HP difference 250F V 250T stroke?

ten more for the two stroke

34 for the 250F

47 for a 250 2T

32-33 for a 125. But it's all about the torque and power spread.

What's the weight difference between the 250F and 250T?

[quote="r_outsider":2smw0tqp]32-33 for a 125. But it's all about the torque and power spread.[/quote:2smw0tqp]
Yep, peak hp has little relevance in a comparison of mx bikes.

[quote="ACMYERS":321fnlsl]all right. How do they come up with a 250T being equal to a 250-F? Why are the pro's not offered this option. It would seem like the entire lites field would be two strokes.[/quote:321fnlsl]
they are trying to bring back affordability to the am's. the pro's are more likely to have the $$$ to replace the top ends on the 250F's when they grenade....

Holy bejeezus! The '08 RM250 weight about 5 to 9 lbs. [u:yn1bt4dy]heavier[/u:yn1bt4dy] than the RMZ250! I never woulda thunk it. They must really have a lot of exotic, lightweight metals on those thumpers! Same goes with the YZ and YZF's! Is it the frames?

[quote="jtomasik":3fg4xssv]Holy bejeezus! The '08 RM250 weight about 5 to 9 lbs. [u:3fg4xssv]heavier[/u:3fg4xssv] than the RMZ250! I never woulda thunk it. They must really have a lot of exotic, lightweight metals on those thumpers! Same goes with the YZ and YZF's! Is it the frames?[/quote:3fg4xssv]
the YZ's frames are aluminum... the thumpers needed to become light as possible for people to not refer to them as diesels... " title="Laughing">, but the KTM250SX is lighter then them all! and the 125 sx even more!

The 250T was supposed to be raced in the same class as the 450. I could be wrong but I do belive there was a weight req. that might have something to do with the weight.

[quote="jtomasik":6li64sq8]Holy bejeezus! The '08 RM250 weight about 5 to 9 lbs. [u:6li64sq8]heavier[/u:6li64sq8] than the RMZ250! I never woulda thunk it. They must really have a lot of exotic, lightweight metals on those thumpers! Same goes with the YZ and YZF's! Is it the frames?[/quote:6li64sq8]
As a rule, never trust weights published by manufacturers.

[quote="WhKnuckle":3o2bh55q]
As a rule, never trust weights published by manufacturers.[/quote:3o2bh55q]

Good point. But, I never expected "creative" marketing to get the F's that close!

The only way to make things fair is to race two strokes against 2 and 4 against 4 but then people bitch that we already have a packed race day.

[quote="ACMYERS":1vlq4uqr]all right. How do they come up with a 250T being equal to a 250-F? Why are the pro's not offered this option. It would seem like the entire lites field would be two strokes.[/quote:1vlq4uqr]

If you compare the area under the dyno curve, you'll see that the 250F makes near peak hp and tq over a much broader rpm range. The 250T makes 10hp more but that only happens over a short rpm range. The 250F is easier to ride fast because of it's broad power and thumper hookup.

This is one time that I totally agree with the AMA. It's a good rule.

those 2 strokes are out of line, big time. those things were road blocks at the Texas rounds and no way is it fair to line them up against the 250f's.

[quote="j100":1m1xef1b]those 2 strokes are out of line, big time. those things were road blocks at the Texas rounds and no way is it fair to line them up against the 250f's.[/quote:1m1xef1b]


Which ones were the roadblocks? The two strokes or the four strokes?

250fs are faster than 250s on the track, especially an outdoor track.

[quote="Trinitite":2b6ls13y]250fs are faster than 250s on the track, especially an outdoor track.[/quote:2b6ls13y]

Not from what I've been seeing in Cyclenews.

I'm curious what happened at Texas.

[quote="Trinitite":2hc9dj44]250fs are faster than 250s on the track, especially an outdoor track.[/quote:2hc9dj44]
didnt malcom stewart win a 250F class on a 250 2 smoke? seems to be more of a rider being a roadblock than the bike...

From what I've read in Cyclenews, seems to me that the majority of riders, including the top runners, are still on the F's. But, the smokers are starting to win anyway.

[quote="Trinitite":2eayremp]250fs are faster than 250s on the track, especially an outdoor track.[/quote:2eayremp]You people that are making quotes about the 2's vr's 4's haven't been to the amateur nationals. The 2 stokes got most holeshots and were in the way, trust me. The 2's were motoring the 4's up the hills at Whitney.

Oh, and Malcom Stewart showing up on one of James' old factory bikes and winning a title on it goes to show you. How did I get there, look at the Oak Hill results vr's Lake Whitney and you'll see my point.

I was there and it was a nightmare going up against those guys all week. Lorettas won't favor the 2 strokes as much, because it's flat, but it's still going to be tough to get the start against them.

Bottom line, the rule is BS and needs to go away. Or, let them run those in the mod, but not the stock. Stock vr's stock is just not fair.

[quote="rockcrawlerdude":1vcnm80m][quote="Trinitite":1vcnm80m]250fs are faster than 250s on the track, especially an outdoor track.[/quote:1vcnm80m]
didnt malcom stewart win a 250F class on a 250 2 smoke? seems to be more of a rider being a roadblock than the bike... [/quote:1vcnm80m]yes, he was on 2 strokes all week at Whitney. He killed it in the mod class and it was quite obvious that the bikes were an advantage, because he was so far back at Oak Hill were they didn't allow them.

From what we're seeing, it's apparent that rules of similar displacement favor the 2 stroke. I'm not sure if it was just fishing from Trinitite's post, but a slightly modified 2 stroke has more hp than a 450, much less a 250F. Since it's unreasonable to expect the tracks (and even the AMA itself) can come up with rules that are always "fair" to the technologies, I say they just go to displacement limits and let the manufacturers sort it out. There's no reason to try to make it "fair" to one technology or the other. If it means that 2-strokes start to dominate again, then that's the way it is. Who's going to suffer if -smokers are the better racing machine? Certainly not the racer.

The problems arose when the AMA tried to make rules to "even the playing field" between the technologies. They in fact made rules that favored a more expensive technology, which is really not beneficial to the riders. Now we have excessively expensive and noisy machines dominating the industry, and, more importantly, now we have rules that aren't even honored by all tracks, resulting in inconsistencies for the racers (Colorado's SRAC doesn't support the new rules).

It's simple. Make it displacement-equivalent-based rules for all classes (including the pros). Let the inherent advantages of the technologies sort out what's on the track, not bureaucrats.

There's no question that four stroke motocross bikes are an invention to conform to rules that favored their development. It's simply not possible to build a four stroke engine that is better than a two stroke engine of equal displacement.

The only reason four stroke exist is they were given a 100% displacement advantage.

[quote="WhKnuckle":2uunl2d0]The only reason four stroke exist is they were given a 100% displacement advantage.[/quote:2uunl2d0]

[quote:23furhr3]Oh, and Malcom Stewart showing up on one of James' old factory bikes and winning a title on it goes to show you.[/quote:23furhr3]

I guess you could always "claim" it, couldn't you?