How much air??

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

Quoted message said:

I have a Trek 7200, the side of the tire says 60-80 psi. When I bought

the

Quoted message said:

bike the owner of the store told me to put it about 100 psi. So I did.

Ran

Quoted message said:

it that way for well over a year. Last week both tire went flat on the

same

Quoted message said:

day. The rim liners had holes and that led to the holes in the tubes. Replaced rim liner with
cloth ones. I am a big guy 235 lbs. Of course I like running 100 psi and don't really mind
changing a tube ever year or

so.

Quoted message said:

What pressure would you run. Most rides are 10-20 miles just for a little cardio and
stress relief.

What are they, 700x37c? I'd probably go with 80, personally, but 100 would help prevent pinch flats,
which is probably what the shop guy was thinking. You could probably use less in the front tire,
since on a hybrid most of your weight is on the back.

Liners shouldn't fail that soon. I hope your shop replaced them for free.

RichC

In article said:

I have a Trek 7200, the side of the tire says 60-80 psi. When I bought the bike the owner of the
store told me to put it about 100 psi. So I did. Ran it that way for well over a year. Last week
both tire went flat on the same day. The rim liners had holes and that led to the holes in the
tubes. Replaced rim liner with cloth ones. I am a big guy 235 lbs. Of course I like running 100 psi
and don't really mind changing a tube ever year or so. What pressure would you run. Most rides are
10-20 miles just for a little cardio and stress relief.

Most rim liners on mass-produced bikes are not very good quality anyway. If you were to change
anything I would suggest running the largest tire that will reasonably clear the frame and fork. If
you have big air volume you won't need to exceed the recommended inflation. But I don't think
running the tire at 100 pounds was really an error.

--Paul

David Lawson said:

I have a Trek 7200, the side of the tire says 60-80 psi. When I bought the bike the owner of the
store told me to put it about 100 psi. So I
did. Ran it that way for well over a year. Last week both tire went flat on the same day. The rim
liners had holes and that led to the holes in the tubes. Replaced rim liner with cloth ones.
I am a big guy 235 lbs. Of course I like running 100 psi and don't really mind changing a
tube ever year or so. What pressure would you run.

It really depends on the tire. If these are pretty wide tires, then maybe 80 psi is enough for your
weight. If they aren't, maybe you should get wider ones -- they would be more comfortable and would
allow you to use lower pressure without getting pinch flats.

Flats can happen for a number of reasons. It seems like yours were due to cheap rim tape.
Replacing that is the first order of business. Any rim strip should be able to withstand 100+ psi
with no problem.

But I would worry about using higher than rated pressure. It would, maybe, be OK, but maybe not. Why
do you like using 100 psi better?

--

David L. Johnson

__o | The trouble with the rat race is that even if you win you're _`\(,_ | still a rat. --Lilly
Tomlin (_)/ (_) |

The Trek website lists 700x38c tires for this model. Maybe 100 psi works for you because of your
weight, but lighter weight people would be better off at the recommended pressures. Keep in mind you
have a harsher ride at 100 psi. The owner was probably thinking of avoiding "snake bite" flats where
the tire and tube compresses against the rim so hard over bumps that the tubes get characteristic
side-by-side holes. The usual cause is low pressure in the tube. The higher pressure probably
contributed towards the rim liner failure. The stock thin rubber liners wear down pretty fast
anyway. If you can get away with changing tubes only once per year, you're doing great. Those of us
with skinnier 700x23c tires go through tubes and tires more often. We get lots more flats too. I
hope you take along a spare tube, tire levers, and a patching kit on your rides. Or maybe just a
cell phone.

rick

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

Quoted message said:

I have a Trek 7200, the side of the tire says 60-80 psi. When I bought the bike the owner of the
store told me to put it about 100 psi. So I did. Ran it that way for well over a year. Last week
both tire went flat on the same day. The rim liners had holes and that led to the holes in the
tubes. Replaced rim liner with cloth ones. I am a big guy 235 lbs. Of course I like running 100
psi and don't really mind changing a tube ever year or so. What pressure would you run. Most rides
are 10-20 miles just for a little cardio and stress relief.

Thanks David

"Rich Clark" <[email hidden]> wrote in :"]news:[email hidden]:

Quoted message said:

Liners shouldn't fail that soon. I hope your shop replaced them for free.

