Less than full PSI on tires?

christob

Well-Known Member
I tried searching the Forums for this; apologies if I missed a relevant post.
Just curious about the pros/cons of not running my tires at stated top PSI?
Schwalbe Fat Frank 29 28 x 2.0 (#50-522) -- sidewall of tire says 30 - 65psi, and they're currently at 65.
When I got the bike delivered to me, I think they were probably at about 40 -- but upon my first visit to LBS, one of the guys said 'we really gotta get you up to 65 - don't want any pinch flats!'
But it makes sense (from other posts I landed on before this) that a lower pressure also builds in a little more shock-absorbing (the bike doesn't has a suspension fork.) Bigger guy here, about 280, and the bike itself is about 50.
It is a fairly stiff ride, it seems to me (ride almost exclusively on paved surfaces thus far.) Just wonder about the pros/cons/risks of taking it down, to say 50? Would I feel a ride difference? Would I be jeopardizing the rims or tires?
Thanks!
 
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50 psi will be fine. You will have a smidge more rolling resistance, but in return you will get a slightly cushier ride. You could take it down to 40, but you are a big guy so you would run a higher risk of pinch flats, although if you stay on pavement, don't plow through bumps or jump curbs, 40 should be okay as well. If you really like the lower pressures, you can avoid pinch flats altogether by going tubeless.
 
Being a bigger guy you should run your tires closer to the max pressure, especially the rear. Unless you really feel the ride as uncomfortably harsh, it is worth the protection of the wheels and its more efficient and faster.
 
https://www.schwalbetires.com/bike_tires/road_tires/fat_frank

¿29 inches?


The total weight is 150 kilograms and the maximum joint for pedelec is 120/135 kilograms, exceeds in 15 kilograms the maximum authorized weight.

It is a k-guard 3 and weighs 875 grams, does not have a pedelec or s-pedelec label.

that series tire holds 135 kilograms

Personally in your case after spending the current ones, I would look for one that was 1100 grams with more protection.25/50 km/h label.

(Link Removed - No Longer Exists)

Due to the great excess of weight there is no option, to have them to the maximum of pressure for their safety. The most dangerous situation is in descent at high speed where the wheel turns and brakes abruptly.

Undercutting may occur.That is not solved with patches or liquid, also could damage the aluminum or steel wheel.



Within the weight of 130 kilograms with a tire very resistant to punctures could put maximum psi on the rear wheel and lower 5 / 10psi less on the front wheel.


This allows to raise inclinations of 3º positive or rise as if it were flat terrain.



Greetings
 
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Just to toss in my experiences, if you have tubed tires I have found that running higher pressure means that when you get a flat,it will make the puncture bigger,when I ran max pressure and got a puncture it meant a new tube,as it seemed it blow out more explosively,with lower pressure I run about 25psi,I could then patch tube.
 
My fat tires are rated at 20 PSI. I run a little lower for trail riding to help with traction in sandy and rocky conditions. I run as high as 22-23 PSI when work commuting for speed and efficiency. I usually double-check my psi weekly and adjust for the type of riding.
 
I usually run the tires a little over 20 PSI on my Yukon Fatbike. I usually ride on pavement and the ride is fairly spongy and comfortable. I weigh around 230 or so. I love the wide variability in the tire pressure.
 
Just to toss in my experiences, if you have tubed tires I have found that running higher pressure means that when you get a flat,it will make the puncture bigger,when I ran max pressure and got a puncture it meant a new tube,as it seemed it blow out more explosively,with lower pressure I run about 25psi,I could then patch tube.
No matter the size of the puncture or max pressure? A small thorn would cause the tube to blow out? That's opposite of my experience. Running the Kenda 20x4 1/4 on my Fat-Tad trike at max 35psi. Had a small thorn come through the tire and get stuck there. Tiny pinhole in the tube I found latter. I was 3 miles from my van, so went to the gas station, inflated it a lot (no gage) and rode the 3 miles back. I definitely carry a kit now! On my Trekking bike, I run the max 65psi. The only flat I had almost looked like an abrasion on the tube. Never found anything in the tire. It didn't blow either. In fact the only way I knew it was flat was the next time I rode it.
 
I found that when I got a puncture it looked like a bullethole in glass,tiny actual puncture then sort of splintering around it.But after I reduced pressure any punctures were just ther actual puncture. But I suppose it also depends on the tube,admittedly I was using chinese ones.
 
Tried cheap tubes for a while. No more, go to the LBS and get a quality tube, always, worth it no question.

On the PSI, it's kinda like asking how much ketchup to put on your fries, try it and see how it works for you. Softer ride vs more resistance and maybe slightly more flats. At your size you have less safety margin, hard bumps will hit it HARD.

I run mine full up cause I need the range, and speed, and the difference in comfort wasn't that big. YMMV

Another avenue to investigate is if you can run significantly wider tires on your current rims, which did work out well for me, but requires some careful matching. It did NOT work out well on the first try.
 
Converting to a tubeless setup is always an option. I did this about 10 days ago on my Juiced CrossCurrent S.
This allows you to run lower pressures without the worry of pinch flats. Its also inherently lower resistance than a tubed tire. This way you can set pressure to your preference for comfort, speed, etc. You are also less likely to get flats because the tubeless sealant seals most punctures very rapidly. I did the conversion for the flat protection honestly as removing the rear tire on a hub motor setup is more time consuming and I'd rather not have to do it on the side of the road. I still run higher pressures (65 psi currently) but down from 75 when I had tubes. I honestly can't say I've noticed any difference at all in rolling resistance.
 
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