Go Back  Bike Forums > Bike Forums > Road Cycling
Reload this Page >

Havenít biked in years, starting over. Whyís everyone riding on less psi now?

Notices
Road Cycling ďIt is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.Ē -- Ernest Hemingway

Havenít biked in years, starting over. Whyís everyone riding on less psi now?

Old 09-19-20, 01:54 PM
  #1  
Sapience
Senior Member
Thread Starter
 
Join Date: Oct 2009
Posts: 136
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2 Times in 1 Post
Havenít biked in years, starting over. Whyís everyone riding on less psi now?

I havenít biked in forever and now Iím a fatty. Iím trying to get back on the bike and ride myself back into shape. Itís been fun reading these forums again, especially that thread on Gatorskins because I just bought some again last week (I live in AZ where thorns are everywhere so go easy on me)

One thing Iíve noticed is a lot of people are running on less PSI. I weigh 155 and used to run 110 in my front wheel and 120 in my rear. This seems to be uncommon now. Whatís the rationale for less psi and what should I be riding at these days? Thanks all
Sapience is offline  
Old 09-19-20, 01:58 PM
  #2  
GlennR
Passing on your left
 
GlennR's Avatar
 
Join Date: Nov 2011
Location: Long Island, New York, USA
Posts: 7,026

Bikes: Trek Emonda SLR, Sram eTap, Zipp 303

Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 2101 Post(s)
Liked 1,054 Times in 565 Posts
That's because wider tires distribute the weight over a wider contact patch.

When you ran 110/120 were you on 19mm or 23mm tires? These days 28mm are very common and some run 32mm. Tubeless also reqire less pressure.
GlennR is offline  
Likes For GlennR:
Old 09-19-20, 02:03 PM
  #3  
Sapience
Senior Member
Thread Starter
 
Join Date: Oct 2009
Posts: 136
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2 Times in 1 Post
Originally Posted by GlennR View Post
That's because wider tires distribute the weight over a wider contact patch.

When you ran 110/120 were you on 19mm or 23mm tires? These days 28mm are very common and some run 32mm. Tubeless also reqire less pressure.
Hey thanks for the info. I was running 23s back then, and I just picked up 25s. Would you recommend I stay at 110/120 psi or come down a bit? Iím running tubed, but keep seeing the GP5000 tubeless mentioned. Not sure if itís worth ditching the Gatorskins sooner than later to switch Tubeless
Sapience is offline  
Old 09-19-20, 02:24 PM
  #4  
masi61
Senior Member
 
masi61's Avatar
 
Join Date: Oct 2005
Location: SW Ohio
Posts: 2,649

Bikes: Puch Marco Polo, Saint Tropez, Masi Gran Criterium

Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 621 Post(s)
Liked 97 Times in 72 Posts
Originally Posted by Sapience View Post
Hey thanks for the info. I was running 23s back then, and I just picked up 25s. Would you recommend I stay at 110/120 psi or come down a bit? Iím running tubed, but keep seeing the GP5000 tubeless mentioned. Not sure if itís worth ditching the Gatorskins sooner than later to switch Tubeless
What rims do you have? Older rims may not be tubeless ready without doing extraordinary measures (i.e. ghetto tubeless).
masi61 is offline  
Likes For masi61:
Old 09-19-20, 02:31 PM
  #5  
Bah Humbug
runner
 
Bah Humbug's Avatar
 
Join Date: Apr 2009
Location: Austin
Posts: 16,493

Bikes: S1, R2, P2

Mentioned: 115 Post(s)
Tagged: 1 Thread(s)
Quoted: 6125 Post(s)
Liked 1,697 Times in 908 Posts
Originally Posted by Sapience View Post
I haven’t biked in forever andnow I’m a fatty. I’m trying to get back on the bike and ride myself back into shape. It’s been fun reading these forums again, especially that thread on Gatorskins because I just bought some again last week (I live in AZ where thorns are everywhere so go easy on me)

One thing I’ve noticed is a lot of people are running on less PSI. I weigh 155 and used to run 110 in my front wheel and 120 in my rear. This seems to be uncommon now. What’s the rationale for less psi and what should I be riding at these days? Thanks all
Bah Humbug is offline  
Old 09-19-20, 02:37 PM
  #6  
DaveSSS
Senior Member
 
Join Date: Sep 2008
Location: Loveland, CO
Posts: 5,962

Bikes: TWO Colnago C-RS w/Chorus 12

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 474 Post(s)
Liked 182 Times in 146 Posts
155 is twenty pounds more than I weigh. I was fat at 148. Now I'm back to 133-135. I can wear all of my old jerseys that date back to the early 90's.

