Rear derailleur body rubs against chain when in highest gear - Bicycles Stack Exchange
MOVKZACV Bike Chain Tensioner Single Speed Adjuster Converter for MTB Road Racing Bike, Cycling Chain Stabilizer Rear Derailleur Chains Guide Single Speed Adjuster : Amazon.co.uk: Sports & Outdoors
Rear derailleurs and chain | UK Electric Bike Centre
Complete guide to rear derailleurs: everything you need to know - BikeRadar