Tire question/issue???

[drjeff]

I need to call upon the brains of the more experienced mtb crew here about what's going on with my rear tire.

End of the season last year I tore the sidewall of my rear tire. Brought my bike to the LBS, where they checked the rim (straigtened it slightly) and installed a new CST Caballero 26x2.25 on it. Before ski season set in, I used my bike for 2 rides, all road totalling about 30 miles. Bike was stored in my basement all winter long. Took my bike out for my 1st ride of the season last week - just did the local paved, very well maintained bike path to loosen the legs up a bit, and heard that lovely sound of air escaping from the tube about 4 miles into my ride Installed a new tube, finished my ride, no problems. Last night I take my bike out onto the trails, 6.25 miles of trail riding - the last mini lap was around the parking lot, so I know that the tire was inflated fully when I hung my bike on the bike rack on the back of my car. I get home 20 min later, the rear tube is fully deflated??? My rear tire spins freely when mounted with no interference from the frame/brakes. I'm trying to figure this out, but my knowledge base isn't that extensive

Not sure if it could be a rim issue?? Pure coincidence?? my 230ish lbs on my hardtail???

My rear tire/rim are going to my LBS today with my wife as she gets her new road bike tweaked a bit, so the guys that know my bike will be seeing things today

 

[bvibert]

What tire pressure are you using? When you replaced the tube on the first ride did you check for anything sticking into the tire that could puncture the tube? Also make sure that the rim tape is covering the spoke holes, and that there's no burs or anything sticking through.

When I have a tire go flat I always inspect the tube once I get it out to try to determine what caused the flat. Most of the time it's pinch flats for me. They're easy to spot sine there will be two holes side by side where the tube got pinched between the rim and something hard. It's doubtful that happened on the bike path, so I'd be looking for something sharp making contact with the tube, inside the tire. Another thing to check is the valve stem, they sometimes tear where they connect to the tube or just don't hold air that well.

 

[drjeff]

What tire pressure are you using? When you replaced the tube on the first ride did you check for anything sticking into the tire that could puncture the tube? Also make sure that the rim tape is covering the spoke holes, and that there's no burs or anything sticking through.

When I have a tire go flat I always inspect the tube once I get it out to try to determine what caused the flat. Most of the time it's pinch flats for me. They're easy to spot sine there will be two holes side by side where the tube got pinched between the rim and something hard. It's doubtful that happened on the bike path, so I'd be looking for something sharp making contact with the tube, inside the tire. Another thing to check is the valve stem, they sometimes tear where they connect to the tube or just don't hold air that well.

I'll check into that. I know when I installed the tube after I flatted on the bike path that I did run my ungloved fingers along the inside of the tire after pulling the tube (which from what I could see had a single, small hole about 1/3rd of the way around the tube from the valve stem) and I didn't feel anything irregular inside the tire(not that I'd probably realize what irregular is unless it's REALLY irregular ). I was also as carefull as I could be when installing the new tube to avoid pinching it, as the guys at my LBS really hammered that concept into my head when they showed me how to change a tube when I bought my bike

 

[marcski]

What tire pressure are you using? When you replaced the tube on the first ride did you check for anything sticking into the tire that could puncture the tube? Also make sure that the rim tape is covering the spoke holes, and that there's no burs or anything sticking through.

When I have a tire go flat I always inspect the tube once I get it out to try to determine what caused the flat. Most of the time it's pinch flats for me. They're easy to spot sine there will be two holes side by side where the tube got pinched between the rim and something hard. It's doubtful that happened on the bike path, so I'd be looking for something sharp making contact with the tube, inside the tire. Another thing to check is the valve stem, they sometimes tear where they connect to the tube or just don't hold air that well.

What he said. +1.

I'm giving serious thought to running tubeless. My LBS guy said that's pretty much all of what he's been setting up. Stan's makes a pack that lets you switch over your existing rims. My buddy runs tubeless...and I have to say its pretty cool...we were riding last week...he went over something and then there's that hiss..of air escaping. So, I'm like well there goes your tubeless..I have a tube you can throw in there. But when we stopped, his tubeless setup already sealed the hole and he just needed to pump in a little more air. It was quite impressive.

