EXC vs. MXC - Tranny diff?

At Dirtweek, I rode an '01 450EXC and an '02 400SX almost back to back.  I really couldn't tell much difference.  But I wasn't paying attention to the tranny.  I think the only time you would notice a difference is if you're crawling in first gear or on an open stretch in high gear.  The close ratio is more suited for acceleration through a more common distance (straights on a track, etc.).  The wide ratio is more suited for changing conditions (offroad riding with first gear trails, and open areas with long straights.)  I've always ran close ratio tranny bikes(except for the DRZ) because we don't have any open areas.  Most of our trails are between 2nd and 4th gear trails.  You'll also find yourself shifting more often with a C.R. tranny.

As far as the 300 vs. 380...I don't know.  I've never ridden a 300, but the 380 I rode was a beast.  I'd be on a 300 if I was riding a 2 stroke.  I don't think there would be much similarity between the 300 and a YZ250.

 

 

on the newer bikes the exc is about 3mph faster then the mxc

I thought you were wanting a 4-stroke, Eric? I recently got an 01 250 MXC that you haven't seen yet. I personally prefer the close-ratio MX tranny to the wide ratio, it seems snappier, always in the power. Same goes for the 250 vs 300. I've ridden a 300 and although it was nice down low, my 250 is much "rippier" and lugs very well with the stock 52t rear sprocket.

I wouldn't mind trying the close-ratio tranny. I've got a 2004 450 EXC with the wide-ratio and with the type of trail riding I do, I never touch 5th or 6th gear. I think I need to consider changing up the gearing a little. I find myself in a weird spot where I'm riding in 3rd gear but revving a little too much. As I'm getting more comfortable with the bike I'm riding more in 4th gear and just lugging the engine more. I feel like I'm riding faster that way but I'd sure like to find a way to bridge that tiny gap between 3rd and 4th gear.

I can speak for the 300's, but I think this goes for most of the other models also. First and second are the same on both. The gap from 2nd to 3rd is narrower on the MXC. Fourth gear on the MXC sort of feels like 3rd gear on the EXC, and 5th on the MXC is like 4th on the EXC (the gear ratios in the manual indicate that 5th gear on the MXC is actually lower than 4th gear on the EXC).

I find that the MXC works better for me when it's all woods and no flat-out staight line open areas. In those places I miss the EXC tranny. But the MXC's narrower gap between 2nd and 3rd makes 3rd gear more usable in the woods. I can short-shift 2nd-3rd a little easier. I compensate for the MXC's lower top end speed by using a 14/50 sprocket combo. Some don't like it because 1st and 2nd gears are too high, but it's fine for me.

I've been riding a 380exc for two seasons now off a 250sx. WOW! You CANNOT beat the power of the 380. I have a riding buddy with a 525sx and in the holeshot he can hook up better but by fourth i can catch him, and in fifth he falls off hard, the bike needs another gear. Another buddy rides a 2001 CR500 and besides the Tank factor he needed to do a pipe/silencer and reeds to match the 380's (another buddy bought one at the same time) I wouldn't recommend one for motocross or any racing for that matter unless you are in great shape. It pulls like a Clydsdale when it can hook up. We ride alot of sandy trails and hills as well as some nasty muskeg and I have never needed more power (only more Cahones!) Unfortunately last I heard they quit making them. so unless I'm wrong you may have to find a used one. Totally worth it though. oh yeah. it;s real fast too. probably 85mph'ish. thats the wide ratio tranny. Good luck with your decision.