Workshop - Wheel building
Building a wheel is not the dark art it seems – with the right equipment and a bit of patience you can master it. We show you the first step – lacing the wheel.
It is critical that the spokes you use are the correct length. Spoke length is measured from the inside of the spoke elbow. There are quite a few spoke calculators on the web: a good one is www.appliedthought.com/danny/Spoke/SpokeCalculator.html. Another one if you run Excel is www.damonrinard.com/spocalc.htm.
Use spokes that are 1mm shorter than calculated for the cassette side of a rear hub and 1mm longer for the opposite side.
1. First spoke
First apply a drop of oil to the ferrules or around the inside of the spoke holes in the rim. Insert your first spoke through any hole from inside outwards on the left (nearside) flange of the rear hub or either flange of the front hub. After this every spoke only has one correct spoke hole.
Insert more spokes through alternate holes on the same hub flange inside outwards.
2. First set of spokes
Lace one of these spokes to the first hole in the rim after the valve hole which is on the same side of the rim as the hub flange. Connect each spoke to the rim every fourth hole and tighten the spoke nipples about three turns. Check that the spacing is even on the hub (every other hole should be empty) and the rim (spoke, three empty holes, spoke etc) all the way around and that the spokes are on the same side of the rim as the flange of the hub.
Connect each spoke to the rim every fourth hole and tighten the spoke nipples about three turns
3. Second set of spokes, first side
Rotate the hub so that the spoke nearest the valve hole in the rim is pulling in the direction away from the valve hole. Insert a spoke from the outside inwards, in any hole in the same flange. Find the spoke hole in the rim which it just reaches. Count the number of spokes it crosses – it should be three. Lace this new spoke in front of the last spoke it crosses and connect it to the rim.
Work your way around the wheel from this spoke fitting the remaining spokes on this side of the hub. There should be one spoke hole empty between each spoke.
4. First spoke, second side
Sight across the hub from the opposite flange at any spoke. You will see two spoke holes either side of the spoke. The first spoke on the second side of the rim will go through one of these two holes outside inwards. If there is a spoke hole empty in the rim between your spoke and the valve hole insert the spoke through the spoke hole and lace it to the nearest of the two you identified to the valve hole. If there is no spoke hole in the rim between the first spoke and the valve hole, lace the spoke inside out through the other hole to the rim spoke hole immediately the other side of the first spoke.
5. Lacing the remaining outside inwards spokes
Lace in the remaining outside inwards spokes; these will need a bit of care as they have to be pushed through the easiest path, which is generally above the last spoke crossing on the opposite flange.The second spoke to go in on this flange goes in outside inwards into the spoke hole, immediately to the right of the first spoke on this side.
Sight across the hub; two spokes will be apparent, one of which will be laced the same way, outer inwards. Lace this spoke to the hole in the rim either behind (if your no1 spoke went next to the valve hole) or in front if not. Finally lace in the remaining spokes inside outwards remembering to insure that they are laced under the spoke at the third crossing in each instance. If you can’t get some of the spokes to reach their nipples, make sure that all the nipples are seated properly in their holes.
6. Final checks
A correctly built wheel should have the spokes on either side of the valve hole parallel. This makes it easier to get at the valve. All spokes should be woven at their last crossing. The spoke pattern should be symmetrical. Adjust all of the nipples so that each is screwed down equally – leaving three or four threads exposed is a good start. If necessary tighten them another turn or two; all should have some tension. All the spokes should have a similar tension except for those on the cassette side of the rear wheel which will already feel a little tighter.
7. Improving the spoke path
With your fingers or a plastic faced hammer flatten the inside outwards spokes down onto the hub flange and with your hands pull the outside inwards spokes towards the hub flange. This helps the spokes take the best line. Now tighten all your spokes by two turns – your wheel is now ready for truing.