Choosing Spokes

It is more than a piece of wire; it is a tensioned member within a pre-stressed structure.  Build quality matters – it affects lifespan, stability, stresses on other components and the overall sum of tension within a wheel. Correct spoke selection is essential for the performance you’re looking for.  Spoke failure is also the most common source of mechanical failure in a wheel.

Choosing the right spoke is normally about balancing cost, compliance, stiffness and weight.  Compliance and stiffness are linked mostly to modulus which we will come to later.  Weight and cost are comparatively easily compared.  For most people the correct spoke is either the Sapim D-light (all rounder), Force (high strength) or CX-Ray (higher performance).

Sapim Leader

This is a premium plain gauge spoke.  It is a stainless spoke and about as strong as a plain gauge spoke comes.  Being plain gauge it is the basic model though.  We likely wouldn’t stock it at all if it weren’t for versatility.  With our Phil Wood machine we can cut these spokes down to something like 74mm minimum.  Which is very, very short and far shorter than we can get any other butted spoke.  So we will use them on little wheels or wheels which require, for whatever reason, really short spokes.  

Sapim Strong

This is a really good spoke – it is single butted and massively strong.  I dislike it from a compliance perspective, but if you’re looking for a really strong and relatively economical spoke – it’s a good choice.  It is also a sound choice if hubs have really large spoke holes as it is 2.3mm thick at the elbow but it still works with a standard spoke nipple at the end. 

Sapim Race

This for a long time was seen as a benchmark.  It’s a very popular spoke.  It’s a ‘classic’ double butted spoke – 2.0-1.8-2.0mm profile.  Butted spokes are more compliant and have a better lifespan.  It is well worth the upgrade to this from the Leader.

Sapim Sprint

I do not know why this is not a more popular spoke.  It is 2.0-1.7.2.0mm.  It is basically a problem free but lighter version of the Sapim Race.  They are really nice and easy to build with and they cost a good deal less than the D-light but the weight difference isn’t that significant.  

Sapim Laser

This should be a great spoke.  It is actually the base spoke for the CX-Ray and the CX-Delta.  The problem is it is just too twisty.  So we don’t recommend it and we really don’t like building with it.  It’s fiddly and fussy and not overly stable.  

Sapim CX-Sprint

The Laser makes the CX-Ray and the Sprint makes the CX-Sprint.  So the flattening process that uprates the CX-Ray from the Laser is used here on the Sprint to make the CX-Sprint.  It’s stiffer than the CX-Ray/less compliant.  Some people like it in rear wheels or perhaps on the drive side of a rear wheel – think road sprinting for example.  It’s a good spoke but I think the CX-Ray has the edge as an all rounder as it is lighter and more comfortable.  

Sapim CX-Delta

We do have some of these but I don’t think we will continue with them long term.  They are a more basic profile – they are not an aero profile they are more angular but they are essentially a CX-Ray.  The problem is they don’t cost enough less to be worth the downgrade from the CX-Ray.  They feel cheaper but they are still fairly costly.  

Sapim Ebike spokes:

There is a range here – E-Strong, E-Race and E-light – being thicker versions of the Strong, Race and D-light.  We do not bother with these spokes for three reasons:

1. Their ride quality will be a lot harsher
2. We do not have the need to build wheels stronger than we can with the Force – even when it comes to really high load and powered applications
3. They do not work in our cutting machine without us dismantling it each time and resetting it around a different gauge.  

So we could offer these, but I just don’t feel the need at all.  Their best use case is if you have a hub motor with really large spoke holes – it makes a better fit here – but given that these are economical builds then the larger gauge Leaders probably make more sense.  I’d still rather use a Strong personally but these products are…without wanting to sound condescending, below the quality we work with.  If you have a premium ebike and you’ll normally end up with a mid-motor drive and a premium wheelset that is simply tougher than an unpowered counterpart – for this, the standard Sapim range is most appropriate – the Force or CX-Ray work well here.  Similarly built around a higher end ebike motor like the Mahle motor then the CX-Ray is an excellent choice.  

Sapim Super and CX-Super

The Sapim Super came out many years ago now and was developed for Tune.  It was a problematic spoke but it boasted very high strength:weight and lighter than anything else on the market at the time.  The CX-Super is the flattened version of that spoke.  They are fiddly to build with and have smaller elbows and threads (1.8mm).  They are also fractionally heavier than the Alpina Hyperlite.  The Alpina Hyperlite is what the CX-Super should/should have been. So we don’t stock these spokes but they were innovative in their day.

