I am running into a problem with screw threads on inner tubes.
Until recently, I thought that valves were straightforward. There were just 2 types if you ignore Woods. So by making sure that I specify the right valve, I never had trouble buying a new pump connector or a new inner tube at different times. Screwing on the pump connector to the valve just worked. So previously screw threads for Schrader valves were compatible or else I have been lucky. Sheldon Brown at http://www.sheldonbrown.com/gloss_sa-o.html mentions just one thread 7.7 mm (.302"😉 x 32 T.P.I.
However two weeks ago, I bought a new inner tube over the web, making sure it was the right valve type (Schrader). However when I tried to attach the pump connector, there is some mismatch. I either fail to attach it completely or succeed eventually in attaching but fail to detach it quickly enough before all the air rushes out. As you can imagine, this is extremely frustrating.
So for Schrader valves, what possible screw threads are there out there? And how does one specify the screw thread when buying over the web? (I would use the local bike shop if it hadn't shut recently - this is the sort of thing they would have known).
I am running into a problem with screw threads on inner tubes.
Until recently, I thought that valves were straightforward. There were just 2 types if you ignore Woods. So by making sure that I specify the right valve, I never had trouble buying a new pump connector or a new inner tube at different times. Screwing on the pump connector to the valve just worked. So previously screw threads for Schrader valves were compatible or else I have been lucky. Sheldon Brown at http://www.sheldonbrown.com/gloss_sa-o.html mentions just one thread 7.7 mm (.302"😉 x 32 T.P.I.
However two weeks ago, I bought a new inner tube over the web, making sure it was the right valve type (Schrader). However when I tried to attach the pump connector, there is some mismatch. I either fail to attach it completely or succeed eventually in attaching but fail to detach it quickly enough before all the air rushes out. As you can imagine, this is extremely frustrating.
So for Schrader valves, what possible screw threads are there out there? And how does one specify the screw thread when buying over the web? (I would use the local bike shop if it hadn't shut recently - this is the sort of thing they would have known).
You'll be better off with a pump connector that just pushes onto the valve rather than screwing on. It'll be compatible with all your valves, and, if it's a good one, won't leak.
You'll be better off with a pump connector that just pushes onto the valve rather than screwing on. It'll be compatible with all your valves, and, if it's a good one, won't leak.
~PB
I'll go along with that. Any decent pump these days will have a reversible washer & insert combination to allow you to use the pump with both Schrader and Presta valves. To be honest I've not seen a pump with a screw-in adapter like that for years and a good job too: they were always a right pain in the backside to use!
So treat yourself a nice new pump. I've always found Topeak to be effective and made to last. And once you've got a sparkly new pump start switching to Presta valve innertubes: much easier to inflate than Schrader IMHO.
I am running into a problem with screw threads on inner tubes.
Quoted message said:
Until recently, I thought that valves were straightforward. There were just 2 types if you ignore Woods. So by making sure that I specify the right valve, I never had trouble buying a new pump connector or a new inner tube at different times. Screwing on the pump connector to the valve just worked. So previously screw threads for Schrader valves were compatible or else I have been lucky. Sheldon Brown athttp://www.sheldonbrown.com/gloss_sa-o.htmlmentions just one thread 7.7 mm (.302"😉 x 32 T.P.I.
Quoted message said:
However two weeks ago, I bought a new inner tube over the web, making sure it was the right valve type (Schrader). However when I tried to attach the pump connector, there is some mismatch. I either fail to attach it completely or succeed eventually in attaching but fail to detach it quickly enough before all the air rushes out. As you can imagine, this is extremely frustrating.
Quoted message said:
So for Schrader valves, what possible screw threads are there out there? And how does one specify the screw thread when buying over the web? (I would use the local bike shop if it hadn't shut recently - this is the sort of thing they would have known).
You'll be better off with a pump connector that just pushes onto the valve rather than screwing on. It'll be compatible with all your valves, and, if it's a good one, won't leak.
~PB
Thanks for the replies on this thread about threads. Yes I now have a pump that pushes onto the valve. It has a lever action to establish connection with the vital part of the valve. As you say, it doesn't critically depend on the screw thread. Problem solved.
Julian Gallop
[reason for delay in acknowledging - I did a lot of travelling for work and had less good Internet connections than anticipated. Replies were appreciated]