 

[bvibert]

I'll check into that. I know when I installed the tube after I flatted on the bike path that I did run my ungloved fingers along the inside of the tire after pulling the tube (which from what I could see had a single, small hole about 1/3rd of the way around the tube from the valve stem) and I didn't feel anything irregular inside the tire(not that I'd probably realize what irregular is unless it's REALLY irregular ). I was also as carefull as I could be when installing the new tube to avoid pinching it, as the guys at my LBS really hammered that concept into my head when they showed me how to change a tube when I bought my bike

Sounds like you're doing everything right. Just make sure there's nothing sharpish on the rim. Could just be some bad luck. I've had similar things happen where the tire was fine and then suddenly lost air while just sitting for a short time.

 

[bvibert]

What he said. +1.

I'm giving serious thought to running tubeless. My LBS guy said that's pretty much all of what he's been setting up. Stan's makes a pack that lets you switch over your existing rims. My buddy runs tubeless...and I have to say its pretty cool...we were riding last week...he went over something and then there's that hiss..of air escaping. So, I'm like well there goes your tubeless..I have a tube you can throw in there. But when we stopped, his tubeless setup already sealed the hole and he just needed to pump in a little more air. It was quite impressive.

I've considered it too. I need to find some tires that I'll be confident that I won't constantly put holes in the side of first though. I seem to have a habit of wearing or cutting holes in the sidewalls for tires in a short amount of time...

 

[drjeff]

Sounds like you're doing everything right. Just make sure there's nothing sharpish on the rim. Could just be some bad luck. I've had similar things happen where the tire was fine and then suddenly lost air while just sitting for a short time.

My guess is its just that bad luck/pure coincidence thing-a-ma-gig thing And since things usually happen in 3's, my guess is that even after the guys at my LBS check it out today and say that they couldn't find anything wrong with it, I'll flat on my next ride!

BTW, I run my tires at 55 psi - I check them each time before I put my bike on the rack to head to the trails (by nature, I'm pretty anal retentive/obsessive compulsive about making sure things are in meticulous shape before I use them )

 

[drjeff]

I've considered it too. I need to find some tires that I'll be confident that I won't constantly put holes in the side of first though. I seem to have a habit of wearing or cutting holes in the sidewalls for tires in a short amount of time...

I'm finding out that I have that same problem Of course the fact that there's about 3/4ths of a mile of rock garden/multiple stone wall crossings on my favorite 6+ mile loop doesn't help :lol:

 

[bvibert]

At 55psi you shouldn't have any problems with pinch flats. I weigh more than you and usually run about 40psi lately. Sometimes I go down to about 35psi, but that gets into pinch flat territory for me.

 

[drjeff]

At 55psi you shouldn't have any problems with pinch flats. I weigh more than you and usually run about 40psi lately. Sometimes I go down to about 35psi, but that gets into pinch flat territory for me.

I've tried running at lower psi (45 psi), but there's just something that doesn't look right to me when I look back and see a decent amount of "sidewall sag" under the combined forces of my bulk and the lower psi - although I'm starting to come around to the idea that a little lower psi is probably worth the added contact patch area on some of the rocks/roots that I usually ride on, even if my brain has a bit of an issue with the appearance of the tire :lol:

Thanks for the feedback BTW!

 

[Talisman]

Sometimes the tire deflation gremlin is a thorn stuck in the tire. After a tire goes flat over night episode I always carefully check for thorns on the inside of the tire. The barest little point can be the culprit.

You didn't ask but 55 PSIG is way too much pressure. Having some flex in the tire saves rims and spokes not to mention your lower back. You may want to consider backing off pressure in 5 PSIG increments until you get a pinch flat and then go up 5-8 PSIG.

