kdx 200/220 to 250 2 stroke or 450f?

[fenderlove01]

Do you think it would be to much to go to a 450? Both kdx's are modded (220 has alot of work done to it) and are pretty quick for what they are. I am 18 and weigh 170lbs, 6'2.

I thought about getting a 250f but I can never find one I like but there are quite a few 450f's I have seen that I may be interested in. But do you think it is to much?

I also want something that I can start getting on a track, I love the woods but that is pretty much all the kdx's can do.

[stlavsa]

problems with 250fs if you trail ride is the gearing for top speed. If you only ride tight woods and dont leave 3rd gear then it wil be fine.

I know around here we have to ride roads/dirt roads/fire roads, open trails and stuff to connect to all the woods trails. A while back i had a kx250f and i just couldnt keep up with all my buddies on 250s when we would hit the open stuff. Just no top-speed.

If your 6'2" and 18 years old you can handle a 450 and you wont out ride the thing like you would a 250f in a couple months. Its gonna have more power, and more over its will last longer. The 250f is a notoriously maintenance intensive bike because it revs to the moon to make the power. U can get away with lower RPMS on the 450 and that extra power comes in handy.

[fenderlove01]

problems with 250fs if you trail ride is the gearing for top speed. If you only ride tight woods and dont leave 3rd gear then it wil be fine.

I know around here we have to ride roads/dirt roads/fire roads, open trails and stuff to connect to all the woods trails. A while back i had a kx250f and i just couldnt keep up with all my buddies on 250s when we would hit the open stuff. Just no top-speed.

If your 6'2" and 18 years old you can handle a 450 and you wont out ride the thing like you would a 250f in a couple months. Its gonna have more power, and more over its will last longer. The 250f is a notoriously maintenance intensive bike because it revs to the moon to make the power. U can get away with lower RPMS on the 450 and that extra power comes in handy.

One other question. I went riding with a friend who had a 05 yz 450f and I expected it to feel really heavy. But it felt WAY lighter than my kdx. I mean it was unbelievable and he was even like what... lol. But the kdx should be slightly lighter than his 450 so is the weight just displaced better on a 450?

[stlavsa]

Ya the KDX is lighter than a 450. Regaridng the 450 a lot of people claim the extra rotating components and the big bore piston add rotating mass, thus creating a greater gyroscopic effect which makes the bike harder to lean over.

If your not noticing it (i dont) then youve got nothing to worry about. The extra power is well worth the extra couple pounds.

[fender bender 59]

problems with 250fs if you trail ride is the gearing for top speed. If you only ride tight woods and dont leave 3rd gear then it wil be fine.

Really???? maybe you need to come ride with my son on his 250f

[Just_a_trail_rider]

One other question. I went riding with a friend who had a 05 yz 450f and I expected it to feel really heavy. But it felt WAY lighter than my kdx. I mean it was unbelievable and he was even like what... lol. But the kdx should be slightly lighter than his 450 so is the weight just displaced better on a 450?

Yes... 450's are heavier feeling than 2 strokes. But they are more planted, have more power and can inspire confidence to go faster if it suits your riding style. When you go faster, they feel even lighter.

Point is... to really understand a bike, you just gotta ride it. Lighter isn't necessarily better. Heavier isn't necessarily worse.

If you feel good on a 450 and like the powerband, suspension, etc... then it may be the bike for you. Nevermind what the scale says.

[CDBiker220]

I went from a kdx200(modded) to a yz250, was sooo much faster on the YZ in the woods, but missed the low end and 6 speed tranny. Now on a GasGas300. and its a dream. Has YZ250 like top end and low end almost like a 450, easy to work on and even cheaper to maintain than my buddies KTM(love the KTM 200's/300's as well). I tried to ride 450's a few times in the woods and absolutely hated it, i just cant toss them between trees as quick as any of the 2 strokes (yz250 won for flickability) and I hated the weight if stuck on a hill or in nasty sections, plus it almost pulled too hard in tight trails. A 250f is much more managable but i hated having no low end. I think ill be on GasGas300's or KTM 300's for some time to come...wish I had tried one earlier.

[stlavsa]

problems with 250fs if you trail ride is the gearing for top speed. If you only ride tight woods and dont leave 3rd gear then it wil be fine.

Really???? maybe you need to come ride with my son on his 250f

What r u trying to say?? Ive owned and raced 250fs and 450fs off-road? You gonna sit here and say they have the same top-speed as a 450f?

Were talkin like 60mph WOUND TIGHT vs 80-85 mph depending on what bike ur talking. In the tight woods i prefer a 250f, BUT if your riding on ROADS it harder on the 250f. The 450 can be rolling mid RPMS in 5th gear for 5 minutes, and the 250f will be off the limiter for 5 minutes...

If your into valve jobs every 20 hours then your son can ride with me

[FRECNDY]

A lot of that depends on gearing. A YZ250 2T will do about 67mph in 5th at 8500 rpm with stock gearing and assuming no tire slip, which is wrong. WRs have a taller top gear.

