am i too big for a kx100?

Given your age and height, I'd say get a 125. You'll love the power, and can grow into it. You'll figure how to "sit off to the side" pretty quick. The KX100 is, like you said, the same thing you already have with a slightly bigger motor. YZ165

Probably best off with a 125. A KX100 would work well for you given your light weight, but will feel a little cramped. Aftermarket triple clamps that move the bars up and foward make a big difference though. Perhaps with a few mods your CR80 expert would last you another season, then you might be a little more comfortable with a 125. IMHO right now you would be better off on the 80 or 100 for trails at your current size, but would like a 125 better on a MX track (I was in your shoes about 6 years ago:)).

good luck

The KX100 isn't much bigger/more bike than the CR80E.... I would definately go for a bigger bike (125, 250F) especially if you want to riding it for the next 2 years. You'll adapt to the 125/250F sized bike well at 5'7" (I'm 5'5" and have no height problems with the big bikes). Plus at 14, you're due to keep growing in the next few years.

Personally, I ride Yamaha, but I think they have the tallest seat heights (like a full 2" taller than the others). I think you should go for a KX125, or whatever fits. Pick a color and see if you fit on it, that's about all I can say. You'll be happy you chose a 125.

All the 125's are very similar in size and weight. Unless your a top pro I doubt the differences would make much differnece. I would decide based on what is most comfortable for you and local dealer support. Personally, I really like the KX's and though I owned a YZ125 for quite some time and even did a few races on it I never got completely comfotable with the handleing or suspension. I'v ridden 97-01 125's from all the japanese companies and liked the KX the best, followed by the CR, then the YZ then the RM. This isn't to say that one bike is universally better than the other, its just that the handleing and egronomics of some brands work better for me than others. Ride them if you can, if not at least sit on them at the dealership to get an idea of what you like. They are all excelent bikes, you really can not go wrong:)

good luck

Red wins more, check it out.

http://www.dirtrider.net/forums3/showthread.php?t=116375

That and they have the coolest frame. It looks tight when polished

A review really will not tell you which bike is best for you, the same bike can feel completely different to different people. For example, in 1997 the YZ125 was hailed by all the mags as the best 125 out by a large margin. I bought one and didn't really like it. I never got comfortable with the handling or suspension, even the motor felt a little flat on top. I rode other peoples bikes and they rode mine just to make sure it was performing as it should, it was and several people liked it, but I really liked the KX's and CR's better. Of the bikes you listed, the CR will have the best build quality, followed by the KX and then the RM. In general, Honda and Kawasaki parts are cheeper than suzuki or yamaha (especially cranks and shock parts). Is there any way you can test ride these bikes? Perhaps go for a lap on a few frind's bikes at a track day/pre-race practice???

If it helps any, a good frind of mine (who was a pro GNCC rider, raced the ISDE in Chech....Also a very competitive MX rider) now owns a Honda/Kawasaki dealership. Of course he pretty much has his pick of whatever new bike he wants and has plenty of opritunity to try out both brands. He typically perfers the CR's, however from 03-on he perfers the KX125 over the CR125. He spoke very highly of the KX and was flat amazed how good it is for MX, he still uses a larger CR for woods(such praise is rare from him).

hope this helps,

Good luck:)