Need help gearing in woods on 05 yz250f

[DirtBikeManiac24]

I live in new york and ride wide open woods. I thought about getting a smaller rear because when I go on the roads, I top out about 70mph and the other people I ride with are doing 80mph or more and I can't keep up. Should I also get a differen't front sprocket too because I also want some more low end. Need help fast. Tell me all of your opinions.

[barton]

If you ride in the woods a lot you might not like the taller gear. You'll get more top end, but you'll also sacrifice bottom end. That combined with the already higher 1st gear of the YZ might lead to some problems maintaining revs in technical sections leading to frequent stalling.

Of course this depends on how often you pick through technical sections in low gear. If you ride fast all the time, it might not even be an issue.

[dirtsquirt101]

sounds to me like you should have gotten a WR.

[RiderX]

You might try going down to a 47 tooth on the rear but honestly you'll suffer in the tight stuff so much that you'll hate it. The 1st gear on a YZ is already too tall for slow technical stuff with the stock 13/48 sprockets. I'm runniong 13/52, it's great in tight stuff and for technical hill climbs but I top out way to quick...probably about 60mph. Since I installed the big bore kit on my bike I plan on going back down to a 51 or a 50.You might look into changing the tranny gears. I believe only 3 of them are different, 1st, 3rd and 5th? I may be wrong......

[Dano426]

the other people I ride with are doing 80mph or more

Sounds to me that you should have gotten a YZ/WR450. You will not be able to keep up with a 250f.

[RiderX]

Sounds to me that you should have gotten a YZ/WR450. You will not be able to keep up with a 250f.

[Carter]

I ride tight mountain woods in western Canada. I have a 2004 yz250f with a bunch of woods mods. One of the mods includes dropping the front sprocket to 12 from 13 teeth which is the same as increasing the rear by 3.8 teeth. For the terrain I ride this inexpensive mod was one of the most important as I live in 1,2,3 gear only. The original sprockets would toast my clutch in no time. This will not help your top speed problem though. Your only solution is a WR tranny and even then I doubt 80 mph is attainable. (who in there right mind wants to go 70-80 mph on a 125 class dirtbike anyway?... buy a car:-))

[RiderX]

I ride tight mountain woods in western Canada. I have a 2004 yz250f with a bunch of woods mods. One of the mods includes dropping the front sprocket to 12 from 13 teeth which is the same as increasing the rear by 3.8 teeth. For the terrain I ride this inexpensive mod was one of the most important as I live in 1,2,3 gear only. The original sprockets would toast my clutch in no time. This will not help your top speed problem though. Your only solution is a WR tranny and even then I doubt 80 mph is attainable. (who in there right mind wants to go 70-80 mph on a 125 class dirtbike anyway?... buy a car:-))

On long straights I damn I have to really control myself to keep from bouncing off the rev limiter in 5th. I'd love to have a taller 5th, or an extra gear. Sometimes I wish I had bought a WR, but sometimes in some ways I'm glad I didn't.

[Looneytunes]

I thought about getting a smaller rear because when I go on the roads, I top out about 70mph and the other people I ride with are doing 80mph or more and I can't keep up.

Here's a thought. Get the lower gearing as recommended above and work your way to the front of the pack while you're still in the woods.

When you hit the high speed stretches, block the riders coming from behind and consider installing a rear-mounted oil sprayer like Robert Mitchum used in the movie "Thunder Road".

Oh.... yeah...., Mitchum ended up fried like a crispy critter when he crashed into a huge neon sign at the end of the movie.............. Must have been the oil/gas/electricity mixture ???

Nevermind ?

[Dano426]

My point was that he will not be able to keep a 250f at 80 mph for long periods of time. If that is what he wants to do, he needs to get either a YZ or a WR450.

[RiderX]

My point was that he will not be able to keep a 250f at 80 mph for long periods of time. If that is what he wants to do, he needs to get either a YZ or a WR450.

Oh, I see. I just didn't quite get what you were saying.

[DirtBikeManiac24]

What about going up on the front one while getting the bigger rear sprocket. I don't want to get up to 80 but more of around 70 to 75. Or just going up on the front one?

[DirtBikeManiac24]

I didn't want the WR because I am a small rider and the yzf weight is enough for me right now anyway and I am putting some guards and tank on so more weight is added.

[RiderX]

Like stated before, the YZ 1st gear is tall. You might try slapping a 14 tooth front on there and see how you like it. You'll be clutching a lot but you'll get the top speed you want. Maybe you should also consider a big bore kit so you can get more power to turn the taller gearing that you want.

[katoom525sx]

You could check in to puting the 5th gear out of a wr in your yz. On my wr on the street I have hit the 85mph mark and that was wide open and not much more left. I would not want to hold it there veary long thoe.

[DirtBikeManiac24]

I plan on getting the drd full system with powernow and plus, powerflow kit, intake and exhaust hotcams with jet kit. Will that be enough power then?

[Dano426]

I plan on getting the drd full system with powernow and plus, powerflow kit, intake and exhaust hotcams with jet kit. Will that be enough power then?

Those upgrade will get your engine to rev faster and pull harder. They will not affect your top speed. Get a big bore kit instead, and then change your sprockets accordingly www.ericgorr.com

[DirtBikeManiac24]

Even with a big bore kit, your still getting more power so it doesn't matter anyways. Same as the regular upgrades.

[Dano426]

More power (larger engine) + Larger front or smaller rear sprocket = Higher top speed

The top speed of a YZ290F with 14/46 sprocket set will be higher than a YZ250F with a 13/48.

[Rudy]

I think he wants to smoke his bike and ruin the valves by running at that speed, not to mention it's against the law. 55mph nation wide unless posted otherwise on the roads. Dirt bikes with loud exhausts going 70-80mph give the rest of us a bad rep. I cruise about 30 to 40mph on the back roads. Man, I would hate to hit a deer on a bike--even a small animal can bring you down hard. Stupid possums abound, and so do racoons. The deer are really starting to move this time of year. Slow down, enjoy the scenery. Life is not a race--and if it is, I hope the finish line is a long ways ahead!