good sprocket ratios

[IRONMIKE113]

what i want to do is gain a little bit more acceleration but still have good torque and top speed right now it has the stock ratio so if anyone out there could help me i would appreciated or if u could explain it to me :confused:

[quad2xtreme]

Hopefully this topic brings about some good discussion.

Once you start modding the engine...short of a dyno, the best way to tell is timed runs. If your engine improvements have resulted in a broader powerband, you could see increased acceleration from going up a tooth on the front or down on the rear. Changing the front is equivalent to changing 3 on the rear so you can make smaller changes on the back if necessary to maximize your improvement. Generally, lower gearing will give you more acceleration and less top end but once modifications are made, you can't be sure that is the best solution. Traction plays a huge role especially when a four stroke engine is pulsing through the power cycle. If you can keep the wheels spinning faster yet keep traction and continue shifting without dropping your RPMs outside the powerband, you will be quicker.

My suggestion is to get a baseline by averaging 5 runs then drop a tooth on the front and take another average of 5 runs. Then go up a tooth on the front (from the original tooth count) and retest. You will quickly see what is giving you the most improvement. Once you find the sweet spot, this is your new baseline. However, you should take 5 new runs to average just before you make any changes. Don't count on your bike remaining perfectly consistent. Small changes can make a difference such as air temperature, humidity level, amount of tread on the tires, changing to lighter or heavier rims, your weight, losing compression, crappy gas.

/Jon

[IRONMIKE113]

good suggestion but it seems a little slow like it wants to go faster but maybe it's just me i like speed mainly but also have good acceleration:devil:

[quad2xtreme]

did you rejet and open up the airbox with that exhaust?

You definitely aren't going to go any higher on the top end unless you change gear ratios or tire size unless your RPMs go up too. I've read about 11-15 mph top end gains on a 450r using an aftermarket CDI with higher REV limit.

/Jon

[tprender]

With the stock engine, it is best to stay with the stock gearing. You might try 20 in tires. If you drop down 1 tooth in the front the top end speed will drop off to much in my opinion. when I did a 440 on my 400 I was able to use 1 more tooth in the front and I still had enough low end I thought. Most of this will be personal opinion by you. You will get people saying the opposite of what I said in there opinion.

[AnthonyWhite]

I went with a 16 tooth front sprocket. I do have a 416 bore with a stage 1 cam and hmf slip on, but it really dosnt make very much difference in my opinion. The only draw back to a 16 tooth in race situatons, you will burn up clutches faster. By dropping down to a 14 tooth front you have lost way to much top speed. Eithor stay with stock gearing or go with 16 tooth front or go a size smaller on the rear (one size on the front = about 2 sizes on the back).

[eagertorace]

with my mods, I went to a 14 in front and 36 in rear.
accelerates good out the corners and pulls hard in the higher gears. I first just changed the front and it seemed like it just slowed me down. It was time to change the rear so I put the 36 on there and WOW!!!!!!!!!!!.

[quad2xtreme]

14/36 is virtually the same as 15/38 and you won't lose as much power since the chain won't be going around a smaller front sprocket.

[IRONMIKE113]

i thank you for ur replies :)