wolfchild

As long the ride is comfortable and not harsh and as long as you're not getting pinch flats, that's all that matters and this is easily achieved by feel. No need for any calculators or complex mathematical calculations..

asgelle

It might surprise you to know there is a fairly large coterie of us who care about how fast we go. So no, comfort and lack of pinch flats are not all that matter.

pepperbelly

I will use a gauge so I have a baseline.
If I just use how it feels the pressure will never be repeatable.
I do care about speed. Comfort isn’t as important. The recommended pressure was calculated by an engineer smarter than I am. I will trust him and adjust in small amounts for my body weight and road surface.

squirtdad

I have not seen a hard number on that. but I would think withing 5 lbs or less delta

example my lezyne floor pump showed 110 psi, but when measured with a topeak it showed 120, so I pump the silca to 100 if and it gets me very close to 110 topeak: https://www.universalcycles.com/shop...s.php?id=44436

did the same compare with my battery pump and the pump matches the gauge the electric pump pumps to slightly over, stops pumping and then lets air out until it reaches the set pressure (milwaukee m18 tire pump got it for cars, but works great with bikes especially by adding a silca chuck)

Alan K

Pepperbelly: I would not go above the maximum rated pressure of tires/rims (whichever is lower).
Use a reliable gauge (ideally a digital) that has been cross checked with another one possibly from you bike shop. Most tires may have a significant margin for safety than rated maximum pressure but I wouldn’t want to take any chances to test the limit.

CrimsonEclipse

4.9"x26"
5psi front 7psi rear

It's more of a tracked vehicle than a bike

Jay Turberville

I just used that online pressure calculator for my atypical road bike (26x1.5" tubeless slicks on a Trek 990 MTB frame) and it spit out numbers almost identical to what I've settled on through trial and error. 60psi front, 65 psi back. Might have been a fluke. Or maybe the calculator is actually pretty good?

SpeedyBlueBiker

I hadn't put more air in my road bike tires for a month despite riding almost every day. When I put air in my tires, I did notice that they were running lower than I had thought. Rode 35 miles on them and they felt a lot better although the ride was a little harsher than before at times.

Garthr

Pepperbelly, I think your pressure is right where you need to be for the given load they are carrying. Yes there are tires that will be marginally fast-er, but at a high price. Tires are an easy visual target, you can buy really expensive tires for marginal gains. The greatest source of drag though is the rider themselves. A big wide sail with arms, legs and a head. You can't buy your way out of that, but you can reduce that drag as best you can, and it's free. Clothing helps some for sure, but the rider has to do the rest in regards to positioning. I know I noticed it for sure, notably going into headwinds.

Maelochs

yup .... when it comes to speed .... a few pounds of air pressure are not the make-or-break issue. If it was, pros would be stopping periodically during races to re-test tire pressure---after all, friction and ambient temperature can affect tire pressure .....

In the same way, a few hundred grams of bike weight are not going to make or break a ride.

It is 99 percent the rider .... and unless you are a pro on a big team (in which case the mechanics do all that stuff) then you are likely going to ride better if you are a little more comfortable .... a little less energy drain, a little less interference, a little more enthusiasm, is probably going to help you ride better ... if that even means "faster" to you or not.