Colour

This is much more relevant here than it is in metal components.  The material used here is white.  It is essentially a white, woven plastic.  You will see pictures of them black and also pictures of them in other colours.  They do sell these spokes in colours AND they sell ‘colouring kits’.  Part of the learning curve with BERD for us was to realise that colouring spokes which are already part of a wheel is…..not something we are going to do.  It is extremely time consuming and virtually impossible to do to a high standard.  It is sufficiently time consuming that it would be faster to unbuild, paint and rebuild.  So if you’re thinking of this process as a builder or an individual – please, take it from me – paint these…as spokes, not as part of a wheel.

On our industrial estate there is a skilled furniture maker/finisher.  He said two important things about painting these spokes:

• Don’t apply the paint with a brush – either spray or dip
• The material will be phobic of any kind of top coat/desired longer term finish – the only way to colour them effectively would be to prime them first.

I would imagine but do not have concrete data either way that painted versions of these spokes behave slightly differently and slightly less consistently on a tension meter than unpainted – which further merits using the natural, white model.

BERD do dip their spokes, but I don’t believe they prime them and I would say that the consistency of that finish is….below what I would like to see on such a premium product.  They’re actually a really kind, helpful company and I don’t want to say anything negative here – I just think when it comes to this kind of spoke – it’s best to just have the white ones.  If you want black or another colour, it is better that they are either professionally painted or painted by BERD.  We are Wheelbuilders, we are not painters.

Compliance/stiffness

The short answer here is very/not very.  As you can see from our modulus discussion earlier these have a lower modulus than even thin steel spokes.  They are thicker but that doesn’t do enough to overcome the low modulus so their stretch/compliance is much more pronounced than a CX-Ray as a benchmark.  As with before it is a case of horses for courses – but the best use case will be when you’re looking for maximum compliance rather than looking for stiffness.  Think Cross Country mountain biking or rutted gravel riding.  If you wanted to make your bike more comfortable – this is a great option.

So they’re slow then?  No….that’s not really how compliance works.  We’ve seen the same phenomenon with larger tyres run at lower pressure – you’d think that would be slower.  However, the key reason why this is not the case is it helps reduce hysteresis loss.  What’s that?  Well – imagine a car that goes over a rumble strip.  The car is slowed down by this – you can feel it.  Why?  Well everything is being forced up and down generating sound and heat – there are losses in this.  If you improve the car’s suspension here, then it slows down less under this environment.  It’s one of the reasons that the pneumatic tyre is such a fantastic invention.  So the more that your wheel behaves like a totally unyielding solid item, the more that imperfections in the surface will slow you down.  That is the case on and off road.  It’s the reason why beautifully smooth road surfaces feel so lovely to ride on – it’s not just that it feels nice, it is faster.  

So BERD spokes are faster then?  Well, not necessarily.  But it is why compliance is relevant.  Compliance is good for reducing rider fatigue, it’s good for handling, it’s good for maintaining grip, it’s good for comfort and it’s good for reducing hysteresis loss.  So sometimes, it is faster….sometimes it is not.  It’s much more likely to make a difference on a rigid bike off road and much less likely to make a difference on a velodrome.  Generally speaking when it comes to road bikes, people are running often more compliant frames now, potentially more compliant components (clothing, saddle, bar tape) and bigger tyres with lower pressures.  So the use case for BERD is much more on gravel than the road and when it comes to gravel much more on people who are riding off road a lot and on rougher surfaces.

Build process

What’s it like to build with these spokes?  Difficult….slow and often quite frustrating.  Let’s start by talking about spoke interface.  There are two key ways you can use BERD spokes – either with their Talon hub or another one in a similar style intended for use with BERD spokes, or with a standard hub.  The interface into the rim is standard and uses a standard nipple – so any rim is fine.  

