Around 6 weeks ago I got a very, very slow puncture on my rear wheel.

 

I had a new tube fitted for 150 baht.

 

Same thing, it would be just noticeably deflating after a few days. Then I nit a big rock and it deflated almost instantly. I got home and pumped it up. It stayed inflated, when for a 20 minute ride and it was fine. I checked the next morning and it was as flat as a pancake again.

 

Got a new tube fitted again, now 4 days later it's almost completely flat. I've been checking it each morning and it gets flatter and flatter. After 4 days it's around 50% deflated. 

 

The front tire is as hard as a rock.

 

What is happening?

 

3 different tubes and the same issue.

 

I presume the tubes come with their own valve, so it isn't that the valve has an issue?

 

What could it be and how can I solve it? 

 

TIA

Might be an issue with the rim or the tire. I'd remove the tire and tube from the rim, run my fingers along the mounting surface of the rim and see if there is something there. I would then do the same with the inside surface of the tire. Perhaps you've picked up a thorn or there is a shard of metal in the rim. Also, if you have the old tubes, pump them up and lay them in a vessel of water and squeeze to see where the leak is. Might give you a clue if they are the same distance from the valve.

Deleted.

My last bout of repetitive punctures I finally ascribed to the tubes being too small - I was using tubes for a 23 - 28 mm tyre in a 35 mm tyre.  I am disappointed that they won't stretch that far, so now I have to carry a larger spare tube, that will not be much use to any of my cycling buddies, and might also be a struggle to get into the rear tyre (I ride 35 mm at front, 28 mm at rear).  

 

I have a spare 28 mm tyre, but it has 4,000 km on it and a small cut, so I don't want to put that on the front.

Could be a bad "run" of tubes if you were getting them from the same place.  

Other than that it sounds as though you could also have a bad rim with a spoke intermittently piecing the tube

i always mark the tyre to the tubes valve, so i can check the tyre in relation to the position of the puncture. sometimes get a small, even minute, piece of glass/ stone/ thorn that you wouldn't feel running your fingers along the inside. 

i do this because of similar problems to yours in the past. i don't get caught out anymore.

It could be your tyres. I was having the same problem, and whilst my tyres looked fine - they were only 1 year old - the side walls had suffered from low pressures and had deteriorated enough to allow easy puncturing... 

This sounds odd but I could see the logic when explained to me, and as soon as my new tyres were on, the problems ceased. 

The tyres I took off and replaced were both Michelin City Pro tyres, which are very grippy, maybe due to the grippyness they are life-limited? Anyhow, change your tyres, it's always nice to do anyway. 

4 hours ago, MaiDong said:

The tyres I took off and replaced were both Michelin City Pro tyres, which are very grippy, maybe due to the grippyness they are life-limited? Anyhow, change your tyres, it's always nice to do anyway.

 

This makes sense.

 

Taking it to a shop and getting them to change the tube and tires, after telling them the issue, and asking them to look for any problems with the rim. 

Go to a better mechanic and ask them what's the underlying problem. 

 

It seems that your mechanic might not know what he's doing.

15 minutes ago, EricTh said:

Go to a better mechanic and ask them what's the underlying problem. 

 

It seems that your mechanic might not know what he's doing.

 

Different mechanics each time. 

 

Though I'm not sure the employees in bicycle shops are called mechanics. 

9 hours ago, JeffersLos said:

Around 6 weeks ago I got a very, very slow puncture on my rear wheel.

 

I had a new tube fitted for 150 baht.

 

Same thing, it would be just noticeably deflating after a few days. Then I nit a big rock and it deflated almost instantly. I got home and pumped it up. It stayed inflated, when for a 20 minute ride and it was fine. I checked the next morning and it was as flat as a pancake again.

 

Got a new tube fitted again, now 4 days later it's almost completely flat. I've been checking it each morning and it gets flatter and flatter. After 4 days it's around 50% deflated. 

 

The front tire is as hard as a rock.

 

What is happening?

 

3 different tubes and the same issue.

 

I presume the tubes come with their own valve, so it isn't that the valve has an issue?

 

What could it be and how can I solve it? 