As for tire pressure, 85 front, 90 rear should be plenty on 25mm.
DaveSSS is offline  
Likes For DaveSSS:
Old 09-19-20, 02:38 PM
  #7  
Sapience
Senior Member
Thread Starter
 
Join Date: Oct 2009
Posts: 136
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2 Times in 1 Post
Originally Posted by masi61 View Post
What rims do you have? Older rims may not be tubeless ready without doing extraordinary measures (i.e. ghetto tubeless).
oh boy Iím on my old 2012 specialized allez. Wheels are 2012 DT Swiss 2.0s that came stock

In the event I keep running tubed gators @ 25 for the interim, what psi would you suggest?


thanks for the help
Sapience is offline  
Old 09-19-20, 02:44 PM
  #8  
Bah Humbug
runner
 
Bah Humbug's Avatar
 
Join Date: Apr 2009
Location: Austin
Posts: 16,493

Bikes: S1, R2, P2

Mentioned: 115 Post(s)
Tagged: 1 Thread(s)
Quoted: 6125 Post(s)
Liked 1,697 Times in 908 Posts
Originally Posted by DaveSSS View Post
155 is twenty pounds more than I weigh. I was fat at 148. Now I'm back to 133-135. I can wear all of my old jerseys that date back to the early 90's.

As for tire pressure, 85 front, 90 rear should be plenty on 25mm.
But then man, what's the word for me at 175lbs?
Bah Humbug is offline  
Likes For Bah Humbug:
Old 09-19-20, 02:52 PM
  #9  
HTupolev
Senior Member
 
Join Date: Apr 2015
Location: Seattle
Posts: 3,470
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 1561 Post(s)
Liked 522 Times in 276 Posts
Originally Posted by Sapience View Post
Whatís the rationale for less psi
High PSI reduces the amount of energy lost due to the tire deforming against the road surface. But, if the tire is pumped stiff to where it's transmitting surface irregularities to the bike and rider (rather than smoothly deforming around the irregularities), that energy spent vibrating the bike and rider is getting stolen from your forward motion. So excessively high pressure is not only less comfortable, it can also be slower.

The "optimal" pressure depends on a lot of variables: the tire size, the mass of the bike and rider, and the roughness of the particular surface, among other things. Smoother surfaces and heavier riders should use higher pressures.
The wider the tire, the less it will deform against the road surface for a given PSI, so lower pressures should be used with wider tires.

When unsure about optimal pressure, it tends to be much better to err low than high.

This is a good article on the subject.
HTupolev is online now  
Old 09-19-20, 03:02 PM
  #10  
Sapience
Senior Member
Thread Starter
 
Join Date: Oct 2009
Posts: 136
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2 Times in 1 Post
Gentlemen I really appreciate the help. Although some things in cycling have changed for me, good to see this community is still active and helpful
Sapience is offline  
Old 09-19-20, 03:08 PM
  #11  
wgscott
Occam's Rotor
 
wgscott's Avatar
 
Join Date: Jul 2013
Posts: 6,370
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 1,480 Times in 746 Posts
Originally Posted by Bah Humbug View Post
But then man, what's the word for me at 175lbs?
Malnourished.
wgscott is offline  
Old 09-19-20, 03:09 PM
  #12  
datlas 
Beyond Bogus
 
datlas's Avatar
 
Join Date: Dec 2007
Location: Malvern, PA (20 miles West of Philly)
Posts: 33,202

