Dirtbikes the new 250 or 450?

takethebounce

Active VIP Member
Joined
Dec 10, 2008
Messages
5,193
Reaction score
8,750
Location
calgary
Most people are going to find flaws in my suggestion, and it doesn't bother me, its only a suggestion.

If you are not racing in a series, go with the largest displacement of a bike you can comfortably handle. If you are riding more offroad and trail than at the track, consider something other than a MX bike like the YZF, KXF, CRF and RMF bikes. These bikes are designed and tuned for track use. Sure MX bikes work great for trail use, but these bikes are geared much more for top rpm range than lugging around tight trails. Heating issues can arise along with motor longevity.

I have a KX250F, I love my bike, its light compared to 450's and easier to toss around, but after not having a bike for a few years I went with what I thought at the time was going to be a 50% track, 50% trail bike and be suitable for it. Its not. I am a short mofo too, 5'3, 150 pounds. I had the seat shaved an inch and had the suspension dropped an inch by a suspension guy. Put spacers in the front forks and a lighter rear spring and small tweak to the rear as MX track bikes are sprung for heavier riders doing bigger things than me. We then set the sag and everything for my riding weight.

This bike is almost %90 trail used now as I only go to the track a handful of times a year now.

If I was going to do it over again I would have went with probably a KTM, and probably done a 350. I also like the KTM 2-stroke XC's, and the CRF X bikes as these bikes all have lighting stators which if you are doing any off road, trail use, lights are not only madatory if you frequent ride areas that have checks, but just make it better for any late finishes that have you coming out at dark. Also some of the off ride bikes have larger fuel tanks so range is never an issue. We have done some pretty long rides in BC and have had to take fuel for the MX bikes.

My next bike is most likely going to have e-start as well, man, riding in narly single track and hair scrambles, stalling and being short sucks sometimes when you are riding a stock height bike, and trying to kick it over and still go uphill. There are auto clutch systems as well that will aid from stalling when you are trying to lug the bike around, but again, MX bikes are just not best suited for this. Maybe e-start is not something that is needed by most, but its handy.

So if you still have an open mind, don't exclude 2 strokes, they still have their place and anyone who has ever sunk a bike in Alberta muskeg can agree they might rather sink a 2 stroke than a 4. Also consider a bike that is more applicable to your riding needs.

If you are going to be at the track every 2 days, then yeah for sure get a 4 stroke MX bike, don't change anything like ride height and suspension components as at the track you only need to touch once in awhile, set the sag to you and maybe look at shaving the seat, but I doubt you will need it unless you have short legs and a tall body.
 

dropitbuster

Active VIP Member
Joined
Jan 2, 2011
Messages
206
Reaction score
256
Location
Terrace B.C.
You seem to have your heart set on a Yamaha. Have you considered a KTM 350F? Pretty much a factory race bike sold to the public. Electric start, hydraulic clutch, fuel injected. My last bike was a YZ250F. Loved it but it wasn't quite enough for my 195 pound fat ass so I big bored it to a 292 and that was better. I also found the 250F got pretty squirrely when you got it reving too high but it was sure fun to throw around. I often jumped on friend's 450s and though they made clearing jumps easy it just wasn't as fun because I love to rev the motor. With a 450 I found that it got me up to speeds that were well above my skill level fast.

I had to trade my 2 wheels for 4 because I moved up north but when I move back to a town with a track a 350F is at the top of my list.

I think of it as kind of like Goldilocks and the 3 Bears. 250F...light and 'flickable' but not quite enough jam. 450F... feels heavy unless your going fast and tear your arms off power. 350F... just right. Also you'll love electric start if your shortlegged like me and you dump your 4 stroke in a sand berm.
 

teeroy

Active VIP Member
Joined
Oct 7, 2007
Messages
9,149
Reaction score
14,426
Location
Roma, Alberta
you make some excellent points 'bounce, a lot of them are why I chose the 450x....e start and lighting coil were the big sellers. last 2 bikes were a KX500, and then went to an XR650L when I got bit by the dual sport bug. the 6 fitty was a heavy beast and just didn't have the poop, saw that there were DS kits that would make a 450X street legal so I went out and grabbed one....got it plated, geared it up, put an IMS tank on it for better range and haven't looked back. the 450 to me is the best all-around machine a guy could ask for, not quite as much explosive grunt as the ol KX had, but incredibly smooth linear power like the big bore 2 smoker. it certainly doesn't wear me out like the KX did, I can thrash it in the hills all day, and ride it home on the highway. I put 5 seasons on it before doing the top end, the valves had been checked but never needed adjustment in all that time either. I would say that is comparable to a 2 smoker for reliability.
 

