lindafranc

I recently changed from 700 x 35 mm semi-slicks to 700 x 41 (or so) heavy treaded tires. I initially found the new tires much harder to pedal, maybe like 30 to 40% harder. It was kind of like lifting weights, not huffing and puffing. My legs kind of burned and it was not fun going up hills.

Then I checked the tire pressure and it was 25! So I pumped them up to near 80 (the max indicated on the tire) and they now feel only slightly harder to pedal than the 35 mm semi-slicks. I have only went on three 4 mile rides so I don't know for sure if it is in fact true. Has anyone experienced this? Does tire pressure make a major difference?

General Geoff

It certainly can, though you probably don't have to run your 41mm tires at 80psi. Try 45. It'll still be a big improvement over 25, and give you better traction and softer ride than 80.

fietsbob

Does tire pressure make a major difference?



this surprises you? Team mechanics for the pros use accurate gages, because it matters a lot to them..

SkyDog75

Yes, tire pressure that's too low makes a huge difference in rolling resistance. It can also cause flat tires and premature tire wear.

But like General Geoff mentioned above, the maximum pressure the tire can handle is probably higher than ideal. Schwalbe, a well-regarded tire manufacturer, has a chart of recommended pressures on their web site HERE. To summarize their recommendations for a 40 mm wide tire...

If you weigh approx. 130 lbs, inflate to 50 psi.
If you weigh approx. 185 lbs, inflate to 65 psi.
If you weigh approx. 240 lbs, inflate to 80 psi.

Cyclist0108

Yes.
Yes.
and ...
Yes.

In my case it was 40mm WTB nanos, and climbing 1700ft. Low tire pressure felt like I had the flu.

Machka 

Yes, of course it does.

In fact, one of the reasons why some of us feel that test riding potential new bicycles may not be all that helpful is because much of the difference you feel between one bicycle and another could well be simply tire pressure.

Troul 

I'm running the 700x32 Schwalbe Marathon HS & the max psi iirc is 75 & i've been running it between 70-75 psi. Def thought about dropping it to 65 psi, but I am leery of spoke issues from riding weight (200) to spoke count (32) . The rolling resistance does seem too high with it being at the max psi, so I can see a lower psi being just as much of a challenge when not within a target psi range (riding weight, tire profile, & wheel design) .

dabac

Tire pressure is important, particularly in combination with tire design.
Tires deform around the contact patch. This kneading, the moving wave or wrinkle this causes in the rubber steals energy. There are two says to reduce these losses:
- a harder inflated tire will deform less, causing less kneading. It loses less energy and rolls easier.
- thinner, more flexible sidewalls and tread means there’s less material to deform and less energy lost.
You went to thicker tread and lower pressure and got a double serving of added rolling resistance.
This makes it easy to think ”I’ll max out the pressure and become faster on any tire” which isn’t really the case. Too much pressure will make the tire bouncy. Every little pebble you run over will try to launch you skywards. That’ll actually add rolling resistance. And reduce traction. And reduce comfort.
Thinner sidewalls or treads is also a so-so fix.
You can get thin-walled and thin-treaded tires that roll well on low pressures.
But supple AND puncture resistant are kinda mutually exclusive.
My ”race” MTB tires roll like you wouldn’t believe for their width.
But I’ve torn sidewalls twice, and I wouldn’t trust the tread to deal successfully with anything worse than pine needles.
This is why you have to invest some effort in finding YOUR preferred compromise.

asmac

If you want to see some controlled testing of various tires at various pressures check out this site: https://www.bicyclerollingresistance.com/


I was surprised to find that my nice, thin, slick Schwalbe Kojaks perform much worse than heavier, bigger, rugged and treaded Schwalbe Almotions. It's remarkable what actual testing can reveal.


While tire pressure certainly makes a difference, the construction of the tire and compounds used seems to be the most significant factor.




.

Flip Flop Rider

pump the tires up and it rolls better, brilliant!

