Tire pressure and bad bike shop advice.

Hiya:
So, when I picked up my new bike at the LBS, I asked about how low I
could/should go on tire inflation. Background: It's a loaded touring
bike with 700x32c tires, max pressure 110 psi, I weigh only SLIGHTLY
less than 150 lb and my food-oriented usual group ride group has an
instinct for finding really bad roads (Harmony Grove Road, 30th St.,
etc. for those who've experience with San Diego and the joys of riding
"deferred maintenance.") And I won't usuallly be riding with a full
load -- I just wanted a drop bar pickup truck that could take the
commute and the grocery store run.
The answer -- "Don't go under 100 or you'll get pinch flats." This
somewhat shocked me, because I've met a few (really slender) brevet
riders who put 90 to 100 psi in 700x23c tires. I mean, what's the point
in getting the big wheel if you can''t get some decent cushioning out
of it?

Robert Leone

wrote:
Hiya:
So, when I picked up my new bike at the LBS, I asked about how low I
could/should go on tire inflation. Background: It's a loaded touring
bike with 700x32c tires, max pressure 110 psi, I weigh only SLIGHTLY
less than 150 lb and my food-oriented usual group ride group has an
instinct for finding really bad roads (Harmony Grove Road, 30th St.,
etc. for those who've experience with San Diego and the joys of riding
"deferred maintenance.") And I won't usuallly be riding with a full
load -- I just wanted a drop bar pickup truck that could take the
commute and the grocery store run.
The answer -- "Don't go under 100 or you'll get pinch flats." This
somewhat shocked me, because I've met a few (really slender) brevet
riders who put 90 to 100 psi in 700x23c tires. I mean, what's the point
in getting the big wheel if you can''t get some decent cushioning out
of it?

Robert Leone

I did a loaded tour on 700x35s' and kept them between 85 and 90. They
were rated for 85. I didn't have one flat in 1200 miles.

Ken
--
You never have the wind with you - either it is against you or you're
having a good day. ~Daniel Behrman, The Man Who Loved Bicycles

Homepage: http://www.bikesandmoreonline.com/

wrote:
Hiya:
So, when I picked up my new bike at the LBS, I asked about how low I
could/should go on tire inflation. Background: It's a loaded touring
bike with 700x32c tires, max pressure 110 psi, I weigh only SLIGHTLY
less than 150 lb and my food-oriented usual group ride group has an
instinct for finding really bad roads (Harmony Grove Road, 30th St.,
etc. for those who've experience with San Diego and the joys of riding
"deferred maintenance.") And I won't usuallly be riding with a full
load -- I just wanted a drop bar pickup truck that could take the
commute and the grocery store run.
The answer -- "Don't go under 100 or you'll get pinch flats." This
somewhat shocked me, because I've met a few (really slender) brevet
riders who put 90 to 100 psi in 700x23c tires. I mean, what's the point
in getting the big wheel if you can''t get some decent cushioning out
of it?

Robert Leone

Uh, ride around the holes. That is one of the advantages of having a
bike and only 2 wheels to worry about instead of a car where you just
know you are going to hit one on the left or right.
Bill Baka

"Bill Baka" wrote in message
. com...
wrote:
Hiya:
So, when I picked up my new bike at the LBS, I asked about how low I
could/should go on tire inflation. Background: It's a loaded touring
bike with 700x32c tires, max pressure 110 psi, I weigh only SLIGHTLY
less than 150 lb and my food-oriented usual group ride group has an
instinct for finding really bad roads (Harmony Grove Road, 30th St.,
etc. for those who've experience with San Diego and the joys of riding
"deferred maintenance.") And I won't usuallly be riding with a full
load -- I just wanted a drop bar pickup truck that could take the
commute and the grocery store run.
The answer -- "Don't go under 100 or you'll get pinch flats." This
somewhat shocked me, because I've met a few (really slender) brevet
riders who put 90 to 100 psi in 700x23c tires. I mean, what's the point
in getting the big wheel if you can''t get some decent cushioning out
of it?

