How to fix a tire puncture on the trail

Most trail flats can be repaired where they happen. A puncture through the center of the tread usually seals with a standard tire plug kit. A cut through the sidewall will not hold a plug and needs an external patch kit like GlueTread. Both fixes are temporary and need a shop inspection afterward.

We have pulled a lot of sharp objects out of tires this season. Nails and screws on the forest roads, and rock cuts on the rougher climbs like Red Cone and Radical Hill. The good news is that most of it is fixable on the trail if you know which repair matches the damage.

A nail in the center of the tread

A tread puncture is the easy one. The tread is thick, backed by steel belts, and it does not flex much, so a rope plug seals and stays put.

1. Find the leak. Soapy water in a spray bottle will show you bubbles if the hole is not obvious.
2. Pull the object with pliers and note the angle it went in.
3. Ream the hole with the rasp tool, working it in and out several times to clean and open the channel.
4. Load a plug in the needle tool and coat it with cement.
5. Push the plug in until roughly half an inch stands proud, then pull the needle straight out.
6. Trim the plug flush, air the tire back up, and check the repair with soapy water again.

Two limits worth knowing. Plugs belong in the center tread only, never the shoulder or the sidewall. And a rope plug is a get-home repair, not a permanent one. The lasting fix is a patch-plug installed from the inside with the tire off the wheel.

A rock cut in the sidewall

Sidewall rubber flexes with every rotation, and that movement works a rope plug loose. A sidewall cut needs a patch bonded to the outside of the tire, which is what a GlueTread kit does.

Prep is most of the job. Air the tire down completely, clean the area, and scuff the rubber so the adhesive has something to bite. A small battery-operated grinder makes that step fast and does a better job than sandpaper on a cold day. Apply the glue, set the patch, let it cure, then air up slowly and watch the edges.

Treat it as a way off the mountain. Drive out at reduced speed and reduced pressure, and plan on replacing the tire. Sidewall damage is not repairable to any standard that belongs on a highway.

Check the glue before the season, not on the trail

Rubber cement and patch adhesive both dry out. A tube that has been riding in a hot bed box since last summer may be thickened or solid, and finding that out at 12,000 feet is a bad afternoon. Open the kit in the driveway, squeeze the tube, and replace anything that has gone stiff. Store the kit in the cab where temperatures swing less.

Round out the kit with a compressor, an accurate gauge, a valve core tool with spare cores, and a real jack that works on uneven ground. Running low pressure is what gets you traction on rock, and it is also what exposes the sidewall to that same rock, so air back up before you hit pavement.

Stay safe and be prepared, Scott

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