Drillium Dude 

I haven't ridden in over two weeks, but I've still gotten two flats during that time. How? Well, I'm not entirely sure, but after doing some poking and prodding, I think I may have the answer. First of all, this is the specific brand of tube I'm having issues with:



Identification and specs marking on the tube - note this one is the flat tube I removed which has a 32mm valve vice the boxed (new) on above with the 48mm valve:



Note the deformation/bulging at the site of the puncture (silver Sharpie). Also note the location, about 10" from the valve hole, and the four raised lines that encircle the circumference of the tube:



Same puncture close-up; the bulges are a little easier to see here:



This first tube let go last week while I was at the computer: suddenly it let go and in about 30 seconds the air whooshed out. I was surprised to see the deformation because only a few days before I'd swapped another tube out which failed at the valve (different brand, same wheel) and put this one in. It had not turned a wheel on the road and the tire/rim interface was clean when I made the swap.

I noted this time the bulging and lined it up on the rim - that's when I realized the deformation/puncture occurred at one of the eyelets - and at the area of the 4 lines circumscribing the tube. I decided to pull the back one (1) because I'd gotten two new tubes, both with 48mm valves. My OCD wouldn't allow me to put a 48mm in front and leave a 32mm out back - no way! - and (2) I was curious as to what it looked like since I'd replaced it at the same time as the front. This is what I found (the rear tube is on top, the flatted front on the bottom in this photo):



In the exact same area with the 4 lines there is more bulging going on. Care to guess where in relation to the rim itself? Yep, directly over one of the spoke eyelets. Here's a closer look - the similarities of the deformity are quite obvious here:



I'm surprised this one didn't go first - it's got two obvious bulges either side. It should be noted that this deformation around the spoke eyelets is not repeated for any other area on the tube with the exception of the area in question. This one has also not yet seen any time on the road:



Here's a perfectly intact rim strip over the eyelet in question:



And here's the money shot - NO protruding spoke-head. This is the front wheel, but the rear looks exactly the same:



So, what the hell is causing this issue? Honestly, I think it's a manufacturing defect. The failure is happening at the same location on the tube, on different wheels with correctly installed features designed to keep this from happening. Has anybody else had issues with these particular tubes? They run almost $9 each, so these failures are going to become stupid-expensive after a while if I can't come up with an alternative.

Tires had been pumped up to 90psi and the bike was hanging from the wall rack with no weight on the tires when the failure occurred.

Thanks for any insight which may lead to an understanding and solution.

DD

thook

i think you nailed it as manufacturing defect. a bad run of product. happens in industry, as i'm sure you know

scozim 

Too coincidental not to be a manufacturing issue. Would be curious to see a tube from another manufacturer and what it looks like at that same spot.

lasauge 

I would also vote for a bad manufacturing run. I once bought a case of 50 tubes of which at least half of them split near the valve stem when inflated.

SJX426 

Wow! Nice root cause analysis without finding the mechanism of failure!

I had a run of tubes a couple of years ago. I bought a batch and every one failed somewhere along the inside (rim side) and almost every one by the valve stem. Too close to patch of course. I thought it was my pumping technique but when I used a compressor with little movement of the chuck and it still failed.....
Some times it would blow within 5 min or just after installing the wheel on the bike.
I had one commute trip where I changed a tube then had to pump it up 3 or 4 times to get to work. Commute was only 11 miles!

I feel your frustration. I could only surmise manufacturing defect. Looking closely at the tube, it almost looked like there were voids in the tube in places.

And yes it gets expensive for a component that was relatively inexpensive only a few years ago. Can't be expensive to produce in China and neighboring countries. Must be price gouging! How long have innertubes been made? has to be as easy as toothpick manufacturing.

Opps, shouldn't use a pointed object as an example!

thook

it is price gouging. or rather profiteering. the most profits are made are on the more inexpensive products manufactured. you can mark'em up several hundred percent and the consumer hasn't a clue. all the while have less of a mark up on the expensive so consumers can simply afford them. profits from the cheap help offset loss in other areas. that's what i see working in retail, anyway. i'm sure the dynamic varies

alo

I think I am stating the obvious, but I would buy a different brand of tube.

nlerner

Seems like a case of bad juju.

10 Wheels

Twice on the same cross country tour bought five tubes. They all turned out to be defective.

thook

that would suck! were you even able to patch them, or did you have to hike it?