The Talon hubs or other hubs of that style have the spokes loop over and that’s relatively straightforward – especially if you’re lacing in a lacing jig rather than in your lap.  If you instead want to use another hub….well the hub itself requires modification in order to prevent the hub from damaging the spoke.  I dislike this from the start as it removes anodising from the hub at the point that you load it – this invalidates the warranty on some hubs.  You then have to thread it through and stop it with these rods which is really, really fiddly and not as precise when it comes to spoke length calculation and they take longer to settle.  Once again – I really recommend that people just use a Talon hub or a hub with the relevant hooks so it is intended, specifically for a BERD build.  That is frustrating as it may mean you cannot have the hub you want and it can also mean that that hub can only be used for BERD spokes in the future including if you had any kind of failure in the future – however, I just think it is realistically part of the cost of admission.  It’s part of what makes BERD a niche product rather than one that will have mainstream appeal.

Because the BERD spokes are a woven plastic spoke – the process of tensioning them is different.  We use a mechanical press on all of our builds.  It is really consistent, it significantly extends the lifespan of components – especially aluminium rims, it provides us with an opportunity to stress test and it can flag up manufacturing defects and it significantly reduces the fatigue on the builder.  I would say, with BERD, it’s basically essential.  Even if you laced/tensioned a BERD wheel and then just walked away and came back to it a couple of days later, it would have lost loads of tension.  A bit like building with wooden rims.  It takes a lot of stress over quite a prolonged period to get these spokes to truly settle.  This press we have really really helps with that.  We actually press for a sustained 30 second interval many times on each side to stress and stretch these spokes until the woven fabric is pre-stressed into a profile that they will sit at.  

Checking tensions on these spokes is much like other spokes but it does require a tension meter calibration rig so you can work out what the correct measurement is.  They are designed to be run at much lower tensions than other spokes and because they are so compliant it is worth using a locking nipple on this.  Something we rarely use otherwise.

Strength/longevity

They perform excellently from this perspective.  There is no need to worry about them in terms of their longevity as long as the fibres aren’t exposed to anything that will cut/damage them.  So sharp surfaces on hub flanges are the only real hazard here.  Apparently they have 15x the strength:weight verses steel and won’t rust or corrode.  That said, I consider that slightly irrelevant as at their end they have a steel spoke insert and then you thread on a standard spoke nipple…I don’t have issues with those products at all – but in going towards BERD you haven’t actually moved away from steel so I don’t really see how they can claim an upgrade on them in terms of ultimate, tensile strength.

Application

I sound negative when talking about BERD.  They are complicated and difficult to build with and they are expensive and they realistically require certain hubs.  These are not factors I like.  However I do consider them to be a frontier product.  They achieve something which other products do not/cannot.  They are really light and they are really compliant.  If that is deeply relevant for you then you will LOVE them.  They suit boutique/high end builds.  I think given the limitations on hubs, the reason to choose them here is for compliance, rather than weight.

Carbon Spokes

Carbon spokes represent the opposite end of the spectrum. Where textile spokes are compliant, carbon is uncompromisingly stiff.

• The Mechanical Reality: Carbon offers the highest stiffness-to-weight ratio available. It creates a wheel that feels exceptionally responsive under power.
• The Trade-off: these spokes nearly always require specific hubs for their use and their compliance is the lowest of all the spoke options mentioned here.  

We avoid hybrid carbon spokes that bond carbon to steel ends, as these introduce unnecessary failure points. We are currently trialing a range of pure carbon designs with dedicated Bitex hubs. These are for riders who prioritise maximum stiffness and accept a harsher ride and a more restrictive ecosystem for replacement parts.

So why not build more wheels with Carbon spokes……?

I’m going to make a confession here.  I just don’t really like carbon spokes.  Maybe there is a degree of irrationality here but here are some key reasons:

1. New standards and standards which seem to vary/fluctuate and are unsettled – but getting better.
2. The inability to repair a wheel like this with a standard spoke in the event of some sort of failure.
3. Availability is patchy.
4. The hubs are normally heavier which offsets much of the weight saving.
5. I’m unconvinced it is the riding experience that most cyclists actually want.  It makes more sense on the professional circuit where riders are far less bothered about ride quality and much more about marginal gains in efficiency in their output.
6. A degree of mystery around their failure.  I like the failure profile of steel – it will, eventually, let go, which often preserves the other components – especially the hub – a bit like a mech hanger.  I worry about the stress that a carbon spoke could place on other components.  Spokes have a somewhat mech hanger like quality to them.
7. Opacity in the supply chain.
8. A lack of longitudinal understanding.  I’m just not convinced that in 5-10 years time which I think is a reasonable service life for wheels, we will definitely be able to repair/maintain wheels with carbon spokes.  We may be able to and it seems to be moving that way – but I’m always cautious.

