rdtindsm

Had a pinch flat and put this tube in. 10 mi later, had my second flat and had to hitch home.

When I pulled the tube, this is what I found. It looks like the spoke well has cut the tube, but the puncture is on the outside (towards the road surface) of the tube. Lines up with 2nd spoke from valve stem. The actual hole is in the curved section below the mold line. I've inspected the rim step and it is in good shape. I can find no problem on the tire - it is intact.

Tube is Vittoria lightweight butyl, rim strip is Vuelta plastic.

I can accept that possibly the tube was twisted, but I don't see any problems with the rim strip. I don't see any other remotely similar marks on the tube. Any ideas? Right now, it's just FM.

jim hughes

Maybe there was something trapped inside the tire, which fell out when you removed the tube. You could look for a corresponding mark inside the tire.

AnkleWork

Is it possible the tube was damaged before installation?

rekmeyata

I can see the inside fabric marks left on the tube, either there's something in the tire, or the tire is flawed, or the tube was flawed, or as one noted you damaged the tube with a tire iron; I personally think it's the latter. It's for weird reasons like that is why I index the tire to the tube, meaning I put the brand label center most letter aligned up with the valve stem, then when I pull the tube out and can quickly find the offending object or hole in the tire.

epiking

Looks like the tube had a patch on it and the patch (for some reason) came off?

rekmeyata

Another good possibility, if this is the correct situation then I can tell that he didn't prepare the tube correctly prior to patching, he didn't sand down the tube ridge seam till it was smooth thus it appears he either didn't buff it all or just did one or two passes and thought it was good to go. In order for the patch to come off like that would suggest either he didn't buff it all, or didn't allow the glue to dry long enough before applying the patch, or perhaps both which is probably the case.

rdtindsm

To the best of my knowledge, the Vittoria tube was unused. I've been preparing to get back into cycling since the first of the year and have been buying a stock of spare tubes and tires online. I don't know where I got the tube. Excel or Nashbar most likely.

I don't inspect new tubes since I assume them to be good. No tire irons were used. The mark does line up with a spoke well, but is on the outside and the rim channel doesn't have anything that would look suspicious. Neither did the tire casing have any anomalies. I'm used to seeing marks from the casings, so that doesn't bother me, but it only had 20 km on it, or less, so not much time for that sort of thing to impress into the tube. I did play with the contrast and exposure in Photoshop, so that gives colors that are off.

The ring shape looks like the imprint from a two layer spoke well, but the cut looks like it was made with a sharp edge. At this point, I'm guessing that it was where some process was trying to insert the valves stem. This might make some sense if the valve were inserted by hand, or at least if the tube were loaded into the machine by hand.