Turning the wheel
Table of Contents
Spoked Wheels
We ride our motorcycles across the land, on motorways, over mountains and through deserts. All on two wheels. And those wheels are very likely to be spoke wheels – especially if you're riding an enduro or a cruiser. But wheels are often out of sight and out of mind. Even when checking tyre pressure, we're more focused on the gauge than the wheel itself. It’s high time to crouch down and take a closer look at the wheels that represent our freedom.
The story begins 4,000 years ago. That’s when the spoke wheel was invented, replacing the heavy wooden disc wheel. Then, for a long time, not much happened. Much later – with the advent of pneumatic tyres (1845 Thomson / 1888 Dunlop) for bicycles – the so-called artillery wheels were developed. These allowed for changing only the tyre and rim, rather than the entire wheel. The first to benefit from this quick tyre change were participants in the legendary Gordon Bennett Cup, the forerunner of Grand Prix racing.
While Daimler’s 'riding car' of 1885 still had uncomfortable wooden-spoked wheels, the first mass-produced and officially designated motorcycle – the Hildebrand & Wolfmüller from 1894 – featured one (just one!) spoke wheel: the front one. The connecting rods of its twin-cylinder engine applied direct force to the rear wheel – a stress a spoked wheel probably couldn’t handle.
Wire-spoked wheels existed even earlier – up to the size of water wheels. Scaled down, they proved effective for motorcycles too, allowing the production of light yet sturdy rims.
Spoke wheels have persisted for a long time, but were continually improved, particularly in the materials used for their three core components: hub, spokes, and rim. In the 1980s, cast wheels gained popularity – a technology Bugatti had already used in the 1920s for car racing. Cast wheels looked modern and offered designers greater creative freedom. Honda also briefly used riveted Comstar wheels – a love-it-or-hate-it solution. Still, spoke wheels never really went out of style. The rise of enduros and choppers brought them back with a purpose, and to this day they remain a feature of both categories – and some retro bikes too – for good reason. BMW, for instance, developed the cross-spoke wheel to enable the use of tubeless tyres on spoked rims. And today? Today, many bikes still roll on classic spoke wheels alongside ultra-modern, featherlight carbon rims – just like the Hildebrand & Wolfmüller did 128 years ago.
The renaissance of spoke wheels wasn’t coincidental. In the case of 1980s choppers and today’s cruisers, style certainly played a role. For enduros, which emerged around the same time, it was technical necessity – and that remains the case today. No serious touring enduro, regularly ridden off-road, comes with cast wheels. The key advantage of spoke wheels is their elasticity and flexibility – crucial off the beaten track.
The Specialist
The profession of building, maintaining, and repairing spoke wheels is known as wheel truing. We spoke with one of the last true masters of this craft – Stefan Oster. He operates his wheel truing workshop on the idyllic island of Oberau in Fachbach, about five kilometres downstream from Bad Ems, near Koblenz, on the River Lahn.
Step inside the charming brick building – whose door is usually open – and you’ll feel like you’ve entered another world. Although lathe, milling and drilling machines are part of the equipment, Stefan Oster’s work is mostly quiet and precise, shaped by years of experience. At the workbench, he measures a wheel – clearly too small in diameter and too wide for a motorcycle – using a dial gauge. The delicate wheel rests nearly frictionless on a balancing stand. Without a torque wrench but with a sensitive touch, he eliminates lateral and radial runout by tensioning the spokes – aiming to minimise any deviation on the gauge. It’s almost like tuning a freshly strung guitar. “This is one of four wheels from a 1954 Maserati A6CGS. The owner, from northern Germany, races it and brings the wheels to me regularly.” “From northern Germany? No other wheel truer up there?” “Wheel truing is a dying trade. In Germany, maybe half a dozen specialists still exist.” After finishing the job, we sit outside on a bench and talk about something few people think about – spoke wheels.
WUNDERLICH
Mr Oster, you’ve just carefully serviced wheels from a classic Italian race car. Do spoke wheels require maintenance? If so, how often and what exactly needs to be done?
