so far as I know — and I have searched the records for years, and employed agents to help me — has ever lost money by underestimating the intelligence of the great masses of the plain people. Nor has anyone ever lost public office thereby.”
H.L. Mencken, (1926)
03-28-20 | 11:06 PM
#28
Mad bike riding scientist
Joined: Nov 2004
Posts: 29,148
Likes: 6,205
From: Denver, CO
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Three!? That’s not being cheap. That’s hardly broken in! I start thinking about giving up on a tube around 20 patches. Twenty five is silly and thirty is starting to reach ridiculous levels but not necessarily impossible.
__________________
Stuart Black
Dreamin' of Bemidji Down the Mississippi (in part)
Plan Epsilon Around Lake Michigan in the era of Covid
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Dreamin' of Bemidji Down the Mississippi (in part)
Plan Epsilon Around Lake Michigan in the era of Covid
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
