Notices
General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

Tire pressure suggestions

Old 07-18-18, 01:34 PM
  #1  
Yossarian22
Junior Member
Thread Starter
 
Join Date: Dec 2017
Posts: 19
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Tire pressure suggestions

Anybody have thoughts on what the minimum safe pressure would be with a 32mm tire (tube-type) on a wider (21mm inner/25mm outer) 700c rim?
Yossarian22 is offline  
Old 07-18-18, 01:36 PM
  #2  
Milton Keynes
Senior Member
 
Milton Keynes's Avatar
 
Join Date: May 2016
Posts: 2,661

Bikes: Two-wheeled human-powered vehicles, but that's not important right now

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1170 Post(s)
Liked 87 Times in 48 Posts
It should be marked on the tire.
Milton Keynes is offline  
Old 07-18-18, 01:55 PM
  #3  
JanMM
rebmeM roineS
 
JanMM's Avatar
 
Join Date: Jan 2006
Location: Metro Indy, IN
Posts: 15,580

Bikes: RANS V3 ti, RANS V-Rex, RANS Screamer

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 487 Post(s)
Liked 43 Times in 39 Posts
Depends on rider weight, bike weight, wt distribution, tire construction etc.
I run about 50/85psi F/R with 26/1.25 559-32 tires on slightly narrower rims on a long wheelbase recumbent. Much less weight on the front. Diameter of wheel shouldn't make a difference in pressure.
__________________
RANS V3 Ti, RANS V-Rex, RANS Screamer
JanMM is offline  
Old 07-18-18, 02:02 PM
  #4  
brianmcg123
Senior Member
 
brianmcg123's Avatar
 
Join Date: Oct 2002
Location: TN
Posts: 1,229
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 333 Post(s)
Liked 11 Times in 8 Posts
Iíve run my 35mm tires as low as 40psi. They are still safe, but just feel too mushy for my tastes. I really like them at 60-65.
brianmcg123 is offline  
Old 07-18-18, 02:09 PM
  #5  
toast3d
Senior Member
 
Join Date: Jul 2018
Posts: 144
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Yossarian22 View Post
Anybody have thoughts on what the minimum safe pressure would be with a 32mm tire (tube-type) on a wider (21mm inner/25mm outer) 700c rim?
Look at the sidewall of the tire. It will say what the minimum and maximum recommended pressures are. Adjust to your liking within that range.
toast3d is offline  
Old 07-18-18, 02:41 PM
  #6  
avole
Banned.
 
Join Date: Dec 2017
Location: France
Posts: 1,031

Bikes: Brompton, Time, Bianchi, Jan Janssen, Peugeot

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 598 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Yup. Always go with manufacturer's recommendations.
avole is offline  
Old 07-18-18, 02:53 PM
  #7  
Oso Polar
Senior Member
 
Join Date: Mar 2018
Location: Westchester County, NY
Posts: 160

Bikes: Trek 3500, Jamis Renegade Escapade

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked 3 Times in 3 Posts
It depends on the load (combined weight of bicycle + rider + whatever else you are carrying with you on the bike).
Second calculator here is a good starting point: Bicycle tire pressure calculator
It is possible you can get quite lower. Pressure range on the tire itself, lower boundary of it, is bogus.
Oso Polar is offline  
Old 07-18-18, 02:56 PM
  #8  
Oso Polar
Senior Member
 
Join Date: Mar 2018
Location: Westchester County, NY
Posts: 160

Bikes: Trek 3500, Jamis Renegade Escapade

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 88 Post(s)
Liked 3 Times in 3 Posts
Originally Posted by avole View Post
Yup. Always go with manufacturer's recommendations.
Manufacturer will be cautious and will probably put quite a high lower recommended pressure to be safe for 200+ pound riders. If you are light and bike is light it is quite possible that this lower boundary is too high. It'll definitely be safe but it may be unnecessary too harsh.
Oso Polar is offline  
Old 07-18-18, 03:01 PM
  #9  
Kedosto
Ambulophobic
 
Join Date: Nov 2008
Location: San Leandro, CA
Posts: 1,170
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 445 Post(s)
Liked 135 Times in 83 Posts
The pressures indicated on the tire sidewall are lawyer limits. Your PSI will be dictated by the variables listed by previous posters. Try the pressure calculator as a starting point and adjust to your liking from there. The limits? Too low may result in pinch flats and poor handling. Too high may result in harsh ride and loss of traction in loose conditions. Try different pressures and see what feels and works best for you.


-Kedosto
Kedosto is offline  
Old 07-18-18, 03:03 PM
  #10  
toast3d
Senior Member
 
Join Date: Jul 2018
Posts: 144
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Tire pressure might be the least of your concerns if you are a 200+ pound rider.

Of course, you may be very tall. Or very muscular. Or both. If either is the case, you are the exception and not the rule.

Body weight is very important on a bike. More important than the weight of the bike itself.

