Hey everyone, I'm pretty new to this forum, but have been getting lots of great info from everyone. So I figured I would do a little write-up on a sprocket install I did.
I live in AZ, in an area with a lot of extremely rocky, steep trails. Everyone around here has 4x4 quads, but after riding a couple, I didn't much care for the tractor feel they have. I looked at Raptor 700s, but with 4" of ground clearance, it would never survive these trails. I picked up a basically new totally stock 08 700xx off craigslist for $3,800, and have loved everything about it.
The only thing I didn't like was the gearing, it was way too tall for most of the trails I ride. I installed a 12t front sprocket, and that helped a lot. But then I got 24" Kenda Bear Claws, and lost some of the low end again.
I looked into a larger rear sprocket, but only found aluminum 40T sprockets that were a bit expensive. I saw a company that does custom sprockets for our 700s, but those are almost $100.
I knew there had to be something out there that is cross-compatible, so I got measurement from my current sprocket and started searching. What I found was a 40T JT Sprocket that was $20 on Amazon, free shipping. The part # is JTR1490.40 They also have 37T, 42T, 43T, 44T, 45T
Looks almost the same, only difference is the inner support on the JT sprocket that prevents it from just slipping on over the left axle. You could probably cut off the support ring on the JT sprocket, and never have a problem. That would make it a much easier install.
So I pulled apart the rear end as per the service manual. No big deal since I had all the tools.
Next I installed it on the left axle, everything lined up just fine
I put everything back together and got the chain on. I had to take off the front sprocket, put the chain on the rear, and then re-install the front sprocket with the chain on it.
I've put over 100 miles on it with the 12/40T gearing and have had zero issues. You loose a lot of speed with this of course, since it's now a 3.33:1 gearing vs the 2.64:1 stock gearing. At 45mph it's over 5k RPMs, so it's only worth doing if you want a 700 that really crawls. If I ever want more speed I'll put on a 13T or 14T front sprocket, or just switch back to the 37T rear.
I don't imagine many of you are going to do this, but I thought I'd throw it out there as an option for anyone interested.