Getting your wheels running straight and true might seem like a dark art but if you take it slowly and methodically, it’s not too hard.
1. Remove tyre and tube
To check if a wheel is true, start by turning your bike upside down or clamping it in a workstand. Remove the wheel you’re going to work on – in this case, the rear – from the bike. Remove the tyre and tube, then refit the wheel in the frame. Check the spokes are all tensioned by giving each pair a light squeeze between your thumb and forefinger.
2. Check spoke tension
If there are any loose spokes or if they all seem a bit baggy, this is likely to be the root of your problem. If there are single loose spokes, use your spoke key to tighten them half a turn at a time – by turning them clockwise, viewed stood facing the rim bed. Feel for tension every half-turn. When the tension starts to feel similar to the other spokes, stop tightening.
3. Tension spokes
If the spokes all feel a bit baggy, start at the valve and work around the wheel, tightening each one a quarter turn. When you get to the valve again, use your thumb and forefinger to make sure they’re all evenly tensioned. If you don’t know how tight the spokes should be, compare them to the other wheel (in this case, the front). If they still feel baggy, repeat this step.
4. Check rim for dents
Now your spokes are all tensioned, have a look around the rim for any dents, running your finger around the rim wall to be sure. If you find any, highlight them with a permanent marker so you know where they are. Take your time, because these dents will throw you off in the next few steps if you don’t allow for them all.
5. Check for buckles
Spin the wheel again. This time you’re looking for any sideways buckles in the rim. You can make a gauge that’ll help you check for this, using a rubber band and a ballpoint pen or lolly stick. Hold the pen/stick at 90 degrees to the chainstay or seatstay and use the rubber band to secure it in place, making sure it’s wrapped tightly around the stay.
6. Check roundness
Position yourself at the back of the bike, facing the rim bed, and spin the wheel again. Slowly push the pen/stick closer to the wheel until it’s lightly touching the rim. This will show you where the rim is off center. Slow the spin down and use your permanent marker to mark the last spoke before the buckle and the first spoke after the buckle.
7. Address buckle 1
Add a quarter turn of tension to the spokes attached to the opposite side of the hub to the buckle – so, if the wheel is buckled to the right, you’ll need to tighten the spokes that run from the affected area of rim to the left-hand side of the hub. Now run the rim past the pen/stick again.
8. Address buckle 2
If there’s still a buckle in the same place, loosen the spokes attached to the same side of the hub as the buckle by a quarter turn. This will release the tension on that side of the rim and help the newly tensioned opposite-side spokes pull it back into line. Repeat steps 7 and 8 until the buckle you’re working on is removed.
9. Check opposite side
Work around the wheel, removing every buckle in the same way. Once you’ve fixed one side, swap your truing gauge to the opposite stay and repeat the process. If there are any buckles where the spokes won’t pull the wheel into shape, or that last for over a quarter of the wheel’s circumference, you’ll probably need a new rim, get some advice from your bike shop.
10. Check wheel is true
Spin the wheel and use your truing device to check that it’s running totally straight and true. Take your time and don’t be afraid to keep working at it – this is a real skill. You’ll probably need to swap the gauge from side to side a couple of times at least until the wheel is perfectly true.
11. Check vertical damage
Now the wheel has no sideways buckles, it’s time to look for vertical deflection. Inspect the wheel slowly, looking for flat spots in the rim. These are caused by big impacts and aren’t something you can cure with a true-up. If you find any, mark them with a pen or small sticker to make sure you don’t try to cure them in the next few steps.
12. Mark damage
If you find a high spot, where the rim moves further from the hub, count the number of spokes attached to the affected section of rim, highlight them with your marker pen and tighten them all a quarter turn, making sure you tighten an even number of spokes. Repeat until the high spot has been removed. Repeat with any other high spots.
13. Loosen spokes
If you find a low spot, where the rim dips closer to the hub, count the number of spokes attached to the affected section of rim, highlight them with your marker pen and loosen them all a quarter turn, making sure you loosen an even number of spokes. Repeat until the low spot has been removed. Repeat with any other low spots.
14. Check wheel dish
Now check the wheel runs centrally in the frame, with an equal distance between the rim and each chain/seatstay. If this measurement, called ‘dish’, isn’t equal to within a couple of millimetres, tighten all the spokes attached to the hub on the side with the bigger gap by a quarter turn, then measure again. If the wheel is more than 5mm out of dish, visit your LBS.
15. Check wheel is true
Now the wheel has been dished correctly and trued both vertically and laterally, give it a spin again to check it over. Don’t expect perfection the first time – the wheel will probably need another lateral true before you’re finished, so repeat steps 5-10.
16. Post-ride check
After your first ride, get the bike back in the workstand and have another look at the wheel you’ve worked on. The spokes will bed in after some riding time, so may need adjusting a bit more to keep them perfectly tensioned. Don’t forget this step or all your time and effort could go to waste!