Robert Leone

Uh, ride around the holes. That is one of the advantages of having a bike
and only 2 wheels to worry about instead of a car where you just know you
are going to hit one on the left or right.
Bill Baka

I put 2500 km on my 700X32's last year with 75 rear/70 front. They are rated
at 85psi Only flat I got was when I picked up a piece of wire - no pinch
flats. I weigh 200 lbs

Mike

Weather Guy wrote:
"Bill Baka" wrote in message
. com...

wrote:

Hiya:
So, when I picked up my new bike at the LBS, I asked about how low I
could/should go on tire inflation. Background: It's a loaded touring
bike with 700x32c tires, max pressure 110 psi, I weigh only SLIGHTLY
less than 150 lb and my food-oriented usual group ride group has an
instinct for finding really bad roads (Harmony Grove Road, 30th St.,
etc. for those who've experience with San Diego and the joys of riding
"deferred maintenance.") And I won't usuallly be riding with a full
load -- I just wanted a drop bar pickup truck that could take the
commute and the grocery store run.
The answer -- "Don't go under 100 or you'll get pinch flats." This
somewhat shocked me, because I've met a few (really slender) brevet
riders who put 90 to 100 psi in 700x23c tires. I mean, what's the point
in getting the big wheel if you can''t get some decent cushioning out
of it?

Robert Leone


Uh, ride around the holes. That is one of the advantages of having a bike
and only 2 wheels to worry about instead of a car where you just know you
are going to hit one on the left or right.
Bill Baka


I put 2500 km on my 700X32's last year with 75 rear/70 front. They are rated
at 85psi Only flat I got was when I picked up a piece of wire - no pinch
flats. I weigh 200 lbs

Mike


Aren't you putting in a lot of extra work pushing a half flat tire and
defeating the road bike skinny tire thing?
I run my mountain bikes at 65 psi and I go from 170 (fat) in the winter
to 140 (skinny) in the summer.
Curious.
Bill

So, when I picked up my new bike at the LBS, I asked about how low I
could/should go on tire inflation. Background: It's a loaded touring
bike with 700x32c tires, max pressure 110 psi, I weigh only SLIGHTLY
less than 150 lb and my food-oriented usual group ride group has an
instinct for finding really bad roads (Harmony Grove Road, 30th St.,
etc. for those who've experience with San Diego and the joys of riding
"deferred maintenance.") And I won't usuallly be riding with a full
load -- I just wanted a drop bar pickup truck that could take the
commute and the grocery store run.
The answer -- "Don't go under 100 or you'll get pinch flats." This
somewhat shocked me, because I've met a few (really slender) brevet
riders who put 90 to 100 psi in 700x23c tires. I mean, what's the point
in getting the big wheel if you can''t get some decent cushioning out
of it?

100psi might be a bit higher than needed for a 32c tire, but if the roads
are truly that bad, and the shop knows that, it might not be totally
unrealistic. As for comfort, simply having a 32c tire to begin with helps
greatly in that regard.

Those running 90 to 100psi in a 23c tire (and not getting flats) have an
angel on their shoulder. Unfortunately, there seems to be a shortage of such
angels to go around.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

wrote:
Hiya:
So, when I picked up my new bike at the LBS, I asked about how low I
could/should go on tire inflation. Background: It's a loaded touring
bike with 700x32c tires, max pressure 110 psi, I weigh only SLIGHTLY
less than 150 lb and my food-oriented usual group ride group has an
instinct for finding really bad roads (Harmony Grove Road, 30th St.,
etc. for those who've experience with San Diego and the joys of riding
"deferred maintenance.") And I won't usuallly be riding with a full
load -- I just wanted a drop bar pickup truck that could take the
commute and the grocery store run.
The answer -- "Don't go under 100 or you'll get pinch flats." This
somewhat shocked me, because I've met a few (really slender) brevet
riders who put 90 to 100 psi in 700x23c tires. I mean, what's the point
in getting the big wheel if you can''t get some decent cushioning out
of it?


