My BMW G650X is mostly road geared. When Im not carrying luggage or extra fuel Im happy enough with the gearing for use the road and in the Devon lanes.
But when I load it up with26L of fuel and all my camping gear and tools it struggles both on and off tarmac. On main roads it isnt happy pulling 5th gear under 55 mph, on the rough stuff I feel for the clutch a lot.
As standard the sprockets are 15 / 47, Ive ordered a new 14 tooth front sprocket and have found a 49 tooth rear on tinternet.
Ive heard 1 less tooth on the front is the same as 4 extra on the back, is this a good rule to follow.
As said Rich - 3 on the back is worth 1 on the front as a good guide.
Going down one tooth and adding 4 extra on the back may make it too revvy on the road - I'd do the gearbox sprocket first and try it out fully laden as well as on the fast roads to see if it's still too tall a gear - if so, then I'd add a rear with 2 extra teeth rather than 4 as well. Or just put one on the rear with 4 extra while keeping the stock front one as a 15 tooth front will wear the chain out less quickly than a 14t. You will of course have to lengthen the chain unless it's already quite well worn.....
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Caution - the poster may well have been drinking........
