yeah i wanted to gear my 660 down a little so i changed the stock 13tooth front sprocket to a 12 tooth and kept the rear sprocket stock. what will be the difference in acceleration with the 12 tooth on it and how much top speed will be knocked off of it. i havent rpde it yet cause im still working on it. please help me out thanks

 

You will notice a bit of a pickup in the lowend. Your topend will not change because a stock raptor motor doesnt have enough power to reach the rev limiter.

 

I have ridden raptors with 11, 12, 13, and 14 tooth front sprockets. My experiences with my buddies are that Yamaha geared the raptor pretty good from the factory. Yes a 12t will be better for the woods because its more controllable and you will come out of corners a little faster.

We have found that for drag racing, the 13 and 14 are the best. The 12t is the best for the woods and the 11t is the best for wheelies. This is true reguardless of how it feels on the seat of the pants. It fooled us a little.

Top speeds:

11t - 69.4mph (02' with gutted stock pipe, uni filter and high pressure in rear tires) ......engine was humming
12t - 71.3mph (03' hmf slip-on with normal rear pressure for woods)
13t - 76.7mph (05' stock firm tire pressure)
13t - 73.7mph (02' bone stock low pressure hot day)
14t - 81.1mph (04' no spark arrestor, k&n replacement, woods tire pressure, decent day)
14t - 84.3mph (04' no spark arrestor, k&n replacement, raised tire pressure for the road, good day)

Stock Raptor on the rev-limit in 5th would be 91-92mph, this is impossible for obvious reasons.

After riding a raptor you know how it makes power, and from the results you can tell what is happening. The 11t sprocket revs out further than the rest. From this you can see that the 12t @71.3mph is at about the same rpm as the 14t at 81.1mph (about 5mph per front tooth), the 13t isnt far off of these two, but the 11t is definitley pulling more rpm. From this you can see that its almost at the same rpm regaurdless of gearing, disregaurd 11t, that the raptor quits pulling.

hope this help, its interesting anyway.

 

Thanks man for the info!!! But i just hope i can tell a difference between the 13 and the 12 tooth. Im hoping it accelerates alot faster

 

It wont accelerate a lot faster. Honestly you probably wont even notice a difference unless you ride a lot.

 

JLsparky7 is right. It will be primarily better when you are coming out of corners and hillclimbing.

 

Top speed will drop a few mph.

There's a significant difference in off-the-line acceleration and rideability. On a stock or piped machine this gear change typically makes the bike's power easier to use for the average recreational rider but can diminish the purpose of 1st gear.


I'd simply suggest waiting until you can go and ride it, especially if you've already installed it.

 

ok thanks for the info. i cant wait to ride it!