Learn How to Repair a Puncture with Toby and Ken...

Mechanics Group
puncture1
Source: http://www.theguardian.com

Toby and Ken didn't use water - they felt for the escaping air instead. (Photo 7)

They used an air compressor instead of a bike pump to pump air into the tyre.

They used a valve core tool to remove and check the valve (Photo 4)

They didn't need tweezers to remove the sharp object in the tyre - it was a large

splinter of wood which they removed by hand.

They didn't need chalk to mark the puncture - it was a very large slit!

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1. Take the wheel off the bike, and using the tyre lever to lift the tyre over the rim.

Two levers a spoke or two apart make the first lift easier.

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2. Take the tyre off one side of the rim so you can pull the inner tube out.

At this point also check the tyre for glass, thorns or nails.

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3.Remove the inner tube, starting by pushing out the valve.

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4. A valve core tool is useful to push down the valve mechanism to release air

from the tyre, to remove the core from the valve stem and to clean the valve

stem screw threads.

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5. Checking the inner valve core for damage to the rubber seal and for dirt which

may prevent the valve working properly and may cause air to leak out of the tyre.

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6. Blow up the tube. Toby used an air compressor but a bike pump will do.

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7. You can find the puncture by listening or feeling for the hiss of escaping air.

Alternatively you can put the tyre in water and watch for air bubbles which

indicate the hole.

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8. Mark the puncture - use chalk to mark a puncture that is very hard to see.

Our hole was a very large slit!

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9. Use fine sandpaper to clean the area around the hole. Clean an area larger

than the patch you intend to apply.

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10. Smear a thin layer of rubber solution around the hole. Don't add too much.

Wait until all the solvent has evaporated and becomes tacky.

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11. Peel the protective layer off the patch. If the patch has paper on one side

and foil on the other, it’s the foil that comes off. If it has paper and cellophane,

it’s the paper that is removed.

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12. Apply the patch to the layer of glue so the hole is centred under the patch.

Push the patch on to the inner tube with a smooth implement – a tyre lever

works well. This action encourages the patch to bond to the inner tube.

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13.Carefully remount the tube into the tyre. Start by putting in the valve stem.

Be careful not to pinch the inner tube between the tyre and the wheel rim.

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14. Insert and tighten the valve core with the valve tool.

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15. Pump up the tyre until almost full.

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16. Squeeze the tyre to make it sit symmetrically around the wheel rim.

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17. Finish pumping up the tyre. Done!

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When Joe undid the axle bolt all the bearings fell out. He had to re-seat them

by bedding them in grease. The bearings enable the wheel to run smoothly

around the axle.

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The bearings re-seated, the axle in place and the nut assembly tightened.