FIM goes to 350cc 4t again?

[jeffd]

Our old friend, AJSB, posted this over on thumpertalk... FIM looking at dropping mid-bore class from 450cc 4t to 350cc 4t...

http://www.motorcycledaily.com/23december07_why350.htm

I would like someone to build a long stroke and bored version of a 250 to give me a 325 4t with 250-like weight... I think that new gasgas trials motor with 320cc displacement (keep the long stroke, please) and six speeds would be a very fun ride - and very, very light... It probably wouldn't win a drag race but get in the tight stuff and walk away from anything without a drop of sweat expended in the process... That motor looks like it weighs less than an xr200 motor...

jeff

 

[Skidad]

Our old friend, AJSB, posted this over on thumpertalk... FIM looking at dropping mid-bore class from 450cc 4t to 350cc 4t...

http://www.motorcycledaily.com/23december07_why350.htm

I would like someone to build a long stroke and bored version of a 250 to give me a 325 4t with 250-like weight... I think that new gasgas trials motor with 320cc displacement (keep the long stroke, please) and six speeds would be a very fun ride - and very, very light... It probably wouldn't win a drag race but get in the tight stuff and walk away from anything without a drop of sweat expended in the process... That motor looks like it weighs less than an xr200 motor...

jeff

Surely you must know about the HT Racing 340 stroker KTM 250F motor. Awesome motor from what I read.

 

[jeffd]

Many here don't like ktms for several reasons...

1. The PDS suspension does not work as well as a linkage type suspension (in a variety of terrain).
2. KTMs like to go in a straight line and lack the turning prowess of the gasgas...
3. They look like a rotting pumpkin (orange and black) and are very, very ugly...

The extremely short stroked motors of today can't be modified greatly without sacrificing reliability. And although many companies will make overbore piston kits for these bikes (athena, etc.) - they take the bore versus stroke relationship into an area where power gains are not that great. Having a bike that was designed with a longer stroke and a torque producing bore/stroke ratio, like the new gg 4t motor, would have many advantages over the mx oriented 4 strokes that exist today... The primary one in my mind, is that it would be a very fun bike to ride...

jeff

 

[LAWMAN]

I have been waiting for someone to come out with a 350ish 4-S w/ a six-speed + electric start, no more than 235 lbs. or so. the 250Fs aren't enough, the 450s are a handful in the tight. I thought long & hard about building up a 250XC-F into a 340, but did not want to invest that much time & $ into the project (including working on the KTM suspension). I bet it won't be long before several of them are out. I'll be hanging on to my 2-stroke, tho.

 

[GMP]

A 3XX designed as one for the woods, built on a dedicated platform. That would bring reliability up and maintanence down. I like the 250Fs in certain conditions but not as my only bike. The softer power is good in the grease but I hate revving the hell out of them constantly when it opens up. A 325 in the GG frame would be perfect, more than a 250F but less than a 250 2t. The side valve design would certainly give a nice low CG, question is could you get ENOUGH mid to top power out of it to satisfy.
What about a 4 valve side valver, 2 on each side? Interesting concept.

 

[roostafish]

Jeff, as a OSU Beaver. I am taken aback at your comment of KTM's being ugly. If they actually worked, I'd buy one because I dig the color combo. I think they look great!

Now, if they'd just fix the suspension. It would also be nice if they turned properly.