4 stroke vs. 2 stroke

[Cactus Jack]

Cactus, Okay if I read you right then your belief appears to be that the 2 strokes of the same CC have an unfair advantage of some kind. On the other hand you agree that the 4 strokes yield faster lap times. One could claim you've contradicted yourself

So you think that :

YZ 250 = 250 cc x 10,000 pulses per minute @ 10,000 rpm = 2,500,000 cc/pm

Is equal to :

YZ 250F = 250 cc x 5,000 pulses per minute @ 10,000 rpm = 1,250,000 cc/pm

For a start ... I never said that a YZ250F was faster than a YZ250 ...... I basically agreed that a 450F can be faster than a 2 stroke 250 ..... with the right rider on board .... A bike only goes as fast as the rider can make it go ........ so a fool on a 450 can get flogged by an 80 ......

[One could claim you've contradicted yourself]

WTF ??? It's all about the power delivery suiting the track .... for instance you can change the cam profile in a 4 stroke (say CRF150R) to produce 27.5 peak HP @ 12,000 RPM but pull slower lap times than you can on the same bike with a stock cam or even smaller than stock cam ....... purely because you've put the power curve out of whack to suit the type of track you're on .... the bike MUST suit the track .... that's a well known fact .... Sprint car racers , drag racers , rally car racers , short circuit and speedway racers , ALL know that !! Stock MX 2 strokes do NOT suit a lot of tracks ...... BUT 4 strokes do because you can adjust their power better with your right hand .......

You can actually pull faster lap times on a bike with LESS power ...... The main reason why most two strokes are slower is because the turkeys riding them haven't got the physical prowess or capability to keep the things hammering thru turns .... the riders sh*t themselves and back off all the time .... most go thru corners in 2 gears too low ...... they can't keep the things singing thru the gears like they can on a straight smooth track ..... that's why they want to ride a bike with a quick powerband hit that makes up for their riding inability and fear .....

Along comes a new wave of physically strong 4 stroke racers who hammer late into turns then power slide or keep their bike revving thru the same corners two gears higher than the two stroke guys and the 2 stroke crowd can't hack it ...

 

[I_THUMP]

Well said jack

 

[Cactus Jack]

Although the MX 4 strokes rev like formula 1's ..... there's no need to flog them thru the gears like a two stroke for the entire race ...... You go thru corners in taller gears and torque them around the track ..... It's only the idiots who ride them like they're thrashing a two stroke thru "band" all the time ..... as in all day long who blow them up then complain about them .... Those guys should keep a "piggy bank" in their bedrooms and put $10 in it everytime they go for a ride as if they're going on a ride at an amusement park ..... Most of the fools are using purpose built motocross bikes for purposes other than properly sanctioned MX racing .....

That is sheer stupidity since MX racing is a series of short motos on selected race days ...... the bikes are built to put out high power on the condition that they be serviced at the specified maintenance intervals .... When used for MX racing they get a hell of a lot less use coupled with the proper scheduled services than they would with the fools who take them out to flog around trail racing in the bush all day long ......

Anyone using an MX bike for trail riding , enduro , motard or anything else other than actual competition MX racing and complaining about it is an IDIOT .... That's like complaining because your formula 1 , drag car , speedway solo bike , or Nascar can't run reliably for ten times longer than the manufacturer built it to do ...

Get real and sell the MX bike or join an MX club and become a real racer .... then go buy the Enduro version that was built to go stacks longer between services for your other usages ....... If the bike isn't a road registerable version then there's the entire problem in a nutshell .......

 

[I_THUMP]

and again Jack, its good to be reading some factual information

 

[Cactus Jack]

LOL ...... It WILL be good to see clean and efficient 2 stroke bikes making a comeback for those who can't afford to race and maintain an MX four stroke ... but if they can't compete in classes as the rules stand ..... then bad luck ....

You don't adjust racing classes to accommodate the losers ...... you lobby to get new "poorboy with lousy mechanical skills and cheap to maintain bikes" classes started .......

Hey , we want riders of 85 class two strokes and CRF150R's to have to wear lead weighted vests to slow them down to our lap times so we can compete in the class on our cheap chinese bikes .... It'll be fantastic for racing because there'll be stacks more competitors who can afford to race

We actually went to our local MX track and they simply won't allow pit bikes to race ...... You can't even race modified XR/CRF80/100 sized bikes or 4 stroke Jap motors fitted into CR85 frames ...... you have to race a late model purpose built off the showroom floor MX bike .......

So as far as I'm concerned ..... they don't WANT too many people to get interested in racing .......

 

[I_THUMP]

What tracks are they?

 

[michelin man]

the ones that get run by small minded wankers that obviously don't need the money

 

[Cactus Jack]

They're in with the bike shops (Jap Bikes) and are prejudiced against chinese bikes ........

Welcome to Maitland District Motorcycle Club

 

[Mack]

Hey there guys, I can't believe how often miniriders turns up in google results...I was looking for a cheap kx450 and this thread came on up. So while I'm here.. any of you guys know of or need to unload one please PM. I'm really after a bike with a badly blown engine to pricey to fix, thats in a good chassis.