Bikes: 1986 Alpine (steel road bike), 2009 Ti Habenero, 2013 Specialized Roubaix

Mentioned: 463 Post(s)
Tagged: 2 Thread(s)
Quoted: 13047 Post(s)
Liked 1,914 Times in 1,014 Posts
I suggest you try 80F 90R. You can tweak up/down 5-10 based on road conditions.
__________________
Originally Posted by rjones28 View Post
Addiction is all about class.
datlas is offline  
Likes For datlas:
Old 09-19-20, 04:15 PM
  #13  
Litespud
Senior Member
 
Join Date: Oct 2017
Location: Chapel Hill NC
Posts: 951

Bikes: 2000 Litespeed Vortex Chorus 10, 1995 DeBernardi Cromor S/S, Nashbar 3sp commuter

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 365 Post(s)
Liked 328 Times in 185 Posts
Originally Posted by Sapience View Post
Hey thanks for the info. I was running 23s back then, and I just picked up 25s. Would you recommend I stay at 110/120 psi or come down a bit? I’m running tubed, but keep seeing the GP5000 tubeless mentioned. Not sure if it’s worth ditching the Gatorskins sooner than later to switch Tubeless
I'm 185# and I run tubed 25s at 90psi front and 95psi rear. 110/120 at 155# will rattle your fillings out
Litespud is offline  
Old 09-19-20, 04:29 PM
  #14  
genejockey
Klaatu..Verata..Necktie?
 
genejockey's Avatar
 
Join Date: May 2007
Location: SF Bay Area
Posts: 2,501

Bikes: Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 778 Post(s)
Liked 900 Times in 480 Posts
Originally Posted by Bah Humbug View Post
Might be 5 foot nothing.
genejockey is online now  
Old 09-19-20, 04:34 PM
  #15  
genejockey
Klaatu..Verata..Necktie?
 
genejockey's Avatar
 
Join Date: May 2007
Location: SF Bay Area
Posts: 2,501

Bikes: Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 778 Post(s)
Liked 900 Times in 480 Posts
This was also my happy discovery when I started paying attention to road bike tech again after a dozen years. Running 28s at 90/95 on two of my bikes, and 25s at 95/100 on the other two has been a revelation!
genejockey is online now  
Old 09-19-20, 05:48 PM
  #16  
Bah Humbug
runner
 
Bah Humbug's Avatar
 
Join Date: Apr 2009
Location: Austin
Posts: 16,493

Bikes: S1, R2, P2

Mentioned: 115 Post(s)
Tagged: 1 Thread(s)
Quoted: 6125 Post(s)
Liked 1,697 Times in 908 Posts
Originally Posted by genejockey View Post
Might be 5 foot nothing.
Tire pressure donít care though. A 155lber, no matter how they get there, has more leeway in pressure than you or I do.
Bah Humbug is offline  
Likes For Bah Humbug:
Old 09-19-20, 05:58 PM
  #17  
noodle soup
Senior Member
 
noodle soup's Avatar
 
Join Date: Nov 2015
Posts: 8,536
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 4446 Post(s)
Liked 1,549 Times in 842 Posts
Originally Posted by genejockey View Post
Might be 5 foot nothing.
Originally Posted by Bah Humbug View Post
Tire pressure donít care though. A 155lber, no matter how they get there, has more leeway in pressure than you or I do.
5' and 155 pounds is pretty fat for that height, but it's still only 155 pounds as far as tire inflation is concerned,
noodle soup is offline  
Old 09-19-20, 06:01 PM
  #18  
bruce19
Senior Member
 
bruce19's Avatar
 
Join Date: Jul 2006
Location: Lebanon (Liberty Hill), CT
Posts: 7,383

Bikes: CAAD 12, MASI Gran Criterium S, Colnago World Cup CX & Guru steel

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 1262 Post(s)
Liked 603 Times in 363 Posts
I'm running 25's that are tubeless and I run approx 85-90 psi rear and 75 psi front. I'm 185 lbs.
bruce19 is offline  
Old 09-19-20, 06:02 PM
  #19  
genejockey
Klaatu..Verata..Necktie?
 
