bike tires always lose pressure

"Ablang" <[email hidden]> wrote in message
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Quoted message said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

Do you have a schrader valve, or a presta?

--
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On Mon, 9 Feb 2004 00:55:15 +0000 (UTC), Ablang

from AOHell Sucks said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

Losing a little bit of air is normal. Losing 15 psi a week is at the high end of normal. You may
have a really slow leak, or you may not.

--
[email hidden]
Bridges - build - burn.
38

Ablang said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The tires
are rated for 65 psi, but they always tend to be low at least 15 psi every time. I always use an
air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

Yes. This is normal.

Try this. After inflating your tires to 65 lb., detach the pump. Then immediately reattach it and
note the pressure. Is it 65 lb., or less?

"Ablang" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

--
Hilary Duff turns 18 in this amount of time (I know you're waiting for

it):

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=2005&hour=00&m

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In article <[email hidden]>, [email hidden] says...

Quoted message said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

My road bike tires used to, until I started tightening up the presta valve closures a bit more. Now
they lose hardly anything (< 10 psi per week, even when kept at 120).

--
Dave Kerber Fight spam: remove the ns_ from the return address before replying!

REAL programmers write self-modifying code.

On my mountian pike, which has schrader valves, the pressure remains constant - I check them
frequently. My road bike on the other hand has presta valves. The front remians the same while the
rear needs to be re-inflated regularly...

"Ablang" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

--
Hilary Duff turns 18 in this amount of time (I know you're waiting for

it):

Quoted message said:

timeanddate.comcustomcounter.htmlOpen ↗

Quoted message said:

=2005&hour=00&m

"It's not that some people have willpower and some don't. It's that some people are ready to
change and others are not." -- James Gordon, M.D.

In article <[email hidden]>, [email hidden] says...

Quoted message said:

Ablang said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I always
use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

Yes. This is normal.

Losing some is normal, but losing 15 psi out of 65 in a week seems a bit much to me.

--
Dave Kerber Fight spam: remove the ns_ from the return address before replying!

REAL programmers write self-modifying code.

Ablang said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

Yes, but the speed of loss depends on size of tyre and size & type of inner tube. All tubes are
porous so they continually loose air. Thicker and wider tubes hold air longer, and the loss is less
noticeable the fatter the tyre is.

Your gauge may also be releasing air. I suggest only checking by hand when not inflating with a
gauge on the pump/compressor. You should get to know what feels right. Press both thumbs hard into
the sidewall.

~PB

Ablang said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

If you're using cheap Schrader tubes, the problem might be cheap valve cores. You can buy spare
valve cores and a valve tool from an automotive parts store. Replacing the cores often slows leaks
considerably.

Quoted message said:

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

I'd consider losing 15 psi per week too much, and would replace the tubes if necessary. Personally,
I like Michelin Air+ tubes, as these don't leak as fast as many others:
cycleus.webmichelin.comtubeairplus.htmOpen ↗

John

"David L. Johnson" <[email hidden]> wrote in message
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Quoted message said:

Doug said:

On my mountian pike, which has schrader valves, the pressure remains constant - I check them
frequently. My road bike on the other hand has presta valves. The front remians the same while
the rear needs to be re-inflated regularly...

I don't believe it is the valve that is the difference. Properly closed Presta valves are very air-
tight. You, and the OP, may well have a slow leak. Bent presta valves also can leak, so if one is
not careful when inflating with a frame pump/mini pump, problems can develop.

Check the tube. Take it out of the tire, inflate until is is fairly full for being out of the
tire, and put it in a tub of water. Look for bubbles. You can also take the wheel and tire and
dunk it (partially) into a tub of water, but then localizing the source of the leak can be a
problem.

--

David L. Johnson

__o | There is always an easy solution to every human problem - neat, _`\(,_ | plausible, and
wrong. --H.L. Mencken (_)/ (_) |

Before you pull the tubes out, mix up a bit of soapy water, inflate the tires to normal pressure,
and then apply some of the soapy water to the valves to see if you get bubbling. I chased these slow-
leak sort of problems on my road bike tires, thinking I must have pinhole leaks in the tubes, but
discovered what was actually leaking were the Presta valves. Some have removable cores that have a
small band of plastic on them to act as a seal. It's easy for these bands to be cracked from too
much torque, or alternatively for the core to be a bit too loose. Either will cause a leak.

Quoted message said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

Hilary Duff turns 18 in this amount of time (I know you're waiting for

it):

I don't know how heavy you are to start with, but it probably won't matter one way or the other to
Hilary Duff that you're losing 15lbs/week.

