The key to happiness: Why gravel cyclists need to know about Shadow+

It is an unassuming black – or sometimes grey – lever that is probably fitted to millions of bicycles. Yet it is quite clear that many cyclists are unaware of its function. The result: it’s not uncommon for the shifter to remain in the wrong position – and a useful feature of the Shimano rear derailleur goes unused.

We’re talking about the Shadow+ or Shadow RD+ lever on Shimano rear derailleurs. For gravel cyclists, the GRX and Cues series are particularly relevant here. The Japanese manufacturer has been using this lever since 2012 to prevent chain slap. This is designed to provide a smoother ride off-road and keep the chain more securely on the sprockets. This is achieved by dampening the joint between the rear derailleur body and the derailleur cage. As a result, the cage – and therefore the chain – is less likely to rattle and knock.

The lever can be used to engage and disengage the derailleur cage damping. This is because, when damping is engaged, it is significantly more difficult to fit or remove the rear wheel. This means that the lever should be set to ‘Off’ for fitting and removal. You can then push the derailleur cage forwards without much effort, and the rear derailleur becomes more mobile, allowing the cassette to be released.

When riding, however, the lever should always be set to ‘On’. If you leave the damping switched off, you’ll be missing out on an important feature of your Shimano derailleur. Especially on rough terrain, the lever can have a significant impact on the noise levels on the bike. This is because a chain that’s hitting the frame causes unnecessary clattering and rattling.

The ‘On’ and ‘Off’ positions are clearly marked on the derailleurs or on the lever itself. Good to know: It is often mistakenly assumed that the lever increases chain tension. This is incorrect. The damping simply restricts movement in the derailleur cage’s hinge. The tension on the chain remains the same. Nevertheless, chain slap is significantly reduced.

By the way: The latest generation of the GRX groupset does away with the grey lever. The new Shadow ES technology operates entirely without a lever, but is said to provide significantly more damping.