Help! Tyres deflating

George Bond

Finding my (electric) wheels
Mar 18, 2018
6
2
81
Milnathort, KY13
I have a friend who has a Raleigh array about two month old ever since she bought the tyres deflate quickly after a few days they have gone fron 60 psi to 30 psi approximately the valves are not leaking anybody any ideas. Thank you
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
6,922
2,668
Basildon
How do you know the valves aren't leaking? Yesterday, I had to fix a Raleigh with exactly the problem you described. I tested it with soapy water and didn't see anything, so I took the tube out and checked it for leaks with soapy water, but there were none, so I checked the valve again and gave it more time. Sure enough, after about a minute, I could see a bubble forming. After taking the valve out and cleaning it, it leaked worse, so I screwed it in tight, but it still leaked, then, after a few blasts with the pump, it stopped leaking, and it's since held its pressure.
 
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richtea99

Pedelecer
May 8, 2020
93
50
At great risk of teaching Grandma how to suck eggs...

Whip the tubes off, pump them up a little, dip them under water and look for bubbles - take a few seconds for each section since they're obviously small leaks. Check the valve for bubbles too.

If they're Presta valves, do the screw up tight (you should be doing this anyway).

No bubbles? Give up and buy fresh tubes. Compared to the price of the bike, they're peanuts!
 
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Gringo

Esteemed Pedelecer
Jun 18, 2013
1,162
714
Northampton
Just because it’s new doesn’t mean it won’t leak. I had a brand new tube that would hold pressure for two days, after that it would stay at around 10-15 psi indefinitely.
obviously when testing the tube In the open air it can never reach its working pressure so the leak went unnoticed on the first inspection, it was only when I put the inflated tube totally under water for 5 minutes that I could see the smallest of bubbles forming at the valve stem, at this low pressure it was only about one bubble every 3 or 4 minutes. It was like a pressure release valve, the more I pumped the faster it went down until it reached about 10psi when the leak sealed itself.
Unfortunately shirt happens, thats just the way it goes sometimes.
 

Gubbins

Esteemed Pedelecer
I have 3 bikes of which 2 are tubeless and they all loose pressure over time. 2 have high volume mtb tyres which I generally pump up to 25 psi and after 5 weeks they were both showing less than 10. The 3rd bike has tubes in and does the same albeit taking a bit longer .. I assumed this was normal..
 

mike killay

Esteemed Pedelecer
Feb 17, 2011
2,889
1,493
Question,
Does slime stop this?
I remember in the late 1950's Dunlop brought out new tubes, I think they were called 'Air seal'
They certainly held their pressure for weeks, although in those days it was not possible to measure the pressure with Woods valves, we just pumped the tyre up and did the 'thumb test' as long as it felt hard we assumed it was up to pressure.
 

L6mbt

Finding my (electric) wheels
Feb 1, 2019
24
4
Slime is the answer. Since adding slime to my tubes, the tyres stay hard much longer.
 

L6mbt

Finding my (electric) wheels
Feb 1, 2019
24
4
If I get a "big" puncture in a slime filled tyre, I would expect to replace the tube anyway.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
11,959
4,639
57
West Sx RH
Slime doesn't always do the job I have only tried it once in tubes and it was a dead loss, all that occurred was a big mess as the tyre had to be patched. I was in the middle of a trail/bridle way on the north downs and had two Blackthorne needles puncturing.
 
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L6mbt

Finding my (electric) wheels
Feb 1, 2019
24
4
I am aware there are opposing views on the use of slime. I can only say it works for me. I have not had a puncture since using it two years ago whereas beforehand I regularly got punctures. I have always carried a spare tube anyway, preferring to replace a tube rather than attempt a roadside repair.
 
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L6mbt

Finding my (electric) wheels
Feb 1, 2019
24
4
Why? Because, as you said, slime in a tube makes it impossible to fix big punctures. It's a trade - off; it's a price I'm willing to pay to make punctures far less likely.
 

WallyM

Pedelecer
Aug 10, 2020
39
18
The eternal tire deflating....its a drag sometimes, and due to the extreme temperature fluctuation in summer I noticed that a lot in the last years. Nothing more than the above Tips one can do, except that I used an easier method to check the leak are..
I use a big basin and then place the entire wheel into it, which saves me at least the work to take out the wheels.
After having found the potential leak I can then go to "work". Very often it's a valve.
Also, if helps a bit to extend the lifetime of tubes to change the protecting rim rubber.
And use quality tubes for replacement, its worth it.
Anyway this is one point I look for my future e-bike- quality OEM tires !