stroudmears

Should I even be worried about exceeding the advised PSI limit on my tires with a simple frame pump?
It's a decent lezyne pump, and I pump the tires until it gets pretty hard to put more air through it.
It works fine and with 25mm tires, smooth roads and 78kg bodyweight, I want them pretty hard.

So my question is, is it easy to exceed the pressure with a hand pump?

GlennR

I have a Bontrager floor pump and put 100psi in the 25mm tire. I think the max on the tires is 120psi. When I get past 90psi a single pump only puts a few psi in so there's no way to accidentally hit 120psi.

pdlamb

Never say never; for all I know you're an NFL linebacker who'll stop for 20 seconds between pumping to rest and recuperate.

But I agree, it's unlikely you'll exceed 120 psi with an ordinary frame pump. You'll probably get tired or bored before you blow the tire up.

grizzly59

Pump it up to where you want with your floor pump. Now pinch your tire with your thumb and forefinger. Do it again tomorrow. Now you know what it feels like, and you won’t exceed that with your hand pump.

aclinjury

with a frame pump, you'd need to be a gorilla to put in 120 psi in a 25mm tire, but even before that, he pump will probably break at 90 psi

Ever tried to hold a 120lb dumbell with just 2 fingers? that's the sort of effort it'll take at 120 psi

CliffordK

It might take you a few hours pumping, but you should be able to get a decent amount of pressure with your air shock pump. Most are rated at about 300 psi.



Of course, most should have a gauge when new.

stroudmears

Exactly the responses I was hoping for, thanks all.

biker128pedal

From flat count the number of strokes. I’m the opposite. I NEED 110 psi rear and 100 psi front otherwise I will pinch flat.
Lezyne Long.
Front 205
Rear 230

but I’d did buy the hose with a gauge and use presto to Scheader adapter.

Gresp15C

One of my habits is to make a mental note of how much my tires pooch out under my weight. That's my gauge when I'm out on the road. In practical terms, my arm strength and/or the compression ratio of the pump are likely to limit the ultimate pressure that I reach. On larger tires, boredom.

Drew Eckhardt 

Full size frame pumps work fine at 90 psi, which is achievable using cyclist's little T-rex arms.

Hardly.

Silca frame pumps use a 3/4" piston totaling 0.439 square inches which would require 53 pounds of force to achieve 120 psi.

Other frame pumps made for road bikes are similar.

sledgefisher

Pump your tyre up until it compresses by 15% under your weight, for instance I have found that my 25c tyre needs around 85psi on my rear and 80psi on my front with my weight of 79kg. But without a gauge on my hand pump I just pump it up then sit on the bike and if it compresses too much I just add more air. I only know the psi because I have a track pump at home where I usually inflate my tyres.

rollagain

You could get one of these ...

https://cyclingspares.com/bicycle-pu...-9-9cm-silver/

It only delivers about a teaspoon of air at a stroke. Your arm will fall off before you can overinflate the tire.

JanMM

Can’t tell from your posts if your only pump is the frame pump. If you don’t have another pump with a gauge or a separate gauge, then you are just guessing at tire pressure.

aclinjury

That's just theory. Real world is different. My Lezyne handpump says "160 psi". Yet, when I pump a tire until I can no longer pump due to arm pump, it was 80 psi when I got home and measure the pressure with a guage. Nobody is pumping their tires to 120 psi with a frame pump, especially not with noodle t-rex arms.

Drew Eckhardt 

Lezyne does not sell full size frame pumps. Zefal and Silca seem to be the only remaining companies that do.

My Blackburn (discontinued, because worthless micropumps are all the rage) gets me to 90 psi with 100 strokes.

With an optimum cycling weight of 136 pounds at 5'10", I have scrawny t-rex arms.

Zefal HPX users report reaching 120 psi easily, although I assume they're large enough to require that.

Gio800

There is a safety factor for the tires. Probably take 200 psi to blow.

Ogsarg

Pump your tires up to within a couple of PSI of normal then put your frame pump on and see how much effort is needed to get any more air into it. This will give you a reference for when you have to pump it up out on the road. Having fixed a fair number of flats with a mini pump, I find that overfilling is about the last thing I expect to happen.

Elvo

You could also get one of these and monitor your pressure. Or use a bluetooth pump?

https://www.sram.com/en/quarq/models/wh-trwz-a1

GlennR

Wow... just learned something new I don't need.

My wife has valve caps that came on her Specalized Roll that have a pressure indicator, green=OK and red=low.

I can tell you that yesterday I was on a ride and after a few miles realized I didn't pump up my tires before leaving. I have latex tubes and they tend to drop 10psi even over night. I normally ride 90/100 and the back felt sluggish, squishy and bouncy. I decided to continue on and visit the LBS not far away and top up.

fietsbob

Learn what the proper inflation pressure feel like, floor pump with a gauge,

then when you have to top it up on the road, you will know what adequate feels like..






...

greatscott

You can buy a small cheap little PSI gauge from Topeak, it fits in my saddle bag.

I also use and like the Lezyne pump, but since you have one of those you can get a inline pen hose gauge from Lezyne, which I don't think will be all the accurate since it's a ball float type of gauge, anyway you remove your old hose and replace it with the new one. I prefer the separate gauge because I transfer between several bikes, while one is the Lezyne, the 2nd one is a Topeak and the other is a Zefal frame pump, none of which have gauges so having one gauge I move around fits me the best.

rollagain

First thing I thought when I saw this was, "Won't that put your wheels out of balance?"

canklecat

I have a mini pump with a gauge. More trouble than it's worth. It's a nice looking, well made "Pro Bike Tools" mini pump. But it's the least functional of my four mini pumps, by far the most difficult to pump. And it tends to either shut the Presta valve or unscrew the entire core.

My Topeak RaceRockets and Blackburn Core Slim are far better mini pumps. No gauge but it doesn't matter. I just pump until it's ridiculously difficult -- around 200-300 strokes -- then ride. It's usually around 60-90 psi, depending on the tire and pump. Good enough to finish a ride.

greatscott

This site tested a bunch of pumps and will tell you how many strokes it took to get to a specifc PSI: https://cyclingtips.com/2019/08/the-...ike-45-tested/