Spokes and Lacing Patterns

To read all about the different types of spoke we stock at DCR, read David’s special article on the subject. If you would like to purchase any spokes through us or would like any help in choosing the correct spoke for a wheel you would like us to build for you, please get in touch or visit our parts store: bitexhubs.co.uk. 

A bicycle wheel can only be as good as its parts. A wheel is made of three main parts; hubs, rims and spokes. If any of these is poor then it will lead to a poor wheel. Even a stout rim will go out of true rapidly the wheel is built badly; and a good build requires good spokes. Spokes literally hold the whole item together. Sapim define a spoke as, ‘being the link between the hub and the rim’.  Spokes enable wheels to have remarkable strength with surprisingly little weight.

We use exclusively Sapim and Alpina spokes. They offer a big range products, allowing for an excellent option any wheel.  We have no concerns about the quality of DT Swiss spokes; there are a small number of subtle difference between them, however the Sapim range delivers a better solution for good value, high performance wheels that last for many years.  We offer almost the entire Sapim stainless spoke range.  We do not offer their more basic range.  Sapim have a permanent research centre so despite being established in 1908, they are still continuing to innovate and keep up with market developments. All Sapim spokes are made in either Belgium or France.

You can learn all about the different types of spoke we stock at DCR by reading this page.

There are three spoke types when it comes to their profile construction. The plain gauge spoke, the butted spoke and the aero spoke – an aero spoke in itself may or may not be butted as well. The plain gauge spoke is the basic spoke used in the vast majority of wheels. There are two versions that Sapim makes; the Zinc spoke and the Leader spoke. The Zinc spoke is the most basic version and is quite simply a cheap spoke. If you want a spoke which lasts and you want one which works well in conjunction with alloy nipples, a stainless spoke is required – especially in the UK where our weather conditions can be very harsh on components. So for this reason, their Leader spoke is a good economical spoke for economical but durability focused wheels. There is a big variety in plain gauge spokes, although you may be unable to tell this by eye. Sapim’s leader spokes receive the same strengthening treatments as their butted spokes, which means they have a lot more strength than most competing versions. They are also still made from stainless steel. The main disadvantages of the Leader spoke over other Sapim spokes are weight, comfort and fatigue life. The Leader is still only really a basic spoke, best suited to economical wheelsets. They are available in a range of profiles so they can be applicable for builds which require unusually large spokes. They also offer a huge range of lengths which can be modified if necessary. We have a couple of spoke cutting/rolling machines which allow us to produce Leader spokes down to 70mm.

Forces Involved

A spoke is subject to three key kinds of force. One is constant, because of the tension it is held under and the weight of the bicycle. Sapim refer to this as carry. The others are inconstant (impact and transmission); when an impact is made upon the wheel so the spoke needs to help absorb these irregularities. The spoke will only do part of this, some will be absorbed by other components; rim, frame, handlebars etc. Some is passed onto the rider. It is when a wheel receives these sudden forces that butted and aero (which in the Sapim range are also butted) spokes become important. The dimensions of a butted spoke differ from plain gauge because they are not a continuous thickness throughout. Sapim’s butted spokes use the SCFT-system (Sapim Cold Forging Technology). This allows the spoke to be stretched without causing any damage to its molecular structure and Sapim claim this increases the strength in the central portion by at least 48%. Butted spokes can flex and absorb impacts better than plain gauge because their central butting allows them to stretch. The extra material around the elbow and nipple allow strength to be retained in the areas that commonly fail. Finally the thinner central portion allows the butted spoke to be lighter than the plain gauge.

Forces on a spoke:

Carry

Impact

Transmission

When selecting spokes for a wheelset it is important to understand each wheel differently. The front wheel carries less stress than the rear. Therefore it does not need as strong spokes and fewer spokes are required. Sapim Race spokes are appropriate for most front wheels, although Sapim Lasers could be used if weight saving was important or better still CX-rays. A front wheel can normally be both radially or tangentially laced. This means the spokes can either come directly out of the hub to the rim, or they can come out at tangents to the hub. Tangential spokes normally cross three other spokes before they reach the rim. This has given rise to the term 3X, which is the most common lacing pattern. Many hub manufacturers refuse to warranty products built into radial wheels. There have been instances where the spoke has been pulled straight through the hub flange.

