Hey guys I'm in the middle of a complete rebuild and I will be getting 20 inch tall maxxis razr's for the rear of my 250r and my motor is only mildly modded with bolt ons, I do a lot of trail riding but I still want to be able to go fast when my buddies with 450r's and stuff wanna boot. Also the trails are rarely tight, logging road type deal. What would the best combo of front and rear sprockets be? thanks again!
The only thing that sucks is picking the right set up. My 250 is geared great for the woods, but when we hit the road, i am literally left in the dust. What gearing do you have now. And you are just looking to get more top end right.
1 tooth on the front is 3 on the rear to the plus side. So going from 13-40 to 14-40 will give you more top end, it would be like 3 more teeth added to the rear.
There is a gearing calculator on everything2stroke.com
Maybe that can help you out a bit more, but i guess you need to find out what how fast your buddies bikes are running at top end. But remember top speed is at max rpm. So I don't think you want to be pinging it wide open for a long time. Your gonna lose bottom end, but really who uses first gear anyhow. LoL
I thought going up on the front sprocket has the same effect as going down on the rear sprocket. Like going one up in the front to gain some top end was like going down 3 on the rear.
Yea gearing is confusing, i will look at that gearing calculator, im pretty sure i have a stock front sprocket and a 42t rear, so it is geared pretty low i guess, my top speed feels pretty low, i think my brute force could keep up to my 250r, but my 250rs motor is tired and leaking every seal and being rebuilt right now so maybe that might fix some of it
when it says "primary gear" on the calculator, what does that mean?
Front sprocket is primary
Take the axle sprocket divided by the countershaft sprocket and that's your gear ratio. Very helpful tool. I always like to use a bigger counter sprocket and a smaller axle sprocket but that's just me.
example:
40/14=2.85
43/15=2.866
The higher the number the higher your ratio will be this will help with small tweaks and tuning on your gearing I know it helps me out greatly when I go to the track I take about 10 different sprockets so that could be a pile of combinations.
okay thats simple enough, I'll see what the ratio is on there right now and change it
i would probably gear a little taller than stock if you have a slightly built engine and still want top speed. with a little more power you should be able to rev you gears easier and get a little more rpm. +1 or +2 in the rear and run 20" tires. 1st gear IMO is really low and revs easy on a stock 250 so shouldnt be a problem for your reworked engine to do it.
ummm taller rear sprocket means lower top speed.......
I was a little confused when I read that too, you mean the front sprocket? I'm thinking about dropping 2 teeth off my rear sprocket cause I'm pretty sure the 42 I have is 2 more than stock, and see where that goes
i said gear taller not a larger(taller) rear sprocket, phone "auto corrected" to + from -
or as Homer would say "doh!"