I have a 28" Pashley with the 29" WTB Nanoraptor tire,
and I constantly get flats on this thing. The pressure is set
at 50-60 lbs. and I do light trail/street riding for a few miles at
a time – no hops. One time I went riding with a brand new
tube, and 15 minutes later, I got a flat. Most of the time it
will go flat after sitting for a few days, with a very small pinhole
at seemingly random points along the tire. I’ve washed out
the insides of the tire with water and it’s made no difference.
Is there a particular size tube that’s required? Usually
I get whatever 700mm size that’s available at the bike
shop. I almost never have these kinds of flats on my
24" Schwinn.
Import Car Fan <dsholt@hotmail.com> wrote in article
<NgfL8.22120$LC3.1643353@bgtnsc04-news.ops.worldnet.att.net>…
>
> tube, and 15 minutes later, I got a flat. Most of the time it
> will go flat after sitting for a few days, with a very small pinhole
> at seemingly random points along the tire. I’ve washed out
> the insides of the tire with water and it’s made no difference.
>
Small pinholes at random points along the tire sounds like spoke ends
poking through the tube.
Is there a rim strip covering the end of the spokes? If so, is it the
rubber kind that might have
slipped and exposed one or more of the spoke ends?
In article <NgfL8.22120$LC3.1643353@bgtnsc04-news.ops.worldnet.att.net>,
Import Car Fan <dsholt@hotmail.com> wrote:
)
)I have a 28" Pashley with the 29" WTB Nanoraptor tire,
)and I constantly get flats on this thing. The pressure is set
)at 50-60 lbs. and I do light trail/street riding for a few miles at
)a time – no hops. One time I went riding with a brand new
)tube, and 15 minutes later, I got a flat. Most of the time it
)will go flat after sitting for a few days, with a very small pinhole
)at seemingly random points along the tire. I’ve washed out
)the insides of the tire with water and it’s made no difference.
)
)Is there a particular size tube that’s required? Usually
)I get whatever 700mm size that’s available at the bike
)shop. I almost never have these kinds of flats on my
)24" Schwinn.
It’s possible that the rim strip isn’t seated properly. Next time you
have the tube off, look to see if any of the spoke holes are exposed
anywhere along the inside of the rim. If so, you can get new rim tape
at any bike store, or use nylon strapping tape to cover them up. (Actually
I prefer the Hutchinson red polyeurethane rim strips).
Your tube needs to be large enough for the tire–I doubt many bike stores
carry tubes marked for 28" or 29" tires, but make sure you get the largest
700c tube you can. A tube that’s too small could have odd flat behavior.
And make sure when you install the tire that the tube isn’t pinched between
the tire bead and the rim.
-Tom
Run your fingers along the inside edge of your rim…it’s possible there may be a sliver of metal sticking out…just file it down smooth (if you detect one)
The rim strip I’ve been using on my MTB for years, is 3 wraps of black electrical tape…it’s perfect.
> And make sure when you install the tire that the tube isn’t
> pinched between the tire bead and the rim.
Another possible reason for chronic flats is something lodged in your tire.
If a sharp object is protruding to the insides, it can cause one flat after
another. Carefully run your hands around the inside of the tire looking for
anything that snags.
Thanks for the replies. The spoke ends are recessed in the
rim, so they don’t protrude out, and the rubber strip around
the rim is secure. There are no sharp edges around the inside
of the rim, or anywhere else on it.
I looked at 4 of the failed tubes, and all of them had pinholes
at the outside edge of the tube, where it meets the tire, in between
the sidewall and where the tire touches the ground. Two
of them had holes in the same spot relative to the valve stem.
Sometimes I remove the tire completely and wash the inside
when changing the tube, other times I just leave it on and
don’t move it relative to the stem.
I turned the tire completely inside-out and checked the tire
thoroughly for any signs of defects or foreign objects, rubbing
my fingers along the inside surface, and could find nothing wrong.
There was not a spec of dirt anywhere.
I feel like it’s probably the tube and not the tire, because the
time it takes to get a flat varies widely from 15 minutes to
several weeks, and only the variable between flats is the tube.
Could be a pinch flat. Pinch flats usually usually come in pairs like a snake bite, but they can happen where you only get one puncture.
The solution to pinch flats is thicker tubes, more pressure in the tire, and/or a wider rim.
Those rubber rim strips truely are evil. Replace it with Velox tape. Even if the rubber rim strip hasn’t caused any of your flats yet, it is a future flat just waiting to happen.
