Since the Eco-Fair I have added some links (at the bottom of this article) to some good sites for more information on bike repairs and maintenance, I'll try to add a few more over the few days.
Thanks to all of you who came to the Bike Maintenance workshop today -Neil, Bryan and Dell
To help avoid punctures check the tyres regularly for anything in the tyre, you can often find and remove slivers of glass etc before they puncture the tyre or damage it. To reduce the risk of punctures many tyres are now available with a strip behind the tread to prevent most punctures, It is worth remembering to check these from time to time as slivers of glass, tacks etc can be in the tyre and may work there way in and make a puncture eventually.
Before removing the rear wheel to mend the puncture the chain should be on the smallest cog at the back and middle or large front chainwheel. This makes putting the wheel back on much easier. Then to release the wheel the quick-release (qr) must always be tightened by moving it through 180 degrees, not by simply rotating it until it feels tight. The qr lever should preferably be on the pavement side, and always face to the rear when tightened so can’t be accidentally knocked into the “loose” position. Some brake levers have a button to allow the brakes to open more to get the wheel in and out.
Check quickly for thorns, nails etc they may be visible, remove and note position so as to check inside tyre for any remaining thorn etc. Before removing the tyre, push the bead (edge) of the tyre away from the wheel rim, and push the valve into the rim a bit, to create space in the rim well to allow room to more easily remove the tyre.
Remove the tube, marking the valve position on the tyre. Inflate the tube and locate the puncture, either by hearing it, feeling the escaping air on your fingers The cause of the puncture in the tyre should be the same distance from the mark on the tyre as the puncture in the tube from the tube valve, so locate and remove the cause. There may be second thorns etc., so carefully run fingers round inside of tube, both ways, as thorns could be angled and so not felt in one direction.
Never mend punctures on the roadside, wait until you get home. Therefore always carry at least 1 or, better, 2 spare inner tubes.
Modern tyres often have a “direction of rotation” arrow on them, as tyre treads are often more specific these days (note – if your bike is upside down, the arrow should be rotating anti-clockwise to give “direction of rotation”)
On a mountain bike (mtb) the lightly- inflated inner tube can be inserted inside the tyre, and the whole lot simply put back onto the wheel. Amazingly easy.
The recommended air pressure will be marked on the tyre wall. Always run at this pressure – many people run with too little air in the tubes, this makes for more punctures, and harder work as more rolling resistance. A track pump, from £20, is wonderful to quickly inflate your tyres to high pressures, buy one.
To repair a puncture (at home, I sometimes put the punctured tubes in a box and then have a session doing a few together) find the hole, pump up the tube, sometimes you can hear the air escaping, or feel it on your top lip. Failing that a bowl of water will quickly show the puncture position, if it is a fault at the valve, or valve seat scrap the tube. There are 101 uses for a dead inner tube, but that could be a hole new session/article. Dry the tube and mark the position of the hole, rub down the area around the hole, apply glue thinly around the hole, wait for the glue to feel dry, remove the foil from the patch and press firmly over the area of the hole, make sure the edges are stuck. stretch the patch to tear the paper backing across the middle of the patch, carefully remove the paper backing from the middle tear - so as not to lift the edges of the patch. Now apply powder to the patch and around, stops any excess glue sticking to the inside of the tyre, lightly inflate and set aside to see if the pressure is held, and then roll up as a spare.
Try to keep the chain on your bike as clean as possible.
People tend to neglect their chain which is a big mistake - it's a job well worth spending 15 minutes on.
If you don't clean and lubricate it properly, it will make pedalling much harder and mess up the other components on your bike. To avoid the chain doing this or becoming squeaky or too slack make sure you clean and lubricate it at least every month - more often when the weather is wet. To check if the chain has stretched and become slack, try lifting one rivet at the front of the chain ring. If you can pull it away even slightly then the chain is worn. Chains stretch with use, a tool that measures this is available.
If your chain is caked in mud then hose it clean first. If it's only covered in oily dirt then give it a quick wipe with a rag or an old T-shirt. Then use the edge of a cloth to scrape out the muck between the sprockets and to wipe the teeth of the chain rings. Spray the chain rollers with solvent and scrub with an old toothbrush. After you've thoroughly cleaned the chain dry with a rag. Then complete the job with chain lube (lubrication). Run the chain through at high speed, or a link at a time allow to soak in (overnight) and then wipe off the excess lube.
Should always be oiled at the ride end or when the chain has been cleaned and dried after the ride. This gives time for the oil to really get to parts, whereas oiling it just before you set off will mean that most of it is effectively just thrown off. Modern oils really do lubricate places that 3 in 1 type oils won’t reach.
