Bike Maintenance

Bike Maintenance

1. CLEANING Accumulated dust and mud can be very damaging to your bike. Regular cleaning helps to prevent corrosion and excessive wear. While the easiest way to clean a bike is with a high pressure cleaner, this method is quick but has SERIOUS DRAWBACKS. The high-pressure jet is likely to enter bearings and dilute the lubricants leading to accelerated corrosion and wear. High-pressure cleaners can also lift paintwork and damage decals (stickers). The BEST way to wash your bike is to use low pressure water from your garden hose (without spray nozzle) or to use a bucket and sponge. Also, when washing your bike by hand you are more likely to notice any problems. After washing you should thoroughly dry it. This helps to prevent staining of paintwork by hard water and corrosion. You can then protect the bike by applying either a hard wax or silicone spray. Waxing or coating with silicone makes cleaning your bike easier next time. WARNING: Do not wax or silicone the braking surfaces of the rims. Remember to check and lubricate your chain after cleaning.

2. CHAIN MAINTENANCE Correct maintenance and lubrication of your bike chain will help to prevent wear and corrosion. Clean dirt and oil from the chain with a rag. There is generally no need to use degreasers or solvents. Having cleaned the chain, apply a lubricant as you rotate the crank. This will help to evenly distribute the lubricant. It is most important that the lubricant is evenly spread. You don't need lots of lubricant just an even coating. Silicone spray is quite good for chains, as the silicone does not make the chain sticky and therefore does not collect dust like other lubricants. Next check chain tension by flexing the chain up and down. If your chain is too tight it will be under severe strain and is likely to break. If it is too loose, it could slip off the sprockets. The chain should move up and down no more than 1cm at its loosest point. To tighten or loosen the chain you move the rear wheel backward or forward (respectively) in the drop-outs. Because chains don't wear evenly around their length, make sure you adjust it at its tightest point. Loosen the axle nuts and pull the wheel straight back (or forward) and then nip up the axle nuts. Now turn the cranks slowly while checking the chain tension all the way round. This is important because on most bikes you will find that the chain tension changes as you rotate it around the front cog. Note that some bikes have integrated chain adjusters fitted to the rear wheel’s axle, however the procedure is basically the same. With chain adjusters fitted you do not have to pull the wheel back manually, you simply use the adjuster on each drop-out to move the wheel back or forwards. While adjusting your chain also check the condition of the front sprocket (chain ring) and the rear sprocket (freewheel) for worn or damaged teeth. You will need to ensure the wheel is running true in the frame by spinning it and looking along the centre of the tyre and sighting along the bottom tube. You can also check this by measuring the distance between the sidewall of the tire and the chain stay tube and then comparing it with the measurement on the other side of the tyre. Now you need to check if the brakes have been effected by the adjustment. Make sure that the brake pads are correctly aligned with the braking surface of the rim and not fouling the tyre. The brakes can be way out of alignment when you put a new chain on.

3. RIM, AXLE & TYRE MAINTENANCE Both rims should be checked regularly for deformation or cracking. If you are jumping a cracked/deformed rim could be disastrous when landing. For your own safety cracked rims should be replaced immediately. Deformed rims may be repairable and this is best left to the experts. Spokes should also be checked regularly for damage or loose spokes. Incorrectly tensioned spokes cause rim deformation. It is best to get your bike repairer to handle spoke repairs or tensioning. You can detect loose spokes by spinning the wheel gently and letting a light metallic object tap against each spoke. A loose spoke will make a dull sound compared to a tight spoke. There are several varieties of hubs/axles but there are a few checks you can do on any of them; - Firstly spin each wheel and make sure it runs freely. If there is any grating or grinding noise from the hub then it is likely to be a damaged or dry bearing. - Next try to move the wheel from side to side to check for slop in the bearing. - Check that the axle nuts are firmly tightened. Inspect your tyres regularly for cuts, splits and wear. Tyre pressure is a personal preference but most people start out by inflating their tyres to around the maximum recommended working pressure (to minimise rolling resistance) and then work back from there if improved traction is required. Changing a flat tyre is quite simple. After removing the wheel from the bike, open the valve to release any residual air pressure. Using a pair of non metal bicycle tyre levers roll one edge of the tyre off the rim and you will then be able to remove the tube. Roll the edge of the tyre back in the opposite direction so that you can see the hole in the rim for the valve stem. Insert the valve stem of the new tube in the hole and then fit the tube inside the tyre. Now you can begin to roll the edge of the tyre back onto the rim starting opposite the valve and being very careful not to pinch the tube between the edge of the tyre and the rim. Now you can re-inflate the tyre whilst making sure the edges of the tyre seat correctly around the rim. Finally, re-fit the wheel to the bike.

4. BRAKES Inspect your braking system carefully. BMX rules state that your brakes must be working correctly and, even though you may not have to use them all that often, safety dictates that they must be working. Firstly check that the brake pads are correctly contacting with the rim, especially if you have adjusted or changed your chain. Inspect the nipple at the brake lever end of the cable for wear and that the cable is securely connected to the brake lever. Also make sure the end of the cable that is attached to the brake calliper does not have bits of wire poking out dangerously. You can lubricate your brake cable by squirting lubricant between the cable and it’s outer sheath. Make sure that the outer sheath of the brake cable is not kinked or split as this can hinder the cable moving inside the sheath and prevent the cable from operating the brakes. Check that the brake lever is firmly fixed to the handlebars. Most brake levers can be adjusted for reach so make sure this is comfortable for you. Your brake lever position on the handlebar should also be adjusted so that it is easy to operate whilst standing up on the bike. Now check and adjust the brakes so they work correctly and comfortably.

5. PEDALS & CRANKS Make sure that the pedals are securely tightened to the cranks and that there is not excess bearing play. Check that pedal cages or screw in pins are tight. Ensure that the cranks are securely attached to the shaft and that there is not excessive bearing play in the bottom bracket. Tensioning of crank bearings is best carried out by a service technician at the bike shop. While inspecting the cranks you should also check the chain ring spider and the tension of the screws securing the chain ring to the spider.

6. STEERING HEADSET Inspect for excess play in the bearings. Turn the handlebars from side to side and listen for any grinding noises from the bearings, particularly the lower bearing which collects a lot of dust and grit thrown up by the front wheel. While turning the bars, feel for any stiffness or binding. New headset bearings are very cheap so replace them if there is any sign of wear.

7. HANDLEBARS Inspect the cross bar for cracks and check the tension of the bolts that secure the handlebars to the head stem. Even bolt tension on all bolts is critical, as uneven bolt tension can help to promote stress cracking, especially in aluminium head stem parts.

8. GRIPS Ensure that they are tight on the handlebars. A good squirt of hair spray into the grip before sliding it onto the handlebar will glue it in place nicely, just leave it overnight to set. Handlebar ends must be plugged or fully covered. Unplugged bar ends are extremely dangerous in an accident. Ensure that they are not split or cracked.

9. SEAT Check the condition of your seat and the securing of the seat and seat post clamp. Ignore this one and you risk serious and embarrassing injury!