Stefan Oster
With motorcycle spoke wheels, the same principles apply as with the Maserati's. There are a few key points to watch. A spoke wheel "works" under load. The more demanding the terrain, the more attention it needs. There’s a big difference between jumping your bike in a sandpit and rolling to the ice cream parlour on Sundays. When checking spoke wheels, we first assess the trueness and the stability of the wheel. Trueness is achieved by minimising both lateral and radial runout. The wheel’s stability comes from the degree of spoke tension. Safety-wise: stability always takes precedence over perfect alignment! This has long been the motto of motocross riders, who tension their spokes to the max for extra stability. If needed, imperfect alignment is accepted – especially off-road, where you wouldn’t feel it anyway. By the way, adjustments are always made on the dismounted, bare rim – without the tyre – to achieve precise alignment, especially for radial runout.
WUNDERLICH
That already answers our next question: can a wheel go out of true slowly over time, or is it always caused by an incident?
Stefan Oster
Both are possible. As the wheel “works,” the spokes can stretch, tension is lost, and the wheel gradually loses alignment – eventually becoming noticeably out of true. If you know your bike, you’ll sense it as a vague, wobbly ride – similar to riding with low tyre pressure. That should never be ignored. One loose spoke leads to more, and in the worst case, the wheel could collapse. If tyre pressure is fine, inspect the wheel!
If a wheel goes out of true suddenly – from a pothole or kerb hit – the rim must be replaced. As mentioned earlier, the spokes connect the hub and rim. Trueness is achieved by centring. A rim is a bent profile welded at the join. It’s always somewhat flexible. True stability only comes from tensioning it with the hub and spokes. A deformed rim can no longer be trued – it has to go. The good news is that a spoke wheel can be repaired. Cast or forged wheels, in such cases, are total write-offs.
Also worth noting: suspension geometry affects wheel alignment. A stiff fork – with large tubes and triple clamps – or BMW’s Telelever is more forgiving than sensitive setups when a wheel isn’t perfectly true.
WUNDERLICH
So, if I feel a vague ride, action is already needed. Can I prevent it? Is there a way to detect problems early?
Stefan Oster
Yes – it’s called the sound test. With the bike on a centre stand, spin the wheels by hand. Then, gently tap each spoke with a screwdriver held between two fingers. Every spoke should “ring.” Not necessarily the same pitch – but none should sound dull. Dull = no tension = check immediately.
WUNDERLICH
Why don’t they all have to sound the same?
Stefan Oster
Spokes connect the hub and rim. To centre the wheel, all spokes must be under base tension. From there, truing is done by tightening individual spokes – which increases their pitch. So while all spokes are under tension, some will ring higher. That’s normal – not a fault. The idea that they must all sound identical is a persistent myth. If I tuned by sound alone, I'd never get a properly centred wheel – unless every component was perfect, and that’s never the case. So, the rule is: they must all ring – but never dull.
WUNDERLICH
OK. I’m riding my adventure bike in the High Atlas mountains and realise I have a wobble. No workshop in sight. Any advice?
Stefan Oster
Let me say first: I generally advise against DIY repairs! Every case is different and can only be properly assessed in person. Riders must judge for themselves if limping to a garage at low speed is worth the risk.
If you’re off the grid with no help in sight, do what the motocross crowd does: forget alignment for now – aim for stability. Tension all spokes. But ride cautiously and be fully aware that the wheel is compromised.
Important: BMW’s cross-spoke wheels use grub screws on the hub side to secure the spoke heads. These must be loosened before adjusting spoke tension. It’s no big deal – but you need to know. Same goes if you have to replace a broken spoke in the wilderness.
WUNDERLICH
What’s better: rubber or metal valves?
Stefan Oster
That’s really a matter of personal preference.
WUNDERLICH
What about balancing weights? Any tips?