genejockey's Avatar
 
Join Date: May 2007
Location: SF Bay Area
Posts: 2,501

Bikes: Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 778 Post(s)
Liked 900 Times in 480 Posts
Originally Posted by noodle soup View Post
5' and 155 pounds is pretty fat for that height, but it's still only 155 pounds as far as tire inflation is concerned,
Yes, but Bah,Humbug highlighted "I'm a fatty" and "I weigh 155" and added a headscratchng icon, so I pointed out a situation in which those two statements are not at odds.
genejockey is online now  
Old 09-19-20, 06:05 PM
  #20  
genejockey
Klaatu..Verata..Necktie?
 
genejockey's Avatar
 
Join Date: May 2007
Location: SF Bay Area
Posts: 2,501

Bikes: Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 778 Post(s)
Liked 900 Times in 480 Posts
I use the Silca and SRAM calculators, then aim in between. The only times I've ever pinch flatted were both hitting God's Own Potholes at >25 mph (dappled sunlight). One of the times the hit was so hard I managed to turn the bar down in the stem, and both bottles popped out of their cages.
genejockey is online now  
Likes For genejockey:
Old 09-19-20, 06:08 PM
  #21  
znomit
Zoom zoom zoom zoom bonk
 
znomit's Avatar
 
Join Date: Sep 2006
Location: New Zealand
Posts: 4,124

Bikes: Giant Defy, Trek 1.7c, BMC GF02, Fuji Tahoe, Scott Sub 35

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 336 Post(s)
Liked 332 Times in 159 Posts
Drop the pressure until you get pinch flats, then add 10psi.
znomit is offline  
Likes For znomit:
Old 09-19-20, 06:13 PM
  #22  
Bah Humbug
runner
 
Bah Humbug's Avatar
 
Join Date: Apr 2009
Location: Austin
Posts: 16,493

Bikes: S1, R2, P2

Mentioned: 115 Post(s)
Tagged: 1 Thread(s)
Quoted: 6125 Post(s)
Liked 1,697 Times in 908 Posts
Originally Posted by genejockey View Post
Yes, but Bah,Humbug highlighted "I'm a fatty" and "I weigh 155" and added a headscratchng icon, so I pointed out a situation in which those two statements are not at odds.
Not in abstract, but yes, I meant in the context of tire inflation.
Bah Humbug is offline  
Old 09-19-20, 06:20 PM
  #23  
GlennR
Passing on your left
 
GlennR's Avatar
 
Join Date: Nov 2011
Location: Long Island, New York, USA
Posts: 7,026

Bikes: Trek Emonda SLR, Sram eTap, Zipp 303

Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 2101 Post(s)
Liked 1,054 Times in 565 Posts
Originally Posted by znomit View Post
Drop the pressure until you get pinch flats, then add 10psi.
That's like tighten till it snaps and back off 1/4 turn.

I determined my optimal psi by trial and error. I started high and went for a ride. Over the next few weeks I lowered it until If felt better and then squishy.

Your weight, the tires you pick, the size of the rims and your personal feel. I did the same with my collector car when I went with different size wheels and tires.
GlennR is offline  
Likes For GlennR:
Old 09-19-20, 06:21 PM
  #24  
genejockey
Klaatu..Verata..Necktie?
 
genejockey's Avatar
 
Join Date: May 2007
Location: SF Bay Area
Posts: 2,501

Bikes: Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 778 Post(s)
Liked 900 Times in 480 Posts
Originally Posted by Bah Humbug View Post
Not in abstract, but yes, I meant in the context of tire inflation.
If you don't mind my saying so your post was rather minimal. I don't think my interpretation was entirely out of left field.
genejockey is online now  
Old 09-19-20, 06:22 PM
  #25  
znomit
Zoom zoom zoom zoom bonk
 
znomit's Avatar
 
Join Date: Sep 2006
Location: New Zealand
Posts: 4,124

Bikes: Giant Defy, Trek 1.7c, BMC GF02, Fuji Tahoe, Scott Sub 35

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 336 Post(s)
Liked 332 Times in 159 Posts
Originally Posted by GlennR View Post
That's like tighten till it snaps and back off 1/4 turn.

I determined my optimal psi by trial and error.
So, you mean like trialing lower pressures until you find an error (a pinch flat?).
znomit is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

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