Regarding your Magna, you've probably got standard car-style valves in your tubes (not the presta
valves found in higher-end bikes). All tubes lose a bit of air over time, but 15lbs/week is a bit on
the high side, so I'd check to make sure you're not getting some leakage at the valve core. You can
go fancy and use soapy water, but a bit of saliva/spit on the valve will test for leaks just fine.

If your valve cores aren't leaking, you might remove the tire & tube from the rim and check for very
tiny thorns (or anything else sharp) protruding through the tire. You'll also want to make sure the
rim tape is properly covering the spoke holes, and that there are no sharp edges on the inside of
the rim. But the rate of leakage is slow enough it might be very difficult to find the actual spot
in the tube where the air is coming out.

--Mike-- Chain Reaction Bicycles chainreactionbicycles.comchainreactionbicycles.comOpen ↗

Assuming your p.s.i. reading is correct, you probably have what's known as a Very Small Hole in your
inner tube. In the western half of the US, the best way to get these is from a tiny goathead spike
which makes the Very Small Hole but also plugs it near-perfectly, resulting in an ultra slow leak.
When you repair or replace the tube, be certain to seek and destroy the spike before stuffing the
fresh tube into the tire.

If you live in the eastern part of the US, it's probably something else, perhaps a "Michelin wire."

Robert

On Mon, 9 Feb 2004 00:55:15 +0000 (UTC), Ablang

may have said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

15 psi in a week is a little high, but if it's from both tires equally, I'd guess that it's just
porosity loss. If that's the case, you'll just have to inflate as needed. Bike tires do lose some
air normally; the narrower the tire, the faster the pressure drop tends to be. You might try
tightening the valve cores just a bit; this is a frequently overlooked source of slow leakage.

--
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I had the same problem with my road bike using 700CX19 tires. I tried different tubes, some were
better than others but they all seemed to lose PSI and I had all sorts of flat tires. Eventually I
bought a special tubeless tire made by TUFFO Corp. I can pump this clincher to 175 PSI, use no tube,
and lose no air. They also make other tires for other sizes. You can go to www.tuffo.com for more
info and you can order them from Clive de Sousa at glorycycles.comtufo.htmlOpen ↗ . I have put
on about 1000 miles and the tires show almost no wear too!

"Ablang" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

--
Hilary Duff turns 18 in this amount of time (I know you're waiting for

it):

Quoted message said:

timeanddate.comcustomcounter.htmlOpen ↗

Quoted message said:

=2005&hour=00&m

"It's not that some people have willpower and some don't. It's that some people are ready to
change and others are not." -- James Gordon, M.D.

Quoted message said:

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

yes, however, with some variation. my roadbike will lose perhaps10-15 percent of the pressure in a
long day´s ride, whereas the mtbs will lose 1 percent or less. The road bike has twice the pressure
of the mtb, about 8.5 bar, and much less air volume, can´t say how much less, but I doubt it is even
20 percent of the air on a mtb.

Per lowdin.nulowdin.nuOpen ↗

Per Löwdin said:

Quoted message said:

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

yes, however, with some variation. my roadbike will lose perhaps10-15 percent of the pressure in a
long day´s ride,

Holy moly, it took a week or so to drop that much on my old road bike with 23x700c tires.

Greg
--
"Destroy your safe and happy lives before it is too late, the battles we fought were long and hard,
just not to be consumed by rock n' roll..." - The Mekons

If you use the fattest tubes you can get in, you will lose least.

Quoted message said:

If you use the fattest tubes you can get in, you will lose least.

I don´t see the loss of air as a problem, typically I will pump it up to 8,5 bar before the ride,
then we will ride 150 km or so and afterwards it will be down to 7,5 or 7 bar. It is a Klein Quantum
with very skinny tires (Bontrager Racelite) and probably pretty skinny (light) tubes too, have done
some 3200 km without a flat, so I have had no reason to have a look at the tubes. The leakage is
fastest at higher pressures: i.e., when there is less pressure it seeps out slower. Now, the bikes
have been standing idle for 3 month and I figure the pressure is down to 4 bar or less (have not
measured) and I will let it go down further to spare the wheels before the road season starts.

Per lowdin.nulowdin.nuOpen ↗

Ablang said:

I ride my bike (Magna) no more than once/week. Before I ride, I check the tire pressure. The
tires are rated for 65 psi, but they always tend to be low at least 15 psi every time. I
always use an air compressor to pump it back up to 65 psi.

I'm curious. Does this happen to your tires, whether you have a road bike, dirt bike, or
touring bike?

Yes, particularly for high pressure tyres and latex tubes.