Instructables

Thorn Proof Bicycle Tire Tube Flat Protector

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I struggled trying to find a thorn proof or at least very very thorn resistant bicycle tire tube protector. I have unsuccessfully tried tire tube liners as they seemed to cause more rubbing flats then they fixed though I now realize a step in this instructable could help remedy that. I have also tried a thorn resistant tire but its biggest drawback is the protection area is too small.

I am in a desert like area that is sandy and has lots of prickly tumbleweeds and other thorny vegetation. After a windy day new thorns are strewn all over. I am also not near any stores and supplies are limited so I had to use what was available.

This instructable is pretty simple and it has worked effectively for a couple weeks now(I ride one hour each day) and I have had 2 flats in my rear thorn resistant tire that I purchased since then. I basically use a plastic tube and a old tube to protect the real air pressurized inner tube. The result is a much stiffer and heavier tire that is at least a very very thorn resistant. It seems kinda like what I would imagine one of those airless tires to be but without the hassles of trying to mount it on the rim. I only needed to put in enough air in the tube to make the tire bead stick on the rim which I found was about 10-15 lbs. I use this on the front wheel of a mountain bike with a front shock fork so I still have shock absorbancy because a lot is lost using this plastic tube in the front tire. I have not currently tried it on the back tire because I don't have any more plastic tube available. The plastic tube I did get was found out in the sun in the burn pit/junkyard. The area of protection coverage is much higher than either of the two commercially available solutions mentioned above with the extra weight and tire stiffness being the drawbacks. For me it was a choice of being able to ride or not.

Additional Materials Beyond Normal Bike Tire Setup:

* 1.25" diameter plastic tube; mine has a coil of imbedded stiffener in the plastic itself.

* Old tire inner tube

Step 1: Cut the plastic tube to the proper length.  3.14(pie) times the wheel diameter or just fold the plastic tube around the rim and cut where they meet. Then cut the entire plastic tube lengthwise so it can be split open.

Step 2: Prepare the old inner tube. Cut out the inner tube stem but not all the way through the inner tube. Then cut the entire inner tube lengthwise like the plastic tube was above. Put the old cut inner tube around the good inner tube.

Step 3: Insert the good inner tube with its old inner tube around it, inside of the plastic tube. I had to pre-spread apart my plastic inner tube due to the imbedded coil stiffener.

Step 4: Insert this tube assembly into your regular tire and rim and install as you normally would. It will take a bit more pushing and prodding to insert all of this than normal. You may even have to cut and adjust the length of the plastic tube. Inflate and install on the bicycle and you are done.

If you look in sports-wheelchair catalogs you can find Kenda polyurethane inner-tubes (not generic foam ones for kids at Walmart, made to support adult weight and re-use for several tires).

http://www.kendatire.com/en/wheelchair/foam-filled...
pay attention to make sure you get the right size. 26x1 3/8 is not the same rim as 26x1.95 or 26x2.1 There is a chart in there. That should solve your problem for desert riding, and let you pick real tires.

Cool idea. That might work well for a "junk" bike, to use for camping or hunting.
Gorilla Tape works great for conventional tube-tire rim tape, lasts for years.

Have you had any problems with the hose-liner "walking" or rolling inside the tire (so the split moves)? Have you had any blow-outs caused by tube cuts?


I made tire liners once out of thick red fire-hose (fiberglass reinforced). Nothing ever poked it, but it chafed a couple tubes. "Paper" tubes don't work with any tire liners. They chafe a hole in them. no problems with super-tubes and tire liners, but it's heavy. For desert thorns, you might need super tubes and mower tire-sealant, or Stan's tire sealant and UST tubeless tires. If you have a cheaper/older bike, you can make the "ghetto tubeless" system or use a Stan's rim tape and valve kit with sealant.

I have used Amerityre polyurethane tires before. I've put them on by hand even. Don't use concentrated soap! it stains them. For desert riding, they should last years. On concrete, they wear some (some knobs may flake off after a year).

Wildbilly66 (author)  Yard Sale Dale1 month ago

Amerityre wouldn't ship to an APO address :( I won't be trying them out.

Wildbilly66 (author)  Yard Sale Dale2 months ago
I have not had any problems with the hose/tube sliding around. It is quite a tight fit so it's not a problem.

I put the old tubes around the inner good tube for the rubbing puncture issue.

I recently only had a larger thicker tube hose to use. It was about 2.5" in diameter. I cut it back to fit but it was very very stiff and tough to get in. I actually punctured the tube trying to get it in.

You can use bands of gorilla tape or quality electrical tape to hold the tube (barely inflated) and liner in place, for inserting in the tire. Use multiple (3 to 6) plastic nylon tire levers to delicately seat the bead without denting the rim, snapping levers, or tearing the bead.

gmh57601 year ago
Try these...
http://www.airfreetires.com/shopping/c-1-bicycle.aspx

Sadly, I've had very bad results with airfreetires.com. Check them out at the Better Business Bureau (http://www.bbb.org/central-florida/business-reviews/tire-dealers/air-free-tires-in-new-smyrna-beach-fl-24000243). They have a long history of taking people's money and never shipping them product, then refusing to so much as respond to phone calls and emails. This includes me; only after purchasing the website AirFreeTiresSucks and threatening to build up the SEO on that site did the owner relent and refund my money.

And it's such a shame- solid bike tires had a great reputation during 50's and 60's; and even today it's common in many parts of the world to just stuff a blown tube with rags or hay in order to use it till it blows apart...

Now that would be an instuctable!

Wildbilly66 (author)  gmh57601 year ago
Yeah, I seen those online. I dug around and found that they are very very stiff and hard. People have damaged their rim trying to get them installed. I don't have any personal experience with them. If you do let us know how it went. Thanks!
sidmarx1 year ago
Beware of measuring tape! I used the thin kind around the inside rim instead of rim tape. It worked perfectly for a few months until it rusted, split in sev. places, and caused a flat.
(some instructables advocate using a strip of steel meas. tape between the tube & tire.)
Me, i've had fine results with a strip of tire tread tucked into sections of old tube, which keeps the tread edge from sawing at the tube.
Looks like a good idea. I wonder if "wiring harness" sold at Home Depot could be used in place of the plastic tubing. It is already cut and comes in varying length, but may have a somewhat deeper corrugation.
Aron3131 year ago
Age old question
Viaticus1 year ago
Brilliant! Thanks for sharing this idea. I can imagine there might be room to expand this, but it is definitely genius from the start!
Great idea! For all the times we've got flat tires in our baby strollers, this is a tip that makes me think .. what didn't I think of that??! Great work!
ilpug1 year ago
Oh man, you are a genius.
Wildbilly66 (author) 1 year ago
Thanks MM. I did forget to mention that you should pump up the tire pressure more to get the bead of the tire to lock in good and then let the air out until it hits the desired pressure/stiffness. The low final tire pressure also enhances the protectiveness of this solution as it makes it harder to puncture the tube.
serious props, dude.
cheap, easy, useful, and simple.