Front and rear sprockets

[Hawkeye]

Does anyone have any experience with running a 18 t front sprocket with a 31 t rear.

 

[TwoManyXS1Bs]

Have you seen Jamesgs4's thread?

http://www.xs650.com/threads/denver-to-mexico-and-back-for-the-edr-2017.49259/page-2#post-506566

 

[Bryan77xs650]

I just went from 17t front 32t rear (I changed the rear last year, it was a 34t) to 18t front 32t rear (this week) on my '77 XS650. It made a huge difference on the freeways. And I still have plenty of touqe city driving. I'm also a bigger guy 245 lbs. and have no issues with the motor bogging down. It's the second best thing I've done to the bike. The best being the tappered steering bearing kit to replace the stock ball bearings in the yoke.

 

[fredintoon]

I just went from 17t front 32t rear (I changed the rear last year, it was a 34t) to 18t front 32t rear (this week) on my '77 XS650. It made a huge difference on the freeways. And I still have plenty of torque city driving. I'm also a bigger guy 245 lbs. and have no issues with the motor bogging down. It's the second best thing I've done to the bike. The best being the tapered steering bearing kit to replace the stock ball bearings in the yoke.

Hi Bryan,
17/30 will have a slightly taller (1.76 vs 1.78) ratio as 18/32 and 17/31 a slightly shorter (1.82 vs 1.78) ratio.
Using a 17 front sprocket lets you use a heavy sidewall (H.D. O-ring, X-ring) chain that an 18 will make gnaw at the shifter shaft.
(I got the gnaw-marks on mine to prove it)
If you haven't yet done the front brake smaller master cylinder/stainless brake line/drilled disk upgrade that'll be a 3rd thing to add to your
"best things" list.