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Tech Tip – Tube tyre repair

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This entry is part 11 of 17 in the series Adventure Rider Issue #22

Last issue we had a look at tubeless tyre repair.

This issue we’ll tackle the far more involved process of replacing a tube. Note we didn’t say ‘tubed-tyre puncture repair’. Using a patch is a process we constantly see done incorrectly and we’ll tackle that separately.

For now, we’ll assume you’re carrying a spare tube and the tools you need. If you haven’t sorted out the equipment you need to carry for tyre repair, no amount of advice from us or anyone else is likely to help you. Also, we still see a lot of people reciting tyre-repair advice they’ve obviously recalled from enduro riding in years past. There’s nothing wrong with that, but the enduro bikes and tyres of our youth were a far cry from the bikes and tyres used by modern adventure riders.

We’re going to step through a process that’s aimed at getting a new tube in place on a modern bike with a tough tyre, and get bike and rider going again. We’re not trying to show how to get the job the done in the fastest possible time. We’re just showing how to get it done.

Mind the step, and be ready to improvise for your individual situation and as things don’t go to plan…

1 Get the wheel out of the bike. Those with centrestands should find it easy. Those without will have to find a log, rock or do the balancing act on a stick. We actually carry a small, telescopic stainless-steel rod that lets us lift either wheel against the sidestand.

2 Have a careful look and see if you can spot the cause of the puncture. If you can find it, remove it and be thankful you found the prick of a thing. If you can’t find an obvious culprit, continue on.

3 Remove the valve stem and locking nut. Even though the tyre seems flat, you don’t want to have to battle even a small amount of air in there while you’re removing the tube. The job’s likely to be tough enough without that. If you’re running a rim lock, make sure that’s as loose as you can get it.

4 Lay the wheel flat. If possible, put something solid – like a branch or block – under the rim. With your boots on, step firmly on the tyre wall as close to the rim as possible. You need to ‘break the bead’. In other words, you want the bead of the tyre – the part that seals against the rim – to let go of the rim and slide down into the well of the wheel where the spoke-nipple heads are, hopefully covered by tape or a rim liner. This can be a very difficult process on big adventure bikes. You may have to bounce up and down on that tyre wall for a while, or it may well be you need to carry a bead breaker. A good tip is to use the sidestand of a mate’s bike to do the job. We don’t recommend it, but if the bead absolutely refuses to break and the situation is really desperate, you can ride on the flat tyre for short distances at low speed. The heat will expand the tyre and make breaking the bead easier. It’s risky, though. The tyre can very easily be destroyed, and so can the wheel. The tyre can also quickly and unexpectedly work it’s way off the rim and cause a serious decking. Don’t ride on the flat tyre unless the situation is extreme.

5 Once the bead is first broken it should be easy to work around the tyre and ensure the entire bead is down in the tyre well all the way around. It’ll look sort of floppy and loose on that side when you have it right. Some wheels won’t need the bead broken on the opposite side, but some will. You’ll have to learn what needs doing on your bike. The job will be easier if you can leave the opposite bead in place.

6 Here’s where some good technique can help. If you’re worried about the rim being damaged, there’s rim protectors available from www.motoplace.com.au. With the tyre bead down in the wheel well all the way around, slip your tyre levers in close to, and either side of, the valve to catch the inside of the tyre bead. Gently ease the tyre levers back, using the rim as a fulcrum (or lever point). As you apply pressure, make sure the tyre bead on the opposite side stays in the wheel well.

7 If everything is right, the ends of the tyre levers in your hand should move down to the wheel hub. Slip one lever behind a brake disc or sprocket. Make sure it’s secure. Once the first lever is secured and there’s a little of the tyre bead visible over the rim, remove the second lever by swinging it sideways. When it’s free, insert it between the bead the rim and do the same thing: ease it back toward the hub. Don’t try and grab too much tyre. ‘Small bites’ should be your motto for all phases of this operation. If you look carefully there should be a tiny little spot where there’s a gap between the tyre and rim quite close to the first tyre lever. That’s where you should be aiming to insert the second lever.

8 With both levers holding up a section of tyre bead you’ll have to deal with a fair load of force. Make sure you’re well settled and the levers are secure. If you allow the tyre to take over and flick those levers back, you could well end up with a serious injury and a flat tyre will be the least of your problems. You should now be able to remove one lever and end up with the bead still caught up there on the rim and remaining lever. If you have, hooray! If you haven’t, keep reworking the previous steps until you do.

9 Ideally you now have a lever free in your hand and one holding the tyre. Insert the free lever a little further along the bead – ‘small bites’, remember – and lever up a little more of the bead. Keep repeating this around the rim until the entire bead of the tyre is free and above the rim.

10 Make sure the valve stem is poked back through the rim and is free inside the tyre. Now it’s time for some muscle work. Plant your foot on the hub, stick your fingers under the bead of the tyre and pull the tyre wall up. While you’re doing that, and before you drop a plum in your pants, stick your other hand in and grab the tube. Grab it and reef that bastard out of there. Once you get the tube free you can have a little heartie if you need to, but not before.