Changing chains regularly, as this should (hopefully) ensure the expensive cassette and chainset will last much longer, I try to use 2 or 3 chains and change them when I do the thorough clean (as if the chain is not replaced for a long time, the whole drive train will have to be replaced.)
One of the causes of the chain slipping is that a link is not freely bending as it goes over the gears. Finding this link may be difficult if simply moving the chain round slowly in the normal direction – moving the chain backward however should always find the faulty link.
There are 2 types of inner cable - brake and gear. So you will need to carry both types with you if on a tour. Brake cables have 2 types of fixing, pear and barrel, the gear cable a single smaller one. A quick visual check will show what types you have on your brakes. Brake cables come in a single size, and need to be cut down, depending on the length required, i.e. front or back brake (note, if need be, i.e. on the road with no good cutters, any excess length can simply be coiled up until you get to a bike shop with good cutters. There are also different outer sleeves for brake and gear cables, so make sure you have the right one (there are sound engineering reasons for this difference, but you don’t need to know why.)
An alternative approach to this technical stuff is to renew the cables long before they break or you set off on tour! Spares still advisable though.
Brakes have adjusters, for both distance from the tyre rim and angle towards it (the “toe-in”). On V brakes the adjusters for rim distance are nuts at the brake base. Squeaky brakes are often a sign that the brakes are poorly angled to the rim, and there are 2 washers on the actual brake block to adjust this – the front of the brake block should touch the rim (toe-in) before the rear part. Check the brake block for signs of wear, some block have wear indicator lines to show when they need replacing. Check also when the wheel is out for grit, etc in the pads, a pin can get it out, it just wears the rims down if left.
If the chain is not fitting exactly over the gear and hence being noisy etc, there are usually micro- adjusters to alter the gear cable tightness – one where the cable enters the rear dérailleur, and one either on the brake/gear lever or on the downtube. If the chain is quiet at the start of a ride and then becomes noisy, only adjust the micro- adjusters, a slight turn should improve the gear change, if not turn the adjuster the other way, only a slight turn is needed. The H (High) and L (Low) screws on both the dérailleur and chainset. should not need touching
Mountain bikes need a good scrub down after a muddy ride but any bike looks better after a wash and polish. Do it after a mucky cross-country ride or every month or two in dry weather. It should take you an hour to do the job properly including cleaning and lubricating the chain. Ten minutes if you're in a real hurry.
Cleaning kit: Washing-up liquid, Water Dispersing Lube, Spray Degreaser, Brush-on Degreaser. Bottle brush, washing-up brush, old toothbrush, sponge, old sponge for the chain, chamois leather. Squirt plenty of washing-up liquid into half a bucket of hot water. Mop over the whole bike and let it soak in. Wash the whole bike again. This second wash will shift most of the dirt, but there may be areas where the dirt is more stubborn.
Use a toothbrush or a paint brush for all the nooks and crannies. Where the foam seems to form droplets and roll off, use a degreaser (a solvent that dissolves grease) to break down the film of oil. Do the same to the chain. Work it with the brush to ensure the dirt and oil mixes with the degreaser. Get a bucket of clean warm water and rinse the foam away. Use a sponge to cascade water over the frame, the mudguards and the chain. Dry the frame, mudguards, saddle and handlebars with a clean rag or a chamois. Then squirt spray lube over the chain, gears, hubs and headset to drive out any water that has got in. Then lubricate the chain.
Dos: Do not wash your bike in the sun. The water will dry off too quickly leaving you with dull paint and a lot of streaks. Keep the bike upright, whether it's standing on its own wheels or in a bike stand.
Don'ts: Never use a pressure washer. Bike bearings are not designed to keep out water under pressure. For the same reason, keep the pressure down if you use a hose.
Tools on the bike -
The following tools are the minimum you should carry whilst riding and should ideally be left on your cycle at all times, in order to ensure that you have everything necessary to continue your ride or simply get home again:
Pump; Inner tubes x 2; Tyre levers 2 or 3; Allen key set; Chain breaker; a little small change; MOBILE PHONE !
Links to web sites with bike repair information -
Park Tool - lots of good information
Sheldon Brown-load of information - a unique resource
CTC Technical information CTC have a Technical FAQ section that covers lots of topics
"Park tools Big Blue Book of bike repair" is an excellent book around £18.00 available from bike shops, or Google to find online.
This was based on article originally by Mark Bazeley in the Summer 2006 KDCS Newsletter