Emergency Trail Sidewall Repair

By: Jay Hart

Everyone carries a full sized spare tire on the trail right? What happens if you hit such a nasty obstacle, that you end up cutting two tires?

 

This trail repair will help you get back out to civilization, so you can buy another spare and get home.

 

Everyone is familiar with plugging the tread of a tire. It is straightforward: remove the item that punctured the tire. Ream the hole in the tire with the reamer. Prepare a plug on the insertion tool, being sure to coat it with rubber cement. Finally, shove the plug in the hole, keeping what little pressure that remains inside the tire.

 

What if you cut a sidewall? Any tire shop you bring a cut sidewall to in most cases will not perform any repair. This is because of the location of the damage. The sidewall is continually under stress, in both supporting the weight of the vehicle, and in flexing, each and every time the tire makes a full rotation.

 

Does this mean you are walking out of a trail or hitching a ride in your buddy’s rig, while you abandon yours? No.

 

While a sidewall repair is not recommended or safe for the street, it is just fine to get you “out of the woods”.

 

You will need a source of air, though, as there is no way you will repair a cut sidewall fast enough to have any pressure left in the tire. Don’t even try.

 

What’s the first thing you will need? You will need an off-road tire with a good cut sidewall for starters. Thanks go out to Bill Thebert for driving to the garage to ask them if they still had the damaged tire that came off his Scout. I only wish I was there… I’m sure they thought he was nuts for wanting his junk tire back. He must have taken a little flack for that one.

 

I used a yellow grease pencil to mark the damaged area as best as I could from the other cracks, which are not through the sidewall, but just, surface cracks.

 

Just to show that this sidewall is truly cut, I shoved a grease pencil through the cut and snapped a quick picture.

 

Here is a picture of my tire repair kit that rides with me. I have modified its contents as of this article, as I ran across a big problem with my material selection. There’s more on that later. The dental floss has been replaced by large diameter (19 gauge) lock-wire. The fishhooks, although big enough, were cheap and have been replaced with more expensive, larger fishhooks.

 

Although I have changed the materials to be stronger, I will include the first attempt at the fix and tell you what went wrong. The second attempt is documented, but will be more general in description, as the principals are the same.

 

The first thing I did was to lace the needle. In this case, it was a large fishhook.

 

The next step is to figure out a way to hold the hook steady while it is forced through thick rubber, and nylon chords (plies). I decided on standard locking pliers to do the job.

 

In order to assist the insertion of the hook into the tire, I used needle nose pliers. This made it easy to see what is going on, and aided in the repair.

 

Here is the first insertion:

 

It is very difficult to pull the hook through the tire due to the eye on the hook. You may need pliers to grab a hold and yank. Just be safe about it. Most likely if you ever have to do this trail fix, you are probably miles from a hospital.

 

By now, you are getting the idea that we are sewing the tire shut. You will have to knot the beginning some how. It doesn’t have to be pretty… it just has to work.

 

Now that the knot is done, you can continue sewing.

 

As I stated, I have changed the quality of the hooks I carry now.  I found out too late that the hooks I had were not very strong! You don’t want to save $ .50 when you need to do this on the trail, trust me. I was not happy about this.

 

As you can see, the piece of junk hook is not fairing well against the BFG.

 

I pulled out my awl to help the failing hook through the sidewall. This helped it to last… longer than it would have.

 

The other thing you will want to be sure about is spacing. Be sure to space the holes back far enough away from the edge of the cut. If the holes are too close, they might tear. I should have left more room than I had. About ¾” would have been a good safe distance. They are a little too close to the cut here. I was probably running about 3/8” to ½”.

 

When you are nearing the last stitch, you will need to finish off a knot. You will need to tie this off to something. I chose to tie the end back to the stitching, as expecting a knot to hold from pulling through the rubber is not the way to get off the trail. If you simply knot the line, it will pull through, and you will say all kinds of new words!

 

Finish the knot with a few different types of knots, and in opposing directions. Dental floss will not hold without a lot of effort.

 

Now the next step is to begin plugging the hugs gash you just sewed up. DO NOT REAM THE HOLES. The reamer will shred the dental floss to pieces.

 

I have no picture for this step, because when I inserted the plug, I caught the floss with the insertion tool, and tore the floss. All my efforts flashed in front of me. Had I been on the trail, I might have chosen at that point to drive out on the rim, and buy a new rim and tire when I finally made it. I said a few new words right then and there, and decided a change was in order.

 

NOTE: I have done this repair before and with dental floss, so I know it can be done. Although the cut was not as long, the repair worked as promised.

 

Now for the second attempt:

I went to Wal-Mart in search of stronger fishhooks. As I was browsing, I fell in love with the fishhook and steel leader idea. That solved the problem of the dental floss, and gave me a stronger hook at the same time. I decided on 8.0 hooks with an 18” leader, which is rated at 80#.

 

As I mentioned earlier, the principals are the same. I even used the same tire, but was unable to hit the original holes, complicating the final result, as there was a little leakage when I was done. I was unsuccessful in plugging all the original holes along with the new holes, and the cut. It was just too much to cram into a small area. But there is good news. Read on.

 

I needed to do the same thing, knot the line, to continue sewing.

 

 

This time, I was not as concerned with sealing the tire for longevity, due to all the holes I made in the first attempt, so I spaced out the second set of penetrations, and went further away from the cut. I imagine I was close to ¾” on one side and close to 1” on the other. You will notice in this picture near the swivel, the first penetration I made is already tearing a little toward the cut. Be sure and leave plenty of “meat” between the cut and the penetrations from your hook.

 

The dilemma of finishing this off with a knot was solved, when I was able to open the swage sufficiently enough to pull the wire through. I figured I would re crimp the swage when I was done with the knot, and it would hold the line firmly.

 

The swivel was too perfect for me to use when making my knot, so I took the last stitch back to the beginning and through the loop in the swivel.

 

 

Then it was back down through the swage, where it would be re-crimped to hold everything fast.

 

 

After this was all done, it was again time to plug the whole mess. I bought a cheap brand of plug, because it was black and would be easier to visually document. The black plugs are used to plug the cut. I ended up using over 10 plugs in the cut itself. The blue plugs are plugging the new holes we made during the stitching process. The object is to get it all sealed up.

 

Don’t forget to use rubber cement if you have any available. For such a temporary repair, I am sure it is possible to use plugs without the rubber cement.

 

When Bill gave me his old tire, it was without a rim. I mounted it on a rim I have, because I wanted to inflate the tire to test the repair.

The repair held well enough, along with good soapy water, to seat the bead! Only the backside of the rim needed the soapy water. The front seated itself when I put the tire on the rim.

 

It took over 17 PSI to seat the bead. I decided not to find out where the limit for pressure was. It settled out at just under 17 PSI, which is plenty for the trail. More likely, you would run a little less pressure, as all your other tires are already aired down as well.

 

Here is a short clip of the finished tire under pressure. It shows the leakage, which to me is not a lot at all, considering the length of the original sidewall cut, and all the extra holes I put into the tire on the first (dental floss) attempt, that were not sealed.

 

Click here for video of the test.

 

Hopefully this will give you enough information to be able to help yourself of someone else off the trail when the going gets tough!