Find a new LBS.

Sheldon brown recommends 75psi for 32mm wide tires carrying 100 lbs of
load per tire (200lbs for the whole bike). Take a look at:

http://sheldonbrown.com/tires.html#pressure

Personally, I ride 700x32 tires commuting on bad roads in the city with
a fiar load. I used to inflate my tires to 90psi, but these days I
won't go above 80psi, as they are so much comfier that way. When I
finally get around to top up the pressure, they are usaually around 65
psi, and I don't get pinch flats - my flats are caused by sharp pieces
of metal - staples, nails, cotter pins, etc, etc.

Later,
Mark Muller

On Sun, 12 Mar 2006 22:27:39 +0000, Mike Jacoubowsky wrote:

So, when I picked up my new bike at the LBS, I asked about how low I
could/should go on tire inflation. Background: It's a loaded touring
bike with 700x32c tires, max pressure 110 psi, I weigh only SLIGHTLY
less than 150 lb and my food-oriented usual group ride group has an
instinct for finding really bad roads (Harmony Grove Road, 30th St.,
etc. for those who've experience with San Diego and the joys of riding
"deferred maintenance.") And I won't usuallly be riding with a full
load -- I just wanted a drop bar pickup truck that could take the
commute and the grocery store run.
The answer -- "Don't go under 100 or you'll get pinch flats." This
somewhat shocked me, because I've met a few (really slender) brevet
riders who put 90 to 100 psi in 700x23c tires. I mean, what's the point
in getting the big wheel if you can''t get some decent cushioning out
of it?

100psi might be a bit higher than needed for a 32c tire, but if the roads
are truly that bad, and the shop knows that, it might not be totally
unrealistic. As for comfort, simply having a 32c tire to begin with helps
greatly in that regard.

Those running 90 to 100psi in a 23c tire (and not getting flats) have an
angel on their shoulder. Unfortunately, there seems to be a shortage of such
angels to go around.

Lately I've been riding with 7 bar (101psi) in my front tire (23mm).
I'm about 170#, not particularly careful, and I ride some pretty rough
roads. I never get pinch flats.

I've been told by two different pro team mechanics that they also use 7-8
bar for most riders. Pros may be lighter on average but ride faster --
so they probably hit harder, plus anyone who has raced knows hitting
potholes and other hazards is inevitable when boxed in by the peloton.

If so many of us can ride successfully at ~100psi with 23mm tires, then
surely you can use much lower pressures with 32mm, especially if you're
lightly loaded.

Matt O.

wrote:
wrote:

Hiya:
So, when I picked up my new bike at the LBS, I asked about how low I
could/should go on tire inflation. Background: It's a loaded touring
bike with 700x32c tires, max pressure 110 psi, I weigh only SLIGHTLY
less than 150 lb and my food-oriented usual group ride group has an
instinct for finding really bad roads (Harmony Grove Road, 30th St.,
etc. for those who've experience with San Diego and the joys of riding
"deferred maintenance.") And I won't usuallly be riding with a full
load -- I just wanted a drop bar pickup truck that could take the
commute and the grocery store run.
The answer -- "Don't go under 100 or you'll get pinch flats." This
somewhat shocked me, because I've met a few (really slender) brevet
riders who put 90 to 100 psi in 700x23c tires. I mean, what's the point
in getting the big wheel if you can''t get some decent cushioning out
of it?



Find a new LBS.

Sheldon brown recommends 75psi for 32mm wide tires carrying 100 lbs of
load per tire (200lbs for the whole bike). Take a look at:

http://sheldonbrown.com/tires.html#pressure

Personally, I ride 700x32 tires commuting on bad roads in the city with
a fiar load. I used to inflate my tires to 90psi, but these days I
won't go above 80psi, as they are so much comfier that way. When I
finally get around to top up the pressure, they are usaually around 65
psi, and I don't get pinch flats - my flats are caused by sharp pieces
of metal - staples, nails, cotter pins, etc, etc.

