These are some notes from my recent bike maintenance workshop we conducted in the Cycling group. I've also added some links to illustrative articles and videos. Note that I am not, by any means, an expert. Most of my knowledge comes from:
- Advice picked up while riding with Portsmouth CTC
- Internet searches (especially YouTube)
- Trial and error
The internet is a great resource for finding out how to tackle some bike maintenance. Searching for a specific component often finds videos showing you exactly what to do.
I used a bike stand for the workshop as it makes it easier to get to bits on the bike. Alternatives are to:
- Suspend the bike from a beam, or similar
- Use something to prop the bike with the back wheel off the ground (so you can turn the cranks)
Click any of these headings for more information...
Use a bucket of water - as hot as you can manage. Add some shampoo - I use waxless car shampoo to avoid contaminating my disk brakes. Ordinary detergents contain salt, so not such a good idea.
Use a sponge or similar to wash the bike starting at the top and working down to the bottom.
I use a mix of cloths, old brushes and old toothbrushes to get to hard-to-reach bits.
It helps to remove the wheels and clean them separately (see below).
I have some Isopropyl alcohol for removing grease.
A small flat-bladed screwdriver is good for cleaning jockey wheels.
Make sure to dry your chain when you've finished to avoid rust and stuck links.
You can wax painted parts - I don't.
Cleaning is a good opportunity to spot issues with the bike.
3-in-1 oil is not good for chains as it is too light. Most of what you apply ends up on the floor. WD40 (and similar) is far too light and useless for lubricating chains. Instead, use chain 'lube', one of:
- Dry lube. Small particles of wax suspended in a carrier liquid. After application the liquid evaporates leaving the wax particles to do the lubrication. Best applied the day before you need to ride. Dry lube leaves the chain looking clean and the chain doesn't pick up as much dirt. However, it washes off easily so has to be applied more often and certainly after cycling in heavy rain.
- Wet lube. Viscous oil that sticks well to the chain so does better in wet weather. Attracts dirt, however. After application turn the cranks to work the oil into the chain then use a rag to wipe off as much oil as possible (the useful oil is between the plates of the links and can't be wiped off).
I apply oil to individual bushings (the axles in the chain). Some people run the nozzle along the chain while turning the cranks but that's wasteful in oil.
You can clean the chain on the bike. I use a rag soaked in WD40 and run the chain through it (prevents WD40 getting onto brake surfaces). You can also use chain cleaners that attach to the chain but they are expensive and wasteful in cleaning fluid. Once the cleaning fluid has evaporated, re-lube.
It is easier to deep clean the chain off the bike. Remove the chain (see on). I use WD40 and a rag to remove the worst of the grease. I then immerse the chain in white spirit (pickle jars work well) and swirl the chain around occasionally. Leave as long as practical then remove from the white spirit and allow chain time to dry before refitting and re-lubing.
Chains are said to 'stretch'. In fact the bushings wear down so the chain gets longer. Chain stretch will, over time:
- Damage front and rear cogs
- Cause the chain to slip on the cogs
- Result in a broken chain
Best to replace a chain as soon as stretch becomes significant. That protects the rear cassette which will last three chains, or so. Waiting until the chain starts slipping usually means having to replace the rear cassette at the same time.
Detect chain stretch with:
- Simple chain guage. £2-3 on eBay. Two sides, When the first side fits flat against the chain the chain is close to needing replacement. When the second side fits flat against the chain it needs replacement.
- Use a 12 inch ruler. Chains are spaced one inch apart. When the chain has stretched more than 1/8th inch it needs replacement.
This video shows different methods to detect chain stretch:
Replace brake pads
Two broad types of brake:
- Rim brakes that work by gripping the rim of the wheel
- Disk brakes that work by gripping a rotor attached to the wheel's hub
Pads have grooves in them. Replace before wear removes the grooves.
To replace, remove the wheel (see on). Two main types of rim brakes:
- Racing bikes use calipers that fit closely around the wheel. The pads are held in place by a small screw. The pads slide out of the caliper towards the rear of the bike. They can be stiff. Slide the new pads in and secure with the provided screw. Make sure to re-engage the cam after refitting the wheel so the brakes work OK.
- Other pads come as pad/holder/bolt/nut assemblies together with a range of spacers. Undo the nut and remove the old pad keeping a note of which spacers go where and which way around. Replace with the new pad making sure the spacers are in the same places. Makes sense to replace one pad at a time so you always have a correctly fitted pad to use as a reference.
Test your brakes after refitting. Make sure the pads are not close to touching the tyre surface. If they touch they will wear the tyre quickly resulting in a blow-out.
Pads are secured by a small bolt that passes through the body of the brake and the pads, making sure they stay in the right place. Usually a fiddly retaining clip makes sure the bolt cannot fall out. Remove the retaining clip and bolt.
Pads slide out from the top or bottom. Two pads held in place by a retaining spring (and sometimes magnets). Pads need replacing if they are worn close to the retaining spring.
Do not touch your brakes while working on the pads. You might force the pistons out and cause the hydraulic fluid to leak. Use a pad spacer if you are at all concerned you might operate the brake by mistake.
