Road bike maintenance - wheels
Time: About an hour per wheel
- Cone spanners
- Small adjustable spanner
- Straight edge
- Quick release skewers
Wheels can be secured either by nuts ('track nuts') on the end of the wheel spindle or, on better quality machines, more usually by 'quick release skewers' (sometimes abbreviated to 'QR'). Track nuts can be more secure (to prevent theft) but quick release wheels are favoured by most club riders as they do away with the need to use a spanner to tighten or remove a wheel - useful not only in case of a puncture but also less hassle just to get your bike in your car or on your roof rack! However, it is essential for your safety that you understand how they work.
It is essential for your safety that you understand how they work.
Check that the quick release lever is in the open position (at a 90° angle to the wheel). Put the wheel back into the dropouts with the quick release lever on the left side (non chain side) of the bicycle.
Close the quick release lever so that it is parallel to the bicycle; you should feel some resistance as you close the lever. If you do not feel much resistance, turn the adjusting nut on the other end of the quick release skewer a quarter of a turn clockwise and try closing the lever once again. Repeat this step until you feel resistance in closing the lever.
For a front wheel, do not point the lever forwards in front of the forks when closed - it could catch on something and spring open. Have it pointing up, down or to the rear of the bike. For the rear wheel point the lever forwards underneath and parallel to the chain stay if a rear, or down towards the ground. Make sure that you can get your fingers behind the lever to open it (not close up to a stay or the fork blade). Finally, lift your wheel off the ground and check that it is secure by giving the top of the tyre a hard tap downwards.
Quick release skewers
Before starting check for obvious external damage to the hubs such as cracks radiating from the spoke holes. Any cracks will render the hub unsuitable for use and it's not worth spending time maintaining it!
Feel how smoothly the wheel spindle turns in the hub. If it feels consistently rough it is almost certain that new cones will be required. If it just feels slightly gritty it probably means that there is dirt in the hub and it simply needs regreasing and new ball bearings fitted. Both of these jobs are probably best left to a good bike shop.
If the bearings have a little play or just feel a little tight then adjustment should be all that's needed (see 1 below). Once the bearings are correctly adjusted it is time to check that the wheels are true side to side and as round as possible (Wheel truing, below).
Adjusting the hub bearings
Rim wear and cracking
- You will need two spanners - one on each side of the hub. Sometimes it is easier to use one cone spanner and one regular spanner.
- Unscrew the quick release skewer from the hub (or remove the track nuts).
- Holding one spanner on the opposite locknut (or opposite cone) undo the locknut on the outside of the hub. The cone (a shaped nut on which the bearings run) sits behind the locknut and has two 'flats' to accept a thin, hardened spanner (usually 13-16mm)
- You can then adjust the position of the cone against the bearings until the axle can turn easily without any resistance.
- Hold the cone you have adjusted in position, tighten down the locknut.
- The axle should rotate freely within the hub with just a very faint trace of play.
- If it is tight or there is excessive play, readjust the cone and locknut.
- Refit the quick release skewer (narrow end of the conical springs pointing inboard) and fit the wheel back on the bike.
- Adjust the quick release and check the wheel for play. The faint trace of play in the bearings should have disappeared.
- If not, remove the wheel and readjust the cone until there's just no play present when the wheel is refitted.
- Rims do, literally, just wear out. This is especially so with modern lightweight wheels (which have thinner rim walls) and more powerful brakes.
- To avoid a serious accident, do check your rims for wear and damage on a regular basis. Offer a straight edge vertically up to the rim. The rim wall should look almost perfectly flat. (The only exceptions are some Campagnolo and FIR rims which have a slightly concave braking surfaces when new).
- To avoid scoring of the rim keep your brake blocks free of grit. See also Brake maintenance
- Carefully check around the spoke holes for any signs of cracking - any cracks also means a written off rim.
- If in doubt, ask a bike shop to check it for you and be prepared to buy a new rim straight away.
Basic wheel truing
- Rim damage is normally caused by riding over a kerb, through a pothole or otherwise hitting a sharpish edge.
- Check for dents by running your finger tips around the top quarter of the rim's braking surface - any dent will be felt as a slight bulge or you may notice a flat spot on the rim.
- The likelihood of rim dents can be greatly lessened by ensuring that your tyres are pumped up to their recommended pressures.
- You can reduce a great deal of damage, especially in town and city, riding by using larger cross section tyres -particularly if your wheels carry a heavy load.
About an hour
- Wheel Truing Stand/frame
- Spoke key
- Metal ruler
- Dishing tool
- Square file
Wheel truing can be very relaxing as long as you don't hurry it. Take your time and be patient. It will eventually come right- as long as you don't make any too large adjustments at a time.
A good quality spoke key is essential. It should be a snug fit around the spoke nipple. Those that fit all four sides of the nipple are more secure and les likely to damage the spoke nipples but they can be slower to use than the open ended type.
