rclouviere

I know there are a lot of opinions on tire pressure, but I’d like to get some opinions. I want to be as fast as possible on my road bike (conti tubeless) and my TT bike (conti clincher). I’velooked at the silcachart and it seems to be pretty accurate?

cxwrench

You're kidding, right? This is the most beat down dead horse of a topic that has been discussed hundreds of times but you're going to crack into it yet again...but not provide any info about your or your equipment? Really?

LarrySellerz

Lots of people will tell you that wider tires at lower pressure are just as fast if not even faster than thin tires pumped up hard. Its bollocks, the fastest tires are narrow and pumped hard. The ideal PSI depends on your body weight and preferred riding style. Some people prefer less pressure to roll over imperfections in the road smoother, some people prefer the harsh ride of a rock hard tire, its really up to you.

Outrider1

OP, what's your opinion on tire pressure? (you started it)

beng1

A lot of top racers us the Silca info so it will be as good as any info anyone puts up here or on any public forum. The only extra thing you could do is check with the manufacturers of your tires to see if for some reason they need different pressures than those of other manufacturers. Let us know what they say..........

easyupbug 

Get a Garmin or something similar and see what works for you.

MTBbumpcrush

Smooth road surface high pressure is fast,rough road bigger tire with lower pressure,actual pressure level put your bodyweight into the scale,there is nothing to discuss about,also carbon spoke wheelset is the future road wheelset with instant response fast acceleration
https://www.elite-wheels.com/drive-c...okes-wheelset/

PeteHski

Use the Silca chart as your baseline then. There are too many variables to perfectly optimise your tyre pressure for every occasion anyway. Looking to maximise speed I would perhaps go a little higher than recommended pressures unless the road surface was rough. In which case I would go a little lower.

smd4

I run my Veloflex 700 x 23C's at 140 psi on smooth pavement. Works for me.

DaveSSS 

I use the tire pressure calculator at zipp.com. It works for me. Tubeless tires at much lower pressures is what I use.

rumrunn6

trial & error for the rear tire
5-10psi lower for the front tire

​​​​​​​I believe air resistance/drag & weight, will have a greater effect on your speed

CAT7RDR

Experiment. Rinse, Repeat.

cxwrench

Larry...just stop it. They're not the suggestions of physics, or the feels of physics, they're the LAWS of physics.

Daniel4

Low pressure has more rolling resistance because at the tangent point ( just before road contact), you are flexing the tire material to a higher angle than a tire at a very high pressure.

billridesbikes

Here is an idea. Run your own experiment. Create a Strava segment on a longish downhill that will take at least a couple minutes to roll down without pedaling. Next start at low pressure and run down the segment a few times. Add pressure and repeat. Any RR difference will show up as an average time difference.

The reason I think that this is a divisive topic is that inflation pressure isn’t that important for speed. It’s down in the noise and difficult to measure a true diffence. Otherwise, if there was a large difference there would be universal consensus on what pressure to run.

Then run the pressure that feels the best to you and you don’t get pinch flats or blow the tire off the rim. There is no wrong pressure. (There, I said it)

rsbob 

I have found this site tremendously helpful when it comes to pressures. Just feed in your data. https://silca.cc/pages/sppc-form

cxwrench

You have no clue. Go join Larry somewhere else.

phughes

Way more to it than that, Larry. https://www.renehersecycles.com/myth...ure-is-faster/

Don't you have a seat post to weld, remove, lower... break? Oh, and you honesty don't know what you are talking about.

ofajen

Sorry, I’ll pass on the opinions but here’s the explanation of the Silca calculator along with a good discussion on the overall topic of rolling resistance of tire casings, the impedance of surfaces and how they interact.

https://silca.cc/blogs/silca/tire-pr...ator-explained

Otto

rclouviere

perfect. Thanks

rclouviere

not on here much. Here goes: I’m 6’, 160+ pounds, have a madone and emonda set up tubeless with conti 5000 tires TLR and a TT bike, speed concept with conti 5000 clincher tires. All tires 25 mm

discussion came when another cyclist, known to be an annoying know it all, made the statement that anyone with tubeless tires who still inflated to 100 psi is an “idiot.” I said i was that idiot. He went in to say i should have wider tires (i have 25mm) and run them around 70psi. There were varying opinions.

bottom line is I’m 65 years old, but still trying to keep up with the youngsters, and need every speed advantage i can get.

rclouviere

I’ve always run at least 110psi. “Feels” faster to and how it’s always been for me. Lower psi just seems slower. I know there’s been lots of testing on this, but I’m just not sure now. The silica chart indicates i should be around 95psi

WhyFi

Ew, David.

rclouviere

I don’t care about comfort, only going faster.

WhyFi

Smooth is fast. Fast is smooth.