 

TIA

 

you have the old tubes?  pump 'em up to find the holes, see if they are all in the same spot.

 

if not, remove the tube from the tire leaving the tire on the rim, marking the rotation direction of the tube so's you can match it up later to the tire.

 

pump the tube up, pump it up too much, make it really big.  moisten one finger, move your hand along the tube until you find the leak.  use the dunk in tub of water method if needed.

 

found the leak?  top or bottom of the tube?  that'll tell you if you have some glass embedded in the tire, or a spoke may be spoking through.

 

lay the tube on top of the wheel, mark on the sidewall and on the rim where the puncture is.

 

now you can take the tire off the rim and look for the gremlin.

 

when you're done, check that no spokes are pushing through the rim tape.  inspect the tire carefully, inside and out.  a tiny flat-blade screwdriver will let you pick little bits of glass and wire out of the tread.

10 minutes ago, JeffersLos said:

 

Different mechanics each time. 

 

Though I'm not sure the employees in bicycle shops are called mechanics. 

 

Bicycle shops? I think they are just amateurs.

 

I suggest you go to one of those Honda or Yamaha shops that have their own repair department.

 

They have much more professional mechanics that can diagnose your bike's problem.

 

Try Saha Panich, I am usually impressed by their machine sets and skills there. They are huge.

4 minutes ago, EricTh said:

 

Bicycle shops? I think they are just amateurs.

 

I suggest you go to one of those Honda or Yamaha shops that have their own repair department.

 

They have much more professional mechanics that can diagnose your bike's problem.

 

Try Saha Panich, I am usually impressed by their machine sets and skills there. They are huge.

this topic is in the 'cycling ' forum.

1 minute ago, jastheace said:

this topic is in the 'cycling ' forum.

Sorry, I thought it was a motorbike and not a bicycle. Didn't see the subforum.

As long as you are not a racing cyclist, very concerned about weight, the best solution I have found to avoid punctures is cut the valve from an old tube and line the Tyre with the old tube, it's a bit of palava to get the old tube to sit right but this works well. Try pushing something through a flat tube as opposed to an inflated tube it gives a lot of protection. Using this method I have run tyres down to almost the canvass with no punctures.

 

As mentioned above find the spot matching the leak in the tube on the tyre check the area carefully to make sure the puncture cause is not still in the tyre - I think this your most likely cause of repetitive same style punctures

 

Check leakage to make sure the leaks are not around the valve seating in the tube, this can be caused by a loose fitting tyre sliding under heavy braking and taking the tube with it tearing the valve seating on the rim but would not expect a slow puncture with this

 

deleted

Have you tried to inflate the tube and checked in a bucket of water?

I've just read that someone had already mentioned the water.

 

13 hours ago, EricTh said:

Sorry, I thought it was a motorbike and not a bicycle. Didn't see the subforum.

Me too! 

I'm taking it to a bicycle repair shop to get a new tire and inner tube, and they'll inspect the rim while changing them. Hopefully an easy solution for less than 1,000 baht.

 

 

Though I remembered there are cats near us, and one likes to come over at the night time, and my son mentioned it was scratching or clawing at the back tire.

 

Do you think a cat's claws are enough to go through the tire and slowly puncture the inner tube? 

Often you get a tiny piece of metal or glass inbetween the outer and inner layer of the tyre, you need to take the tyre off and turn it inside out and look and feel very carefully, sometimes not even visible. I've had this a few times

I paid 900 baht for a new tube and tire at a shop instead of fuffing about myself.

 

I guess I'll know soon enough it it was something from the rim or local cat.

I had a series of punctures on my 50mm MTB rear time - several times two during the same ride. Checked everything every time, removed dirt or grit from the tyre, renewed rim tape etc.m  couldn’t find anything. Bought a new rear tyre and the problem disappeared completely.

7 hours ago, damascase said:

I had a series of punctures on my 50mm MTB rear time - several times two during the same ride. Checked everything every time, removed dirt or grit from the tyre, renewed rim tape etc.m  couldn’t find anything. Bought a new rear tyre and the problem disappeared completely.

 

 

I had a new tube and tire fitted one week ago and the issue's gone.