I have been using slime tubes for a few months. I felt that the rear tyre needed air too often (every second day, though only a few strokes), so I took the tube out and inspected it. No sign whatever of any self- sealed punctures (I'm also using slime liners). I inflated the tube and checked it in water. Not a bubble. I left it to see whether it would go down at all. It hasn't. Now I want to put it back on the bike.
And here's the problem.
When I press the little [censored] at the end of the presta valve, the slime comes bubbling out. I don't want that to happen, so I stopped. But without letting a lot of the air out, I can't get the tube back on and the tyre in place.
In article <[email hidden]>, The Big Baguette <[email hidden]> writes
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I have been using slime tubes for a few months. I felt that the rear tyre needed air too often (every second day, though only a few strokes), so I took the tube out and inspected it. No sign whatever of any self- sealed punctures (I'm also using slime liners). I inflated the tube and checked it in water. Not a bubble. I left it to see whether it would go down at all. It hasn't. Now I want to put it back on the bike.
And here's the problem.
When I press the little [censored] at the end of the presta valve, the slime comes bubbling out. I don't want that to happen, so I stopped. But without letting a lot of the air out, I can't get the tube back on and the tyre in place.
Apparent stalemate.
What do others do?
Please ignore this question. I have now discovered what most people probably already knew -- leave the valve unscrewed and it goes flat of its own accord. -- The Big Baguette
When I press the little [censored] at the end of the presta valve, the slime comes bubbling out. I don't want that to happen, so I stopped. But without letting a lot of the air out, I can't get the tube back on and the tyre in place.
Hanging the tube up with the valve at the top normally works - leave overnight - then let the air gently out.
Hanging the tube up with the valve at the top normally works - leave overnight - then let the air gently out.
No no no - you must put the valve at the bottom! Stale air is heavier than fresh air, and if you don't put the valve at the bottom it won't run out!
Guy === ** WARNING ** This posting may contain traces of irony. chapmancentral.comchapmancentral.comOpen ↗ (BT ADSL and dynamic DNS permitting) NOTE: BT Openworld have now blocked port 25 (without notice), so old mail addresses may no longer work. Apologies.
Please ignore this question. I have now discovered what most people probably already knew -- leave the valve unscrewed and it goes flat of its own accord.
Shouldn't do normally - although perhaps the valve doesn't function properly when there's only a tiny bit of air/pressure left ?
In article <[email hidden]>, Pete Biggs <[email hidden]> writes
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The Big Baguette wrote: [prestas]
Quoted message said:
Please ignore this question. I have now discovered what most people probably already knew -- leave the valve unscrewed and it goes flat of its own accord.
Shouldn't do normally - although perhaps the valve doesn't function properly when there's only a tiny bit of air/pressure left ?
Well, it did. Is this perhaps why I've needed to put small amounts of air in more frequently than I expect? Could the valve be defective? -- The Big Baguette
In article <[email hidden]>, Pete Biggs <[email hidden]> writes
Quoted message said:
The Big Baguette said:
Quoted message said:
[prestas] > leave the valve unscrewed and it goes flat of its own accord.
Shouldn't do normally - although perhaps the valve doesn't function properly when there's only a tiny bit of air/pressure left ?
Well, it did. Is this perhaps why I've needed to put small amounts of air in more frequently than I expect? Could the valve be defective?
Unlikely for the valve itself to be faulty - prestas are simple and extremely reliable (and I've never found one faulty in this way) - although perhaps yours is gummed up (?). The bonding between valve and tube could be dodgy or the tube could have a tiny hole somewhere (despite the slime), but this has nothing to do with valve nut being unscrewed.
A presta tube will normally hold normal pressure whether the nut is done up or not. The only time it might release air through the unlocked valve is if it's ridden when centrifugal force and bumps may cause the valve to momentarily depress.
Inner tube material is porous so all tyres gradually release air all the time - that's usually why they eventually go flat. If the tube is thinner and narrower than you're used to, it will require more frequent inflation - although no common butyl tube should loose much more than about 20psi per day.
No, it's a big fatty. Your comments make me think I've been concerned about nothing. Since recent advice here I've started inflating my tyres (Marathon Slicks) to 100 psi and the 'deflation' has amounted to no more than 10-15 psi over three days and up to 100 miles. This is normal, then? -- The Big Baguette
leave the valve unscrewed and it goes flat of its own accord.
Shouldn't do normally - although perhaps the valve doesn't function properly when there's only a tiny bit of air/pressure left ?
