Hi all fellow riders could someone please help me I keep getting a puncture on my rear wheel on my mountain bike and it seems to be always just around the bottom of the valve stem? Could somebody please give me some sort of advice to avoid this in the future? Thanks everyone.
I've seen this on an MTB where the tyre was a fairly sloppy fit to the rim. Consequently the tyre could slip round the rim during use, dragging the tube with it. The valve stem then bears against the hole in the rim and fails. Some respite was gained by pumping the tyre up harder, so it couldn't drag round.
As its always in a similar area by the valve check...
1- That the tube isn't being stressed as you inflate it if the valve isn't sitting straight out of the wheel.
2- More likely, check the are of the wheel where the valve is located is free of sharp edges or anything that could puncture it.
Other causes I've seen: sharp burr on the rim's valve hole; using the wrong valve type (Presta in a Schrader rim); and most commonly, using a pump that doesn't connect with a flexible hose or clip to a spoke and sawing the valve back and forth as it is pumped up.
I love this idea! I've usually just left the tyre on the rim and then after finding the puncture then lined it up to valve to valve hole and checked around inside the wheel/tyre after locating the area it happened. this would be so much more logical and quicker! Thank you for this lesson
I usually take a chance of running my fingers round the inside of the rim check tape is in place no sharp edges and then nothing left in the tyre or wire mesh poking through that could be damaging tubes so that would be my advice to check those and above listed ideas