Posts
113
Joined
3/15/2010
Location
CA
Edited Date/Time
1/23/2012 6:26pm
Does anyone understand the logic behind the this? Why shouldn't a 250 go against a 250 regardless of engine type?
When the 450 was introduced riders were forced to ride them because they were suddenly at a huge disadvantage if they didn't.
But they can't run a 250 against a 250f because suddenly others would be at a huge disadvantage if they did.
When the 450 was introduced riders were forced to ride them because they were suddenly at a huge disadvantage if they didn't.
But they can't run a 250 against a 250f because suddenly others would be at a huge disadvantage if they did.
The CMA rulebook in the late 70's early 80's allowed four-strokes a basic double-displacement advantage.
This argument is nothing new.
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I'm just trying to understand the contradiction of the rule.
How is that fair? That's like saying you have to run solid rubber tires if you ride an orange bike....we need to look into this issue.
`oG
Generally speaking, up until around the year 2000, the average 500 cc 4 stroke off road dirt bike only revved to about 8-10,000 rpms, the average 250 2 stroke revved to about 7-8,000 rpms. So when yo do the simple math, you can see that the 2 stroke had a distinct power advantage over the 4 stroke as it makes twice as many power strokes over the same period of time as a 4 stroke. It wasn't until the hi revving short stroke 4 stroke engine design (basically 1 cylinder of an F1 engine) reached the ability to operate reliably and affordably at 12-14,000 rpms (twice the max rpm of a 2 stroke) that it became competitive and eventually out paced the 2 stroke. The smoother power delivery of the 4 stroke also makes them quite a bit easier to ride (non explosive power) and provides superior tractability ( hooks up) . I would imagine that there were many "super" 250 2 strokes built during the waning days of the 2 stroke advantage in PRO SX and MX that made way more HP than the 4 strokes they were competing against, but you can only put so much power to the ground in an efficient manner. Look at Cairoli on the KTM 350. He says it's easier to ride, because he doesn't have to focus so much on throttle control as on the 450. If you've had the opportunity to ride a late model injected 450 MX bike and a late model carbed version of the same bike, you'd swear the explosive power of the carbeurated bike would smoke the injected bike based on seat of the pants, but that ain't the case as we've witnessed. At least that's my opinion of it!
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