I am debating between doing an EG295 and WR 1-5 in my YZ and throwing a KDX200 in a 2002 CR125 chassis. I've read and read on the latter, and think I've figured out the combo to make it really straightforward, even using an off-the-shelf pipe for easy and cheap replacement when needed.

I think they'd end up costing about the same, but the hybrid would be even lighter than my YZ, probably 18-ish pounds. I don't feel a need for a lot more power yet, the 295 would just be to help with low end and pull the gaps in the WR gears. On the other hand, a KDX has lower first, only barely shorter sixth, and narrower gaps because it's a six speed. Seems like a really good combo. And because I have "IWR disease" (Itchy Wrench Hand), building my own bike is just a lot more attractive than giving a bunch of Austrians my (what?) extra cash.

Edited December 27, 2011 by FRECNDY

[stlavsa]

A lot of that depends on gearing. A YZ250 2T will do about 67mph in 5th at 8500 rpm with stock gearing and assuming no tire slip, which is wrong. WRs have a taller top gear.

I am debating between doing an EG295 and WR 1-5 in my YZ and throwing a KDX200 in a 2002 CR125 chassis. I've read and read on the latter, and think I've figured out the combo to make it really straightforward, even using an off-the-shelf pipe for easy and cheap replacement when needed.

I think they'd end up costing about the same, but the hybrid would be even lighter than my YZ, probably 18-ish pounds. I don't feel a need for a lot more power yet, the 295 would just be to help with low end and pull the gaps in the WR gears. On the other hand, a KDX has lower first, higher sixth, and narrower gaps because it's a six speed. Seems like a really good combo. And because I have "IWR disease" (Itchy Wrench Hand), building my own bike is just a lot more attractive than giving a bunch of Austrians my (what?) extra cash.

Its ALLL about the gearing. Hell the 250f revs MUCH higher than the 450f yet has lower topspeed, because the gears are so damn short. Give the bike GREAT torque but sacrifices speed.

Im with you the last bike on earth i would buy is a KTM. The best off-road bike IMO is an MX bike with revalved suspension, woods pipe, and off-road gears (WR/KLXR/CRFX/KDX are prime examples).

[Dumb_Fee]

Its ALLL about the gearing. Hell the 250f revs MUCH higher than the 450f yet has lower topspeed, because the gears are so damn short. Give the bike GREAT torque but sacrifices speed.

Im with you the last bike on earth i would buy is a KTM. The best off-road bike IMO is an MX bike with revalved suspension, woods pipe, and off-road gears (WR/KLXR/CRFX/KDX are prime examples).

What your describing sounds a lot like KTMs xc line...just saying

[CDBiker220]

I am debating between doing an EG295 and WR 1-5 in my YZ and throwing a KDX200 in a 2002 CR125 chassis.

If you are serious about kdx200 in a cr chassis your insane. People did that in the 90's or early 2000's before we had good KTM's or GasGas's what your explaining...is a much shittier version of a KTM200 or GasGas200. for your own sake...reconsider. It would never have the handling of the purpose built 200's and the engine couldnt even compare....just a very poor idea.

[FRECNDY]

If you are serious about kdx200 in a cr chassis your insane. People did that in the 90's or early 2000's before we had good KTM's or GasGas's what your explaining...is a much shittier version of a KTM200 or GasGas200. for your own sake...reconsider. It would never have the handling of the purpose built 200's and the engine couldnt even compare....just a very poor idea.

Actually, the hybrids keep getting done over and over because people end up with old bikes around and enjoy screwing around with them in their garages. Each guy does it a little different, and when they write it up, others can learn the lessons. It's not a hack, they're starting to come out really clean. And the fabrication just isn't that big a deal, especially after what I've done with cars.

I happen to like the fact that I can buy parts for a bike on fleabay for cheap all day long. I like that old KDXs are nearly worthless where I live, and blown up 125s are a dime a dozen in dune season. If I ever decided to get rid of it, I could take it out and bury it by the Husky in the desert and lose less money than the depreciation on a KTM or GasGas.

I specifically don't want a low-volume boutique bike, with parts (and especially spares) that aren't well-supported by the aftermarket. I don't want to drop a pile of cash on it and then still have to completely rework the ergomomics and suspension so I can ride it safely. And in my opinion, my belief that a competitive 125 MX bike can be set up to handle well on trails is just as valid as your assertion that it can't.

[stlavsa]

What your describing sounds a lot like KTMs xc line...just saying

Yep props to them for producing a model that i describe, its just the wrong color..

If you are serious about kdx200 in a cr chassis your insane. People did that in the 90's or early 2000's before we had good KTM's or GasGas's what your explaining...is a much shittier version of a KTM200 or GasGas200. for your own sake...reconsider. It would never have the handling of the purpose built 200's and the engine couldnt even compare....just a very poor idea.

OXYMORON!!! ?

[fender bender 59]

What r u trying to say?? Ive owned and raced 250fs and 450fs off-road? You gonna sit here and say they have the same top-speed as a 450f?

Were talkin like 60mph WOUND TIGHT vs 80-85 mph depending on what bike ur talking. In the tight woods i prefer a 250f, BUT if your riding on ROADS it harder on the 250f. The 450 can be rolling mid RPMS in 5th gear for 5 minutes, and the 250f will be off the limiter for 5 minutes...

