For the sprocket twiddlers amongst you…!
A popular conversion for SR500 owners is to use TT/XT drive components instead of the stock SR items.
A stock SR has a 530 chain and a 46/16 rear/front sprocket setup. This is fine for short, city work and the chain lasts well, but the gearing is too low for long trips. Riders are often looking at 5000+ rpm at legal speed limits.
The trail 500s used a 520 chain, which provides less drag (more power and better mpg, but it would be difficult to measure!) and a wider range of sprocket sizes. If this option is used, an extra washer (1 mm) is required on the gearbox sprocket between the nut and sprocket due to the 520 sprocket being narrower.
According to club member Andy Brebner, rear sprockets that will fit the SR range from 40 to 53 tooth. Front sprockets range from 13 to 19, although 17 seems to be the biggest front sprocket you can run without having to modify the outer cases.
A larger front sprocket will raise the gearing (less revs for more road speed) and a smaller rear sprocket will do the same. The opposite is also true – an SR with a 13 tooth front sprocket and a 53 tooth rear would have a top speed of only around 60 km/h, but you’d get there very quickly!
Presuming your engine is OK, it will pull a 40 rear / 17 front comfortably, and you’ll be able to loaf along the highway at legal speed limits without wearing your engine out.