The Science of Cycling: Shadow RD+

Shimano Shadow RD+ - precision shifting no matter the terrain

Mountain-biking has evolved over the years. It started as a way to explore fire roads and hiking trails. But your thirst for adventure took you on more and more remote and technical terrain, the hunger for speed took you onto downhill runs, and the satisfaction of completing an exhausting challenge took you over longer and longer distances. As you seek diversity in trails and push the limits of where you ride, Shimano responded with Shadow RD+ derailleur technology. With a narrow profile and chain-tension customization, Shadow RD+ is designed to keep you on your bike no matter how far you push the ride.

Ride. Must. Not. Be. Interrupted.

Technical terrain places challenging demands on mountain-bike equipment. Obstacles like a wayward branch or an unyielding rock can damage or even destroy your derailleur, ending an amazing ride and stranding you miles from the nearest road.

And what about chain slap? A sloppy drivetrain can interfere with shifting, cause your chain to jump out of alignment, disrupt the flow of your ride, and even destroy your drivetrain.

Shadow RD+ was developed to deal with these two flow-killing risks of taking mountain-biking to your limits. 

Get narrow to escape flow-killing equipment mishaps

Traditional derailleurs extend wider than the profile of the bicycle, leaving them vulnerable to obstacles. A branch can snag on cabling routed out and away from the chain-stay or the mechanism can be hit by rocks or debris as the rider passes. Shadow RD is a more-compact derailleur that fits closer to your frame with more direct cable routing so you can continue to push your boundaries on the bike. Shadow RD reduces main-derailleur body width by almost half. In the largest gears, mechanism extension is reduced by one third. Thus tucks the derailleur into the profile of the frame to keep it out of harm’s way.

Ratchet up then tension – or not

Besides the threat from debris, when you take your bike over uneven, technical terrain, you risk increased chain-slap – the inconsistent release of chain tension when a bicycle is jolted by a rough trail. Chain-slap can be a ride killer because when the tension in the chain that is designed to keep the drivetrain in its most powerful state is lost, the chain can misalign, comes off, and even cause extended damage to the drivetrain.

Shimano's Shadow RD+ system (which allows you to tailor the chain-tension when activated using a simple lever mounted on the derailleur) gives you a stable drivetrain and continuous shifting with minimal chain bounce. The new system also allows you to adjust the derailleur spring tension to customize the chain’s tension, so you can keep on exploring, whatever the terrain. 

For more information on our Shadow RD+ technology, click here.