how?

[400exrider989]

i want more ground clearance at the back of the swing arm where the sprocket and i want it to epaul about the same gearing as a stock 400ex rear sprocket and a 14 tooth front so for it to eqaul a stock rear sprocket and 14 tooth front sprocket the rear needs to be what about 32teth and the front 15 teeth would that eqaul stock rear with 14 tooth front?

[blasterandy]

I would go get a 13 tooth if they make it and a 22in back wheels.

[northwest Texas]

Assuming a 20" tire is truly 20" tall and a 22" is 22" tall you need a 14/39. That would exactly match the stock 15/38 on the older EX's.

However, a 14/38 would give you a 2.46 ratio to the stock 2.53 ratio making it a little faster top speed while sacrificing bottom end.

Again, all this is assuming 22" is 22". I don't think you'd notice hardly a bit of difference if you went to a 14/38 w/a 22" tire vs 15/38 w/a 20" tire.

If you want more #'s, I just happened two weeks ago to do the math as I was changing my sprocket combination as well as configuring for different tire sizes, including the 22 you want to go to. Just holler back and I'll give you more to choose from.

[400exrider989]

just changing the rear sprocket to a smaller amount of teeth would give a bit more clearance from the swing arm skid plate right so what gearing would the front have to be if i changed the rear sprocket to like 32 teeth to eqaul stock gearing?

[northwest Texas]

I doubt anybody makes one that small. When I ordered my new ones from Krause Racing (Sidewinder Sprockets), they had rear sizes from 33 to 44 and fronts from 12 to 16.

However to answer your question I'll give you sizes that correspond closest to what you have stock with respect to the 22's you want in the back.

Stock 15/38 2.53/1
14/39 2.53/1
13/38 2.65/1
14/38 2.46/1
13/37 2.59/1
13/36 2.52/1
13/35 2/45/1
12/34 2.55/1
12/33 2.47/1


If you want to doublecheck my math, the formula is as follows: rear sprocket/front sprocket = Final Drive Ratio

20" tire height/22" tire height = .909

FDR x .909 = new FDR

Again, all that assumes an tire is actually that tall. I've measured mine and they aren't exact but within an inch. All those numbers will get you close to where you want to be though.

[400exrider989]

thanks a bunch i respect the time you took to awsner my question i think my best go is with this set up 12/34 2.55/1
thats with 22 inch tires right and 22' is stock right?

thanks again

[northwest Texas]

No problem, I already had most of the #'s on a sheet of paper already. All I had to do was copy them.

Stock tire size on a 400EX is 20", not 22" Also, I think it was 2005 (other's can correct me if I'm wrong, the year they added reverse) the sprocket combination changed to something different. I'm pretty sure the front went to a 14 from a 15 and I think the rear changed too but I'm only about 50% sure of that.

If your's is a newer one with reverse, let me know and I'll recalibrate your #'s.

[400exrider989]

my 400 is an 03' and just one more question what are the dimensions of the stock rims and like what order do the dimesnions mean? like example 22/11/9 what does the 22 mean 11 and 9 ?
thanks again

[northwest Texas]

22x11x9 = Height x Tire width x Rim Diameter

When you see sizes for rims such as 10x5 that means the rim diameter is 10" and it's width is 5" That would fit on the front of your EX

As for your stock rims, the fronts are either 10 x 5 or 10 x 5.5 I don't remember which.

Your rears are 9 x 8 I believe, maybe 9 x 9 or 9" in Diameter x 8" wide.

You have some flexibility in tire widths so while the stock rears are 20x10x9 you can easily fit tires that are 11" wide on those wheels too.

Things can get more confusing when you mention offsets. I can elaborate if you'd like.