Well, it did. Is this perhaps why I've needed to put small amounts of air in more frequently than I expect? Could the valve be defective?
Unlikely for the valve itself to be faulty - prestas are simple and extremely reliable (and I've never found one faulty in this way) - although perhaps yours is gummed up (?). The bonding between valve and tube could be dodgy or the tube could have a tiny hole somewhere (despite the slime), but this has nothing to do with valve nut being unscrewed.
A presta tube will normally hold normal pressure whether the nut is done up or not. The only time it might release air through the unlocked valve is if it's ridden when centrifugal force and bumps may cause the valve to momentarily depress.
Inner tube material is porous so all tyres gradually release air all the time - that's usually why they eventually go flat. If the tube is thinner and narrower than you're used to, it will require more frequent inflation - although no common butyl tube should loose much more than about 20psi per day.
[prestas] > leave the valve unscrewed and it goes flat of its own accord.
Shouldn't do normally - although perhaps the valve doesn't function properly when there's only a tiny bit of air/pressure left ?
Update: Tested a tube with only a very few psi in it with an undone nut, and it does indeed go flat of its own accord, but I've never noticed this happen when tyre is fully inflated.
In article <[email hidden]>, Pete Biggs <[email hidden]> writes
Quoted message said:
Quoted message said:
although no common butyl tube should loose much more than about 20psi per day.
No, it's a big fatty. Your comments make me think I've been concerned about nothing. Since recent advice here I've started inflating my tyres (Marathon Slicks) to 100 psi and the 'deflation' has amounted to no more than 10-15 psi over three days and up to 100 miles. This is normal, then?
Well it sounds excessive to me, but perhaps not to Pete if he expects to lose up to 20psi per day. I would say a typical figure is more like 20psi per month. I pump up my tyres about once every month or two, if I remember.
Inner tube material is porous so all tyres gradually release air all the time - that's usually why they eventually go flat. If the tube is thinner and narrower than you're used to, it will require more frequent inflation - although no common butyl tube should loose much more than about 20psi per day.
No, it's a big fatty. Your comments make me think I've been concerned about nothing. Since recent advice here I've started inflating my tyres (Marathon Slicks) to 100 psi and the 'deflation' has amounted to no more than 10-15 psi over three days and up to 100 miles. This is normal, then?
Nothing to worry about - a slow puncture or faulty valve would flatten tyre faster than that.
I don't know exactly what tubes you've got (nor do I know the Marathons very well), but yes it's normal for many tyres to go down by that much. It's usually more noticable with skinny tyres though, simply because there's not much volume of air in them in the first place. I have to top up my 700x23 "racing" tyres every day, or every other day if I'm feeling lazy.
If you want to pump less often, change inner tubes for thicker and wider ones if possible. They'll hold the air better. Fat tyres with suitable tubes can hold sufficient air for several weeks without pumping if you're not fussy about loosing a few PSI (so giving them a bit extra to start with helps). Otherwise, they'll still need topping up: say, once every few days to once a week.
Well it sounds excessive to me, but perhaps not to Pete if he expects to lose up to 20psi per day.
...Only with high pressure narrow tyres with ultra light tubes (common enough) - that's why I said "up to".
Another thought for Baggy: Don't test tyres with a separate pressure gauge (one not on a pump). It will release some air each time you test! Thumbs are better.
If you want to pump less often, change inner tubes for thicker and wider ones if possible. They'll hold the air better. Fat tyres with suitable tubes can hold sufficient air for several weeks without pumping if you're not fussy about loosing a few PSI (so giving them a bit extra to start with helps). Otherwise, they'll still need topping up: say, once every few days to once a week.
I reckon to pump up 26 x 1.95 tubes about once in a season - I hired some bikes out yesterday which were last used in September and they were all OK.
If you want to pump less often, change inner tubes for thicker and wider ones if possible. They'll hold the air better. Fat tyres with suitable tubes can hold sufficient air for several weeks without pumping if you're not fussy about loosing a few PSI (so giving them a bit extra to start with helps). Otherwise, they'll still need topping up: say, once every few days to once a week.
I reckon to pump up 26 x 1.95 tubes about once in a season - I hired some bikes out yesterday which were last used in September and they were all OK.
[censored]! Perhaps I don't have enough experience of phaaaaat tyres then. Type of tube and how fussy one is about optimum pressure definitely makes a difference though, and I don't suppose you know how hard those tyres were in the first place - could have been rock hard.
BTW, thanks Sandy for the heaset boot tip. I haven't tried it yet but will do.
