Bicycle Mechanics - chronic flats on rear wheel

SO i just got a new wheelset and tires. Velocity Deep Vs and Schwalbe marathon 700x35 tires. Ive ridden on them for a whole week at work no problem and the other day i wake up to a flat rear tire. The puncture in the tube is on the side facing the rim. I patched the whole pumped it up put the wheel back on my bike and 5 seconds go by and a hear psssssss of air coming out and it goes flat. Removed the tire and tube to check it out and there's another puncture just like in in a different spot on the tube. I patch a second hole and check the rim for any defects the rim strip was slightly off center from the valve whole so i straightened it out. I went for a 40 ride on this bike yesterday and when i woke up this morning the tire was flat again! If it is the rim/tire combination why hasnt this happened on my front which is the same as the rear? Can someone provide some insight about why this keeps happening.

What kind of rim-strip are you using?

Remove the tire, tube and rim strip. Use one or two fingers to feel the entire inside surface of the rim, center and both sides. There could be metal shavings sticking up, from the manufacturing process, or , if there are holes in the rim from a double layer rim, check to see if there are rought spots around them. Clean everything with steel wool. Use a wide rim tape to cover the inside of the rim. If everything is smooth, clean, and no sharp edges, place your tire and tube back onto the rim and pump it up. Rubber rim strips can shift, whereas rim tape cannot. On occasion, the inside of the rim is rough from manufacturing.

Remove the tire, tube and rim strip. Use one or two fingers to feel the entire inside surface of the rim, center and both sides. There could be metal shavings sticking up, from the manufacturing process, or , if there are holes in the rim from a double layer rim, check to see if there are rought spots around them. Clean everything with steel wool. Use a wide rim tape to cover the inside of the rim. If everything is smooth, clean, and no sharp edges, place your tire and tube back onto the rim and pump it up. Rubber rim strips can shift, whereas rim tape cannot. On occasion, the inside of the rim is rough from manufacturing.

Just went thru this very problem w/700x25mm SMP and Sun CR-18 rims. Print this post and do exactly what's been suggested.
IMHO definitive answers like this should go into a BF index of some sort. Short, sweet and right to the point. :thumb:

check your patches too, to make sure they're sound.

Probably the rim tape is too narrow and shifting around. The edges of the holes the spokes go through slice right through the tube. It's very frustrating, I know.

Remove the tire, tube and rim strip. Use one or two fingers to feel the entire inside surface of the rim, center and both sides. There could be metal shavings sticking up, from the manufacturing process, or , if there are holes in the rim from a double layer rim, check to see if there are rought spots around them. Clean everything with steel wool. Use a wide rim tape to cover the inside of the rim. If everything is smooth, clean, and no sharp edges, place your tire and tube back onto the rim and pump it up. Rubber rim strips can shift, whereas rim tape cannot. On occasion, the inside of the rim is rough from manufacturing.

+1 on this advice. Only thing I would add is to carefully check the bead and the inside of your tire with your finger. I was having the same issue as you until I found a tiny metal shaving that was embedded on the inside of my new tire.

GL

Almost certainly a rim tape issue. A roll of Velox tape should fix the problem once and for all.

Almost certainly a rim tape issue. A roll of Velox tape should fix the problem once and for all.

+1
Velox rim tape of the correct width and fully inflate your tires up before each ride.

Al

I have had this problem several times usually it is something embedded in the tire that I can't feel when I patch the tube but when the tire is under a load (sitting on it ) it protrudes just enough to start a slow leak. Have you tried examining the tire cuts on the tread to see if there is anything embedded in them. Flats can be really frustrating I sometimes get them & can find no cause for the flat. Also try pumping up the tube & putting it in water to check for leaks

mike smith