Building bicycle wheels: the best builder is you

Fifty miles in, the bicycle wheels I built for myself a few days ago are as true as an arrow from Robin Hood’s bow. They did not fly into pieces at the first bump in the road and there is no reason why they should. Bicycle wheel building is much easier than, say, knitting or basket weaving. The difference between a wheel built by a professional and one that you build yourself is probably about two hours – a pro will build them a lot faster – but yours will be as good, or possibly better.

The most difficult part is calculating the length of the spokes to buy. The bike shop might do it for you but it’s worth checking because my LBS got them wrong. Some measurements are required but they can usually be found online. Mine were:

Shimano Deore XT HB-M756L front hub measurements:
Left flange diameter 61.0 mm
Right flange diameter 61.0 mm
Centre to right flange 31.7 mm
Centre to left flange 21.1 mm
Spoke hole diameter 2.6 mm

Shimano Deore XT FH-M756L rear hub measurements:
Left flange diameter 61.0 mm
Right flange diameter 61.0 mm
Centre to right flange 18.5 mm
Centre to left flange 32.0 mm
Spoke hole diameter 2.6 mm

DT Swiss TK540 rim diameter (ERD):
600 mm

Spokes required (using the DT Swiss online spoke length calculator):
Front: L 290 mm R 292 mm
Rear: L 291 mm R 290 mm

The rest is very easy. It only requires a methodical approach. So I followed my own instructions from a couple of years ago and it was just as straightforward as it had been then. It also helps to have a built-up wheel to check the lacing against but it must be the same pattern, conventional three cross in my case.

However, there is a decision to make. Trailing spokes can be fitted with their heads either inboard or outboard of the hub flanges and here, there are two opposing schools of thought. If it matters, it matters more on the rear wheel because trailing spokes – the ones which at the hub are angled backwards from the direction of the wheel’s rotation – are the spokes that deliver pedal power to the rim. On a bicycle with braking discs attached to the hubs, the leading spokes – the spokes that point from the hub towards the direction of rotation – receive the braking forces.

The significance of heads inboard or heads outboard is that the strains from pedalling begin from a more direct line when the heads of trailing spokes are on the outside of the hub flange. As these spokes emerge from the inside of the flange (on the opposite side from the head) they are closer to the centreline of the bicycle. In one sense this is better but they will be bent over the third spoke they cross, pulling their line of travel outboard. Instinctively I would rather have most of the length of power spokes – which happens to be the part leading to the rim – acting from closer to the centreline so I’ve laced my wheels with trailing spoke heads inboard (see photos below).

In the centre of the second photo, against the right edge of the hub, a trailing spoke (head inboard) crosses under a leading spoke (head outboard) which pulls it inboard towards the centreline of the bicycle. I prefer this. Others may disagree. Perhaps it doesn’t matter.

Either way, a self-builder can more easily afford to spend whatever time it takes to tension the spokes so that the wheel is perfectly true and that all the spokes on any side are pulling equally, subject to normal imperfections in the construction of the rim. I’ve often seen references to the ‘art’ of bicycle wheelbuilding – this is nonsense. There is not the slightest bit of art involved, except perhaps in hearing that the musical pitch of one plucked spoke is the same as the next.

Rims: DT Swiss TK540
Hubs: Shimano Deore XT
Spokes: DT Swiss Alpine III
Tyres: Vittoria Cross XN Pro
Rotors: Teppan Yaki SP5
Cassette: Shimano Deore XT