If your into valve jobs every 20 hours then your son can ride with me

Who rides either one on roads??? OK.. sure the rednecks without helmets but???

When was the last time you spent more than 1 min. over 60 mph on any offroad/ trails race???? It's all about keeping the speed up... not how fast your 450 will top out. BTW... After our first head rebuilt (45 hr) I haven't even adjusted a valve and it now has over 250 hr...?

[stlavsa]

I know what its all about.. but answer me this..all you do is race at sanctioned events?? See I race harescrambles here in PA (which a 250f is great for) BUT i also trail ride before and after during the race season.. All the trail systems around here are connected by roads, gravel roads, or open fields.

If you guys trail ride im sure you do it just like we do, just like its a race, so your going fast whether its single track in the woods or blasting a power line or ripping through a grass section.

One of our favorite rides starts from my buddies house and requires a few miles of road riding just to get to the trail head. Nobody likes riding the road but its what we gotta do.. Say we are rolling at 45-50 mph up the road leisurely in 5th gear, then theres the guys (i was one) with the 250fs have a choice either cruise at a slower speed or ride along with us and were just cruising and they are at 11k rpms in 5th gear.

In a perfect world i would have a 450 for trail riding and a 250f purely for harescrambles, both piped and revalved, but I just dont have that luxury. I actually had a new kx250f and a new kx450f at the same time but after a while i just sold the 250f because it wasnt worth the extra upkeep of two machines.

[CDBiker220]

I specifically don't want a low-volume boutique bike, with parts (and especially spares) that aren't well-supported by the aftermarket.

Well considering KTM is the biggest manufacturer of offroad bikes in the world, and have the biggest aftermarket following in the world now I dont know where your going with that comment?...this isnt 1998. I dont even own a KTM but will give them credit. Plus, you can pick up a used GasGas cheaper than a KTM, and the parts both OEM and Aftermarket are easliy available, my local dealer has almost every part for my GasGas in stock and tons of aftermarket alternatives, and most of it is cheaper than the parts for my YZ250 were. Your just very ill informed. Also it seams that your opinion is dated about 10 years. Do some research...I had a KDX...modded as well, you could put that engine the best 2012 chassis and the bike would still be shit compared to the bikes/engines in the modern purpose built offroad bikes. The ONLY reason to ever build some hybrid is for the sake of a project, the outcome will be nothing more than a conversation starter...atleast if your serious about riding in any way.

[stlavsa]

Well considering KTM is the biggest manufacturer of offroad bikes in the world, and have the biggest aftermarket following in the world now I dont know where your going with that comment?...this isnt 1998. I dont even own a KTM but will give them credit. Plus, you can pick up a used GasGas cheaper than a KTM, and the parts both OEM and Aftermarket are easliy available, my local dealer has almost every part for my GasGas in stock and tons of aftermarket alternatives, and most of it is cheaper than the parts for my YZ250 were. Your just very ill informed. Also it seams that your opinion is dated about 10 years. Do some research...I had a KDX...modded as well, you could put that engine the best 2012 chassis and the bike would still be shit compared to the bikes/engines in the modern purpose built offroad bikes. The ONLY reason to ever build some hybrid is for the sake of a project, the outcome will be nothing more than a conversation starter...atleast if your serious about riding in any way.

Chances are he just doesnt want a KTM because theres still a LOT of people out there that dont like them. Regardless of how many they sell, they are still dont have the fit and finish of the jap bikes, but have a higher price... Also they have a stigma about them that some people dont want to be associated with.. The latter is the reason i would never buy one.

[CDBiker220]

Regardless of how many they sell, they are still dont have the fit and finish of the jap bikes, but have a higher price...

Are you kidding me??? seriously. I do not and have never owned one, untill my GasGas only had Jap bikes, most recent being a YZ250. So i dont think im biased. my riding buddy (A class GNCC rider), had 5 different YZ250's until this year when he got his 09 KTM. The fit and finish, and general engineering is light years beyond the jap bikes, if there was only one thing we both agreed that was as a hole everything on a KTM is better engineered, the way things go together just make more sense, things that would wear on our jap bikes just dont on the KTM. I argue with him all the time that my GasGas is better than his KTM, but atleast we both agree that they are a huge step above the YZ250's we had before them. If you just dont like KTM because of the people fine, but you cant knock them. O yea...and a 2012 KTM 250sx is $6799....YZ250(5 year old design) is $7299....

[Just_a_trail_rider]

Chances are he just doesnt want a KTM because theres still a LOT of people out there that dont like them. Regardless of how many they sell, they are still dont have the fit and finish of the jap bikes, but have a higher price... Also they have a stigma about them that some people dont want to be associated with.. The latter is the reason i would never buy one.

You are absolutely wrong about the fit and finish. The current and more recent (7-8 years or more) KTM's have outstanding fit and finish. They look different, but they use quality components.

You are right about the stigma though... there's some people who just don't like them because they get bad information from others about them.

Regarding the price... its only a little higher. It you take a Japanese bike and add the same components, upgrade the clutch and brakes, and add the other things... you'd find that the price isnt really all that different.