tire stem failures? SHRADER valve vs PRESTA?

[thedarlington]

hi i was just getting out on my bike today and as i was accelerating moderately, my tire must of slipped with the rim and i ended up with a flat on athick thorn resistant wheel, i just wanted to know if this was common or if anyone had ever expereienced something like this? im thinking getting a presta but how common is this? would getting a presta fix it? my rim is the typical ebikekit one that says velo on it in yellow, its walls raise really high is it tubeless maybe? im just thinkin how is it possible for scooters which have much more torque than us be able to not break valve stems?

 

[amberwolf]

Best guess is your air pressure was low, as that's really the only time I am aware of that a tube could easily slip liek that. Although it is possible for a really high torque takeoff or braking to spin a tire on a rim, if the tire has a really good grip on the road surface, I doubt it would happen without sufficiently low pressure...if the pressure was high enough it would keep the bead seated well enough to not allow it to slip.

If the same thing happened on a Presta valve that was screwed to the rim, and the tube was gripped by the tire well enough, it could still tear the valve off the tube, if a slip like that occurred.

 

[thedarlington]

actually thats the trouble, it had 40psi with gauge and they wherent cheapie tubes eithe they where those thick thorn resistant ones, tho maybe those are easier to slip, but the takeoff wasnt even that strong because im real careful with the axle, im thinking of adding some sort of sticky tacky surface to the rim and hopefully thatll help

 

[johnrobholmes]

How old was the tube? I have had schraeder and presta break at the tube junction. All tubes are points of failure.

 

[Ypedal]

I use good o'l hockey tape as rim tape, it's a fabric material and the adhesive will kinda ooze thru the fabric and stick to the tube ( makes tube removal a pain but i assure you they won't spin !! lol )

I have never had this problem on any of my bikes however, even those with regular rubber rim strips.. I drill all rims with presta to take Shrader valves...

You can get tubes with metal stems too if you really want.. ! :wink:

 

[jag]

I've torn both schraeder and presta stems. This was at low pressure though, well below 40PSI, when running large knobbies on my classic Cannondale M2000 (1988 non-suspension MTB, 10kg full bike). After lots of trial and error I found the problem occured more with some tires than others, and I just stuck th the tires that apparently would grip the rim edge more succesfully to not slip and tear the inner tube.

The inner tubes and tires on my eBikes slip some too, but so far not so much that any valves have been torn.

 

[ZapPat]

I've had this happen with both valve types, and the funny thing is that it seems to happen worse with the heavy duty tubes than thin ones! From what I've seen, there seems to be two reasons for this:
- The thick tubes have even thicker rubber around where the stem is glued to the tube. Because of this, they have trouble bending into the thin recess formed between the rim and tire beads. This stresses the stem's attachement to the tube quite a bit, and I've had them rip off the tube at this point. Wide rims would reduce this problem substantially.
- The second potential problem with thick rubber tubes (of a small diameter as they often seem to be) is if they are used with fat tires then you need *lots* of pressure just to get the tubes pumped up to the size of your tire's inside cavity so it holds it well on the rim. Bigger diameter tubes close to the diameter of the tire (even if thick) would avoid this problem.

I think these are the two main reasons why this type of flat happens. I now use thinner tubes and haven't had the stem rip off since.

Pat

 

[Drunkskunk]

the valve stem isn't going to make any diffrence. the only way a bike tire is going to slip is if the tire is the wrong size for the rim, cheaply made without a good bead, the tube is too small, or the tire is under inflated.

 

[docnjoj]

I got some tubes with Schrader valves that have a thread all the way down and a locknut to screw against the rim. They were expensive ($10) but seem to resolve my problems with the filler getting rotated and cut off. I got them from Hostelshoppe>
otherDoc

 

[amberwolf]

I've used zipties tightly around the base of the stem to keep it from being pushed down into the rim while airing up, although I don't know if it would keep it from rotating around if it slipped.

 

[AussieJester]

I had a failure today sooooo lucky the bike was sitting in my garage when it happened, ~20 minutes earlier i was hurtling donw some mofo hills at 70km/hr
with a tank top and cotton pamts on :-| I had pumped the front and rear tires up prior to my ride today, 55psi in the Hoojworm front tire (rated at 60psi)
i did notice some slime on the valve asumed it seeped out the valve itself, anyhoot...i hear this almight PFFFFFFFFFST look out my door into my workshop to see the front wheel deflating in under 5 seconds :-| closer inspection revealed puddle of slime around the base of the valve stem, i haven't pulled the wheel off been busy editing ride footage shall do so in the morning and see WTF is the story. This sent a bit of a chill through me, i'm in a wheelchair permantly as a result of a front wheel blowout on a motobike when i was younger...

KiM

p.s it is a shrader valve.