Sprocket size

[Hoss250F]

My '01 YZ250F has a 13T front and 50T rear sprocket set. I am new to the game of motocross and was wondering what is the preferred size. I can understand how it all works bigger=more torque, smaller=higher speed etc.
I am just wondering what a good "all around" size is. Should I just o with whats there? I ride a mix of track and trails. No racing, just a middle aged dude trying not to hurt himself. LOL.
Thanks,
Mike

[kwmotocrosspunk]

have you ridden your bike yet? there really isnt a "one size fits all" kind of thing, its really what ever works for you if you do alot of tight tracks with small straights and lots of corners along with riding tight slower technical trails than i would check into getting a bigger front sprocket

if it is the exact opposite than i would go smaller on the front to get more top end speed, if its anywhere in between id just stick with what you have and go from there, if you desire more of one bottom or top, than just go with one tooth at a time, i prefer changing the front sprocket personally, they are cheaper!

[Hoss250F]

Thanks Nick.
What does KW stand for, Kitchener Waterloo by any chance?
I will likely just stick with whats there.
Yes, I have ridden the bike and it seems to work great for what I need.
It goes as fast as my 39 year old body wants it to and handles well in the tight stuff so...
I was looking through parts for sale and noticed all the variations so i got curious.
I like the idea of changing the front sprocket, makes sense.
Mike

[Florida 393]

I would not go any lower than the 13T countersprocket, the chain wear and swingarm rub are problems. The rear sprocket at 50 is probably okay. You might want to have a 51T rear sprocket for tighter courses and woods work. I run between 48T and 51T rear sprockets on my 426 for MX depending on the track. You get a good spread and quicker acceleration out of the corners with the 51T rear sprocket. As KW said, ride the bike at a track and try a larger rear sprocket. Best of luck with your new scoot.

Bill

[Orido]

Just to correct you, smaller front sprocket reduces top end speed and bigger increases.

Originally Posted by kwmotocrosspunk

have you ridden your bike yet? there really isnt a "one size fits all" kind of thing, its really what ever works for you if you do alot of tight tracks with small straights and lots of corners along with riding tight slower technical trails than i would check into getting a bigger front sprocket

if it is the exact opposite than i would go smaller on the front to get more top end speed, if its anywhere in between id just stick with what you have and go from there, if you desire more of one bottom or top, than just go with one tooth at a time, i prefer changing the front sprocket personally, they are cheaper!

[Duran676]

well if you wanted to get reall technical about your gearing divide the rear sprocket by the front 50 / 13 = 3.84 , 50 / 14 = 3.57 etc. etc. and really get to know what gearing works well in certain style tracks.

[pjg351]

Most of the yamaha 250f's i see at the track run either 13/50 or 13/51 for MX, due mainly to their lack of bottom end

[Duran676]

Originally Posted by pjg351

Most of the yamaha 250f's i see at the track run either 13/50 or 13/51 for MX, due mainly to their lack of bottom end

i have a 13/50 on my 03 yz250f works good for me