Fundamentally we are makers, we are craftspeople.  We do sell products but we aren’t salespeople.  So if I do sell you something, I want that something to be something you’ll enjoy and if you need some sort of servicing of it in 5 to 10 years time, I want to be able to service it.  I actually hold myself duty bound here.  So can I build with carbon spokes – sure.  However, i’m only going to build them at this stage for people who understand the implications on service life and interface standard variability.  If there is a problem in the future and I can fix it – I absolutely will – but I cannot guarantee that at this stage.  In contrast, a traditional spoke interface is almost as old as the bicycle itself and it’s nice to think that if you take your bike to a backstreet bike shop in a backwater location around the globe – with basic tooling they can get you rolling again.  I’m currently unconvinced they represent progress unless you are racing.

I have to accept though they seem to be the direction of travel and some (but not all) of my reservations are overcome by spokes becoming available from Alpina, Sapim and Venn.  That said, all of these are all still produced by third parties and that is not the kind of supply chain transparency I like.  The Stren carbon spokes seem to be among the most ubiquitous at the moment and standardisation appears to be settling around that kind of interface.  That said these are frontier products and often frontier products do just change regularly – this can be frustrating but it is what some people seek.

We are going to be stocking, moving forward, Bitex hubs which are compatible with carbon spokes.  We are going to test in advance that these are compatible with Stren, Venn, Sapim and Alpina spokes.

A Summary

Many wheelbuilders avoid aluminium nipples, fearing they will seize or fail. We take a different view. We provide a lifetime warranty on our builds, including the nipples, because we use Sapim nipples.  They are manufactured using the highest grade 7075 T6 aluminium.

In addition, Sapim nipples undergo a specialised anodising process and are finished with a wax coating. This reduces friction during the build and prevents long-term corrosion. We supplement this with our own three-part preparation:

• A carbon-friendly grease is applied to each nipple where it makes contact with the rim – this prevents material being removed during build or unnecessary stress on the tool interfaces.
• A thread prep is applied to every spoke before the nipple is threaded on.  This acts as a lubricant initially and then a mild threadlocker further down the line to prevent loosening.  The prep prevents the nipples from seizing on even in the presence of high use including the wet British climate.
• A specialist wicking threadlocker is applied to prevent loosening and to cap off from the elements.

While brass nipples are a traditional, safe choice, Sapim aluminium nipples offer a significant weight saving at the rim (around 40g depending on number) – where rotational mass matters most – without sacrificing durability.  We stock both in black and silver and alloy can also be offered in a range of colours.

Double Square nipples

Wherever possible we always use double square nipples now.  The slot in a traditional nipple is a weak point and the most common area of failure.  Double square nipples also allow for longer spokes and the thread starts higher up.  This change in effective rim diameter is stronger as it means more of the thread interface is within the rim rather than being suspended beneath it – so the nipple head is far less stressed.  It also allows us to use a bigger range of tools for tensioning which helps greatly to reduce physical fatigue for us.

Technical Specifications: Weight & Profile

Data represents a single spoke at a standard 260mm length. These figures are essential for calculating the rotational mass and determining the build’s overall character.

Does higher modulus mean a stiffer and less compliant wheel?

Modulus is really important when it comes to spoke choice.  It will be the most noticeable difference between the options you could choose.  So if you are a rider who really likes high wattage, punchy sprints, on the road, out of the saddle, hard gear – you are likely to appreciate the ‘feel’ of a stiffer spoke.  You can achieve that with shorter spokes (deeper rims help achieve this especially as they increase the bracing angle), by making the spoke thicker, by changing the material used or by increasing the number of spokes overall in the wheel.  If alternatively you like riding off road, over rutted ground on a fully rigid bike (think a lot of gravel applications) then likely you’ll take ALL the compliance you can get (small number of thin spokes made likely out of steel) – if you are doing track sprints – higher quantities of thicker spokes and possibly carbon spokes would be optimal for power transfer.  For most riders, the CX-Ray spoke is pretty optimal here.