Punctures ... That Arent

[dynamictiger]

Last time I raised this topic I kinda ended up getting swamped...

Perhaps this time it will be easier as I now know a lot more than I did last time.

Last year I started to get a raft of flats which I assumed where punctures. I changed my tyres and most of these 'punctures' stopped for a while.

Moving on, and remember I am still giving this cycling lark a bit of a go, so I am very noob so sorry if this is basic.

I got another 'puncture' this time I found a stone had goine into and worked its way into the tyre...Yeah a cause at last. Anyway, I had the bike booked in for a service so I had the shop change the tube and so on after I dug the stone out.

The shop filled the new tube and off I rode. That was about 3 weeks ago I suppose.

As the tube maintained good pressure I had no reason to touch it...until yesterday.

On my ride to work the tube suddenly lost pressure. Thinking I had a puncture as I had been riding through some glass I thought okay so pulled over to pump the tube up a bit to get to work. On undoing the presta valve the undoey threaded brass knurl fell off into my hand as the wire shaft had broken.

I have had this happen many times in the past and always blamed myself for leveraging with the hand pump or being a bit rough with my floor pump. However here is an instance where I have not touched the valve, all I have done is ride the bike and the valve has 'broken' for no apparent cause.

This is a mechanical item so there is no such thing as no apparent cause. There is simply cause I have not diagnosed as I am not sure where to start. So has anyone else had this type of failure repeatedly and if so how did you solve it?

[foo on patrol]

Um no but the LBS could have bent it and then when the cap was screwed back on it would be possible to compound that bend and when you have screwed it off, it has snapped the shaft. That's as good as I can think of.

Foo

[silentbutdeadly]

So has anyone else had this type of failure repeatedly and if so how did you solve it?

Yes. Solved it by a) using a screw on Lezyne pump head on a hose rather than those direct fit pumps; and b) using Scwalbe or Continental tubes rather than the budget Cheng Shin or whatever is cheapest...

[grantw]

About six weeks ago I was replacing the worn rear tyre on my bike. Start to loosen the valve heard sudden hissing then the screw shot out and bounced around the shed while I cowered by the bike stand. But that's been the only time it's happened to me.

[Mulger bill]

Sure it isn't a Conti tube? Their valve guts are removeable from the stem. Caught me a few times...

[grantw]

Sure it isn't a Conti tube? Their valve guts are removeable from the stem. Caught me a few times...

It was in fact. Well at least now I know.

[open roader]

I get a lot of high speed road gravel and occasional decent sized rocks flung up at my by traffic passing by at 90/100 km/hr or faster......... quite a while back I copped 2 snapped off valve tips inside 6 months - purchased some valve caps and touch wood in a further 3.5 years I've copped plenty more shrapnel but no more valve damage......

[dynamictiger]

I am just thinking these are crap tubes/valves. Too many to be anything else and I do use caps. Just ordered some of the Maxis welter weights from Cell Bikes see if they are any better.

[Baalzamon]

Sure it isn't a Conti tube? Their valve guts are removeable from the stem. Caught me a few times...

One time I got caught was when I was doing a supported tour and pumping up my tyres. There goes the removable valve into the dirt AHHH
Ok bike to side and fix and do I join that queue again or use my hand pump.... Hand pump won. Since that day I've only been caught one other time thanks to a Lezyne pump unscrewing the valve with it
Had a few loose valves that just needed nipping up and that's it