I just took some vacation time and spent 5 days straight riding the ATV & MCCCT trails in Michigan. I had a blast! However, at my usual riding speed it seemed that I was going to fast for first gear and too slow for second gear. I'd like to be able to chug up some of the hills in second gear but it really didn't seem to happen unless I periodically flogged it to spin the rear wheel in the sand to keep the rpms up. My current set-up is 13T front & 42T rear. The KLX has a dynojet kit, KDX snorkel airbox upgrade and stock exhaust. I now have a second bike for road riding (CB500x) and don't mind losing some "on road ability" on the KLX (as long at it isn't too extreme. I know I'll lose top speed and I'd still like to be able to comfortably ride it at at least 55 mph. Is my current 13/42 set-up ideal for what I want or can I do better? I really want to do more of those sandy Michigan trails as they are close by to my home state of Indiana. From what I've read, I won't gain much down low by going 13/45 but It will drastically lower my top speed. True? What would top speed be with 13/45 set-up?

 

If I remember right I was running a 45/13 when I was up there. I was also running a 4.10-18 a shade narrower than the 120/80-18, let it spin up a bit easier. I could run 60 mph no problem on the highway as needed, but wasn't fun. The eastern side trails were great with some dirt mixed in. The trails out of Indian River were miserably deep sand, no rain in a while. No problem getting rolling, only problem was the way the harder base under the sugar sand would make the bike crab to the side. I tipped over a few times, at 0 mph because of it. It was trying to pull the bike one way and I'm trying to steer the other. Last time as I went to step off the bike as it was going down, I hit my right toe on the seat and couldn't complete the step. My left foot was under the bike back at the number plate area, fracturing my ankle. End of riding in north part of the southern penninsula - Indian River area.

 

The KLX is the worst bike I have ever ridden in the sand, I hate it. ... give me rocks any day!!!!

 

Well I'm not familiar with Michigan sand conditions but I ride a wide variety of terrain including both loose sand (silty) and what I'll call grippy sand (crushed granite). I went from stock 14/42 combo to 13/42. It did help some for sure but still left a lot to be desired. I then swapped to a 50 in the rear and it's a whole new bike. I gained a TON down low and torque improved immensely in all gears. I usually cruise along in 2nd or 3rd now in the dirt. 1st is strictly reserved for the tightest conditions. Yes I gave up top speed, but I rarely need to get above 60mph anyway so it wasn't a big deal for me. Love this combo!

 

I'll also add that tires affect ridability as much as gearing - especially in the sand. What are you running for rubber? Maybe it's just a bad photo but your tires are looking pretty warn. If so, that's a bit like running slicks in the snow.

 

It's 'worn', and those tires look like they have 50 miles on them.

 

I ride a lot of sand in the Florida panhandle. On a jetted 250 I had the most fun running 14/49. I was having trouble keeping up with the DR650's on the jeep trails so dropped down to 14/47 and I think that was the sweet spot for everything short of tight singletrack. Still a bit busy at speed, but livable. I've since gone to 331cc's and 15/47... works very well from 'slow to 60mph'.

Note: I run full *****... so pavement is not fun no matter what gearing I'm running.