Abu Mahendra

...and run 50/35psi rear/front. i weigh 77kg. 80psi is definitely too high.

caloso

Yes, tire volume, tread, suppleness, and air pressure all make a difference.

u235

Most if not all 700c tires > 38 are city/hybrid/touring/off road tires. They are built to be better in one or more other areas but not ultra low rolling resistance like what is available in the < 32 size . As time goes on, more features other than "it's a great bullet proof city tire" are working their way into larger 700c sizes. I personally like Conti SpeedRides in 700x42 (except no tubeless) but what I want in a tire might not be what someone else wants. Like what others mentioned, just because a tire is a slick or has minimal tread, it is big or small etc doesn't mean it will roll with less effort than something else. It might be smooth but that is not the same as rolling resistance.

unterhausen

the thing that is dominating rolling resistance for the OP is the "heavy tread," which usually goes along with heavy sidewalls. I started running 32mm Gravelking slicks last year, and I was looking at how much air to put in them. I prefer less air. Turns out that inflation pressure really doesn't make that much difference on a decent tire with supple sidewalls and thinner tread. Inflation pressure on a tire with overbuilt sidewalls makes more of a difference. On my commuter, which has overbuilt tires, going from 20psi to 40psi makes a pretty big difference in rolling resistance. On my gravel bike, with 38mm tires, going from 20 psi to 40 psi is imperceptible.

rumrunn6

optimal tire pressure = the holy grail. good luck finding yours. been tweaking pressure for unpaved riding for a long time. finally got on board w lower than max for my road bike

u235

I can say almost the same thing. The last set of tires I've swapped around on my gravel bike...
Conti Contact Sport 37c slick city/road tires. An intermediate tire with a balance of protection and weight. There is a big difference between 40 and 70 psi with rolling resistance. I also have Conti SpeedRide 42c. A light supple flexible file tread tire with minimal protection. There is very little if any difference in resistance going 40-70 psi on that. That being said, even on the road the larger SpeedRide rolls easier at my normal 40-45 psi than the Contact sport at 70.

Flip Flop Rider

changing gears will affect speed also

Iride01 

If you track your speed/distance/time stats with a cyclometer or such, then you can see easier what tire pressure does for you.

Because your riding conditions are unique to you, it's best to look at your stats over many rides. So fill your tire up and do five or so rides at one pressure. Check your pressure every ride till you learn how fast they leak down.

Then try a higher or lower pressure of say 10 psi different than before. Do another five rides and compare your stats as well as how it felt for your comfort. You can keep trying until you find what's ideal for you.

If you are nit-picky, you might find that on smoother surfaces you do better with a higher PSI, but on rough surfaces you prefer a lower PSI.

lindafranc

Thank you most everyone who replied. My problem started when I ordered a 38 mm for my bike which originally came with 35 mm. The 38 mm actually measures about 41 mm. But now I think I will be ok with what I have. I just don't want the pleasure I had before using my bicycle for everything to now be something I do not look forward to.

If I change to 35 mm in the same tire there still might be hard pedaling issues at lower pressures. I definitely do not want to go back to semi-slicks of any width. They are unsafe for me. And I don't want to be ordering several tires to try out. The cost will be more than my bike!

The moral of the story: If the actual tire size is not indicated on the website contact the manufacturer or distributor and find out what it is.

Iride01 

Lower pressure can also cause handling issues. When your turns are feeling squirrely then check for too low a tire pressure.

You didn't say what type surface you ride on, but I've ridden slicks since the early 70's and don't ever feel a lack of traction on paved surfaces wet or dry. If you are on other than paved, then I can agree with some rougher tread pattern.

Kapusta

Most but not all.

Compass tires roll insanely fast.

superpletch

convert to tubeless, get a good tubeless tire and go faster at lower pressure and have a more comfortable ride with virtually not flats.

bring it on!

u235

True that but prefer to carry a spare tube, not a spare tire

G-One is another option and tubeless but limited to 38 and > $70. The widest 700 "road" tire Schwalbe has. Marathon Supreme in 42 also for > $70, relatively light for a Marathon "touring tire" and it doesn't have the hard protection layer like the regular Marathon so I'm sure it's reasonable supple for what it is but probably not enough and wouldn't like it off road just as there are great gravel/hardpack specific tires I would not use long on road.

I did roughly 2500 on Speedrides last year on road and about 500 on gravel/trail, some with racks and gear and it works and they are cheap. Maybe 10 flats all on road and one eventual trashed tire. Would like other options and tubeless. Tons of people ride 32 and less for more than 500 a year on gravel and off road, I am not one of them.

Tanstaafl

As a relative bicycling nOOB, I was looking into the subject of rolling resistance as I began shopping for new tires. During my search for knowledge I found this site. https://www.bicyclerollingresistance.com

He tests several different tires from road to mountain bike. He also tests at different air pressure. Spoiler: Air pressure make a difference.

Regards,
Jeff

SquidPuppet

I've seen that test. Frankly I'm skeptical. You and I have had Kojaks in our hands. The sidewalls are really thin and supple. The tires are very light for their size. I'm not accusing them of lying, but something seems off with the results. Some kind of error in set up or a hiccup in the software maybe? I have them on two bikes and they roll really well IMO.