Gearing on 07' 400ex

[trx400Rider]

Whats the stock gearing on the sprockets? I counted 14 on front, but don't know the rear sprocket size.

[dubee]

I think 34, but i would wait too see what everyone else says.

[TRX01]

the stock gearing is 15 to 38, 15 front, 38 rear

[dubee]

Yea 38 sounds right, but i think on 05 & up they come with 14 front.

[slightlybent47]

Mine was 15-39 stock.

[trx400Rider]

Id like to drop the front one to a 13, but I'll loose some top end. What size should I go with to regain some topend on the rear sprocket? a 40 tooth?

[TRX01]

no if u go down a size on the front u get more bottom end.....if u go up on the front then u get more top end...if u go up on the rear then u get more bottom end, but if u go down on the rear, u get more top end....weird, i no

[trx400Rider]

Originally posted by TRX01
no if u go down a size on the front u get more bottom end.....if u go up on the front then u get more top end...if u go up on the rear then u get more bottom end, but if u go down on the rear, u get more top end....weird, i no



Thank you for helping me out.

[TRX01]

no problem.........:cool:

[slightlybent47]

There is a chart that tells you what gearing will do to your speed but i can't seem to find it. It's a very handy chart, i'll keep looking.

[flyboy1294]

Originally posted by trx400Rider
Id like to drop the front one to a 13, but I'll loose some top end. What size should I go with to regain some topend on the rear sprocket? a 40 tooth?

First off, if you drop teeth in the front you get more BOTTOM end.

Think of a mountain bike. The gear 1 on the front is the easiest to peddle in, and its the smallest. When you shift up to gear 2, you go faster while peddling the same speed. Gear two is a larger sprocket. The opposite applies to the back. More teeth give you more bottom end, less teeth give you less.

And lastly, if you drop a tooth in the front, then go up a a few teeth in the back, you'll be at the same final gear ratio that you started with, maybe even higher. You can't get more low and then change the back to get more top. It doesn't work that way.

If I remember correctly dropping one tooth in the front is the equivalent to raising the rear sprocket by 2.5 teeth. Don't quote me on that though.

[slightlybent47]

I found it.

Here is the chart.
http://home.earthlink.net/~gellett/400ex.htm

[trx400Rider]

Originally posted by flyboy1294
First off, if you drop teeth in the front you get more BOTTOM end.

Think of a mountain bike. The gear 1 on the front is the easiest to peddle in, and its the smallest. When you shift up to gear 2, you go faster while peddling the same speed. Gear two is a larger sprocket. The opposite applies to the back. More teeth give you more bottom end, less teeth give you less.

And lastly, if you drop a tooth in the front, then go up a a few teeth in the back, you'll be at the same final gear ratio that you started with, maybe even higher. You can't get more low and then change the back to get more top. It doesn't work that way.

If I remember correctly dropping one tooth in the front is the equivalent to raising the rear sprocket by 2.5 teeth. Don't quote me on that though.


Thanks.
I wanted to drop a tooth in the front so I have some more room for the case saver.

[flyboy1294]

Originally posted by trx400Rider
Thanks.
I wanted to drop a tooth in the front so I have some more room for the case saver.

Anytime. I mistakenly read someone else's post and thought they were telling you incorrectly, that is why I made a point to restate the obvious. However after going back and re-reading, we are telling you the same thing. :o

[Ryan'07400ex]

Don't kow if anyone else said this but STOCK gearing on a 2007 400EX is 14/39. You can look on the side of the back sprocket just below the teeth and you will see a little "39"

2004 and down had the 15/38 gearing someone mentioned.

I now have 15/39 on my 07 which is NOT stock I switched from 14 wanting 2nd gear to be a bit higher for trails.