 You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
As title really. Two rides, two dead tubes.
Rims are older Ritchey OCR but the hole on the inside of the rim is huge. I think they may have had a rubber insert at some point that has perished ( they are 10 years old).
It looks like when pumped up the tube is stretching into the hole and then slicing the base of the valve on the hole.
The outer hole is sized for presta.
This is Mrs g-d's bike so tubeless not really an option as she only does family and fun rides and it seems overkill.
I've replaced the rim tape to try and protect the base of the valve a bit but what else can I do?
Talc the tubes stop the tire sticking to the tube and pulling around removing the valve. Used to be a common issue before tubeless(BT)
Use a schrader tube ? Just need to file the rim a little bigger.
But can't see why a sticky tape style rim tape won't work
Cheers guys. I wondered whether I should do a gorilla tape job on them.
The valve seems to be getting stretched into the hole by air pressure when the tube is pumped up and then getting sliced. Never known anything like it in 30 years of riding and fixing bikes!
I think some Schrader valved tubes might be on the agenda.
For tomorrow she can have my spare wheels.
[url= https://www.toolstation.com/shop/p68673?searchstr=gromm ]Rubber grommet (linky)[/url]
Had this a lot when we first switched to disks with skin wall tyres. It was the tyre moving on the rim under braking then. We put a few dots of super glue on the bead on one side. You can still get the tube out the other side if you puncture and it'll peel off if needed. I'd also stick a shraeder tube in there if it'll fit. Its the better valve for MTBs
Its the better valve for MTBs
Better in what sense ? Doesn't do the job any better or worse than the others .
It was the tyre moving on the rim under braking then.
If this has only recently started to happen with relatively old tyres, then based on personal experience I would tend to suspect that the above is the likely cause. In my case the condition of the rim tape on [i]one[/i] side of the valve confirmed it: the tape on that side had been concertina'd by movement of the tube, i.e. the tube moved with the tyre and dragged the tape up against the valve.
New tyres cured the problem.
That said, I also make a point of using Schwalbe inner tubes which have threaded stems and a locknut, rather than the cheap inner tubes which have rubber extending up the valve stem.
Continental inner tubes also have lock rings. One of the inner tubes on my wife's bike appears to have a brass (or some sort of metal) valve; I'm not sure where we got it though.
[i]Better in what sense?[/i]
Better in the sense that this "cutting" problem generally happens with Presta valves, but not with Schraders.
[url= http://singletrackmag.com/forum/topic/puncture-by-valve-stem-coming-out-of-the-innner-tube ]Old thread[/url] on the same topic.
Used to happen on early d521s and baggy as hell early maxxis high rollers under heavy braking with Schraeder dh ( read pretty much Moto X) tubes also.
Better in what sense?
Also less fiddly and no weak bit to break. I'm sure plenty of people have never broken or bent the little screw bit on presta but I know plenty who have. Easily done with cold wet hands. Easier to find a pump in remote locations too. Also in an emergency you can borrow a presta tube, can't borrow a shraeder if your rim is drilled presta only
There are no disadvantages to shraeder and a few, albeit minor, disadvantages to presta
No but I have watched the inept lose the middle bits of my pump trying to make it fit their Schrader valves because they didn't bother their arse to bring a pump.
There you go. Another advantage. Wouldn't have happened if you were using shraeder 😀
Tubeless dictates not happening.
Continental inner tubes also have lock rings.
This. The locking ring acts as an insert and fills the excess hole.
Tubeless dictates not happening
http://www.chainreactioncycles.com/no-flats-tubeless-schrader-valve-kit/rp-prod94761
Presta is unnecessarily fiddly with only downsides compared to schraeder
To the op,nyes had this happen with old baggy high rollers
Was more to do with them gunking up with the fluid. Have had schrader rim strips in the past. Wasn't much fun
This. The locking ring acts as an insert and fills the excess hole.
Yep so long as it's not the inner rim that's drilled large and the outer small. I thought about putting a lockring on the inside but I think that may be asking for trouble.
The rim has ripped tubes from Continental, Specialized and Bontrager so far and it's happened within 20 minutes of a new tube going in on flat tarmac.
I think maybe some drilling (outer to Schrader size) and filing of hole for smoothness may be the answer along with some tighter tyres. More fiddling....
I have seen this thread appear with seasonal regularity over the last 10-15 years. It's just something that mostly seems to happen in the summer. Unsure why. HTH.
@Brant its because people _actually_ ride their bikes in the summer 🙂
Another vote for Schrader here and I run tubeless with no issues. Just less fiddly and sturdier in my experience. I've broken a fair few Presta valve top thing by accident.
[url= https://www.sjscycles.co.uk/rims-tape/mavic-rim-valve-hole-drilling-converter-insert-schraeder-to-presta/ ]Mavic sell this[/url]
I've had this before, turned out it was (as already mentioned above) caused by an old or loose fitting tyre moving on the rim under breaking. New tyres cured it!
Grim
brant - Member
I have seen this thread appear with seasonal regularity over the last 10-15 years. It's just something that mostly seems to happen in the summer. Unsure why. HTH.
Tyres creep more in higher temperature? Before I was using tubeless this used to happen to me in Greece, where temps are often 35+ degrees.
In contrast, I had this happen with new tyres; after four tubes destroyed, talc. proving ineffectual, and having to stop every ten minutes to deflate, tug tyre and tube around the rim slightly before repressurising, I gave up and bought a different set of tyres. (Old, pre-tubeless rims)
Low pressures won't be helping. On trials (motor)bikes it was/is common to put a couple of self-tappers through the rim so the bead of the tyre won't rotate, pulling the tube with it and ripping the valve off.