Many wheel builders refuse to build wheels with radial lacing patterns because of the risk of the spoke being pulled through the flange of the hub. However many major wheel manufacturers have moved towards radial front wheels because of aesthetic benefits as well as some weight saving advantages. I have built many wheels with radially laced spokes and none have ever failed at the hub. However, I always point out before building that with the majority of manufacturers, radial lacing invalidates the warranty. I would also discourage the use of radial lacing unless the hub has been specifically designed for it because it distorts the hubs making for a weaker wheel and it makes for a slightly rougher ride. Another factor in radial lacing is it is a stiffer lacing pattern. This is why most performance wheels now use radial lacing on front wheels. There are two ways you can lace radially. One is heads in, the other is heads out. The spoke can be laced in either orientation. Heads in is stiffer which puts greater strain on the spoke and hub flange. Some manufacturers that allow for radial lacing on the front do so only if laced with heads out. If you are lacing radially for aesthetic reasons, it is best to have heads out. This will offer a more comfortable ride and a stronger build. If you are looking for maximum stiffness and the hub will allow it, lace heads in.

A rear wheel is quite different to a front. It is normally ‘dished’, it also carries a higher proportion of the bike’s load. It cannot be completely radially laced because a rear wheel has turning forces exerted upon it from the hub, these would stress and break the hub flange as the spokes are pulled out. Most commonly rear wheels are 3X, however 40 spoke wheels are done in a 4x lacing pattern. Higher spoke counts still require high cross counts in order to maintain the spoke angle. Other wheels which require particularly short spokes such as Brompton or Rohloff wheels require 1x or 2x. Lower spoke counts necessitate lower cross counts 24 spokes or less requires 2x as 3x would provide compromising angles at the rim as well as the potential for spoke heads to come into contact with other spokes. It is possible to radially lace on the non-drive side of the rear wheel in some instances (not when using disc brakes). This will improve stiffness but again hub manufacturers normally prefer you not to.

Dishing occurs on rear wheels which uneven centre to flange measurements, normally there to incorporate external gears. The right hand flange is moved towards the centre line of the hub in order to fit in the cassette or freewheel. This means that the right hand or ‘drive side’ spokes need to be under greater tension than the left hand or ‘non-drive side’ spokes. The tensions on a drive side are sometimes as much as triple that as on the non-drive side. Wheelbuilders and manufacturers have been creative in their solutions to this problem.

Sometimes people opt for twice as many spokes on the drive side; however quality rims normally have an allocated direction so this can be an inappropriate solution with spokes facing the wrong way in the rim. Moreover this solution requires a stiff rim to remain true; two successive spokes pulling in a given direction separated by only one in the opposing direction makes for a natural waver in the rim. Another solution which I sometimes use is to have different spokes on the drive side to the non-drive side. The non-drive side will commonly use the same spokes as used on the front wheel. The drive side will have heavier duty spokes and importantly spokes with less flex. This means that the spokes flex more evenly on both drive side and non-drive side. A light duty build could use Sapim Laser spokes for the front and non-drive side and Sapim Race for the drive side. Heavier duty could be Sapim Race for front and non-drive side and Sapim Strong for the drive side. You could also use D-Light spokes with Race spokes or Laser spokes to achieve similar slightly varying results. Many wheelbuilders neglect such detail, although it is important for a well balanced wheel. Moreover it does not need to add considerably to the cost of the build. An important factor to consider before doing this is that sometimes a larger spoke elbow (such as the Strong spoke) will sit badly in a hub. Considering the quality of all Sapim spokes, most wheelsets can be laced with the same spokes throughout.

A front disc brake wheel behaves much the same as a rear rim brake does.  There is torsional forces coming from the hub and dish is introduced because of the rotor.  For this reason, we generally encourage that disc brake wheels use the same number of spokes front/rear.  However if you are going to drop spoke count down on one of the wheels, the front is still the obvious choice as it carries less actual weight.