EVERYDAY WHEELS
System wheels are established in the high-price range. But how good are the cheaper models? We tested twelve wheelsets between 100 and 350 euros in the lab and in practice. This time there was no run on the material. As every year, we also provided the participants of the TOUR training camp with test wheels. But it took a while to find enough test riders. Obviously, the twelve wheel sets between 100 and 350 euros did not have the appeal of the expensive carbon fibre wheels - wrongly so. Because as it turned out at the end of the test weeks, the wheels worked without any problems. Two sets each were even ridden for around 1,500 kilometres without any failures or anomalies.
COMPETITION WHEELS
When every second counts, it's time for competition wheels. Seven wheel sets between 499 and 2,750 euros show the limits of what is technically feasible - and sensible.
This sound is motivating: The Zipp "808" bob almost like disc wheels and urge maximum effort even when pedalling uphill. Downhill, however, they show their weakest side: the braking behaviour is miserable. Braking is jerky and barely controllable. The bikes require a lot of forbearance for the shortcomings of carbon - and foresight or courage when braking into corners. This applies similarly to the other carbon bikes in the test. With the Xentis wheels, a test rider shoots straight ahead in a familiar bend because it hardly brakes at all. The Corima makes the fork stutter and sway and conjures up washboards on mirror-smooth tarmac at the braking point before the bend. The Roval is a little more controllable, and Mavic's new "Cosmic Carbon Ultimate" brakes most evenly - without reaching the braking level of 100-euro wheelsets. And all this in dry conditions, mind you. This reveals a major disadvantage of the pursuit of low weight, which is virtually dictated by carbon as a rim material.
You can find these wheels in the PDF download:
- EVERYDAY WHEELS:
A Class ALX 440 SL, Campagnolo Scirocco, Campagnolo Vento, Easton Vista SL, Fulcrum Racing 5 Evolution, Fulcrum Racing 7, Mavic Aksium, Mavic Ksyrium Equipe, Ritchey Pro, Shimano WH-R 550, Shimano WH-R 561, Xtreme Light Wheels
- COMPETITION WHEELS:
American Classic 420, Citec 6000 CX Carbon, Corima Aero, Mavic Cosmic Carbon Ultimate, Roval Rapid Star Carbon, Xentis Mark 1 TT, Zipp 808
DID YOU KNOW? THE WHEEL ENCYCLOPAEDIA:
Spoked wheels are complex, amazingly robust, but also very different structures. The most important backgrounds
What is a system impeller?
The rim, nipples, spokes, hubs and spoke pattern are matched to each other for optimum function. Optimisation goals can be aerodynamics, weight or particular robustness. Advantages of system wheels: they run smoothly for a long time, are durable, require little maintenance and - in contrast to classic wheels - are lighter and aerodynamically better. Disadvantage: the supply of spare parts. You should therefore order individual spare spokes and nipples at the time of purchase.
What influence does the rim shape have?
The shape of the rim significantly determines the aerodynamics of the wheel. Profiles with a teardrop-shaped cross-section are better than those with an angular cross-section. Rims as little as 24 millimetres high can be aerodynamically good (e.g. Shimano WH-R 550). Increasing height usually improves aerodynamics, although this also depends on the rim profile. As the volume increases, so does the stiffness of the rims, so aero rims need fewer spokes.
Why are rear wheels almost always less stiff than front wheels?
The rear wheel becomes asymmetrical due to the sprocket: The spokes are much steeper on the drive side and must therefore be preloaded higher to keep the rim centred between the dropouts. The spoke angle has a major influence on stiffness. Asymmetric rims allow a more favourable spoke angle on the drive side.
Do straight spokes have advantages?
With conventional wheels, spoke breakages usually occur in the spoke bend or in the transition from the spoke thread to the shaft. Many system wheels no longer have spokes with bends - and therefore have one less potential weak point. However, the heads of straight spokes can also burst off - a question of manufacturing quality.
What is the significance of the spoke shape and number?
Classic round spokes work best when they are designed as expansion bolts and are thinner in the centre than at the ends. Aero spokes are forged flat in the centre. The number of spokes can be reduced in favour of aerodynamics and weight if the rim is correspondingly stiff.
Why are the right and left flanges of rear wheels spoked radially?
Two philosophies: 1. radial spoking of the spider side so that only the less preloaded tension spokes of the left flange take over the torque. 2. insert the spider side crosswise and transmit the torque directly there. If the hub shell is sufficiently rigid, both flanges can also transmit the torque if both are cross-spoked. As the force ratio in the wheel is complex and depends on many details, it is not possible to make a statement in favour of one of the variants.
Why is the left flange on some rear wheels offset inwards?
In addition to spoke tension that is too high, spoke tension that is too low can also cause problems due to the flatter spoke angle on the left-hand flange. If the tension is too low or the spoke is inelastic, the tension can drop to zero when the wheel flattens in the ground passage - the risk of the spoke breaking increases. Two counter-strategies: Use fewer spokes on the left than on the right - which increases the tension in the individual spoke (Campa). Or move the left-hand flange inwards and position the spokes at a similar angle to the sprocket side (American Classic).
Downloads:
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