If you've been inside of a crash or damaged the bike in some way, this is the probable trigger. Additionally it is attainable, but more unlikely, that the Restrict screws are triggering this If these screws are misadjusted, the derailleur will not be capable to reach sure gears. Alternatively, inadequate https://donovanbaxsm.blogolenta.com/29744262/the-basic-principles-of-indexing-bike-gears