rc5781

I ride a 27.5 mountain bike mostly in the suburbs and kept getting flats on my rear wheel. I'm guessing they were pinch flats because I wasn't finding any kind of shrapnel in the vicinity of the flat on the tire. Anyway, here's what I did and haven't gotten a flat since.

I took my inner tube that got a flat and cut out the valve system. When replacing a new inner tube I first put the old inner tube into the tire, then put in the new inner tube. This effectively results in an inner tube with 2 times thickness. Worked like a charm. Will be doing this on my front tire as well, but haven't gotten a flat yet. I HATE flats, especially when you're exactly the furthest point from your return destination, thus I share...

CrimsonEclipse

1. you created a tire liner. (nice) If it works for you, perfect!
2. Consider puncture resistant tires if punctures become a problem in the future. (I have ranted about the marginal protection of tire liners and slime tubes over and over so I'll save you some time)

rc5781

"Puncture resistant tires" sound expensive to my thrifty soul. If I run into problems I'll lookup your rants. Also, slime tubes sound weird to me. Not sure how they compare to a 200% thickness inner tube.

79pmooney

If these are pinch flats, much easier is a few more psi of air in your tires. (Are you getting two holes side by side perhaps a half inch apart? Classic not enough air. Yes, enough cushion may stop it but a little more air will save you work plus make your ride a touch faster, sportier, maybe even more fun.)

If these are not pinch flats but caused by debris, carry on or take CrimsonEclipse's advice (or use sealant or go tubeless or ... Lots of options and many threads on the subject.

veganbikes

There is a difference between thrifty and just cheap. Buying good tires that will last a long time and help prevent flats are a good thing and the thrifty choice. Cheap tires and cheap parts are more expensive generally as they need more replacement or in this case can cause more flats.

In terms of liners I would go for Tannus Armour which is a thick lightweight foam which actually gives you something. A thin rubber liner maybe from an old tube is marginally better maybe in some situations but at that point I would rather just have a good tire and quality tube.

RCMoeur 

Just about any thorn-resistant tube that meets the end of its service life around here gets repurposed in this manner. Not for my own bikes (I use SpinSkins or good plastic liners), but bikes I build for others and nonprofits.

When installing the tube, the added thickness of the added liner can affect the tube diameter, and so it's a good idea to have as much air out of the tube as practical to avoid folding the tube in on itself - which is eventually likely to create a flat on its own due to rubbing of the folds.

base2 

You could take another tire with a minimal number of knobs or none at all like a smooth road tire..., cut the beads off it and use it to line the new tire. Install & inflate a thorn resistant tube. Bingo-bango. A tube in a tire in a tire! Roofin' nailz got nuthin' on you.

#no-flatz-4ever

freeranger

If you're inflating the tire to 80% psi, it's very unlikely that you're getting pinch flats.

Moe Zhoost

I'm not sure that an additional liner, DIY or otherwise, would do much to prevent pinch flats. I hope it works for you, though.

Kontact 

Careful adding another tube. It is difficult to get both in there without any creases and will eventually cause the tube to fail.

rc5781

I inflate to maybe 20psi. Deflate and inflate to maybe 30 psi. Maybe repeat one more time and then fully inflate to avoid this.

base2 

But then you keep that tube & add another. Just keep going until you need to drill a hole to squirt in a can of expanding weather foam.

soyabean

Using a discarded inner tube as a liner is an old trick that gets done to a lot of kids bikes.

I hate flats, especially for my ebike since I can venture out very far with it.

Tire failure prevention is not difficult at all.

Your first line of defense is a good strong gravel tire or ebike rated tire, Schwalbe has a ton of those.

Then for the tire liner, I use Mr.Tuffy, go read up about them.

Last, choose a inner tube that's as large as possible so it don't stretch. If the tire is a 700x35, don't use a 700x23-35 inner tube. Use the one that is 700x35-50.

I have yet to experience a failure from doing the above three.

Sorry I hate goo slime forever. Perhaps because every time I remove a tire from a rim, I get a messy surprise.

Iride01 

A tube in a tube? Seems like you are doubling the rolling resistance that the tube causes. It's partly the reason some went to tubeless tires. To get rid of that extra rolling resistance. Perhaps we should use latex tubes? But then again that would seem to be about as beneficial as just a butyl tube. Maybe not.

I haven't flatted in almost a year and a half. I'm not sure why I'd even worry so much about trying to prevent a flat.

pdlamb

You can also get solid rubber tires, no inflation needed.

Benefits: Never flats. You get to enjoy the history before John Dunlap invented the pneumatic tire.

Downside: You find out why Mr. Dunlap invented the pneumatic tire.