Replacement pads should come with replacement retaining spring, bolt and retaining clip. Dispose of the old ones. Use a flat-bladed screwdriver to push the pistons back into their housing. Replace the pads in the opposite direction they came out (if you're struggling to get them in you might not have pushed the pistons in far enough). Fit the bolt through the pads and (if possible) the retaining clip.
Once fitted, it is essential to bed the new pads in. You do that by riding the bike and doing some gentle braking, gradually increasing speed and strength of braking. Ideally finish with some downhill braking. It's tedious but necessary to reduce the risk of brake squeal and glazing the surface of the pad (which renders them useless).
Important to inspect tyres regularly. Flints, in particular, can get embedded into tyres and will act like little axes and will eventually get through the tyre and cause a puncture. Also look for evidence of wear such as:
- Bare patches showing underlying material
- Flattening of tyres that have little or no tread
Frequent punturing is a cue to replace the tyre.
Puncture resistant tyres are a good investment in our area. Folding (as opposed to beaded) tyres are a little more expensive but they are easier to get on and off, lighter and easier to pack as standbys when touring.
Tyre sealants that go into the inner tube and plug small punctures can be effective (and essential for tubeless tyres), but messy and no protection against larger punctures. I don't use them.
Check pressures regularly (I check after every three rides, or so). Correct pressure range is shown on the side of the tyre. Important to use a pump with a guage. Low pressure (almost inevitable if you use a pump without a guage) increases the risk of punctures.
The pressure you decide to use is a preference. Using a lower pressure in the range increases comfort, using a higher pressure reduces the work needed to cycle.
Escaping air when you remove your pump is normal and the pump (rather than the tyre) depressurises. Similarly, pressure in the tyre will drop when you attach a pump as the pressure between pump and tyre equalises. Do not expect refitting a pump to a tyre you just inflated to show the same pressure.
This video explains how to inflate tyres fitted with the two common types of valve:
- The schrader valve
- The presta valve
The video helps you find out which you have.
Removing and replacing your wheels
You'll need to remove your bike's wheels to fix a puncture or to clean your bike throughly.
This video is a good explanation of how to remove and replace the back wheel from a bike equipped with 'V' brakes. The chances are your bike will have that kind of brake.
Removing and replacing the front wheel is the same as the back except that you don't have the hassle of disentangling the chain from the gears.
This video is a good explanation of how to remove and replace the wheels from a bike equipped with calliper brakes. If you have a road/race bike, there's a good chance this is your type of brake.
This video is a good explanation of how to remove and replace the front wheel from a bike equipped with disc brakes.
Take a look at one of the above two videos to see how to get your rear wheel disengaged/engaged with your gears.
Bikes with disk brakes sometimes use a through axle (no slot for the wheel to come out of the forks) in which case you will need to remove the skewer completely before you can separate the fork from the wheel.
Fixing a puncture
If you have a puncture on the road, consider safety first. Make sure anyone behind you knows you have to stop. Look for a way to repair the puncture off the road. Perhaps a pavement or a gate entrance. Make sure everyone with you gets off the road too.
Having said that, you need to stop as soon as you can safely. Riding on a flat tyre can wreck the inner tube.
Replacing the inner tube is faster and more reliable than a repair. In any case, a major puncture can't be repaired, so it's a good idea to carry one or two replacement tubes with you. I also carry self-adhesive patches in case of multiple punctures. You'll also need to carry some tools:
- Good tyre levers – the ones you get in cheap kits can be too bendy, making them useless; hard plastic are easier on rims than metal ones
- Pump – preferably one with a pressure gauge
- Self-adhesive patches or a puncture repair kit
- Something with a sharp point to remove whatever caused the puncture from your tyre
- A small biro is useful for marking a puncture
It's a good idea to practice puncture repair at home before you need to do it out on the road.
Once you are safe, to repair a puncture, follow these steps:
- Remove your wheel (se above).
- Make a note of the position of the valve in relation to the tyre (not the wheel). That will help you find the cause of the puncture later on.
- Use tyre levers (see the videos below) to remove the tyre.
- Remove the inner tube. You might have to unscrew the collar from the valve before you can remove it from the rim. You will need to remember which way round the inner tube came out of the tyre, or you can mark which way round it was with a biro.
- Add some air to the inner tube and use your hand or your lips feel around the tyre to find the puncture. Note you might have two punctures at the same place - one at the outside of the tube and one at the inside.
- If possible, mark position of the puncture with a biro - that makes it easier to find it again when it comes to placing the patch.
- Place the valve next to the tyre in the position where it was when you removed it, with the inner tube the same way round as when you removed it.
- Look for what caused the puncture at the place in the tyre corresponding to the puncture location. The sharp is probably embedded in the tyre. If you fail to find it, you risk a second puncture if it's left in the tyre. Feel round the inside of the tyre carcass for a thorn. Look for a flint or piece of glass that might be deeply embedded in the tread of the tyre. Remove the offending article with a sharp point.
- Replace or patch the inner tube. See the videos below for examples of patching an inner tube with self-adhesive patches or patches you have to glue on.
- Add just enough air to the inner tube to give it some shape.
