I've seen boards and people swear by them as cheap alternatives to "expensive" track bikes.  Thoughts?

I prefer bikes with tanks that bubble. 

A lot of people love those things!! Just read these myself.

http://ducatimonsterforum.org/index.php?topic=37112.0

and

http://ducatimonsterforum.org/index.php?topic=2613.0

Might be worth the purchase just to have something to throw around! 

With something that light and minimal power one set of track tires would last half a season 

It looks like from your post that the Ninja is intended primarily as a track day ride.  Good choice for Cresson especially since the straight is not that long.  

Being so light and not heavy on the displacement, the Ninja would be great for honing your technical skills and pushing the limit; I would think a spill on a liter bike might be at least a level of magnitude worse than on a 250 - and more costly to fix.

That being said, I think you may find the lack of suspension adjustability a problem fairly quickly.  

Just my random, pre-caffeine, .02  

Just re-read the spec sheet for the newer Ninja 250; the rear shock is adjustable for pre-load.

Compared to what a decent track setup sv650 or cb/gsx/r/600 costs, I'm not sure you save any more.  Once you start trying to add adjustable bits, rearsets, dampers, bodywork etc.  Also coming from an S4R, it may feel a tad puny 

ps I know where there is an awesome 675 which just needs some race plastic to go.  And it already feels as light as a 250

Quote from: webspoke on April 16, 2010, 05:32:36 AM
ps I know where there is an awesome 675 which just needs some race plastic to go.  And it already feels as light as a 250

You are talking about some other 675, correct. 

Um, yeah, I guess so...   

Track bike only but Sue might convince me otherwise

You know what else you may want to look at is an Aprilia 250.  Full-on track bike.  Two-stroke little screamer.  Fun as hell with adjustable everything.  I got a chance to ride one at Cresson last November (Alessandro with RPM brought a demo    ).  OTD could probably be had for just below 6 grand.

i think ninja 250's are a blast. Uglier than hell, but in their own way, it becomes attractive. There's nothing to 'em, and you can't really "break it".

But if you could find yourself into a Aprilia 250, that would be more fun. More expensive, and more fun.

I'd get an SV650 to be honest.  You will find parts everywhere, it will actually have a bit of stomp in the motor, and they are a dime a dozen on the used market.  While the ninja 250 would certainly be a blast, I think you'll be begging for more bike sooner rather than later.

Quote from: Jester on April 16, 2010, 07:14:36 AM
I'd get an SV650 to be honest...

While I believe you're right -and I follow your logic...
(and I would probably do the same)

...there is something inside me that wants to have a cheap piece of shit I can just flail away on... 

I'm after technique, not speed although speed would be nice I like the cheap factor of the ninja