Thursday, April 22, 2010

The Hole Truth: A Quick Guide To Roadside Tire Repair

It can take months of saving, weeks of planning, and days of packing to begin a motorcycle trip, and only a single nail in your tire to bring it all to a wobbly halt. Here's what to do if this happens to you.

Being stuck in the middle of nowhere with a flat tire on a fully loaded bike has to be one of the most helpless feelings a rider can experience, yet surprisingly many riders have no clear idea what to do in case of a flat—fewer still even bother to pack the tools to deal with it.  Knowing what to do can mean the difference between finishing your trip on your bike, or with your bike in the back of a truck.

What to do depends in large part on the kind of tires on your bike. Thanks to the cruiser boom, spoked wheels and tube-type tires—once on the verge of disappearing from street bikes—are once again as common as they were in the days before cast wheels and tubeless tires became the norm.

One of the reasons tubes fell out of favor is their tendency to deflate rapidly when punctured, giving very little warning before going flat. But tubeless tires—assuming a small, round puncture from a nail or screw and not a tear that rips open the tire's carcass—tend to deflate more slowly, giving you more time to notice the problem, slow down, and get off the road. Sometimes, in fact, they don't deflate at all—the penetrating object acts as a seal—which is why you need to inspect your tires now and then for anything stuck in the tread.

To repair or replace a tube, you have to take the wheel off the bike, then the tube out of the tire. If this doesn't sound like the sort of job you want to do by the side of the road, that's because it isn't. Even if you've brought all the necessary tools along, if your bike doesn't have a centerstand you'll still have to improvise a way to raise it up off the affected wheel so you can remove it.

A centerstand makes the job easier, unless you get the flat in the front tire. In this case you'll have to figure out a way to tilt the bike so the front wheel is off the ground, either by propping it up with something under the frame or by placing weight on the rear of the bike. Given the complications of fixing a tube on the road, maybe the best tools you can have with you are a cell phone and a motorcycle towing service membership.

Plugging a hole in a tubeless tire is a lot easier, because you don't have to take the tire off, or even jack the bike up—just find the hole, insert a plug from the outside, reinflate the tire, and be on your way. But this method, though apparently simple, is not without controversy.

I couldn't find a single major motorcycle tire manufacturer that recommended using external plugs to fix a tubeless tire. The only method any of them endorsed was to remove the tire from the wheel and seal the hole from the inside with a plug and a patch.

They also gave the thumbs-down to liquid sealants in both tube-type and tubeless tires. Dunlop's website, for example, says sealants "may adversely affect ply material and mask secondary damage caused by a penetrating object. Reliance upon sealants can result in sudden tire failure and accident."

I asked a number of motorcycle shops whether they'd plug a tubeless tire. They all said no, not even using the manufacturer-approved method. One said when a customer brings in a tubeless tire with a hole, they recommend taking it to an automotive tire shop that will install an interior automotive plug and patch. Once the tire is repaired, the motorcycle shop will mount it on the wheel, but will note on the repair order that the customer brought in a repaired tire, and refuse to accept liability for subsequent problems.

A few tire manufacturers acknowledge that external plugs can be used in a "just get me home" situation, as long as a permanent approved repair is made as soon as possible. In these litigious times no one at Cycle Guide Magazine is going to tell you to go ahead and ignore the tire manufacturers' recommendations. Still, many riders have used external plugs to fix a flat and then ridden on the tire for thousands of miles afterward without problems. It's a choice you'll have to make for yourself.

Roadside tubeless-tire repair kits are seductively simple to use. The procedure varies some from kit to kit, but in general it's the same.

Locate and mark the hole. Ream it out with the tool provided with the kit, then use an insertion tool or a plug gun to insert either a glue-covered strip of patch material or a rubber mushroom plug.

With strip patches—also known as gummy worms—you push the strip all the way into the tire, pull it halfway back out with the insertion tool, and cut it off flush with the tire tread.

The mushroom plug (shown at right being inserted into the plug gun) is pushed into the tire until the head pops out inside. Withdrawing the plug gun leaves the “stem” end of the plug sticking out of the tread. Pull on it with pliers until it stops, which indicates the head is flush with the inside of the tire—no glue needed, just a little bit of oil to lubricate the plug so it doesn't tear—then trim the excess. Plugging a tire either way can take only a few minutes, and you don't even need a centerstand.

Some riders complain that greedy tire companies only want you to replace a punctured tire instead of plugging it so they can sell more tires. But just as some plugs stay put and do their job for the life of the tire, others have been known to fail, sometimes catastrophically, because of improper insertion, or because the normal flexing motion of the tire's contact patch caused the carcass plies or the metal belts under the tire's tread to scissor the plug in half.

Whether you look at tire repair kits as a permanent fix for a flat tire, or agree with the tire manufacturers that they should only be used for temporary emergency repairs, there's no reason not to take one on every ride. Most are small and easily packed in a tank bag or under the seat, and many include CO2 cartridges (right) so you don't need to carry a pump.

But few kits come with enough cartridges to get a large rear tire up to a safe operating pressure—you have to ride slowly to a gas station to air it up to full pressure. The other problem with CO2 is it's a finite source of inflation—once it's gone, it’s gone. It's not impossible to get two flats in the same day.

A better alternative takes up a bit more packing space, but can do the job over and over. Most auto-parts stores carry foot-operated air pumps, which are far easier to use than bicycle-type pumps. They also carry 12-volt electric air pumps, as do some motorcycle accessory suppliers.

A long time ago I got a 12-volt pump (right) at Wal-Mart for eight dollars. Once I removed it from the enormous plastic case it was housed in, it was about as big as my fist. I spliced an SAE plug onto it to match my electric-vest outlet, put it in a padded fleece bag, and tossed it in the saddlebag. It saved me several times over the years, until I upgraded to a better model.

Note, however, that if in the course of getting a flat a tubeless tire comes off the bead, you're through. Virtually nothing short of a shop air compressor will push enough air fast enough to expand the tire sufficiently to reseat the bead.—Jerry Smith

Here are a few places where you can get tire-repair kits:

1 comment:

  1. Even in this convenience store world, there are still gas stations (not necessarily full service garages either) That have air hoses that will seat a bead.