Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

tire pressure

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

tire pressure

Old 06-19-10, 06:08 PM
  #1  
Senior Member
Thread Starter
 
Join Date: Jun 2010
Location: Louisville KY- lots of rolling hills
Posts: 88

Bikes: Cannon dale t700 touring bike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 43 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
tire pressure

I weigh 220 and ride a touring bike. I replaced the tires with a 28C to get a little more speed.

Bike is cannondale 700 (aluminum) and the saddle just beats me to death. I installed a compression seat post and that helps some.

Normally I fill by tires to 120 lbs. Recently read an article that suggested I should only be using 80 lbs. So I am confused.

Do higher PSI help prevent flats or rim damage? lowering the pressure should improve the ride which would let me go longer.

Looking for opinions, recommendations. Thanks, Len
Lenkearney is offline  
Old 06-19-10, 06:37 PM
  #2  
Senior Member
 
Join Date: Mar 2005
Posts: 1,442
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Considering your size, I'd go for the maximum pressure indicated on your tires. Otherwise, you'll be collecting a lot of pinch flats. Each tire is specific, you must look at the manufacturer's minimum/maximum pressures on the sidewall.
Bikewer is offline  
Old 06-19-10, 06:52 PM
  #3  
just pokin' along
 
desertdork's Avatar
 
Join Date: Aug 2008
Location: the desert
Posts: 1,095
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Likes: 0
Liked 1 Time in 1 Post
I think you'll find some variance in the recommended PSI between varying 28mm tires. What tires do you have? What tires did you replace?

Failing to inflate your tire to a minimum PSI can leave you more prone to flatting (pinch flats) and possibly rim damage. So you can only lower your pressure so much.

A heavier rider would require higher PSI than a lighter rider, all other factors remaining constant.

There's a good possibility that a larger tire (such as a 30-32mm) at a lower PSI would be just as fast...but more comfy...than your 28mm choice. Lots of opinions on this, though, and the variances in tire construction and materials used will play a role here.

All opinions, of course...
desertdork is offline  
Old 06-19-10, 07:28 PM
  #4  
Senior Member
 
peripatetic's Avatar
 
Join Date: Oct 2004
Location: NYC
Posts: 2,124

Bikes: All 70s and 80s, only steel.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
You're heavier, so you should have higher pressure in your tires:

(from Jim Langley's site)

"The Right Pressure Makes a Big Difference
Most people put too little pressure in road tires and too much pressure in off-road rubber. Road tires usually take from 95 to 125 pounds per square inch (psi). If you weigh less than 150 pounds, go toward the lower end and vice versa. For mountain tires intended for off-road use, a good range is from 35 to 45 pounds. Use the same rule for weight. With off-road rubber, you’ll find that less air means a softer ride and improved control because the tire has a larger footprint on the trail."
peripatetic is offline  
Old 06-19-10, 07:31 PM
  #5  
Senior Member
 
Join Date: Mar 2010
Posts: 1,797
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 403 Post(s)
Liked 144 Times in 107 Posts
28mm tires @ 110 to 120 psi should not be too hard -- particularly if you weigh 220. I'm kind of a fatty being 205, down from about 240, and I run my 28mm tires (Panaracer Pasela TG) at about 110 or so and ride a B17. It's not a problem as far as comfort. My limiting factor, recently, is getting enough hydration in the Houston heat -- it's quite a chore to drink enough liquid to replace the liquid lost (maybe 1.5 oz/ mile). The 28mm tires @110 psi are plenty squishy on any Houston roads, maybe you're running rougher roads. I have one bike with 35mm tires (Schwalbe Marathon Plus) that I run at 100psi. Anything less feels like riding on jello.

