Are modern two strokes really better?

[evo550]

Yep, bottoms up, it's Monday night....

[Slakewell]

Yes.

The big advances come mostly from ignitions and power valves. The new 300's are just great motors. 

[Lozza]

Modern materials, electronics, CAD/CAM design and manufacture last but not least the benefit of knowing what not to do. Unfortunately in dirt bikes only a tiny fraction of the past 10 years of two stroke engine development has been applied.

[KTM47]

Yes of course they are better, but they haven't had the development the four strokes have had.  But I don't think we want that.  More development means more cost.

I rode a 2014 YZ125 at CD10 and I was very surprised by how good it was even down low.

The SCBs need to re-introduce a 125 clubman class. Bring back cheaper MX.

Apparently KTM have fuel injection for the two strokes but don't want to bring it in because of cost.

Also please note the last two stroke to win the 500 MX Champs was only a 360.  500s were just too much.

[bigk]

I have a modern 250 2t, it's super light weight, goes unreal & is extremely civilized & easy to ride. The big bonus is I'm not rooted at the end of a long day by fighting a heavy 450 4t. Having said all that last time I timed myself on a new bike against an old bike (1980 Husky CR390), I was only 3-4 seconds a lap slower on the old girl. I'm sure it was only the brakes that made the difference.
K

[NR555]

I jumped off my 1993 CR250 straight on to a new YZ250 and I found the biggest difference was the frame.  It's amazing how rigid the aluminium frame is.  It just thuds into the bumps, where you can really feel the chassis working on the old steel bike.  The motors on both bikes were lineball, maybe the YZ has a bit more up top (both motors are fresh).  Motocross Action didn't call that year's CR engine the 'Motor of Doom' for nothing (mine is stock apart from a vforce reed block) - it really was head & shoulders above anything else back then.  On the downside, in stock form, the suspension on the 93 is complete garbage!

[b490]

 My '06  KTM 300 much easier / less tiring to ride through the bush all day ( perfect mid sized capacity & power )   compared  to  my    ( '83  mod)    250 , 490  & 500  cc  2str  enduro  bikes
   but the older bikes have much nicer (comfortable)  seats 

   Regards ,
                    Steve

[Lozza]

Yes of course they are better, but they haven't had the development the four strokes have had.  But I don't think we want that.  More development means more cost.


Apparently KTM have fuel injection for the two strokes but don't want to bring it in because of cost.

Development costs are amortised over the model run , history has proven we are happy to pay for improved performance and an overall "better bike". The cost of a injected KTM can't be the issue as hardware is the same as 4T, that story has only been doing the rounds since 09, but we never see the bike.

[Mike52]

http://twostrokemotocross.com/2008/12/worlds-fastest-dirt-bike/
http://www.bioflexbeast.com.au/inspiration.html

[Slakewell]

Willing told me whilst working for KTM that they tested some different types of FI on the 300.
He implied cost being the main factor in it not being fitted. For those who dont know Willing worked in the R&D after the failed Moto GP project and designed the linkage rear suspension used today.

[XC83]

Sherco have a fuel injected 300 proto type and a video.. https://www.youtube.com/watch?v=j-hTHqF_KeE

I raced my AE500 and WR300 a couple of weeks ago....the WR is more civilised.

[Rusty]

Modern bike makers have realised that they have built in too much rigidity in their frames and are actually going backwards to put more flex in them.

and

Has always been the problem with Alloy frames.   I set my '97 CR250 up with a set of conventional forks off a RM250 and it turned in to a much better feeling and performing bike.

[FourstrokeForever]

Sherco have a fuel injected 300 proto type and a video.. https://www.youtube.com/watch?v=j-hTHqF_KeE

I raced my AE500 and WR300 a couple of weeks ago....the WR is more civilised.

The Sherco prototype somehow sounds fatter but yet more sharper off idle than the carb bike. I wonder if the injection toned the documented aggressive nature of the carb bike?

Having owned a '04 and an '06 KTM300, I can honestly say that if I was to ever buy another new 2st, a 300 would be my choice. They are so easy to live with. The power delivery is incredible. It can be ridden a gear higher up snotty hills etc without having to rev the thing in an attempt to stay on the pipe and then it has enough top end to scare the pants off of any 450st. They really are the 3stroke dirt bike.

[Nathan S]

....
I set my '97 CR250 up with a set of conventional forks off a RM250 and it turned in to a much better feeling and performing bike.

I have a 93 CR250 with a set of 86~89 RWU forks in it, with 93 125 triple clamps (less offset) & adaptors. I barely rode it with the (corroded) 93 USDs, but with the RWUs, it is brilliant: it turns well, and has none of the headshake these bikes were known for.

[Lozza]

http://twostrokemotocross.com/2008/12/worlds-fastest-dirt-bike/
http://www.bioflexbeast.com.au/inspiration.html

speeds at Bonneville are 20-30mph more than Lake Gardiner, 132 for a KX without a fairing is very good.

Willing told me whilst working for KTM that they tested some different types of FI on the 300.
He implied cost being the main factor in it not being fitted. For those who dont know Willing worked in the R&D after the failed Moto GP project and designed the linkage rear suspension used today.

Last I heard Warren was a bit crook