ASK RIDE… pre-balanced and non-balanced wheels?
Hi ,My question is ; why don’t aero wheel manufactures such as Dura-ace 50mm, Mavic, and Zipp 303 and probably all the rest balance their wheels so that the valve doesn’t always fall to the bottom when the wheel spins freely?This imbalance with the valve stem creates a vibration at speed, just turn the cranks fast and hold up the rear wheel and you can feel the bike jumping up and down.Thank you – Ken (Frankton NZ)
There is a mix in the market of pre-balanced and non-balanced wheels. As an example, some manufacturers pre-balance wheels to account for valve extenders using either heavier gauge spokes opposite the valve hole, or even extra laminates of carbon. However it is difficult to predict the exact weight required to pre-balance a bicycle wheel for the following reason;
- Rim weight variation*
- Tyre weight variation*
- Tube weight variation*
- Valve extender length
- Aluminium valve extenders vs. brass /or stainless steel
- Rim tap variation* (Clincher rims)
- Glue application variation* (Tubular rims)
* Variation is used in this context to define heavier/lighter sections around the circumference of the wheel. eg. More glue applied to a section of a tubular rim, or a thicker section of inner tube and tyre.
All the above listed items can effect the balance of a wheel while rotating. This complicates production of a ‘standard’ pre-balanced wheel to meet customers different configurations.
A good example is a car tyre and rim; while being made to a high standard, these still require balancing after fitting due to slight variations in the rim and tyre weights.
So it is possible for bicycle wheels to be pre-balanced during production to account for valve extenders, but difficult in practice because of the variations mentioned above. To achieve a perfect balanced wheel it would have to be done on a case by case basis depending on the customers configuration. As a result balancing the wheel after the tyre is fitted, similarly to that of a car tyre, does present a practical alternative. Mello Bouwmeester
Mello Bouwmeester is the founder of Australian company Bouwmeester wheels. Bouwmeester, meaning ‘Master Builder’ in Dutch, has secured a reputation of quality, outstanding workmanship and attention to detail in all their products. All their wheels are hand built in Australia and are continuing to gain popularity in the elite ranks with several National Titles and UCI victories. www.bouwmeesterwheels.com