Just a thought, if you find that you're putting a lot of weight on your saddle, you might want to try raising the saddle height a bit. Most of your weight should be carried by your legs, not your butt.
desconhecido is offline  
Old 06-19-10, 07:37 PM
  #6  
Thrifty Bill
 
wrk101's Avatar
 
Join Date: Jan 2008
Location: Mountains of Western NC
Posts: 23,547

Bikes: 86 Katakura Silk, 87 Prologue X2, 88 Cimarron LE, 1975 Sekai 4000 Professional, 73 Paramount, plus more

Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1230 Post(s)
Liked 938 Times in 614 Posts
+1 May well be more a problem with set up (seat too low). +1 You need max/near max air pressure in your tires.
wrk101 is offline  
Old 06-19-10, 08:11 PM
  #7  
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 642 Times in 363 Posts
Here's a couple of data points.

My wife and I used to ride a Santana road tandem with 700 X 28c tires. I inflated them to 100 psi front / 110 psi rear. We never had a pinch flat and, trust me, the two of us together weighed more than you. Previously, for a long time we had used 120 psi front and rear. When we tried the lower air pressure we didn't notice any decrease in performance but the ride quality improvement was huge.

I weigh around 200 and one of my bikes is a Bridgestone with 700 x 28c tires. I run those at 90 psi and don't pinch flat.

Last edited by Retro Grouch; 06-19-10 at 08:14 PM.
Retro Grouch is offline  
Old 06-19-10, 08:17 PM
  #8  
"Chooch"
 
ciocc_cat's Avatar
 
Join Date: Jun 2010
Location: Prairieville, Louisiana
Posts: 1,659

Bikes: Late 1990s Ciocc Titan

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
What make of saddle are you using? When I was in my late 30s my Selle Italia Super Turbo felt just fine, but now that I'm 55 I've had to switch to a Selle SMP TRK to keep certain vital male parts from going numb during extended rides.
ciocc_cat is offline  
Old 06-20-10, 11:41 AM
  #9  
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Posts: 6,925

Bikes: 03 Raleigh Professional (steel)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
28C is a pretty wide tire. At 220 lb there's no way you should be riding 120 psi. Try 80. You'll probably stay there.
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers
DMF is offline  
Old 06-20-10, 11:51 AM
  #10  
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,399

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Mentioned: 138 Post(s)
Tagged: 1 Thread(s)
Quoted: 5631 Post(s)
Liked 2,249 Times in 1,262 Posts
Tire pressure and tire section work together to determine ride properties. Nowaways lot's of people are moving to narrower tires looking for more speed, and many are compensating with crazy high tire pressures. That's a wrong approach, and leads to poor traction, more vibration, and lousy handling on poor roads. In some cases excess pressure increases the likelihood or rim failure.

At 220# you'd be far better off using a larger tire if your frame has clearance and dropping pressure back below 95psi. (possibly as low as 75-80). You won't encounter any more rolling resistance, reduce your chances of denting rims, and get a better ride.

Moving to narrower tires makes as much sense for you as putting small sports car tires on your SUV and inflating them to 50psi to get the rims off the ground.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

Just because I'm tired of arguing, doesn't mean you're right.

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Old 06-20-10, 12:11 PM
  #11  
Senior Member
 
Join Date: Mar 2010
Posts: 919
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Try 80 psi. Pinch flat should not be an issue at this pressure with 28c tire. I'm 148 and I run 70 psi with 23c. Also go with 32c or 35c if these tires will clear your frame. FBinNY gives good advice.

