I can't inflate my front tube past 80 pounds.
 

Additional strokes don't move the needle. I don't feel air coming out at the valve. A leak test in water shows no leak. Putting in a new tube doesn't help. But I have no trouble inflating my rear to 100. They both lose about 10 pounds/week.

Try switching front/rear.

Perhaps try a different pump.

Try replacing the tube or the Valve core.

your 10 psi a week is spot on with what I experience.

try changing the tube valve. sometimes they just get weird and dont work like they should.

-SP

Using a floor pump? Are you pushing the handle all the way down on the pump? If the handle isn't going all the way to the bottom then you need to put more of your weight on it. Sometimes the check valve in the pump is sticky and needs extra pressure to open it.

Might be time to clean and rebuild the pump or if a inexpensive pump, just get another.

I always pump my front tire first....

I’ve never experienced this with identical tubes and tires. The first obvious thing to try, but is a pain, is to swap tubes. The rear tire should only inflate to 80 lbs.

I’m betting that the valve is bad on the front tube. And by some coincidence the new tube valve is also restricting airflow.

Your pump might also be close to its max capacity and any restriction is too much to overcome.

If you can try a different pump with a higher rating it might inflate the tire to 100 even if there is some air restriction in the valve.

On presta valves when I have not backed the valve release nut/cap enough it is a pain to try and inflate. But another turn increasing the air flow solves it.

John

It's almost for sure that the valve core is bad. The valve core has a stopper end piece which has a rubber seal ring on it. In a cheap quality core this ring would either be too loose, or become too loose. Now it expands out and becomes an o-ring, and seals all incoming air. The more pressure you pump in, the harder it seals!

Failure to burp the valve is the usual culprit but if that doesn't resolve it, get a different tube or swap the core.

why wouldn't you just ride at 80, anyway? I ride at 70-75 every day.

A shop air compressor and an INF-2 is my best friend.

Are you there Arthur Peabody ?

Everything okay? Just wondering why the crickets.