The length of the cage doesn't the limit size of sprocket
Although an old school short cage RD won't actually take up all the slack on an 11-42 cassette :-)
You could still run it, you'd just end up with chain flapping around :)
@Howard started
London Fixed Gear and Single-Speed is a community of fixed gear and single-speed cyclists.
Howard
Although an old school short cage RD won't actually take up all the slack on an 11-42 cassette :-)