Bought my daughter a bike for her 3rd birthday, she was incredibly excited but when we got it set up and ready to ride the front tyre went flat immediately. Having retried pumping up a couple of times, no joy, so fitted a replacement inner tube. It’s still happening – as soon as it’s pumped up it immediately loses air and goes flat. Before you can even get the dust cap on. No issue with the back tyre, and having now checked the previous inner tube there was no puncture. Am I missing something super obvious here?
by jk8923
11 Comments
Check inside the tyre. Also your brake pads are upside down. The curve towards the tyre.
Either you’re not seating the pump on the valve properly and not actually inflating or there is a piece of debris inside the tire that is causing every tube to flat.
1) take the tire off and run your finger around the inside. If you find any debris then remove it
2) see if when you remove the old tube it can hold air
If it holds air outside the tire then you aren’t seating the pump in the vape properly.
If it doesn’t hold air then you have an issue with debris inside the tire.
sounds like it’s losing air very quickly if you can’t even get the cap on.
question- while you’re pumping it and the pump is attached, is it holding air? does it ever get filled?
or, when you pump, can you hear the air rushing out immediately on each stroke of the pump?
OP, have you checked the tube(s), out of the bike, and inflated, in a water bath ? It’s not possible for a tube to be good, go bad in the bike, then go back to good when removed.
These bike have a rubber rim strip which likes to migrate away from the spike heads. Most likely a puncture from the exposed nipples.
Either way. Ya gotta remove the wheel, remove the tire and tube, inflate the tube and look to where the hole in the tube is.
Since the air escapes faster than it take to put the valve cap on? The hole should be fairly obvious.
Long story short, get a new tube and make sure the rim strip is centered. You can use duct tape or electrical tape wrapped two times around the rime to compensate for a damage rim strip.
As others have said something is puncturing the tube, also check the valve hole doesn’t have any sharp edges that could cut into the valve stem
Check your old tube again. I’d put money on there being a little cut at the base of the valve stem. Sometimes you need to bend the stem around to see it.
Inexpensive rims often have a little burr in the valve hole. Or the tire rotates on the rim. Both cause this type of puncture
Check to see if the Schrader valve body is completely seated within the stem. There is a small “driver”that is used to twist the valve body firmly into the stem; any tire shop should have one. Then,if the air continues to escape while pumping it up, you have a tube with a hole in it. Replace the tube.
Check to see if the tube holds air on its own. If it does, then there’s no puncture – this is good. Next, when you put the tube onto the rim, make sure the Schraeder valve is absolutely at a 90-degree angle relative to the rim and the valve is not pressing the sides of the valve hole in the rim. My suspicion is that the valve is pressing against the rim, which pushes it at an angle, resulting in released air.
I dont think it easy to find a tube that size. I might consider pouring some sealant in if I have some lying around and trying that.
Remove the tube from the tire, pump up the tube and see what’s going on.