help for mechanically inempt on changing a flat

[Phil Blumenkran]

OK I admit I'm all thumbs when it comes to bikes. While
trying to change a flat: (a) the new tube (right size I
think) didn't seem to stuff in right, it got all bunched up.
When I finally got it in, the tire was still flat, I took
most of the tube out and there were two holes (probably
pierced while trying to get tire/tube back on wheel). I
patched holes. Only NOW, when I pump the tube up to check
the fix, the tube constricts in the area where I got the
flat (the patch did stop the leak). Suggestions?

 

[carlfogel]

On 22 May 2004 11:59:00 -0700, [email protected] (Phil
Blumenkrantz) wrote:

>OK I admit I'm all thumbs when it comes to bikes. While
>trying to change a flat: (a) the new tube (right size I
>think) didn't seem to stuff in right, it got all bunched
>up. When I finally got it in, the tire was still flat, I
>took most of the tube out and there were two holes
>(probably pierced while trying to get tire/tube back on
>wheel). I patched holes. Only NOW, when I pump the tube up
>to check the fix, the tube constricts in the area where I
>got the flat (the patch did stop the leak). Suggestions?

Dear Phil,

Outside the tire, any tube will expand dramatically and
constrict where it's patched.

But inside the tire, the tube is constrained and hardly
expands at all, so the patches are no problem.

Carl Fogel

 

[Zog The Undenia]

Phil Blumenkrantz wrote:

> OK I admit I'm all thumbs when it comes to bikes. While
> trying to change a flat: (a) the new tube (right size I
> think) didn't seem to stuff in right, it got all bunched
> up. When I finally got it in, the tire was still flat, I
> took most of the tube out and there were two holes
> (probably pierced while trying to get tire/tube back on
> wheel). I patched holes. Only NOW, when I pump the tube up
> to check the fix, the tube constricts in the area where I
> got the flat (the patch did stop the leak). Suggestions?

A bit of talc on the tube seems to help with getting the
tyre on. It makes the tube slide over the rim but still
allows you to get a grip on the tyre. Some tyre/tube
combinations are awful to mount but generally speaking,
start mounting at the valve so the last bit is opposite the
valve, squeeze the beads together so they are in the centre
of the rim bed (if possible) and try a combination of
pulling the bead over the rim and pushing it with the balls
of your thumbs. If you must use tyre levers ensure the lever
is *under* the tube so it's not trapped between the lever
and the rim. You may still get a pinch puncture if the tube
is trapped between the tyre bead and the lever.

Even the really recalcitrant tyres go on reasonably well
once they've been mounted for a while and the bead has
stretched.

 

[Zog The Undenia]

Phil Blumenkrantz wrote:

> OK I admit I'm all thumbs when it comes to bikes. While
> trying to change a flat: (a) the new tube (right size I
> think) didn't seem to stuff in right, it got all bunched
> up. When I finally got it in, the tire was still flat, I
> took most of the tube out and there were two holes
> (probably pierced while trying to get tire/tube back on
> wheel). I patched holes. Only NOW, when I pump the tube up
> to check the fix, the tube constricts in the area where I
> got the flat (the patch did stop the leak). Suggestions?

A bit of talc on the tube seems to help with getting the
tyre on. It makes the tube slide over the rim but still
allows you to get a grip on the tyre. Some tyre/tube
combinations are awful to mount but generally speaking,
start mounting at the valve so the last bit is opposite the
valve, squeeze the beads together so they are in the centre
of the rim bed (if possible) and try a combination of
pulling the bead over the rim and pushing it with the balls
of your thumbs. If you must use tyre levers ensure the lever
is *under* the tube so it's not trapped between the lever
and the rim. You may still get a pinch puncture if the tube
is trapped between the tyre bead and the lever.

Even the really recalcitrant tyres go on reasonably well
once they've been mounted for a while and the bead has
stretched.

 

[Werehatrack]

On 22 May 2004 11:59:00 -0700, [email protected] (Phil
Blumenkrantz) may have said:

>OK I admit I'm all thumbs when it comes to bikes. While
>trying to change a flat: (a) the new tube (right size I
>think) didn't seem to stuff in right, it got all bunched
>up. When I finally got it in, the tire was still flat, I
>took most of the tube out and there were two holes
>(probably pierced while trying to get tire/tube back on
>wheel). I patched holes. Only NOW, when I pump the tube up
>to check the fix, the tube constricts in the area where I
>got the flat (the patch did stop the leak). Suggestions?

If it's the right size of tube, it's twisted. Put a little
air into it *before* you try to put it into the tire; if
it's obvious that it's way too large in diameter for the
wheel, you can stop before you make it worse. Having the
tube slightly inflated keeps it from getting twisted when
it's inserted, and it also helps to keep it out of the way
of levers and such.

--
My email address is antispammed; pull WEEDS if replying via
e-mail. Typoes are not a bug, they're a feature. Words
processed in a facility that contains nuts.

 

[daveornee]

Originally posted by Werehatrack
On 22 May 2004 11:59:00 -0700, [email protected] (Phil
Blumenkrantz) may have said:

>OK I admit I'm all thumbs when it comes to bikes. While
>trying to change a flat: (a) the new tube (right size I
>think) didn't seem to stuff in right, it got all bunched
>up. When I finally got it in, the tire was still flat, I
>took most of the tube out and there were two holes
>(probably pierced while trying to get tire/tube back on
>wheel). I patched holes. Only NOW, when I pump the tube up
>to check the fix, the tube constricts in the area where I
>got the flat (the patch did stop the leak). Suggestions?

If it's the right size of tube, it's twisted. Put a little
air into it *before* you try to put it into the tire; if
it's obvious that it's way too large in diameter for the
wheel, you can stop before you make it worse. Having the
tube slightly inflated keeps it from getting twisted when
it's inserted, and it also helps to keep it out of the way
of levers and such.

--
My email address is antispammed; pull WEEDS if replying via
e-mail. Typoes are not a bug, they're a feature. Words
processed in a facility that contains nuts.

I agree with werehatrack.
I think it also helps to practice at home.
I suggest that you lightly inflate the tire... after following werehatrack's method.. and then check 360 degrees around on each tire bead to make sure the tube isn't trapped under the bead. Pump up slowly to make sure the beads are properly seated and the tire runs smoothly all around.
If you can practice sufficiently you should be able to mount and remove most tires from most rims without any tools. Some tires are slightly undersized and some rims are slightly oversized... so this won't work on every combination.
Your patching constraint situation is normal... but better than many first timers, as it isn't leaking.
Park Tool has many great repair procedures on their site. They have one that covers this subject that may help further:

<http://www.parktool.com/repair_help/FAQtires.shtml>

 

[John Everett]

On Sun, 23 May 2004 03:00:03 GMT, daveornee
<[email protected]> wrote:

> If you can practice sufficiently you should be able to
> mount and remove most tires from most rims without any
> tools. Some tires are slightly undersized and some rims
> are slightly oversized... so this won't work on every
> combination.

After rolling the skin off my thumbs more than once I've
given up battling with tight tire/rim combinations. I ride
mostly with 700x20s, so a tight fit is more common than with
MTB tires for example. I just reach for the tire levers
first thing.

jeverett3<AT>earthlink<DOT>net
http://home.earthlink.net/~jeverett3