What kind of rim strip did you have? The cheap rubber type can't handle high pressure and will fail
pretty quickly. Cloth rim tape (e.g., Velox brand) is a little more expensive ($2 instead of 50
cents), but much better.

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

Quoted message said:

I have a Trek 7200, the side of the tire says 60-80 psi. When I bought

the

Quoted message said:

bike the owner of the store told me to put it about 100 psi. So I did.

Ran

Quoted message said:

it that way for well over a year. Last week both tire went flat on the

same

Quoted message said:

day. The rim liners had holes and that led to the holes in the tubes. Replaced rim liner with
cloth ones. I am a big guy 235 lbs. Of course I like running 100 psi and don't really mind
changing a tube ever year or

so.

Quoted message said:

What pressure would you run. Most rides are 10-20 miles just for a little cardio and
stress relief.

Hi David,

As a commuter, I too change a tube every year or so. I'm your weight, bit more right now. I always
run my tires 10 pounds lower than max, well ok, that's for 700 wheels. On 26X2.1 I usually run 30-40
psi on tires rated for 35-65. I run 40-50 on 26x1.75 tires rated for 35-80, and on 700x37 rated for
70max I run 50-60.

When I started riding, my cheap 2.25 tires had a huge penalty for low pressure, similar to what
happens below 25 psi on reasonable 2.1 tires, it can become extremely difficult to pedal. So I
pumped them to max and got sore hands and wrists... yeah, butt too.

Then I rode 700X25 at 50psi and got pinch flats often. Finally I found the 10 pound lower rule
of thumb that's reasonably easy to pedal (I'm not a racer), is pretty comfy, and gets flats
very seldom.

Maybe a more important hint, don't try to squeeze the last bit of life out of your tires. The
sidewalls wear, the treads pick up bits of glass & wire that over time work their way through.
You can't even fill your gas tank for the price of a pair of tires. Just buy a new pair before
they're dead.

Now if you're talking $2.00 rim tape, why try to save 50% on that when it means you might have to
change a flat?

Doug Toronto

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

Quoted message said:

"Rich Clark" <[email hidden]> wrote in :"]news:[email hidden]:

Quoted message said:

Liners shouldn't fail that soon. I hope your shop replaced them for

free.

Quoted message said:

What kind of rim strip did you have? The cheap rubber type can't handle

high

Quoted message said:

pressure and will fail pretty quickly. Cloth rim tape (e.g., Velox brand)

is

Quoted message said:

a little more expensive ($2 instead of 50 cents), but much better.

They were the inexpensive rubber rim strip, replacement cost 50 cents. Now have cloth that were $3
each but looked a lot stronger.

David

"David Lawson" <[email hidden]> wrote >

Quoted message said:

They were the inexpensive rubber rim strip, replacement cost 50 cents.

Now

Quoted message said:

have cloth that were $3 each but looked a lot stronger.

David

So you have fixed the problem, pretty much. If you liked the way your bike felt and
handled, carry on.

"len" <[email hidden]> wrote in message news:R%b0b.565$xf.320@lakeread04...

Quoted message said:

"David Lawson" <[email hidden]> wrote >

Quoted message said:

They were the inexpensive rubber rim strip, replacement cost 50 cents.

Now

Quoted message said:

have cloth that were $3 each but looked a lot stronger.

David

So you have fixed the problem, pretty much. If you liked the way your

bike

Quoted message said:

felt and handled, carry on.

You might want to consider lower pressures all the same. I switched to lower pressures after people
told me high pressure was bad for my wheels and then later I broke wheels and axles. With lower
pressures I still broke wheels and an axle but the wheels were cheap machine-made hybrid wheels and
the axle was on a freewheel, not a freehub. So not a clear proof, but it seems to align with my
prejudices. 😉

Aside from that, some tires have a hard time holding to the rim and tend to pop off and blow out. If
you're going to run 20 pounds over on older tires bouncing over potholes in heavy traffic, I suggest
you use my test and whenever you top up your tires, over inflate another 40 pounds as a pothole
simulation. If the suckers don't blow, then you might be safe zooming down that hill 20 pounds over
with the dump truck right behind you.

Doug Toronto