The quest for a small, simple, quiet, smooth-running and maintenance-free lower chain guide has been on for more than 20 years. This widget from German company Bionicon, famed for their adjustable travel and geometry full-suspension bikes, could be the missing link in the fight against chain loss.
Fitted to the chainstays much like the old DCD (for those with long memories) only with a couple of zip-ties, the chain runs through a small plastic guide, and that’s it. The chain runs cleanly and, if kept lubed, very quietly through the guide and does so across all three rings (two if you’re running dual rings) and shifting isn’t affected. There's a little side-to-side movement, which simply allows the guide to move with the chainline as you shift, just helping to keep everything quiet.
Who'll want this? We think the trail riding community will be the biggest users where riding fast in rough conditions can cause chain loss. Maybe the well-heeled might go for the XTR Shadow Plus rear mech, but this is a good option if you’re using a standard rear derailleur, but want a similar level of security.