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I've scoured the internet for this answer, as I recently just tried to repair a tube on my Purefix fixed-gear bike which I assume uses tires and tubes similar to road bikes, as the tire size is 700cx28. Anywho, the patch pinched the tube and was no longer usable. I used the pre-glued ones, but the problem seemed to be that the patch pinched the tube.

  1. Does the type of patch (pre-glued, non-pre-glued) matter a ton?
  2. Should I apply patch to a partially inflated tube or deflated tube?
  3. Does the tire-liner stuff really work in preventing flats?
  4. Are my tires to blame for all my flats?

This is my first time on a bike that isn't a mountain bike, and I've had 3 flats now in 2 months and I haven't been able to patch them. Thanks for all the info guys and gals!

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The "Related" questions at the right seem to answer 3/4 of your questions. Put "tire-liner" in the search box at the top for answers to the fourth qn. –  andy256 Oct 10 '13 at 4:46
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The right way to patch a tube is at home. Always carry at least one, maybe two spares, so you don't have to do the patching on the side of the road. Otherwise, I prefer the sort that come with a tube of glue. Apply it to the deflated tube. And get belted tires. –  Daniel R Hicks Oct 10 '13 at 12:42
    
I don't know if I'm on my own here but I'll almost never patch a tube. Any damage and it gets binned. In contrast to Daniel the only time I'd ever resort to patching would be out on the road - and even then only if the two spares I carry got punctures. –  PeteH Oct 10 '13 at 19:57
    
Very valuable forum. Thank you! I patched one tire that has been going for over a year. Yet, when cruising down a hill at 50 plus mph my mind often wanders to that patch. –  ken Jan 20 at 21:58
    
@PeteH This is the solution many road bikers take. For me, this is just too expensive. A patch (20ct.) versus an inner tube (~8$) is quite the difference. –  arne Jan 21 at 8:41
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3 Answers

When I make a repair, I also do the following extra steps, to make sure that the patch holds. I have never had a patch come off/leak when using this technique.

  1. Use a little bit of sandpaper to remove any ridges on the area to be patched, such as a manufacturing join.
  2. Clean the area to be patched, this makes the glue/solution adhere better to the tube. Especially so if you have sanded the area. I would usually use methalyated spirits and a lint free cloth of some sort.
  3. Once the patch is applied, apply some chalk dust to the area, this makes sure that the solution/glue does not bond to anything else.
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I've never used a fluid to clean the patch area, and have never had a problem. If I patch on the road (which I rarely do) I'll use something (talc, roadside dust, a bit of tissue) on the exposed glue to keep it from sticking to the tire. –  Daniel R Hicks Oct 10 '13 at 12:42
    
The above will ensure that the patch will last as long as possible and is really only something to do back at base. If you intend to keep the tube for as long as possible, then a more meticulous repair will last longer. –  Phil Oct 16 '13 at 21:02
    
I also inflate the tube after patching and let it sit overnight to see whether the patch really is tight. –  arne Jan 21 at 8:42
    
I would like to emphasize #1. if you don't sand the seams down flat, they can create a pocket where the patch can't conform tight enough. The air could collect in this pocket and find a way to the edge of the patch. I had a patch that held up for days but ultimately failed because of this. The alternative is to not place the patch on the seam, but close to it, as per the situation allows. –  BPugh Jan 21 at 17:02
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  1. Typically the old style patch kits work better than the pre glued ones, but properly applied ones should hold up.
  2. Follow the directions in the patch kit to apply it properly.
  3. You need rim tape, but not a tire liner (check to see its in good condition). Sheldon Brown says tire liners can cause more flats: http://sheldonbrown.com/flats.html
  4. Check for things on the inside of the tire (or outside) or canvas showing. Those can cause flats, but what is the shape of the damage to the tube?
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  1. Does the type of patch (pre-glued, non-pre-glued) matter a ton? Based on my experience I have more confidence in the non-pre-glued ones, but I've used both types succesfully.
  2. Should I apply patch to a partially inflated tube or deflated tube? I always apply the patch to a deflated tube. Since you have a leak, inflating and then applying the patch before it deflates again just leads to sloppy work and possibly airbubbles between tube and patch.
  3. Does the tire-liner stuff really work in preventing flats? I don't think so. (see also batman's answer).
  4. Are my tires to blame for all my flats? Possibly, if they are really very thin, or there are sharp bits sticking through to the inside (you do check for that when fixing the tube I assume). However, with frequent leaks the first suspect I turn to is tire pressure. You should properly inflate your tires, this prevents more leaks then any specific tire can. 4 bar for bigger MTB-style or hybrid bicycle tires, upto 8 bar for thin road-bike tires. Not enough pressure leads to frequent pinch-flats.
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4. above was going to be my answer, if you are concerned about the number of flats you are getting, and are coming from an MTB background, then checking your pressures is the number one thing to check. It's possible your MTB pump may not be able to reach the minimum level suitable for a road bike, and it's good to invest (if you don't already have one, this is an assumption that you don't) in a proper stand pump with pressure gauge. –  stuffe Oct 21 '13 at 14:57
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