Be careful to protect your eyes whilst truing a wheel - if a spoke breaks or the nipple twists off, the end can fly out with considerable force. Either wear protective goggles or leave the rim tape in place.
If the rim is not of very good quality or has been damaged by an impact or fall it may not be possible to true it to within ±1mm roundness and sideways truth which is the ideal to aim for in a good quality wheel.
If there are broken spokes it is usually best to take your wheel to a bike shop for attention.
Check the wheels in a truing stand if you have one, or if not you can use a guide held against the forks or stays (even just watching the line of the rim against your brake blocks can suffice). If your wheel deviates more than about 2mm from side to side or up and down it definitely needs to be trued.
The roundness and sideways 'truth' of a wheel is determined by the spoke tension. Ideally, the tension should be virtually identical in every spoke and this will produce a perfectly round and true wheel. It is actually possible to build a wheel that looks pretty much round and true with wildly differing spoke tensions - however the life of a wheel built like this is short. So whilst truing a wheel it is important to be aware of how tight each spoke is.
The spokes entering the rim from the left side of the hub if tightened will pull the rim leftwards and similarly the spokes from the right side of the hub will pull the rim rightwards.
Conversely, if the spokes are loosened the rim will move in the opposite direction.
Tightening all the spokes in one area of the rim will pull that part of the rim inwards and loosening the spokes in one area of the rim will allow that part of the rim to move outwards.
Correcting lateral truth
- Set the jig's indicators (or your brake blocks) about 1cm from the sides of the rim.
- Spin the wheel slowly, noting the 'high' points where the indicators touch the rim or where the rim gets closer to them.
- Tighten the spokes on the opposite side of the rim to the high spot about half a turn at the most extreme point and going down to a 1/8 of a turn at the edges of the high spot.
- If the high spot is very prominent, slacken the spoke or spokes on the opposite side of the rim a similar amount.
- Work around the wheel making small adjustments to spoke tension - the adjustments will get smaller as you get nearer to the wheel becoming perfect.
Checking and correcting wheel dish
- Set the jig's indicators to check concentricity (roundness) and watch the up and down movement of the rim.
- Work on the high spots first, tightening spokes to pull the rim inwards - as with lateral truth tighten the spokes at the centre of the high spot most but not more than a complete turn initially.
- Now turn your attention to the low spots, loosening spokes in the same manner - loosening most at centre of the low spot. Near the rim joint it may not be possible to get the rim round to better than 2mm or so but provided the rim is not too old or damaged it should be possible to get the wheel within 1mm of being perfectly round.
Removing spoke wind up and final truing
- All front wheels are built with the rims centred between the hub flanges.
- Rear wheels with are built with the rim centred between the hub locknuts, not the flanges.
- The spokes on the side with the cassette will be tightened more than those on the opposite side of the wheel in order to pull the rim over.
- The hub is not symmetrical in these cases - there is extra space between the locknut and hub flange to allow for the cassette but the rim must still be centred between the locknuts (although it will not be centred between the spoke flanges). This is known as a dished wheel.
- To check that the rim is centred wheel builders use a 'dishing tool' but you can simply turn the wheel around and see if it sits centrally or off to one side.
- Place the dishing tool over the rim and adjust it so that its pointer or sleeve touches the hub lock nut.
- Without adjusting the pointer, remove the tool and place it on the other side of the wheel in the same manner.
- If there is a gap between the pointer and locknut, this indicates that the opposite (original) side spokes need tightening.
- If however the pointer sits inboard of the lock nut, this indicates that this side spokes need tightening.
- Tighten by one complete turn all these spokes and recheck the dish.
- Repeat until the dish is correct.
- If the spokes on one side become very tight loosen all the spokes on the opposite side by one half or whole turn.
- During the initial wheel truing and dishing the spoke nipples will sometimes wind and twist the spokes rather than turning on their threads.
- Rest the hub on the floor so that you are looking side on to the wheel.
- Push down firmly on either side of the rim.
- Revolve the wheel about 1/8 of a turn and repeat until you have gone all the way round the rim.
- You will hear a few tinkling sounds as the spokes unwind.
- Don't press too hard, as it is possible to collapse the wheel! (A safer but not quite as effective method is to stand the wheel upright and press down vertically down on it).
- Turn the wheel over and repeat on the other side of the rim.
- Whilst removing the spoke windup the wheel will have lost a little of its truth.
- Repeat the previous stages until the wheel is once again accurate to about 1mm but this time making much smaller adjustments to spoke tension. You should not need to turn a spoke nipple more than a 1/4 turn - mostly it should be about 1/8 of a turn. Repeat the removing spoke windup procedure but slightly less aggressively than the first time and then make the very final odd small tweak to ensure your wheel is as perfect as you can get it.
- With plain channel rims check that no spokes protrude through the nipple - any that do should be filed smooth. With box section rims spokes that protrude a little will not present any problems with a stiff rim tape. If spokes protrude above the upper bed of the rim, shorter ones must be substituted.