Pumping up Presta / Does Anyone Else Have This Problem?

HugoFurst

HugoFurst

New Member
Region
Australia
I have a Blackburn entry level dual head floor pump. I usually pump up my presta valve/tires to 105 psi. I noticed that when I remove the head, some air still comes out, no matter how quickly I try to remove the pump head. I wondered how much air I am losing here, so I ran a test. After pumping to 105 psi and removing, I re-attached the pump head and locked down with the lever. No air came out at this time, however I noticed that there is no reading on the pump. I then raised the pump handle to max and depressed one time. The reading then came up to 95 psi. I am losing 10 psi by just removing the pump head? I know on a presta valve that you have to unscrew the cap and then if you press down , air will quickly escape, but is this normal for my pump not to read until I pump one time? Thanks.
 
10 psi is on the high side of normal but I wouldn't be too concerned about it. I'd say 5 psi is a lot more like business as usual. As to the pump not registering until you've given it a pump, that may be normal for that pump, but its not normal for presta pumps in general. Certainly not any of mine over many years. Usually thats a sign that you don't have the pump head on deep enough, in cases where you have say a short 32mm valve stem and a double wall or deep-ish rim.

The Blackburn brand isn't what it used to be. It was sold off many years ago. I still have some of their products but not racks - which were their big original thing - or pumps
 
Yes, I had that problem. My pumps would not seal well. Even the huge stainless steel community pump they installed at the bike path was problematic. I use Shrader adapters on the Presta valves.
 
Worth clarifying: When I said '5 psi is more like it' I was keying off of the thread author's statement that he normally pumps to 105 psi. Thats skinny road bike tire territory. Say, 700x23C. 5 psi or even 10 psi is not out of the question when you are pumping tires up that high and they are little skinny road bike tires without a lot of capacity.

If instead we are talking 26x2.0 or more for your typical ebike tire ... then yeah thats way out of line.
 
I wouldn't fuss about 5-10psi. That's less than 5-10% from where you started. If it really bothers you, go 10psi over and you will settle out at the 105psi you want. Unless you are competing in a major race, would you even notice 95psi over 105psi?
 
rich c said:
If it really bothers you, go 10psi over and you will settle out at the 105psi you want. Unless you are competing in a major race, would you even notice 95psi over 105psi?
Click to expand...
Thats what I always did. 120 psi on tires that were rated for 110. And yes even though at the time I only weighed 135 lbs and was riding a sub-20 lb road bike, the loss of rolling resistance (on an analog bike powered by legs, to be fair) was very noticeable. But that was also back in the day when little tires like that had to be aired up daily as they bled out 10 psi a day normally.

Nowadays I go right up to the line and no more, and my screw-on chucks have turned out to be the solution to giving zero air loss when airing up tires.
 
My Lezyne pump has a magic reversible screw-on end, one for presta and one for schraeder. When using the Presta connection, there's a button to release air pressure from the hose, which causes the presta valve to close without losing any air pressure. It's a pretty sweet setup.
 
It is normal to lose some air when removing a pump head from a Presta valve, but losing 10 psi seems a bit excessive. The loss of air could be due to the pump head not sealing properly or the valve not closing quickly enough.
Regarding the pump not showing a reading until you pump one time, this is also normal. When you reattach the pump head and lock it down, the pressure inside the tire is not yet equalized with the pressure in the pump's gauge. By raising the pump handle and depressing it once, you equalize the pressure between the tire and the pump, allowing the gauge to show an accurate reading.
https://www.bikethesites.com/how-to-inflate-presta-valve/
 
Last edited:
smorgasbord said:
www.cyclingnews.com

Schrader vs Presta: Understanding the differences

Explaining the similarities and differences between two kinds of bike valves
www.cyclingnews.com www.cyclingnews.com
Click to expand...
My experience with valve types does not match the article. MY Gazelle ebike has the first Presta I've had in 60 years. Hate them to the extent I might replace with Schrader (wheel will accept, LBS confirmed when replacing tube). Every time I go to ride, tires need to be topped off; both mine (~70 psi) and my wife's (~50 psi). I could go months on Schraders; including the 25mm pumped to 110 psi on my first 10 speed. and 100 psi on my touring bike.
 
Roamers said:
My experience with valve types does not match the article. MY Gazelle ebike has the first Presta I've had in 60 years. Hate them to the extent I might replace with Schrader (wheel will accept, LBS confirmed when replacing tube). Every time I go to ride, tires need to be topped off; both mine (~70 psi) and my wife's (~50 psi). I could go months on Schraders; including the 25mm pumped to 110 psi on my first 10 speed. and 100 psi on my touring bike.
Click to expand...
that has nothing to do with the valve but the tube loosing air.
 
Roamers said:
My experience with valve types does not match the article. MY Gazelle ebike has the first Presta I've had in 60 years. Hate them to the extent I might replace with Schrader (wheel will accept, LBS confirmed when replacing tube). Every time I go to ride, tires need to be topped off; both mine (~70 psi) and my wife's (~50 psi). I could go months on Schraders; including the 25mm pumped to 110 psi on my first 10 speed. and 100 psi on my touring bike.
Click to expand...
Agree with @fooferdoggie thats not the Presta valve. Your tubes suck somehow. I mean... maybe it IS a problem with the valves but thats not because they are Presta. Maybe they are made by chimps or something.
 
Don't know what would be different with tube material. Schraders were on OEM tubes and LBS replacements as are tubes with Prestas.

Article indicated Presta holds higher pressure better; not my experience, but I haven't pumped them up to 100+ like I used to with the older bikes with Schraders.

My current Hybrid analog with Schraders holds pressure longer than Presta ebike ( both ~70 psi).
 
I've been using this setup for years and it works GREAT !
Link: https://a.co/d/8cFtIJv
Enjoy !!!!

1679452965495.jpeg
 
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