In article <[email hidden]>, James Annan <still_the_same_m [email hidden]> writes
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The Big Baguette said:
In article <[email hidden]>, Pete Biggs <[email hidden]> writes
Quoted message said:
Quoted message said:
although no common butyl tube should loose much more than about 20psi per day.
No, it's a big fatty. Your comments make me think I've been concerned about nothing. Since recent advice here I've started inflating my tyres (Marathon Slicks) to 100 psi and the 'deflation' has amounted to no more than 10-15 psi over three days and up to 100 miles. This is normal, then?
Well it sounds excessive to me, but perhaps not to Pete if he expects to lose up to 20psi per day. I would say a typical figure is more like 20psi per month. I pump up my tyres about once every month or two, if I remember.
Which is how it is for me on the front one. So I do wonder whether there is a defect there somewhere. -- The Big Baguette
No, it's a big fatty. Your comments make me think I've been concerned about nothing. Since recent advice here I've started inflating my tyres (Marathon Slicks) to 100 psi and the 'deflation' has amounted to no more than 10-15 psi over three days and up to 100 miles. This is normal, then?
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Well it sounds excessive to me,[...] I pump up my tyres about once every month or two, if I remember.
I find the Schwalbe tubes on the 'bent need a topup once a week or so, losing maybe 10psi over 1 week / 100 miles (I think time elapsed is the issue), but the Michelin tubes on the wedgie last somewhat longer and would only drop 5psi or so per week. Both have Presta valves. Schaeders seem to go down faster than you can pump them up if you're inflating to over 60psi :-(
Guy === ** WARNING ** This posting may contain traces of irony. chapmancentral.comchapmancentral.comOpen ↗ (BT ADSL and dynamic DNS permitting) NOTE: BT Openworld have now blocked port 25 (without notice), so old mail addresses may no longer work. Apologies.
Tested a tube with only a very few psi in it with an undone nut, and it does indeed go flat of its own accord, but I've never noticed this happen when tyre is fully inflated.
I have once or twice had to take out the valve core and clean the core and , with a paper clip and a cotton bud, the valve stem and seating itself to remove some of the cotton wooly stuff that forms the clots that stop the holes.A trace of this in the valve seating obviously causes a leak in proportion with the size of the offending lump of fluff. When dealing with slime tubes I try to let the slime drain away from the valve and keep it up at the top before doing anything that might let slime into it. If the tube is still in the wheel put the valve at 100 or 240 degrees so the slime runs away from the valve before letting air out *slowly* so as not to draw up slime which will try to plug the leak. I find that my slimed tyres seem to need inflating very infrequently, but perhaps that's because they are run at lower pressure and I'm not so fussy with them.
Well it sounds excessive to me, but perhaps not to Pete if he expects to lose up to 20psi per day. I would say a typical figure is more like 20psi per month. I pump up my tyres about once every month or two, if I remember.
Which is how it is for me on the front one. So I do wonder whether there is a defect there somewhere.
I would still expect it to loose a lot more than 15psi after three days if there was a defect (even minute punctures flatten a tyre in under 24 hours), but maybe I'm wrong, and if the front tyre and tube is identical to rears then it is odd.
A thorough check of the inflated tube under water should reveal any problems (include a wiggle/tugging of the valve under water to test its base).
In article <[email hidden]>, Pete Biggs <[email hidden]> writes
Quoted message said:
The Big Baguette said:
Quoted message said:
Well it sounds excessive to me, but perhaps not to Pete if he expects to lose up to 20psi per day. I would say a typical figure is more like 20psi per month. I pump up my tyres about once every month or two, if I remember.
Which is how it is for me on the front one. So I do wonder whether there is a defect there somewhere.
I would still expect it to loose a lot more than 15psi after three days if there was a defect (even minute punctures flatten a tyre in under 24 hours), but maybe I'm wrong, and if the front tyre and tube is identical to rears then it is odd.
A thorough check of the inflated tube under water should reveal any problems (include a wiggle/tugging of the valve under water to test its base).
I did that -- couldn't see any problem at all. I'll stick with the tube fro a while and see what happens. -- The Big Baguette
In article <[email hidden]>, "Just zis Guy, you know?"
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Both have Presta valves. Schaeders seem to go down faster than you can pump them up if you're inflating to over 60psi :-(
As a tip for those who don't know. Before you start to inflate your tubes dab the centre core of the valve so that any loose impediments which may be in the valve are blown clear - saves a lot of hassle afterwards.