It is of course also true that tire manufacturers are a bit conservative with their recommended pressure range.
toast3d is offline  
Old 07-18-18, 03:24 PM
  #11  
pdlamb
Senior Member
 
Join Date: Dec 2010
Location: northern Deep South
Posts: 5,366

Bikes: Fuji Touring, Novara Randonee

Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 1019 Post(s)
Liked 81 Times in 55 Posts
Depends on the load and the tire. I had one model with metal rods, like you see in the tire beads, embedded in the sidewall. One of them broke around 70-75 psi (under a pretty good load), which ruined the tire and caused four flats before I found it.

I personally don't like the feel of a 32 tire below 75 psi. So try the lowest rating on your tire, and adjust until you like the ride.
pdlamb is offline  
Old 07-18-18, 03:30 PM
  #12  
Kapusta
Cyclochondriac
 
Join Date: Feb 2017
Posts: 2,441
Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 1045 Post(s)
Likes: 0
Liked 155 Times in 110 Posts
To suggest a tire pressure without knowing how much you weigh is like suggesting a shoe size when we havenít measured your feet.

Start with the tire pressure calculator. It is just a starting point, but a good starting point in my experience. I have never pinch flatted using those guidelines.

Of course, I usually drop it from there to see what happens. At some point, the front gets squirmy in the corners or I pinch flat on potholes. Then I know how low I can go.

Last edited by Kapusta; 07-18-18 at 03:33 PM.
Kapusta is offline  
Old 07-18-18, 03:49 PM
  #13  
Paul Barnard
For The Fun of It
 
Join Date: May 2007
Location: Louisissippi Coast
Posts: 3,935

Bikes: Lynskey Backroad, Litespeed T6, Lynskey MT29, Burley Duet

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1011 Post(s)
Liked 132 Times in 81 Posts
If it has been mentioned, I missed it. The road surface will also play a roll in the minimum pressure you will want to run. Really rough surfaces may put you at a risk of pinch flat if you run too low.
Paul Barnard is offline  
Old 07-18-18, 11:36 PM
  #14  
avole
Banned.
 
Join Date: Dec 2017
Location: France
Posts: 1,031

Bikes: Brompton, Time, Bianchi, Jan Janssen, Peugeot

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 598 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Originally Posted by Kedosto View Post
The pressures indicated on the tire sidewall are lawyer limits. Your PSI will be dictated by the variables listed by previous posters. Try the pressure calculator as a starting point and adjust to your liking from there. The limits? Too low may result in pinch flats and poor handling. Too high may result in harsh ride and loss of traction in loose conditions. Try different pressures and see what feels and works best for you.


-Kedosto
Having nealy crashed out when going round a bend on an underinflated rear tyre, I'm prepared to believe these are not "lawyer limits", but valid safety ones. It's your bike, your body, your bones, so feel free to experiment, but don't cry if something bad happens, it'll be entirely your own fault.
avole is offline  
Old 07-19-18, 12:04 AM
  #15  
Kapusta
Cyclochondriac
 
Join Date: Feb 2017
Posts: 2,441
Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 1045 Post(s)
Likes: 0
Liked 155 Times in 110 Posts
Originally Posted by avole View Post
Having nealy crashed out when going round a bend on an underinflated rear tyre, I'm prepared to believe these are not "lawyer limits", but valid safety ones. It's your bike, your body, your bones, so feel free to experiment, but don't cry if something bad happens, it'll be entirely your own fault.
i would take the written limits seriously for the max, but not the minimum pressure.

If the tire was under-inflated, it was under-inflated for YOUR weight and riding.
Kapusta is offline  
Old 07-19-18, 01:52 AM
  #16  
avole
Banned.
 
Join Date: Dec 2017
Location: France
Posts: 1,031

Bikes: Brompton, Time, Bianchi, Jan Janssen, Peugeot

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 598 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Don't play the 'blame the victim" game. A tyre underinflated according to the manufacturer's specs is sheer stupidity, and to claim it is merely "lawyer limits" both unprovable and irresponsible, in my opinion anyway. But if you really know better, have conducted sufficient laboratory tests plus real-life tests with sufficient people in all weather, and can prove it, please supply a link to all the necessary documentation.
avole is offline  
Old 07-19-18, 07:34 AM
  #17  
rumrunn6
Senior Member
 
rumrunn6's Avatar
 
Join Date: Jul 2008
Location: 25 miles northwest of Boston
Posts: 23,321

Bikes: Bottecchia Sprint, GT Timberline 29r

Mentioned: 93 Post(s)
Tagged: 0 Thread(s)
Quoted: 3197 Post(s)
Liked 220 Times in 172 Posts
at 218 lbs, I used 40 front, 60 rear, on a recent ride w 45mm tires over dirt, gravel & broken roadway ...

rumrunn6 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bluemonkey136
Fitting Your Bike
11
03-30-17 07:45 AM
michael_runs
Road Cycling
6
07-07-15 09:57 AM
jwchef
Clydesdales/Athenas (200+ lb / 91+ kg)
13
06-15-13 08:47 AM
jkandell
Bicycle Mechanics
5
06-19-11 03:23 PM
papertigerbob
Bicycle Mechanics
11
06-17-10 10:23 AM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

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

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.