Haven’t biked in years, starting over. Why’s everyone riding on less psi now?
 

I haven’t biked in forever and now 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

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? 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

What rims do you have? Older rims may not be tubeless ready without doing extraordinary measures (i.e. ghetto tubeless).

:foo:

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.

oh boy I’m 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

But then man, what's the word for me at 175lbs?

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.

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

Malnourished.

I suggest you try 80F 90R. You can tweak up/down 5-10 based on road conditions.

I'm 185# and I run tubed 25s at 90psi front and 95psi rear. 110/120 at 155# will rattle your fillings out

Might be 5 foot nothing.

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!

Tire pressure don’t 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,

I'm running 25's that are tubeless and I run approx 85-90 psi rear and 75 psi front. I'm 185 lbs.

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.

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.

Drop the pressure until you get pinch flats, then add 10psi.

Not in abstract, but yes, I meant in the context of tire inflation.

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.

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.

So, you mean like trialing lower pressures until you find an error (a pinch flat?).