I'd also investigate a sprung saddle like the Brooks Flyer to dampen road vibrations.
furballi is offline  
Old 06-20-10, 12:18 PM
  #12  
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Posts: 6,925

Bikes: 03 Raleigh Professional (steel)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Also work on spending more time out of the saddle. Remember, it's a saddle, not a seat. You're not supposed to have your butt on it all the time.
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers
DMF is offline  
Old 06-20-10, 04:52 PM
  #13  
Senior Member
 
Join Date: Jun 2008
Location: Louisville, KY
Posts: 798

Bikes: Jamis Coda

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
I'm 238 (down from 285) and also ride 28s. At your weight you don't need 120psi. I run 85/95 front/rear in my tires and have had no problems. When I was 285, I was only running 100/110 front/rear.
barturtle is offline  
Old 06-20-10, 05:10 PM
  #14  
Senior Member
 
Join Date: Feb 2009
Posts: 6,660
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 582 Post(s)
Liked 171 Times in 138 Posts
https://www.adventurecycling.org/res...SIRX_Heine.pdf
davidad is offline  
Old 06-20-10, 05:39 PM
  #15  
Advisor
 
Join Date: Mar 2008
Location: Central New Jersey
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
I agree with a lower tire pressure. A heavier person does not need higher pressure, they need a wider tire, either 25 or 28 would work in your case. A tire needs to bounce on the road, what I mean by that, the sidewalls need to flex when you go over bumps. With a higher pressure, the sidewalls can't flex. If the sidewalls don't flex then the wheel takes the brunt of the bumps, potholes, and undulations in the road and your wheel life will be shortened. Manufacturers design tires and bikes to have a 15% tire drop, means when the rider sits on the tire, the tire will drop or squash 15%. If it doesn't, you either need to adjust the tire pressure or the width of the tire.
Lawrence08648 is offline  
Old 06-20-10, 08:02 PM
  #16  
Senior Member
 
Join Date: Jun 2010
Location: South Australia
Posts: 212

Bikes: Aegis Aro Svelte

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Tire pressure is a personal thing. Rolling resistance is bull.

I weigh 200 lbs. I ride 120 psi front/rear. I have tried to ride with 110 psi on my full carbon racing bike. However, I can see and feel the front tire buckling when climbing out of the saddle. The rear tire is sloppy when descending at speed in the saddle. The carbon soaks up most of the road on my bike. At 110psi the cracks in the road are less noticeable; however, there aren't enough cracks to justify lower pressure.

Rarely will you read someone riding less than 120 psi at you weight, however it a personal feel.
wheelgrabber is offline  
Old 06-20-10, 08:06 PM
  #17  
Senior Member
 
Join Date: Jun 2008
Location: Louisville, KY
Posts: 798

Bikes: Jamis Coda

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by wheelgrabber
Tire pressure is a personal thing. Rolling resistance is bull.

I weigh 200 lbs. I ride 120 psi front/rear. I have tried to ride with 110 psi on my full carbon racing bike. However, I can see and feel the front tire buckling when climbing out of the saddle. The rear tire is sloppy when descending at speed in the saddle. The carbon soaks up most of the road on my bike. At 110psi the cracks in the road are less noticeable; however, there aren't enough cracks to justify lower pressure.

Rarely will you read someone riding less than 120 psi at you weight, however it a personal feel.
You might want to state what size tire you're using, as that will make a huge difference as to what pressure you are going to run for any given weight.

For example rarely will you read of someone of any weight riding a 700x60c at 120psi.
barturtle is offline  
Old 06-21-10, 01:06 PM
  #18  
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Posts: 6,925

Bikes: 03 Raleigh Professional (steel)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by wheelgrabber
Tire pressure is a personal thing. Rolling resistance is bull.
If you don't care about rolling resistance, that's your choice. But most of us do.

Counter-intuitively, an over-inflated tire is less efficient. If the sidewall can't flex, then the entire mass of the bike is lifted over a bump, dispersing much more energy than would the softer tire. A "harsh ride" indicates that the tire is not absorbing the bumps, and that you're wasting energy.
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers
DMF is offline  
Old 06-21-10, 01:12 PM
  #19  
Senior Member
 
rumrunn6's Avatar
 
Join Date: Jul 2008
Location: 25 miles northwest of Boston
Posts: 29,499

Bikes: Bottecchia Sprint, GT Timberline 29r, Marin Muirwoods 29er, Trek FX Alpha 7.0

