How loud your hub is? This is the topic that polarizes opinions. For some of us a noisy hub not only adds to personalization of our ride. Other say about its more practical purpose of as alerting others, who otherwise would remain unaware of our presence. In certain circumstances this seems to be a safety feature. Urban riding and riding in bike parks are good examples. Those who regularly takes part competing in endurance disciplines, say that riding a noisy hub, when sitting on someone else’s wheel, helps to add on the pressure on a pursued rider. Arguably, the noise that is coming from behind may be a distracting factor. At the same time, if not for descents, you are not likely to be freewheeling that much when racing. Pretty the opposite to a regular ride with one’s fellow riders. When there is no time pressure and less time is spent powering the cranks. In those cases, the noisy hub may be annoying. It may disturb a friendly chat or break the silence of natural surroundings.
There are probably other reasons out there on why it may be a good or a bad thing. Without exploring them any further, we are going to run few tests and collect the data for you to help you to educate yourself on the topic, compare with other relevant information and be prepared to make your own informed decision.
In general, higher POE hubs demonstrate higher noise level, compared with those that are slower to engage. Though not always, and not for all types of the engagement designs. We encourage you to read more on this topic in Hub Engagement Designs – Part 1.
All the hubs were in 142×12 mm configuration with Shimano HG freehub. We used the same tire for three tests and a matching tire – manufacturer, model, compound for the last one. Cassette is the same across all tests. We tested Trailmech XC Classic rear hub with two different versions of Vortex by simply swapping the mechanism between tests. All hubs were lubed with synthetic oil 10W. Type of a lube may have a drastic impact on the noise level. We followed own recommendations of using thin, that is with low viscosity grade, oil. If we to compare results with other, thicker type of oil, or any kind of a grease, the readings would have been lower. At the same time, neither a thicker oil nor any kind of grease are recommended. In short, they lead to an unstable operation of the mechanism. Measurements were recorded at room temperature.
The rear wheel is cranked up until it reaches 40 km/h measured with a cycling computer. Then the noise level in freewheeling mode is measured with Extech Instruments 407750 Digital Sound Level Meter.
The MAX recorded noise level during each test is shown in the table below.
|Hub Model||MAX, dB|
|Trailmech XC Classic – Vortex 60T||87.2|
|Trailmech XC Classic – Vortex 72T||81.6|
|Trailmech Enduro Rear – Vortex 50T||74.2|
|Trailmech XCR Rear – Vortex 50T||81.2|
Our observation is that Vortex mechanism with 60 teeth is the loudest in the test. What is interesting is that XCs newer version of Vortex with 72 teeth is less noisy and is on par with Vortex 50 teeth of the new XCR hub. The latter uses the same mechanism as Trailmech Enduro/Downhill series. More teeth or POE does not necessarily mean a noisier hub. Other aspects of hub’s design have direct influence on its noise level. This is why Enduro model, tested with the same 50 teeth Vortex mechanism as the XCR model, demonstrated quieter operation.
What about comparison with other hubs? Thanks to the comprehensive work done by fellows at MTB MAG (https://www.mtb-mag.com), this information is available.
|Hub Model||MAX, dB|
|Industry Nine – I9 Hydra, Enduro 305 Wheelset||86.2|
|DT Swiss – 240s, Star Ratchet 54T||81.9|
|DT Swiss – Ratchet EXP||82.5|
|Hope Technology – Hope Pro 4||78.4|
|Newmen Components – Star Ratchet 36T, Evolution SL30 Wheelset||82.1|
Few things to keep in mind about the data. Industry Nine – I9 Hydra and DT Swiss – 240s were tested without tires. We also do not know at what wheel’s speed the measurements were recorded.
Should you be interested to check on these and other tested samples, not listed in the table below, navigate to MTB MAG’s channel.