- With one side of the tyre fitted to the wheel, fit the valve into the rim. Make sure the valve is in straight. If appropriate, make sure the tyre is fitted right way around (look for an arrow on the tyre indicating forward rotation). Line the valve up with an obvious point in the tyre (the first character of the maker's name, for example) - so it's easier to find the next puncture. Fit the tube inside the tyre.
- Fit the other side of the tyre over the rim - this can be difficult. You will usually get to the last six inches, or so and find that there's not enough slack to fit the rest of the tyre. Work around the section of the tyre that you have fitted squeezing inwards to force the tyre into the deeper part of the rim (you might need to deflate your inner tube). You should then be able to fit the rest of the tyre. Take care not to pinch the inner tube, especially if you have to use a tyre lever.
- Screw the collar to the valve if it has one.
- Reinflate the inner tube to a suitable pressure, checking as you go that the inner tube is not escaping from the tyre.
- Replace your wheel (see above). Job done!
This video demonstrates how to repair a puncture using a self-adhesive patch (my preferred method - patches are simpler and less fussy than glue-on patches):
This video demonstrates how to repair a puncture using glue-on patches. The visual references to the Mony Python 'Bicycle Repair Man' sketch date the video - or perhaps the presenters - but the method hasn't changed:
Note that neither video properly shows you how to find what caused your puncture.
Removing a chain
To remove a chain from your bike you first have to 'break' it. That means undoing one of the links.
If you have a special link in your chain, you can break it there, sometimes without tools. There's an article discussing different types of link here. Otherwise you will have to use a chain breaking tool which forces one of the pins securing each link out of the chain.
This video shows the different types of link and how to use a chain breaking tool. Note, however, it really isn't necessary to buy special pliers. The article about links describes some alternative methods to undo a difficult link.
Replacing a chain
You will first need to buy a replacement chain. Chains are interchangeable. You don't need to match the manufacturer of your gears, provided you choose:
- The right 'speed' - this refers to the number of gears on your back wheel. Modern bikes are usually 10 or 11 speed.
- The right length. It's unlikely you'll find one exactly the right length. Instead make sure it's longer than you need (by counting links) so you can cut it to the right size.
Costlier is not necessarily better.
I suggest buying a chain that comes with a reusable link. Specifically, I advocate Wippermann chains that come with their connex link which can be removed and reused easily without tools.
Before replacing a chain, make a note (and perhaps take a photo or two) of how the chain winds around your bike's rear wheels. Then:
- Put your gears into the smallest rings front and back (to make it easier to get the chain back on later).
- Break the old chain.
- Run your new chain alongside the old one to determine how many links you need to remove from your new chain. To use a link, both ends will need to be narrow (if you used a chain breaking tool on your old link it will be one link longer) see video below for an illustration. Check you have the right length carefully - if you are unsure how the link on your new chain will work, consider a trial run before the next step.
- Use a chain breaking tool to remove excess links from your new chain.
- Fit the new chain to your bike making sure it follows the same path as the old one. It should go around the smallest cogs at the back. For the time being don't fit it to the front cogs but lay it alongside the smallest ring. If the chain has manufacturer's markings they should be on the outside of the bike.
- Secure the chain with the supplied link.
- Pull the bottom of the rear derailleur towards the font of the bike to loosen the chain and put it onto the smallest front ring.
- Turn the cranks to make sure the chain is running freely.
- Lube the new chain. Some people say that step is unnecessary because the chain comes already lubed; I'm unconvinced, I think it comes with a coating to protect its appearance, but it doesn't look like lube to me. It doesn't do any harm to be sure.
This video shows how to replace a chain:
Replacing a cassette
Arguably an advanced topic because it needs specific tools (a cassette removal tool and a chain whip) but - if you have those tools - the job is really easy and you can save a lot of money:
- Using a hub at replacement prices
- Avoiding labour costs and transport costs
This video provides some hints for detecting chain wear:
This video shows how to replace a cassette:
- It's usual to change chain and cassette at the same time; a worn chain is a cue to consider cassette replacement (some people always replace cassette with every worn chain - seems excessive to me)
- When choosing a new cassette, you must match the 'speed' (i.e. the number of gears of the old cassette)
- You might be able to fit a cassette with a larger number of cogs in its biggest gear. That will give you easier hill-climbing. However, each type of gear has its limits - exceed them and your bike will not change gear correctly. You'll need to check the specs of your specific gears online. You will probably need to replace your chain with a longer one too. Safest is to fit one the same as you are replacing or (if you are unsure about limits, use a bike shop, explaining what you want to do).
- Shimano and SRAM cassettes are interchangeable.
- When you remove your old cassette from the hub do one of the following to ensure you know how to reassemble the new cassette (in case you let it fall apart by mistake):
- Keep the cassette intact (don't let it separate into separate bits) - perhaps use string or a cable tie to keep the bits together in sequence; or
- Remove each element (sprockets and spacers) separately and lay them out in the order you remove them.
- If you are fitting a 10 speed cassette onto a wheel that takes 10 or 11 speed, you will find there is an extra spacer that doesn't come with your new cassette - you'll need to refit that spacer before replacing your cassette.