10 Wheels

The first batch was from Continental. All the Valves were bad.
I was with some other riders and they shared a tube with me..

thook

oh...continental. i've twice been disappointed with their tires in recent years. two different models. cracking before the tread is even 50% down

glad to hear you had support, fred. i've been on a couple/few rides where one of us had to ride all the way back to the car and return to pick the other up due to no go flat repairs. once from a broken chain and no tool, even. real buzz kills. certainly not comparable to being mid-tour, though

10 Wheels

thook

everyone had flats...on conti's?
is that a personal video of yours?
one of them smiley people you?

thank you for sharing, in any case. enjoyed it

10 Wheels

NY to LA. 4200 miles. 57 days. I had 12 Flats. Chad on the Purple Bike had 8 Flats in the same day.

thook

good grief....hahaha! then again, i've never been on a proper tour, so maybe that's not anything extraordinary. bad roads or just subpar equipment? i'm interested to know if it is conti related, though. i have been avoiding their products and will continue contingent on ride reviews

10 Wheels

In The Heat of Summer. Had to fix our own Flats. Got PAID $120 a day to wear The 42 Jersey.
Tour leaders made all of the reservations for each night.

thook

nice!!

Drillium Dude 

The consensus seems that these are indeed defective; as such I will bring this to the attention of my LBS and hopefully get a refund. Thanks!

DD

davester

I don't know about the tube, but that photo of the spoke eyelet seems to indicate that the spokes are too short. Too many unoccupied threads in the nipple. Having built a number of wheels, one of the critical tasks is to correctly pick spoke length so that the threads are filled (or close to) without too much spoke protrusion. I'd guess that the longevity of that wheel might be a bit short. If you start snapping the heads off the nipples, you'll know why.

Johno59

Obviously it is not road surface as the punctures are on the inside circumference ie. away from the road surface. They aren't pinch flats as they don't have the characteristic paired 'snake bite' failures evident when a too soft tire bottoms out against the rim and the tube fails on the inside surface.
The bubbled tube depicted in the photo indicates to me the rim tape not being robust enough to stop the tube expanding into the vacant area present in double walled or deep rims. Using old school rim tape is not a good option as BITD the pressure was much lower and the nipple head actually supported the rim tape as they were proud of the rim surface. The tell-tale sign of this is the double bubble in one of the photos. Obviously the tube depicted in the foto punctured somewhere, it was removed and repaired and when put back in the vacant region wherein the spoke sat was slightly different at the second go and the bubble hence was located a little further on but not a full spoke away different.
Get rim tape suitable for deep rims, if not a viable option wind two layers around rim but be careful the extra tape doesn't unseat the bead of the tire from where it sits on the rim.
Also bolstering this possibility is the tell-tale stretched weave evident in one foto of the rim tape. The distortion is circular ( like the cavity for a spoke well) . The pressure has forced the tube down into the well and left a circular shaped weakening of the fabric of the tape. You need stronger rim tape.

Drillium Dude 

You must take into account the photo is an extreme close-up; the end of the spoke is barely a millimeter below the screwdriver slot.

The wheelset is at least 10 years old - probably closer to 15. The same woman who built this wheel (and its mate) also built the other three pairs I've relied upon regularly since 2002 or so; still ride them, too.

DD

Drillium Dude 

What did I just read.

DD

thook

he's saying your rim tape is not strong enough to support the high inflation pressures and is creeping into the spoke well in that one spot causing the tube to bubble. my question is, if the tape is too weak, why wouldn't the tape cave under pressure at other spoke locations? moreover, why am i not having the same problem? i use the same rim tape. and, with double walls rims

Kabuki12

If the tubes let go in the same location perhaps the defect is localized at that spot . If you patch the tube and wait to see if the problem goes away maybe save the tube. The only reason I say that is I am having some trouble finding short valve stem tubes. I have been patching and riding tubes I would normally dispose of because they have been previously patched. My LBS is having 48mm as short now. They can’t get 32 or 33 anymore. I just bought two on the bay but they are Kenda and I am not a fan of Kenda but I will try them and if they work, buy a couple more. We are not getting any rain down here so there are still plenty of goat heads on the roads from our dry winds. It is flat season extended!
I am glad I had John change the wheels on the Colnago to clinchers. I got my first flat on it a couple of weeks ago.