better acceleration times?

less shifting?

I am at a loss, any ideas on why 12t front sprocket might be more useful than stock?

I know you lose top end

what else should I take into consideration before I give this $12 mod a try?

 

changes your whole gear spectrum . depends on what your weight is . how you ride , what you ride in and wear ,

 

I've got a twelve tooth and a stock sprocket that i have been switching back in forth. I am still trying to decide which is better. With the 12 tooth, first gear is pretty much useless, however second seems to be a good range and is what I stay in the most in tight trails. With the lower gear my Raptor would lift the front end very easily, even more so than stock. (I can lift the front end in 1st-4th gears with the 12 tooth 1st-3rd with the stock sprocket) Drag racing you accelerate faster but loose top end. I actually do better drag racing with the stock spocket cause I can get off the line better. (12 tooth starts were tricky for me - hard to keep the front end down which slows me down) Right now I am back with the stock sprocket and I seem to like it better. If I were you I would go ahead and try it and see, you might like it better. I didn't have to cut my chain to get it tight. (i am still running stock chain) so I can switch back and forth pretty easily - 10 minutes tops.

 

I dont know for sure, but maybe a good compromise between the two would be to go with a 42 tooth rear and leave the 13 tooth front. It would lower the gearing a littlte but not as much as going with the 12 tooth front. I believe that is what Im going to try, just a guess though[img]i/expressions/face-icon-small-wink.gif[/img]

 

Personally I don't like the 12 tooth front. My friend runs it on his, and I run the stock 13 and find it much better, for where I ride.
Then again I'm kind of a dumb kid and bought an 11 front and a 15 front also just for fun.

 

One big advantage if you do any tight trail riding is that it makes reverse much more manageable... Don't know if you have ever been stuck nose first over a hill because the trail has a tree down and no way to turn around... but it does make it easier!

Also if you ever do any very slow trail riding like maybe a friend of your is in front of you on his big ute just put putting along then first is awsome with a 12/40.. you can just let out on the clutch and cruise along behind them...

Just depends on what kind of riding you do I guess! Good luck with the choice and have fun!

 

I switched to a 12 and love it! I had some trouble on the tight trails before, as it seemed like there wasn't a correct gear for my speed. With the 12, Second gear is great for trails and no chugging or having to rap it out in first. Also, with the stock gearing, I couldn't pull 2nd gear drag starts, it would always bog. With the 12, it holeshots much better!

 

same about the trails and hills. I do not like to shift between 1st and second and second wouldnt lug out enough. then with 22" rear tires. i have a 44 on the back and the 12 on front wich is the same as 12x40 with 20". you can go from 5 - 45 in a blip of the throttle and then hit a stump [img]i/expressions/face-icon-small-wink.gif[/img] I have yet to try it on anything but my own track wich i ride in 3rd mostly although i shift allot, I will take my other sprokets to the dunes in a couple weeks but i doubt i will change cuz really how often do you cruise wide open in 5th gear. i have no need for that 8mph lost or whatever it is. On loggin roads if i gonna go cruising i will change the gears. back up.

 

[img]i/expressions/face-icon-small-cool.gif[/img] Greetings Voodoothenoob. First, I am sorry for being long-winded, but essentially, you need to understand the power characteristics of your ATV and apply it to the gear performance ratio you're looking for. In stock form, a Raptor has a ratio of 3.07 to 1, or in other words, the countersprocket turns 3.07 times to move the rear sprocket one rotation. Assuming a 20 inch tire diameter, your Raptor would cover about 62.8 inches of ground. Not much work for, say 40 horses, at the rear wheel. Now, reduce the countersprocket to a twelve tooth and the ratio is now 3.33 to 1. To move the same 62.8 inches, the sprocket spins 3.33 times or better yet, for the same amount of work as stock ratios, the Raptor only moves about 56 inches. Less moving mass over a shorter distance equates to the engine working less and accelerating harder. The overall effect is better acceleration because the engine can spin up faster (less moving mass). The limiting factor is that in top gear (combination of tranny planetary gear system and final drive), the engine raps out at peak power but can't perfrom the same amount of work due to the increased ratios, so you lose top end. But, go to a 14 front, and the ratio is now 2.85 to 1. The engine now has to struggle to move the same 62.8 inches because of the reduction in countersprocket ratio. It will achieve a higher top end, but at a slower acceleration because you would eventually overcome inertia. Now, if you had increased horsepower (let's not get into torque conversions), you could overcome the ratio reduction and really make a screamer with stock or taller gearing. Ever notice that dragsters can hit 300mph+ at 6.00 ET with 800HP? But, the same 800HP in , say, a Chevy Vette would only result in 200MPH at 9.00ET. That's because the gears limit the power application. With enough HP and Torque, you can turn taller gears at extreme accelerations.

So, the reduced front teeth will help your acceleration (a bit), but you may not like the end result. Have you considered boosting the power of your Raptor?

 

If you have a stock bike, its great. If you have a full pipe and filter, its still pretty nice. If you have over 50 hp, you should be running stock or a lower gear ratio.

I did notice that it greatly improved acceleration on my stock bike, and even more on my piped one. But as the distance increases, you lose speed. Not a big deal for a short race or tight trails, but not desireable for fireroads or longer drags.