Tuesday, 21 May 2013

[Tutorial] How to fix a bicycle puncture

If you are riding a bicycle that has tyres with tubes - you are going to need to know how to mend those tubes when something sharp crafts a neatly frustrating hole in them. This is a quick tutorial on how to do just that:

STEP 1: Gather your tools

In this instance we will be fixing the tube rather than just replacing it with another one (that's cheating and not great for the environment), so we have a puncture repair kit, a set of tyre levers and the bike we are working on doesn't have quick release hubs, so we're using a trusty 15mm spanner.

STEP 2: Take the offending wheel off

You're going to need to firstly undo the brake calliper - in this case our bike has V-brakes, so we just unhinged them.

Then using your 15mm spanner, loosen the wheel nuts and remove the wheel.

STEP 3: Take off the tyre

This is where your tyre levers come in handy. Starting at the furthest point from the valve, stick a tyre lever between the rim and the tyre lip and ease it over the rim. Fasten the lever on a spoke using the clever hook provided at the other end of the lever.

Using another lever (you should have three) stick it into the gap your fine work has created and progressively ease the tyre off the rim. It should unzip like taking off a wetsuit.

Now that the tyre is loose from the rim, take out the tube.

STEP 4: Seek the leak

The offending hole in the tube might be clearly visible, but if not you're going to have to go a bit of a MacGyver trick to find it. Pump some air into the tube, fill a basin with water, stick the tube into the water and look for air bubbles.

This is a bicycle right of passage that has been handed down through the generations. Leak found - dry the tube and mark the problem area with some chalk.

STEP 5: Fix the hole

Use a bit of sandpaper to rough up the rubber surrounding the hole. This will help the glue to stick and make you look like you really know what you're doing.

Making sure all the air is now out of the tyre, squeeze some glue over the area and on the tyre patch that you are planning to use.

Allow the glue to dry for a few minutes, till it gets tacky and then slap your patch over the hole.

Don't bother trying to take the cellophane thing off. Give the new union at least 10 minutes to dry and fall in love with each other.

STEP 6: Put the wheel back together

Once the glue has dried - it's time to reassemble your wheel again.

Starting with the valve, pull the tyre that is over the rim way back and jab the valve into the valve opening in the rim. Then lift the tyre back over the tube making sure you don't pinch it and give yourself another puncture.

Slip the tube back inside the open tyre and make sure it's seated nicely.

When that's done, start at the valve point and progressively slip the tyre back inside the rim. It will be easy at first.

When it gets to the last bit to go, it will become impossible to do by hand. At this point, grab your tyre lever again and flip it over. You'll see there's a node on the back that will help with this bit.

Stick the lever inside the last bit of tyre that needs lifting over the rim. Using the lever,carefully ease the last taught bit of tyre over the rim.

STEP 7: Put the bike back together

Right, you should be feeling pretty happy with yourself so far. It's time to pump the tyre up to the recommended pressure as indicated on the tyre.

Then slip the wheel back onto the fork and progressively tighten the nuts. Finally reconnect your brakes and set them up as they were. Spin the wheel to make sure it has good clearance and everything is rolling as it should.

That's pretty much it. Time to go riding.

Check out our previous articles:

How to save money on petrol - Camissa Bicycles
How to take your bike on a train or bus in South Africa - Camissa Bicycles
Cycling to work: 5 tips on how to get there with less sweat - Camissa Bicycles