Stefan Oster
Once the wheel is trued, the tyre is mounted. Balancing is done on the complete system – wheel and tyre – using a balancing stand. Physics dictates the heaviest point moves down, so we add a weight opposite. On modern rims, any imbalance is usually from the tyre pressure sensor. The type of weight depends on various factors: for typical cross-spoke setups, we use flat adhesive weights – now available in various colours and visually discreet. Customers with post-war bikes often want traditional cone weights on the spokes. For pre-war models, we use soft wire, spiral-wrapped around the spokes. Modern weights are made of zinc alloys, as lead is banned. Downside: lower density means they’re bulkier and more visible.
WUNDERLICH
Thank you, Mr Oster, for the fascinating insight into your craft!
Contact
Radspannerei Köhler e. K.
Owner: Stefan Oster
Insel Oberau 1
56133 Fachbach
Tel.: +49 2603-933 460
Email: [email protected]
Good to know
- Spoke wheels consist of a hub, a number of spokes (depending on intended use), and a rim. The spokes connect the hub to the rim and ensure the wheel’s structural stability.
- One of the key benefits of spoke wheels is their flexibility. Unlike cast wheels, they can flex when dealing with bumps or impacts – providing additional shock absorption, especially off-road.
- Spoke wheels are generally lighter than cast or forged wheels, improving acceleration and agility thanks to reduced inertia, gyroscopic forces, and unsprung weight.
- A drawback is their more intensive maintenance: spokes need regular inspection and adjustment to ensure correct tension.
- Spokes are designed to handle tension only. They are pre-tensioned in such a way that they are never subjected to compressive forces, which would otherwise cause them to buckle.
Typology: With or Without Inner Tube
- Spoke wheels can be used with tubes or tubeless (e.g. BMW cross-spoke wheels). Tubeless options are less prone to punctures from valve or inner tube failure (they're lighter – offering more agility). However, they require specialised tubeless tyres and an airtight rim seal.
Pros and Cons vs Cast or Forged Wheels
- Spoke wheels offer superior shock absorption and flexibility, making them ideal for off-road bikes and enduros.
- Cast or forged wheels are generally stiffer and provide more precise handling and road stability. However, they are usually heavier and more complex to manufacture than spoke wheels.
Cleaning, Care, Maintenance, Spoke Inspection, Preservation
- When cleaning spoke wheels, make sure to remove dirt and deposits thoroughly, as they can cause corrosion on the spokes.
- Regularly check spoke tension to detect any loosening or overstretching early. Special spoke wrenches are used to re-tension the spokes.
- To prevent corrosion, you can treat the spokes with specific protective agents.
- It’s essential to identify damage to spokes or rims early on and adjust or repair them as needed.
What Not to Do When Handling Spoked Wheels
- When fitting tyres, ensure no tools or levers come into contact with the spokes, as this can damage them.
- Do not use aggressive chemicals when cleaning spokes, as they may damage the spoke surface.
What to Do If There Is a "Wobble" in the Wheel
- If the rim becomes untrue, identify the cause – it may be a loose or overstretched spoke.
- It's advisable to visit a workshop for professional truing and tensioning of the wheel.
Self-Help on the Road
- When out and about, you can attempt a basic alignment using a spoke wrench – enough to continue riding safely. But a precise adjustment should be done at the next available workshop.
Flat Tyres: Sealant or Repair Kit?
- If you suffer a flat, it’s best to use a repair kit for a temporary fix to continue riding until you reach a workshop. Tyre sealants can sometimes help too, but shouldn’t be seen as a permanent solution.
Why Spoked Wheels Are Particularly Suitable for Enduro and Off-Road Motorcycles
- Thanks to their flexibility and shock absorption, spoke wheels are particularly well suited to off-road use. They handle impacts and vibrations more effectively and are less likely to suffer damage from rough terrain.
- The ability to replace individual spokes also makes repairs in remote areas easier and quicker compared to cast or forged wheels, which often require full rim replacement.
Disclaimer
All information and guidance provided here is for general informational purposes only. It does not constitute advice. In particular, it cannot replace individual technical assessments or risk evaluations that consider specific cases. Where we describe certain scenarios, they are examples only and may not be representative of other situations.
Every rider is responsible for their own motorcycle. Please bear this in mind.