Just curious what tire pressures people are running.
Post here if you’re <125 lbs with your setup
Road - 700x23c 95psi
Mountain - 2.3" 650B with tubes 16psi front 18psi rear
140-145 and about the same psi
.
What is considered light weight?
I’m 160 and run 23mm tires on 24mm wheels at 90 psi.
i’m 124, 23mm and run 90. mainly cus that’s what i read on flo.
would be interested to lower the psi by 10psi and test my speed assuming same power.
john
138-142 lbs lately. Run 95 psi on smooth pavement, 85 on rough, 80 on super rough/chip seal. Conti 4000S 23mm (runs almost like a 25 on Bonetrager Aeolus).
I’m 115lbs with 650cx23mm HED Jet 6 and ride with a PSI of 100 (this is down from 110psi that I used to ride). I’m sure multiple people will reply that this is too high (don’t bother - I’ve heard it before).
I’m 147 lbs and run max psi written on the tire. Thought that would create the lowest rolling resistance?
Kinda surprise to see so many of you riding at much lower psi like 90. What am I missing? 
What would the performance and feel effect be for me to go from 120 psi to 90?
Going too high with tire pressure actually raises rolling resistance. It causes the bike to bounce over surface imperfections in the road vs. the tire deflecting around them. This is not to say lower is better; it’s that there is an optimal pressure based on your weight, the tire, and the road surface (the rougher the surface the lower the optimal pressure).
On a smooth surface (velodrome, or a smooth testing drum) higher pressure will test better.
Weight: 150lbs
105 up front and 110 rear (23c)
Running Zipp 404 FC clinchers both front and rear
.
What is the source of this?
I’m 115lbs with 650cx23mm HED Jet 6 and ride with a PSI of 100 (this is down from 110psi that I used to ride). I’m sure multiple people will reply that this is too high (don’t bother - I’ve heard it before).
and yet you continue to use a pressure that increases the power required to complete your races as well as increasing the fatigue due to rough ride. I guess successfully completing 39 triathlons and several Gran Fondoes outweighs carefully done science;) So keep on riding slower that you would and beating your body up more than necessary. Obviously one can’t fix a case of deep rooted obstinance.
Hugh
Michelin.
I don’t know what assumptions are made in producing that chart, so I take it with a grain of salt. I use 23mm tires, but my rims are 24mm wide at the brake track. I noticed a clear difference when going from 19mm wide wheels to 24mm wide wheels. I use 90 front and back, probably should try 85 up front, have never had a flat of any kind in 1.5 years of riding. That includes 3 potholes that I can recall.
My wife is 112 lbs. She is running Michelin Pro4 Endurance 700x23 on Flo wheels.
90 psi in the back, 85 in the front. No issues this season - no flats, etc. Tires do not appear to be over deflecting at ground contact.
I’m 115lbs with 650cx23mm HED Jet 6 and ride with a PSI of 100 (this is down from 110psi that I used to ride). I’m sure multiple people will reply that this is too high (don’t bother - I’ve heard it before).
and yet you continue to use a pressure that increases the power required to complete your races as well as increasing the fatigue due to rough ride. I guess successfully completing 39 triathlons and several Gran Fondoes outweighs carefully done science;) So keep on riding slower that you would and beating your body up more than necessary. Obviously one can’t fix a case of deep rooted obstinance.
Hugh
Unlike some people I’ve found that I need 5 to 10 psi more in a 650C tire than I do in a 700C tire.
I can run a 700X23 all day long at 90-95 psi but if I do that with a 650C I’m going to pinch flat on the roads I train on.
I’ve worked with the Conti GP4000SII and the PR4 on both sets of wheels
Perhaps other tires are different.
Edit: I’m 145lbs
jaretj
This makes sense with 700’s since the total volume of the tire is less. I guess one needs a certain number of air molecules at a given temperature to keep the rider suspended. PV = nRT (after all). If the Volume goes down relative to 700C and you have the same temp it would stand to reason that one needs more pressure to avoid pinch flats.
I’m 115lbs with 650cx23mm HED Jet 6 and ride with a PSI of 100 (this is down from 110psi that I used to ride). I’m sure multiple people will reply that this is too high (don’t bother - I’ve heard it before).
and yet you continue to use a pressure that increases the power required to complete your races as well as increasing the fatigue due to rough ride. I guess successfully completing 39 triathlons and several Gran Fondoes outweighs carefully done science;) So keep on riding slower that you would and beating your body up more than necessary. Obviously one can’t fix a case of deep rooted obstinance.
Hugh
Unlike some people I’ve found that I need 5 to 10 psi more in a 650C tire than I do in a 700C tire.
I can run a 700X23 all day long at 90-95 psi but if I do that with a 650C I’m going to pinch flat on the roads I train on.
I’ve worked with the Conti GP4000SII and the PR4 on both sets of wheels
Perhaps other tires are different.
**Edit: I’m 145lbs **
jaretj
Not too big a surprise that at 30lb heavier than the gal in question you might need a bit more pressure.
Hugh
I had to throw that (the weight) in there as an afterthought and I hoped you wouldn’t miss it.
I had never thought it the 650/700 thing would amount to any difference but as soon as I got a 700C bike I noticed that I could go much lower.
I noticed the same thing with my mountain bikes between a 29’er and a 26". When I was using tubes I would run ~32-35lbs in the 26" but could run 28-30 in the 29’er. Since now I’m tubeless I run much lower.
I have a special formula for these things:
if I am running 21mm then 100PSI front and 100PSI back
if I am running 23mm then 100PSI front and 100PSI back
if I am running 25mm then 100PSI front and 100PSI back
In hot weather I tend to go for 100PSI, in cold weather 100PSI.
If I am going to be riding over cobbles, then 100PSI, if it is a smooth road, then 100PSI.
I find 100PSI works quite well for most situations!
Can put that in a spread sheet? I’m having a hard time following that formula.