Training

Bike tyre puncture quick fixes

Make it home alone

You’ve been planning your ride for weeks, you’re well prepared, but miles from base something goes wrong with your bike and you’re left standing at the side of the road. It’s a scenario all cyclists face, but whether your bike has a puncture, a snapped chain, or a buckled wheel, being able to perform essential fixes will allow you to limp home, if not finish your ride as planned. Armed with just a few simple tools we show you how to carry out six typical roadside repairs, once you’ve moved away from traffic and are in a safe place...

1. Puncture predicament

Mending punctures is the most frequent roadside repair you’ll face. Most riders will look to save time by carrying at least one spare inner tube, but disaster can strike more than once on a ride, so it’s wise to carry a full puncture repair kit. If you’re just fitting a new tube, you only need to worry about getting the old one out and the new one in, while checking for the likely cause of the puncture, but after that you’ll need our full instructions.

Remove the wheel and check the tyre for a likely cause of the puncture. If you spot anything, such as a thorn, take note of where it is on the tyre.

Using tyre levers, prise one side of the tyre over the wheel rim and remove the inner tube. If you spotted a probable cause, check that area of the tube first. If you can’t spot a hole, partially inflate the tube and listen for escaping air or hold the tube against your cheek to feel for it. When you find the hole, check that it doesn’t go through both sides of the tube.

Deflate the tube and us the sandpaper from your puncture repair kit to roughen the area around the hole. Smear some glue on the prepared surface, allow it to become tacky, then apply the patch and hold it in place. Once dry, grate chalk dust over the patch to stop any surplus glue from sticking to the inside of your tyre. Before replacing the inner tube, remove whatever caused the puncture. Return the inner tube to the tyre, and refit the tyre and wheel.

2. Ripped tyre

A ripped tyre is a double blow, as it often means that the inner tube is also punctured, leaving you with two repairs to deal with. Unlike repairing a punctured inner tube, which is a permanent fix, mending your tyre is only a temporary solution to help you get home. You will need to replace the tyre.

To repair the tyre, remove the wheel, then take off the tyre and inner tube.

If the inner tube is punctured, set it aside for now, as there’s no point repairing it until you know that the tyre can be patched.

Check inside the tyre to see the extent of the damage and remove any debris from whatever caused the rip, most commonly broken glass. Also, check that the are no sharp cords exposed from the tyre casing that could re-puncture the inner tube.

Unless you carry a proprietary tyre patch you’ll need to find a piece of flexible and durable material to line the inside of the rip to prevent the inner tube herniating through. A piece of thin plastic works best (like the wrapper from an energy gel), as it won’t lose strength if it gets wet.

Position the tyre so that the damage is nearest the ground and place the patch over the hole. Make sure the patch overlaps the edges of the hole and extends to both beads.

With the patch in place, refit the tyre to the wheel and insert the inner tube, having repaired any punctures first. Slowly inflate the inner tube to about 50 per cent of its normal pressure, and watch to ensure that the patch stays in place. Assuming the patch holds, refit the wheel and ride home carefully.

3. Spent spokes

A broken spoke won’t stop you riding your bike but its worth fixing as it will affect the trueness of your wheel, and slap around, scratching your frame and even your legs.

If your multi-tool includes cutters, cut off the snapped spoke close to the rim. If not, twist it around a neighbouring spoke to hold it in place.

To check the trueness of your wheel, use a small stick as a guide. Hold it close to the rim of the affected wheel. If your bike has rim brakes, rest it against the callipers. Spin the wheel and watch to see how it deviates from true relative to the guide. If the wobble is only minor, and you don’t have far to go, ride home carefully and repair it there.

If there is a pronounced deviation that could reduce the integrity of your wheel or impair the performance of your brakes, try truing the wheel.

Loosen the spokes either side of the broken one in small increments using the spoke key on your multi tool. Turn each one fractionally, then check the wheel’s trueness by holding the guide against the rim and spinning it. Keep adjusting the two spokes and checking the rim until the wheel runs as true as possible. Replace or repair the wheel before your next ride.

4. Broken chain

Bike chains don’t often brake but it’s worth carrying a quick link or a multi tool that includes a chain tool. Unthread the broken chain from your bike. If you have a quick link, just remove the damaged chain link. Using the chain tool to push the pin through the outer and inner plates. Rest the front of the chain on the bottom bracket shell and route the rear end through the front derailleur, across the cassette and through the rear derailleur. Draw the two ends of the chain together below the chainstay and join them using the quick link. Replace the chain onto the chainring.

If you don’t have a quick link you need to remove two links from the chain, including the broken one. Use the chain tool to push the pin through the broken link, only as far as the furthest outer plate as you need to reinsert it. Route the chain across the bike as previously described, then join the ends using the chain tool to push the pin back through the plates. The new join is likely to be stiff, so flex it with your hands until it moves freely. Return the chain ring, and avoid shifting to the larger cogs to prevent putting too much tension on the newly shortened chain.

5. Damaged derailleurs

The rear derailleur can become bent or damaged without you realising, for example if your bike has fallen over. If you are riding off road, mud and grit can clog it so the chain won’t be able to run smoothly. In the event of a broken derailleur, converting the bike into a single speed to get you home is easy. Firstly, you need to bypass the broken derailleur – us an Allen key to loosen the gear cable from the rear derailleur, and tie it up so that it’s out of the way. You can use it later when fitting a new derailleur.

With an Allen key remove the rear derailleur from the hanger. Shift the derailleur into the smaller ring and move the chain onto the smaller front chainring. Break the chain and unthread it from the rear derailleur.

Select a suitable gear on the cassette that will allow the chain to run in a fairly straight line and ensure that your chain doesn’t twist or drop. Shorten the chain to remove the slack caused by removing the rear derailleur – the aim being to ensure that the chain has sufficient tension that it won’t slap the chainstay or drop off the chainring. Rejoin the shortened chainring.

6. Damaged wheelrim

Hitting a pothole or striking a kerb is all it takes to damage a rim, knocking it out of true. There’s nothing you can do if the wheel is clearly buckled, but there is hope if it still turns within the fork or stays.

Spin the wheel to locate the affected area of the rim. Remove the wheel and use a spoke key to loosen the spokes where the rim is damaged, allowing it to flex.

To straighten the rim, sandwich the buckled area between two sturdy uprights, such as the railings or branches of a tree. Repeatedly pull or push against the rim sideways in the opposite direction to the buckle until the rim straightens. With the spoke key, tighten the spokes to take up any obvious slack. Position the wheel back in the frame, spin it to check for improvement, and repeat the process as required. You can make fine adjustments to the rim by truing the wheel using the technique described to repair a broken spoke.

If you can’t find somewhere to sandwich the wheel, hold the damaged area against a single upright, and push or pull the rim against it in the opposite direction to the distortion. Do this a number of times for a few seconds each, checking the wheel every time. Once you see an improvement, tighten the spokes and true the wheel.