Slow puncture or Faulty valve

[Mart79]

Hi guys,


Couple of days ago I noticed my front tyre had lost a little bit of pressure, so added more air. 24 hours later I checked and it had held the pressure so went out for a couple of hours upon my return the tyre had held its pressure.
However, when I checked this morning it had lost some pressure over night probably half of what was in the tyre.

actually don’t know whether to replace it as I pumped the tyre back up this morning (3 hours ago) and is currently holding its pressure!


I’m contemplating buying a slime tyre but can’t seem to find any for 27.5 tube/tyres

 

[si_c]

Perhaps unhelpfully, the answer to your question is, Yes. Pull the inner tube out, pump it up and put it in some water, if you see bubbles coming off the tube then patch it there, if bubbles are coming off the valve or you can't see anything, then I'd replace the tube. Check to make sure there are no flints/thorns/glass etc in the tyre before you inflate again.

 

[MontyVeda]

either way if it's not staying inflated, just put a new tube on.

You could try to find the leak in a bowl of water and mend it.

 

[Mart79]

Thanks guys, I know it is a bit of pointless thread as chances are with it not holding pressure long term there’s a leak somewhere. Going to pull the tube out shortly and see if I can find any leaks. And repair or just replace.

 

[I like Skol]

Perhaps unhelpfully, the answer to your question is, Yes. Pull the inner tube out, pump it up and put it in some water, if you see bubbles coming off the tube then patch it there, if bubbles are coming off the valve or you can't see anything, then I'd replace the tube. Check to make sure there are no flints/thorns/glass etc in the tyre before you inflate again.

This^^^^^

Anyone that suggests throwing away a repairable inner tube should be publicly flogged!

 

[ColinJ]

If it turns out to be a punctured tube, DON'T just put a new tube in! Whatever caused the puncture might still be in the tyre... Also, as ILS points out - fix the tube. It won't take long and while you are doing it (and forever afterwards) you can bask in a warm environmentally-friendly green glow, secure in the knowledge that no psychotic dolphins will be strangling bunny rabbits with your rubber castoffs! (I usually put upto 4 or 5 patches on my tubes before something eventually finishes them off - faulty valve, ripped seam, whatever.)

I mark where the valve is relative to the tyre so when I find a hole in a tube, I have a head start on where to look on the tyre. Often, there will be a shard of glass or a thorn stuck through. I once found a single strand of narrow gauge wire through one of my tyres - I have no idea how that managed to stay straight enough to get forced through!

 

[glasgowcyclist]

This^^^^^

Anyone that suggests throwing away a repairable inner tube should be publicly flogged!

I don’t even throw away wrecked inner tubes, there are so many uses for them. A common one for me is using small sections as protection under any brackets that I fit to the frame or bars.

 

[Lovacott]

I’m contemplating buying a slime tyre but can’t seem to find any for 27.5 tube/tyres

If you have a Schrader valve (car type) Just buy a bottle of slime and put it in the tube yourself.

It's literally a very easy two minute job with no tools required.

I've slimed my MTB and Hybrid and it works brilliantly. I still get punctures, but they seal up before the tyre goes flat and all I have to do is pop in a bit of air to top up the pressure.

To check if you have a leaky valve, put some spit on your finger and wipe it over the valve opening. If it's leaking, the spit will make a bubble and pop.

 

[PK99]

Perhaps unhelpfully, the answer to your question is, Yes. Pull the inner tube out, pump it up and put it in some water, if you see bubbles coming off the tube then patch it there, if bubbles are coming off the valve or you can't see anything, then I'd replace the tube. Check to make sure there are no flints/thorns/glass etc in the tyre before you inflate again.

Caveat that with "unless it is a removable core valve and the leak is around not through the vale, in which case, tighten the valve core"

That was exactly the problem I had with new tubless tyres.

 

[Lovacott]

I don’t even throw away wrecked inner tubes, there are so many uses for them. A common one for me is using small sections as protection under any brackets that I fit to the frame or bars.

I use old tubes to make catapults which I use to fire bearings at close passing motorists.

 

[Cycleops]

I use old tubes to make catapults which I use to fire bearings at close passing motorists.

Even when you’re not on the bike? 😄

 

[Lovacott]

Even when you’re not on the bike? 😄

Especially when I'm not on the bike.

 

[fossyant]

New bike time !

 

[Lovacott]

If it turns out to be a punctured tube, DON'T just put a new tube in! Whatever caused the puncture might still be in the tyre...

True.

9/10 times, the cause of the puncture is still there. I check the old school way by running my fingers around inside of the tyre until I feel pain. I carry a tiny set of pliers for pulling out offending items. I swap the tube out for a new one and then take the old one home for repair ready to become my new spare tube.

 

[rogerzilla]

Many punctures are caused by rim tape failure, so check that too. I have a set of wheels that ran for years with 23mm tyres and Spesh rim tape. Changed to 25mm tyres and started getting punctures on the inside of the tube (rim side) every 30 miles. I even fitted new rim tape and different 25mm tyres, no difference. After the fourth or fifth of these, I changed to Velox tape and it was solved. Some tyres can displace a rim tape and allow the edge of the tape to cut the tube, or allow the tube to creep underneath the tape and find a spoke hole.