Ktm Sx 144

[Lee Majors]

From what I have read online this bike seems to be somewhat competative against 250F fourstrokes....is this true? :ride:

I have always loved 2-strokes...is this to good to be true? :bang:

I have been out of the motocross scene for 2 years letting my body heal and working on other hobbies (drag racing diesel trucks) and for some reason the bug bit me when my father showed me a magazine article with the bike showing how its pretty much dead even in all tests against a 4-stroke. Can these be bought in the US yet? I haven't been to a local track to check it out and see if there flying around yet.

Also im 210 pounds with no gear on....(nakie :p ) am I to heavy for a 144cc bike? My last bike was a 05 CRF 450 and after scaring the poo :uh: out of me several times I sold it
Was going to go back to my last before that 04 cr250f but just lost the bug and moved on.

Let me know guys im anxious to get another bike :laugh:

 

[Lee Majors]

I just read back in a few searches that 144cc production bikes were turned down by AMA ...not sure what year that was? Has this been changed? I know that from what I have read a bored 144cc or 154cc 2-stroke without multiple costly mods will not have as useable of a power range as a fourstroke 250F correct?

 

[occupant]

The 144 was banned from the pro class by the AMA, it is legal in the other ranks. That was changed this last year to allow up to a 153 2 stroke againts the 250f, but still not in any pro class. At 210 lbs you will be to heavy for it without re-springing it for any of the bigger jumps.

 

[Lee Majors]

I understand I would have to re-spring the bike. But would a from the factory SX144cc bike be able to keep up with a 250F. I can guess that it will out turn the 4-stroke as will any 2-stroke. But power wise will it run with the thumpers?

 

[Lee Majors]

So in local racing I could use this bike in any class other than pro.

I don't see why you can't use this in pro racing. Here locally back when 2-strokes were the thing every 125 was either 144 or 154 and some 164 yamahas.
All pros were running cheater motors.

 

[Chili]

The 144 was banned from the pro class by the AMA, it is legal in the other ranks. That was changed this last year to allow up to a 153 2 stroke againts the 250f

The 153 rule was a proposal that did not pass AMA congress, here is what replaced that proposal and has been passed for the 2008 rulebook.

Proposal #59: Chapter 4, Section S, Paragraph 2A, Page 45: Complete class listing of approved amateur class structure for AMA Motocross events. All classes are approved for competition and promoters must advertise any classes to be run. All classes must have a minimum wheel base of 53" (except Women’s class). All classes may be divided into A, B and C skill levels at the promoter’s discretion.

CLASS NAME DISPLACEMENT RULES
125cc 122cc - 125cc 2-Stroke
250cc 122cc-250cc
Open 122cc-Open cc
14-24 122cc-Open cc
Plus 25 122cc-Open cc
Vet Plus 30 122cc-Open cc
Vet Plus 35 122cc-Open cc
Senior Plus 40 122cc-Open cc
Senior Plus 45 122cc-Open cc
Senior Plus 50 122cc-Open cc
Women (12+) 99cc-250cc

So you can run the 144 in the 250 class against 250F's but you can also run a 250cc 2 stroke in that same class now so you choose 144 or 250?

 

[Lee Majors]

Are you serious?

 

[ericz103]

makes me feel good about 144 kit i just put on. And why do people think the AMA is worthless???

 

[Lee Majors]

That does not seem like a fair rule....I could see 144cc being legal with the 250F but a 250cc 2-stroke against a 250F fourstroke...?

Is this really the rule? Where can I find this online ? on AMA website?

 

[2 strokes for life]

It is realy and fair. They are the same CC so why not. Thats the only way i would say a 2 stroke and 4 stroke should face each other. CR500 against a CRF450R seems fair too me.

 

[Combat767]

On a tighter track a 250F and a 250 2T are pretty competitive against each other. Our track at the JoDaviess County fairgrounds in Northwest Illinois is a fairly tight stadium track. Riders probably never get out of 3rd gear accept maybe in the back stretch. In the past couple of years we have allowed riders to ride their 250F's in the 250/450 class. My observations are that a 250F can hang everywhere on the track with a 250 2T. You might see a 250 2T or a 450T pull them just a touch in an open section, but they are very competive against each other. We have had a couple of pro riders opt out of riding their tricked out 450 because it was to much bike for the track.

450F rider speeds seem to stay the same year after year because a 450F is a handful and most riders don't ride the bike to it's full potential. As the 250F's get faster each year you'll see them close the gap in speed and start hanging with 450F's on even the more open tracks.

Here's hoping the 144 and 250 2T bikes get a little resurgence in racing.

 

[Rice#67]

The 153 rule was a proposal that did not pass AMA congress, here is what replaced that proposal and has been passed for the 2008 rulebook.

Proposal #59: Chapter 4, Section S, Paragraph 2A, Page 45: Complete class listing of approved amateur class structure for AMA Motocross events. All classes are approved for competition and promoters must advertise any classes to be run. All classes must have a minimum wheel base of 53" (except Women’s class). All classes may be divided into A, B and C skill levels at the promoter’s discretion.

CLASS NAME DISPLACEMENT RULES
125cc 122cc - 125cc 2-Stroke
250cc 122cc-250cc
Open 122cc-Open cc
14-24 122cc-Open cc
Plus 25 122cc-Open cc
Vet Plus 30 122cc-Open cc
Vet Plus 35 122cc-Open cc
Senior Plus 40 122cc-Open cc
Senior Plus 45 122cc-Open cc
Senior Plus 50 122cc-Open cc
Women (12+) 99cc-250cc

So you can run the 144 in the 250 class against 250F's but you can also run a 250cc 2 stroke in that same class now so you choose 144 or 250?

Okay... so they are no longer designating 2stroke or 4stroke? And it is only based on CC now? Would these same rules apply to non-AMA organizations? I used to race in the CMA, GFI, Mutant Motorsports... I wonder if those same rules apply?

 

[Chili]

Can't give you guys much more info on other organizations etc, heck I'm a canuck who only attends one AMA sanctioned race a year. I am up to date on these proposals as I was hoping the CMRC would adopt the same rule changes, but alas they were "proactive" and adopted the 153 proposal instead so once again we will race under different rules. :bang:

Here's a link to all the rule changes that were passed for 2008 http://www.amadirectlink.com/rulebooks/OffRoadUpdates07.pdf

 

[tyler_43]

yeah it seems pretty fair for the large displacement bikes but for 250s? a 250 smoker makes roughly 43+ hp and 250fs are making 33+... like sure when you look at the dyno charts there is a larger usable range on the thumper but I don't see that compensating a 10hp difference... they aren't THAT much easier to ride :P