 

[rueler]

I've considered it too. I need to find some tires that I'll be confident that I won't constantly put holes in the side of first though. I seem to have a habit of wearing or cutting holes in the sidewalls for tires in a short amount of time...

If you run a TRUE tubeless tire, the sidewalls are usually much meatier and durable than a traditional tubed tire. I'm not currently running tubeless on my newer bike yet...but, have with great success over the past several years...never ripped a sidewall...only a couple puncture issues with a shard of metal and glass the other time...one of the punctures resealed itself, the other was too big (so you just use a tube to get out)...The other issue you may get is "burping". I never seem to have an issue with this, but it is common for people who ride a bit rougher or have "heavy" bouncing types of impact (drops, rocky tech sections at speed). Burping is just when you hear air escape the tube...A good seal job with Stan's usually does the trick.

 

[Black Phantom]

Sometimes the tire deflation gremlin is a thorn stuck in the tire. After a tire goes flat over night episode I always carefully check for thorns on the inside of the tire. The barest little point can be the culprit.

You didn't ask but 55 PSIG is way too much pressure. Having some flex in the tire saves rims and spokes not to mention your lower back. You may want to consider backing off pressure in 5 PSIG increments until you get a pinch flat and then go up 5-8 PSIG.

No doubt. It wouldn't take much at this pressure for the tiniest thorn to create a problem.

DJ- do you have another tire to try out?

 

[drjeff]

If you run a TRUE tubeless tire, the sidewalls are usually much meatier and durable than a traditional tubed tire. I'm not currently running tubeless on my newer bike yet...but, have with great success over the past several years...never ripped a sidewall...only a couple puncture issues with a shard of metal and glass the other time...one of the punctures resealed itself, the other was too big (so you just use a tube to get out)...The other issue you may get is "burping". I never seem to have an issue with this, but it is common for people who ride a bit rougher or have "heavy" bouncing types of impact (drops, rocky tech sections at speed). Burping is just when you hear air escape the tube...A good seal job with Stan's usually does the trick.

Sometimes the tire deflation gremlin is a thorn stuck in the tire. After a tire goes flat over night episode I always carefully check for thorns on the inside of the tire. The barest little point can be the culprit.

You didn't ask but 55 PSIG is way too much pressure. Having some flex in the tire saves rims and spokes not to mention your lower back. You may want to consider backing off pressure in 5 PSIG increments until you get a pinch flat and then go up 5-8 PSIG.

No doubt. It wouldn't take much at this pressure for the tiniest thorn to create a problem.

DJ- do you have another tire to try out?

All right, I'll run with 45ish PSI and give that a try.

As for another tire to try out, not currently, although the guys at my LBS this afternoon after seeing it might change that

 

[drjeff]

What tire pressure are you using? When you replaced the tube on the first ride did you check for anything sticking into the tire that could puncture the tube? Also make sure that the rim tape is covering the spoke holes, and that there's no burs or anything sticking through.

When I have a tire go flat I always inspect the tube once I get it out to try to determine what caused the flat. Most of the time it's pinch flats for me. They're easy to spot sine there will be two holes side by side where the tube got pinched between the rim and something hard. It's doubtful that happened on the bike path, so I'd be looking for something sharp making contact with the tube, inside the tire. Another thing to check is the valve stem, they sometimes tear where they connect to the tube or just don't hold air that well.

Sometimes the tire deflation gremlin is a thorn stuck in the tire. After a tire goes flat over night episode I always carefully check for thorns on the inside of the tire. The barest little point can be the culprit.

You didn't ask but 55 PSIG is way too much pressure. Having some flex in the tire saves rims and spokes not to mention your lower back. You may want to consider backing off pressure in 5 PSIG increments until you get a pinch flat and then go up 5-8 PSIG.

Score points for the thorn guessing crew!

Here's the culprit that per my local LBS guy was sticking through about 1/16" from the tire

 

[WoodCore]

Score points for the thorn guessing crew!

Here's the culprit that per my local LBS guy was sticking through about 1/16" from the tire

That'll do it! :smash: