Sprocket/tyre combination gear ratios?

[johannvr]

Came across this interesting site to calc the effect of changing tyre and/or sprocket sizes. Haven't checked it properly for accuracy yet, but assume it would be fairly good - DR650 figures seem to be close to what I've seen being bandied around before.

http://www.gearingcommander.com/

[NordieBoy]

Looks like my ideal would be a 45 rear and 14 and 16t fronts.

Lower than 14/43 for play and still a bit lower than 15/41 for road.

Wonder if I'd have to go to a 112 link chain?

[warewolf]

Nice site. Probably written by a road rider, as it is primarily concerned with sprocket changes. Only the first table shows the effect of changing tyre size, which is an issue for us folks.

[johannvr]

If I read the results correctly, then changing from stock 15/41 to custom 16/45 will need the rear wheel to be moved closer to swingarm pivot by 20.8 mm, so assuming that that amount of forward movement is possible from your current axle position you'd be able to still get away with 110 link?

[johannvr]

Nice site. Probably written by a road rider, as it is primarily concerned with sprocket changes. Only the first table shows the effect of changing tyre size, which is an issue for us folks.

Mmm yea, but been playing around with it a bit based on loading the DR's stock values & then fiddling with tire sizes (I have been running a 130/80 for a long time in preference to the stock 120/90) and then also juggling a bit with custom F&R rear sprocket setups, then X-checking the variance in gear top speed and relative RPM has been quite interesting.

Well, the first 2 combo's were... then it becomes a maze after that to remember what's what