Trailmech Hubs Sound – Ranked

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.

Continue reading “Trailmech Hubs Sound – Ranked”

Hub Engagement Designs – Part 2

In Part 1 we covered some of the engagement mechanisms theory. Whilst these concepts are not too excited to dive into, they are important to understand the practical implementations of various designs that we cover below.

In the classical pawl and toothed ring design the rotational force is transferred with the help of several pawls. In general, three to six pawls are used. Each one carries a substantial part of the total load. But there are other designs, where the distribution of the rotational force is more balanced. The two widely known are of DT Swiss and Chris King. In mid-90’s DT Swiss acquired a technology and since then made it one of the famous designs known as the “Star Ratchet”. It is available in several variants for road and MTB, ranging from 18 to 54 teeth. The main difference compared with the pawls, is that the system has two parts, often referred as rings.

Continue reading “Hub Engagement Designs – Part 2”

Hub Engagement Designs – Part 1

Most of the bicycles come with an engagement system, which is almost always is an integral part of the rear wheel, or to be precise – of the rear hub. There are some exceptions – like track, or fixed gear hubs and trial bikes. The latter often employ the engagement system not as part of the hub, but of the bicycle frame and is integrated with a bottom bracket unit.

The purpose of the engagement system is to temporarily disconnect the drive system from the wheel. That is when a rider stops pedalling, the wheel continues to roll. This mode is also known as “coasting”. Technically, it enables the one-way power transmission from the cranks to the wheel. One-way means that the rotation motions is always transferred from the cranks to the wheel, and not the other way around. All engagement systems automatically switch between engaged and disengaged mode. The system disengages as soon as the rotational speed of the wheel and of the drive unit do not match. The drive unit, or rotor, on the most road and MTB bikes is commonly referred as the freehub. It mounts the sprocket or cassette and receives the rotational motion from the cranks.

Continue reading “Hub Engagement Designs – Part 1”