MXC -vs- EXC

I'm looking at a 450 MXC and 525 EXC. The 525 is almost 1000 dollars more and am not sure the extra 60cc is really worth it. My bigger question is the gearing in the MXC... I know it has a close ratio trans but am concerned that it will not work well for long rides in Mexico. Does anyone know the differnce in the gear ratios between the two bikes. The up side to the MXC is the larger tank for distance riding... I need some advise.

What kind of riding do you do - single track -open desert? The MXC is designed for the oped desert but works good in the tight stuff when geared down. The biggest deferance is the 1st and second gearing. Mostly the first gear on the MXC is very tall - good for desert - less good in the single track unless geared way down.

I really like single track but spend most of my time in the open desert. Are only first and second changed? What about 4 through 6?

These ratios are for the 520/400, I don't know if they have changed for the '03 model year or not.















So first gear on the EXC is a whopping 18% lower than MXC. Second gear is 9%, third is 5%. Fourth is the same, fifth and sixth are about 5%-6% taller on the EXC. Go three teeth smaller on the rear sprocket and the MXC should have the same top speed as the EXC, but no amount of sprocket changing will make first and second on the MXC approximate that tractor-like first of the EXC.

If you do not regularly ride tight trails where the super-low first gear is needed you should get the MXC. It should be able to easily make 95+ mph with a new rear sprocket. If you ride in the dez you will never use first on the EXC anyway. It is very low.

Hope this helps.

Here are the ratios from the '03 525 E/MXC








EXC (These are the same as what was posted previously)







My EXC came geared for 85MPH+ top end. I changed the gearing to 13/52 from 14/48 (16% lower). That should allow me to navigate tight single-track trails much easier (haven't ridden it with the changed gearing yet, we are having a cold spell in KY, temnps are near 0F). The 52T R/S is the largest that will fit the stock chain guide, and just barely at that. I haven't disconnected the shock and moved the rear wheel through its travel yet to verify that the chain has enough slack. It is adjusted per the manual, but given the destrcuctive potential of a chain that is too tight, I want to be certain before I ride it. :)

Extra power is always worth it. The difference in power of the 2 bikes is noticeable. If your going to be doing a lot of really tight trails the 450 probably won't tire you out as fast. If your ridding a mix of dez and tight I would go with the 525. The 02 and 03 tranny ratios are the same for both the MXC and exc. IMHO the exc is a more versatile bike due to the wide ratio tranny. One gear for every situation. Some mxc riders will tell you they can't gear low enough for really tight technical sections and if they do the top end suffers.

If your worried about fuel you can trade your exc tank for an mxc tank - there's always someone looking to trade. Or you can buy an oversized tank or sell the mxc tank and buy a oversized tank. You can probably sell the exc tank for almost enough to pay for the oversized one. The possibilities are endless.

isn't it strange how the MXC doesn't come with a light but has a bigger tank? wouldn't the extended riding time kind of indicate more chance of running into dark hours?

Well, I took the plunge today. I bought a 450 MXC. I'm leary of the close ratio trans. I guess I'll know when I ride on Saturday.

I don't understand the reasoning behind the MXC. If it's a desert bike, why wouldn't it have a higher 5th and 6th gear? My EXC 520 works great in the des, and still has an ultra low 1st for tight stuff, although 2nd works on almost anything unless you want to get off and walk(hike) next to the bike. I think close ratio is better for track use. The MXC(or aftermarket)tank is a must as far distance is concerned. :)

The MXC is For the des. and the EXC is for the woods, but the gear ratios seem backwrds to me I would think the wide ratio (EXC) would be best in the Des. and the close ratio (MXC) would do better in the woods. Why don't both come with lights? I know you can set the MXC up with lights, but why not factory lighting? :)

I've also heard the MXC has a stronger lighting coil. I'm confused. :)

KTM calls the MXC the "Cross Country" model but they never go on to explain just what that means. My first KTM was an MXC and I'll never have another. That was a 98 380. I was coming off a Yamaha WR500 with no lights or odo so I didn't miss those. The low top speed of the close ratio was a drawback, though, especially given it was a 5 speed. Probably not quite as bad with the extra gear the RFS's get.

I don't run in the dez but the guys who do say they like the MXC because it pulls the gears better in deep sand. That does make some sense to me. Gearing is the wild card. You can gear one up or one down or whatever and get all kinds of different results. For my money, I'd get the EXC and gear appropriately. You get the lights and the very nice electronic odo/speedo.


I'm 99.9% sure that the MXC and EXC share identical motors including the lighting coils on the RFS's. The 2 strokes may have some difference in lighting coils between M and E, though.