11 The situation should now be you have a wheel on the deck with the bead still set on one side, and the other side has the bead off the rim and the tyre open. You have the tube dangling from your near lifeless hand and you’re wheezing like a Husaberg with an open airbox. While you’re getting your breath back, pick the wheel up, sit the tread of the tyre on the block or branch you used to break the bead, and lean on it, pushing straight down. The tyre should flatten out across the bock and give you a good view of the inside of the case. Do this all the way around and make sure there’s nothing still sticking through that’ll puncture the new tube. Don’t just rely on your eyesight.Carefully run your bare hand around in there as well. It’s amazing how often a tiny, almost invisible point or spur can be only just protruding through the rubber. Be careful not to cut your fingers when you’re rubbing them around inside the tyre. If you find anything, ferchrissake remove it.

12 Now the next phase. This is important. Don’t try and install a completely flat tube. Put enough air in the tube to give it some shape. The less air the better, but you want the tube to roughly assume and hold its round shape. The idea here is, if the tube is a flappy, flat bit of rubber – as they are when they first come out of the box – it’s much easier to pinch. Just a tiny little bit of shape helps make the surfaces curved and that much harder to grab with the end of a lever. The shape will also help keep the tube from twisting while you’re pushing it into the tyre.

13 Muscle time again. Making sure the valve stem is situated as close to hole on the rim as possible, plant one hoof on the hub again, reach under the bead and grab it, then haul that unforgiving bastard up for all you’re worth. Using the space you’ve created, tuck the new tube inside the tyre. Work your way around the rim, tucking in the tube as you go. The toughest part is the last. Make sure you have the valve-locating nut ready, then place your foot and haul the bead up again. Do whatever you have to do to get the valve stem to pop out through the hole in the rim, then quickly fit the lock nut to stop it slipping back inside. Loud swearing is acceptable during this part of the procedure. If you have a rim lock, it should’ve stayed in place. No problem.

14 With the valve through the rim and the tube in place you’ve almost got this job licked…except that one side of tyre that needs to go back on the rim. This is another part of the process where a lot of people come undone, especially on the big bikes. No matter what happens next, remember that tyre came off there, so it’ll definitely go back on. Technique makes all the difference during this stage. First up, lay the wheel back on the block you used to start with and use your booted foot to press the start of the bead over the rim. Once you have a bit started, drop to your knees and put one knee on the tyre to hold it down in the wheel well.

15 With that start probably half the tyre can be pushed into place using your hands. The more tyre that slips over the rim, the tougher it will be. Keep checking the bead is down in the wheel well on the opposite side to where you’re pushing the tyre. Soon enough you’ll get to the point where you can’t get any more tyre over the rim with your hands. It may be you couldn’t get any more than the initial little bit you pressed with your boot over the rim. It happens, especially on the big bikes. It’s tyre-lever time!

16 This is where tubes are pinched. With your knees holding the tyre down in the wheel well, slip the tyre lever under the highest part of tyre. Make sure you hear the metallic clunk as the lever contacts the rim. Then slide the lever around the rim until it’s as close as possible to where to the tyre is crossing the rim. Small bites, remember. Keeping your head well away from the line of the lever in case it flicks back, lift and push the lever until a little more tyre has crossed the rim and is inside the rim wall. Repeat this process around the rim, moving more and more of the tyre into place, and chasing the set bead with your knees to stop it sneaking up again.

17 Okay. Some lucky people might find it as easy as that, but in the real world, a lot of people get to the point where the last 15cm or so of tyre is stretched so frigging tight it looks as though the tyre itself will split if its forced any further. We’ve seen broken belts and rubber strands in tight tyres. It can happen. But it came off there, so it’ll definitely go back on there. The first thing to check is that the opposite side of the tyre, and as far around the rim as possible, is down in the centre well. Push down with your knees to make sure. You probably won’t have any hands free because by this stage you’ll have two levers in the tyre and they’ll both be threatening to break free and release huge amounts of potential energy – mostly into eyesockets and other tender facial features. If the tyre’s in the well, trying easing one lever by lifting it a little. If the tyre’s caught in place and both levers can be removed, take them out and try a single lever in the remaining bite. Somehow, no matter what it takes, that tyre has to go back on, so don’t go looking for other alternatives. Make it happen.

18 Once the tyre’s back on the job’s all but done. Hook up your pump and sit back while the tyre comes up to pressure. What if the bead doesn’t come up? You can deflate and pump again, you can try a little lube in the trouble spot if you have some, or you can ride away with the tyre not properly in place. In a lot of cases the bead will pop as the tyre warms. Be careful on big-horsepower bikes. A tyre not set properly can be a big safety concern if it starts to creep.What if you pinched it? Go back to step one and do it all again. And this time, try a little more air before you insert the tube.

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