Shimano Shadow RD+: Every cyclist needs to know about this lever!

It is an unassuming 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 is not uncommon for the lever to be left in the wrong position – and a useful feature goes unused.

We’re talking about the Shadow+ or Shadow RD+ lever on Shimano’s rear derailleurs, including the popular Deore and XT ranges. 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 too – is less likely to rattle and knock.

The grey lever is used to switch the derailleur cage damping on and off. This is because, when damping is activated, 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. The derailleur cage can then be pushed 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. Good to know: It is often mistakenly assumed that the lever increases the chain tension. This is incorrect. The damping merely restricts movement in the derailleur cage’s joint. The tension on the chain remains the same.

By the way: The brand-new generation of Shimano XT and Deore rear derailleurs does away with the grey lever. The new Shadow ES technology is nevertheless said to provide significantly more damping.