It may be a moot point now, but since you live in CA, don't forget the whole red/green sticker issue. I'm 100% certain that EXCs are green and can therefore be plated for DS use. I don't think that is true of the MXCs. A riding buddy owns a 525 MXC and got a red sticker from the DMV. If you think you may want to DS your bike, be sure and check the VIN.

I ride often in Mexico, but also do desert and singletrack. Pretty much everything. My gearing is 14/52 and that can handle everything no problem. I was running 13/52, but that made it rough on the engine during long rides in Baja.

The 03 RFS MXC's are green stickerable. Maybe he got one of those very early 03's, like mine, that has the messed up VIN. If so, he might be smart to get that updated from KTM. Even if he doesn't want the green sticker, it'll be worth more when he goes to get rid of it.

I don't understand the reasoning behind the MXC. If it's a desert bike, why wouldn't it have a higher 5th and 6th gear?

Here is how I see the reasoning behind the differences twixt the RFS MXC and EXC line:


Even if geared for the same top speed (a few teeth on the rear sprocket will do the trick) the MXC will have closer spacing between all gears. This is preferred in the dez over the super-low first of the EXC (that is the trade off in simplest terms) because you rarely see terrain that requires that in a desert race, you want the better acceleration up a deep sand wash (for example) that the close ratio gives you. There are still KX500s out there, and there may be one in that sand wash with you.

If you are racing enduros you will want a super-low first gear, if only to sneak up to a check without dabbing to prevent burning it, but more likely because the terrain will require it at some point.


I’ve never even witnessed, much less ridden in, an enduro, but it is my understanding that many of them require the bike to be licensed because there may be a transfer section that consists of a public roadway. Not all states require blinkers to make a bike road-legal, but most, if not all, probably require a functioning headlight and tail light.

BTW, I’ve never raced at night, but I would never do so with a stock light. Ever. I thought the MXC and EXC stators were the same, but it would make sense for the MXC to have a higher output to power the modern lighting systems (one flood, one spot) found on desert bikes.

Of course the larger tank is self explanatory.

My two pennies.

Mjlang, I'm in San Diego too, Fallbrook that is. I ride and have ridden mxc's, but 2-strokes. In the past a 360mxc and now a 300mxc. I too am looking in to a 4-stroke and I'm going with, if I can find one (CA Green sticker) 520 (due to cost). I feel I need the overall power and from what I've read from the N.J. enduro guys, the extra power when geared right makes riding the 520 or 525 better than the 400 or 450 even in the tight Northeastern woods. On to the EXc vrs. MXc, I ride desert; Ocotillo one weekend, and then tracks like Cahuilla or Amajo (Comp Park, I miss that place) the next. The mxc works well at both the tracks and the desert with final drive changes. Any input on how the EXC will work on the tracks. In the desert (less 1st gear) or the USFS trails the EXC should be the heat, but what about the tracks. I can't keep both and my wife said this is the last go round. So I need the do it all bike with a green sticker. Any help from what you have learned our others would be appreciated. Any input on the Husqvarna TE570. I hear that's a power house for our area and it's green sticker to boot. I just can't swap my MXC's (SX) suspension to it and that's a drag.

I bought a 03 525mxc and got a green sticker with the reg. FYI

I have an 03 525 MXC. First gear is too tall for tight trail riding. I am always on the clutch and feel as though I am in second gear. i bought the mxc because i wanted the bigger tank over the exc(i had an exc on order and switched to the mxc). for open desert riding the mxc hauls. i think i should have gotten the exc. the speedo is cool, the gear ratios are better and i'm sure a bigger tank is available. good luck.


This is a very interesting discussion. I'm not debating one way or the other. I had my EXC out in the desert recently on all kinds of trails and conditions. Everything from sand washes to hard pack trails and rocks, even a dry lake bed. It handled great everywhere! I didn't find any disadvantage at all with the wide-ratio gear box. I wonder if it is more a rider style / personal preference thing? What Hick says sort of makes sence. I don't ride the desert that much anymore. Mostly mountain trails. I'd just have to say for a do it all kind of bike the EXC seems to be a very good fit. At least, for me. The 520 may be a bit of overkill for the foot hills and mountains but, in the desert it every bit worth it. :)

Paul, what gearing are you running? I rarely use 1st gear, even with stock gearing. 2nd will pull anything short of walking pace. You will be riding desert, if you get your butt out here! Give me a date, and we'll go for a ride. The only benefit of a close ratio box to me is in closed course racing. On a short track I raced on, I was getting passed by a CRF because his gearing was closer. I'd pull him until we shifted, then my RPM in the next gear was too low compared to his, and he'd get by. I think he won the race, but I'm not sure as I crashed and got knocked out! To me the EXC with a big tank has it all. Capable on all levels, maybe not the fastest everywhere, but very capable. Just an opinion, and you know what they say about opinions. :)

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