Later,
Mark Muller

No argument about the 100 lbs per tire but most of your weight is on the
seat post so it is more like 150/50. And what about sitting up and
riding no hands? Most of us probably do it, safe or not, I admit to it
after about ten miles just to relax my wrists.
Better safe than walking.
Bill

Lately I've been riding with 7 bar (101psi) in my front tire (23mm).
I'm about 170#, not particularly careful, and I ride some pretty rough
roads. I never get pinch flats.

I'm not convinced that pinch flats are the only type of flat reduced by
higher pressures. I don't understand the mechanism, but it seems that my
customers running lower pressures get more flats from objects that become
embedded in their tires as well.

I've been told by two different pro team mechanics that they also use 7-8
bar for most riders. Pros may be lighter on average but ride faster --
so they probably hit harder, plus anyone who has raced knows hitting
potholes and other hazards is inevitable when boxed in by the peloton.

Speed is a key element, along with riding in a pack and not being near the
front. The higher the speed, the more force upon the tire when you hit a
pothole (and the more likely you'll bottom out). Ironically, at higher
speeds, the impact often feels less severe, perhaps because you have more
forward momentum. Riding in a pack is an issue as those toward the back
don't see what's on the road in front of them, and they're also likely
riding "on the rivet" and not as able to take evasive maneuvers when
something is spotted.

If so many of us can ride successfully at ~100psi with 23mm tires, then
surely you can use much lower pressures with 32mm, especially if you're
lightly loaded.

The original poster talked about his bike both set up for loaded touring as
well as lightly loaded. A loaded touring bike can be pretty deadly for pinch
flats, because you can't easily lift the wheels (or jump the bike) over
whatever shows up in front of you. But all things being equal, a tire with
greater air volume will allow for lower tire pressures.

Matt O.

--
--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com


"Matt O'Toole" wrote in message
news
On Sun, 12 Mar 2006 22:27:39 +0000, Mike Jacoubowsky wrote:

So, when I picked up my new bike at the LBS, I asked about how low I
could/should go on tire inflation. Background: It's a loaded touring
bike with 700x32c tires, max pressure 110 psi, I weigh only SLIGHTLY
less than 150 lb and my food-oriented usual group ride group has an
instinct for finding really bad roads (Harmony Grove Road, 30th St.,
etc. for those who've experience with San Diego and the joys of riding
"deferred maintenance.") And I won't usuallly be riding with a full
load -- I just wanted a drop bar pickup truck that could take the
commute and the grocery store run.
The answer -- "Don't go under 100 or you'll get pinch flats." This
somewhat shocked me, because I've met a few (really slender) brevet
riders who put 90 to 100 psi in 700x23c tires. I mean, what's the point
in getting the big wheel if you can''t get some decent cushioning out
of it?

100psi might be a bit higher than needed for a 32c tire, but if the roads
are truly that bad, and the shop knows that, it might not be totally
unrealistic. As for comfort, simply having a 32c tire to begin with helps
greatly in that regard.

Those running 90 to 100psi in a 23c tire (and not getting flats) have an
angel on their shoulder. Unfortunately, there seems to be a shortage of
such
angels to go around.

Lately I've been riding with 7 bar (101psi) in my front tire (23mm).
I'm about 170#, not particularly careful, and I ride some pretty rough
roads. I never get pinch flats.

I've been told by two different pro team mechanics that they also use 7-8
bar for most riders. Pros may be lighter on average but ride faster --
so they probably hit harder, plus anyone who has raced knows hitting
potholes and other hazards is inevitable when boxed in by the peloton.

If so many of us can ride successfully at ~100psi with 23mm tires, then
surely you can use much lower pressures with 32mm, especially if you're
lightly loaded.

Matt O.