rear derailleur after four months and 3,000 miles in SE Asia Published May 30, 2011 at 1067 × 800 in Preparing a Tandem Bicycle for the Andes and the Amazon 4 Our rear derailleur after four months and 3,000 miles in SE Asia very gritty, gunked up, greasy real derailleur from a touring tandem bicycle after four months traveling bad Asian roads