Mentioned: 112 Post(s)
Tagged: 0 Thread(s)
Quoted: 5216 Post(s)
Liked 3,552 Times in 2,324 Posts
80? that's nuts! at least for me and my tires. my tires are quite comfortable even at their MAX pressure but not all tires are like that. mine ar Specialized All-Condition Armadillos (the smooth ones). I crank them to 120. I might go softer like 110 but never lower. There's a bit to the technique of riding that I'm inclined to mention, meaning: getting out of the saddle and coasting over the bumps. I see guys riding over nasty rtoad surfaces that I would be just off the saddle for. try lifting yourself off the saddle an inch or two and give your bottom a break!
rumrunn6 is offline  
Old 06-21-10, 01:41 PM
  #20  
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Posts: 6,925

Bikes: 03 Raleigh Professional (steel)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
I wouldn't ride 80, either. But I'm heavier and I ride 23C.

Do what you want, but don't say that 80 is "nuts". I know riders his size that ride 23C at 85-95 and don't flat.



Well, no more than the rest of us...
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers
DMF is offline  
Old 06-21-10, 01:51 PM
  #21  
Senior Member
 
Join Date: Jul 2008
Posts: 1,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked 18 Times in 14 Posts
Originally Posted by rumrunn6
80? that's nuts! at least for me and my tires. my tires are quite comfortable even at their MAX pressure but not all tires are like that. mine ar Specialized All-Condition Armadillos (the smooth ones). I crank them to 120. I might go softer like 110 but never lower. There's a bit to the technique of riding that I'm inclined to mention, meaning: getting out of the saddle and coasting over the bumps. I see guys riding over nasty rtoad surfaces that I would be just off the saddle for. try lifting yourself off the saddle an inch or two and give your bottom a break!
Of course, maybe the people you see seated have sane tire pressures, and dont' need to abuse their knees to do the tire's job.
dscheidt is offline  
Old 06-21-10, 01:54 PM
  #22  
Senior Member
 
rumrunn6's Avatar
 
Join Date: Jul 2008
Location: 25 miles northwest of Boston
Posts: 29,499

Bikes: Bottecchia Sprint, GT Timberline 29r, Marin Muirwoods 29er, Trek FX Alpha 7.0

Mentioned: 112 Post(s)
Tagged: 0 Thread(s)
Quoted: 5216 Post(s)
Liked 3,552 Times in 2,324 Posts
it depends on the tire of course. if the max is 165 then 80 might be a bad idea, (even nuts). if the MAX is 90 then 80 is within reason. I'm 219 and would not ride 80 on my Armadillos
rumrunn6 is offline  
Old 06-21-10, 02:00 PM
  #23  
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Posts: 6,925

Bikes: 03 Raleigh Professional (steel)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Huh? Stated Max PSI has nothing to do with this question.
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers
DMF is offline  
Old 06-21-10, 02:02 PM
  #24  
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Posts: 6,925

Bikes: 03 Raleigh Professional (steel)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by dscheidt
Of course, maybe the people you see seated have sane tire pressures, and dont' need to abuse their knees to do the tire's job.
"abuse their knees"?? More likely they're not fit enough to stand for any length of time. (Check them for locked elbows.)


Or remember to use your smilies.
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers
DMF is offline  
Old 06-21-10, 02:03 PM
  #25  
Senior Member
 
rumrunn6's Avatar
 
Join Date: Jul 2008
Location: 25 miles northwest of Boston
Posts: 29,499

Bikes: Bottecchia Sprint, GT Timberline 29r, Marin Muirwoods 29er, Trek FX Alpha 7.0

Mentioned: 112 Post(s)
Tagged: 0 Thread(s)
Quoted: 5216 Post(s)
Liked 3,552 Times in 2,324 Posts
when asking for opinions you get what you get. I'm not asking for your opinion of my opinion
rumrunn6 is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.