Sprocket change

After taking the 800 down some single tracks I found it difficult to keep the bike at a slow pace whilst climbing and negotiating obstacles. In order to gain better control I will change the standard sprocket ratio of 17/42 to 15/42 (without altering the chain length). The idea here is to take both front sprockets on the trip and interchange where fuel economy is of concern. We also have the option of changing the rear sprocket to 47 if required however the chain will need to be lengthened to cater for the extra teeth.