Redlineryan

Active VIP Member
Joined
Dec 23, 2010
Messages
199
Reaction score
101
Location
Kimberley
the new fuel injected 450s get way better mileage than the 250s too. because your not reving the piss out of it to get it going. my 2010 yz450 holds less than 7 litres and thats more than enough for cruzing trails and mudholes all day.
 

sumx54

Active VIP Member
Joined
Oct 5, 2007
Messages
5,479
Reaction score
5,702
Location
Rocky Mountain House
Website
www.absoluteadventure.ca
I took the best of all worlds with my KTM 450sx. Its a track bike for the most part. lighter than any XC bike, electric start, 2" bar riser. The SX has only a 4 speed tranny so I geared it accordingly, put an electric fan kit on it and man this thing rocks my world. I race it hare scramble and also some recreation closed track. You hardly have to ever worry about shifting this tractor. I ride competitive even with all my friends. There is no such thing as a scenic trail ride with my group. She's WFO. My point being is that it all depends on how you want to ride it and who your riding with. P.S. don't let your friends bullch!t you and say their 4x4 quads will leave you in the dust. you will be waiting all day long for them boys on the other side of the skeg...
 

jbb

Active VIP Member
Joined
Aug 22, 2008
Messages
20,304
Reaction score
1,717
Location
k town
2011 ktm 380.... 2 smoker.

ktm380-1.jpg
 

jbb

Active VIP Member
Joined
Aug 22, 2008
Messages
20,304
Reaction score
1,717
Location
k town
lite as a 250 2 stroke. more power then a 450 4 stroke.
 

LID

Active VIP Member
Joined
Aug 3, 2008
Messages
1,028
Reaction score
1,104
Location
Calgary and Rocky Mtns
I'm pretty sure I read in Dirtbike the 2012 KTM 250SX 2-smoker makes 54hp.
Where did that 380 come from? Big bore kit on a 300? Or an older KTM engine in a 2011 frame?

Wish I still had my 95 550MXC 2-stroke beast.
 

teeroy

Active VIP Member
Joined
Oct 7, 2007
Messages
9,149
Reaction score
14,426
Location
Roma, Alberta
I'm pretty sure I read in Dirtbike the 2012 KTM 250SX 2-smoker makes 54hp.
Where did that 380 come from? Big bore kit on a 300? Or an older KTM engine in a 2011 frame?

Wish I still had my 95 550MXC 2-stroke beast.
according to MXA, 50 hp for the '12 250 SX
 

jbb

Active VIP Member
Joined
Aug 22, 2008
Messages
20,304
Reaction score
1,717
Location
k town
crf450 48.1 ktm 380 54.73 stk
 

jbb

Active VIP Member
Joined
Aug 22, 2008
Messages
20,304
Reaction score
1,717
Location
k town
on what planet is that? the 380 makes less than 50hp, crf 450r is 55....

and ive owned both troy. that 380 will beat the 450. its like your old kx 500, just way more controlable.
 

teeroy

Active VIP Member
Joined
Oct 7, 2007
Messages
9,149
Reaction score
14,426
Location
Roma, Alberta
and ive owned both troy. that 380 will beat the 450. its like your old kx 500, just way more controlable.
that dyno result is the highest that I've seen for sure. found lots of results that are under 50 hp, 49.97 was the highest. crf dynos are anywhere between 50.9 to 55 for the high. guess we'll just have to line 'em up
 

jbb

Active VIP Member
Joined
Aug 22, 2008
Messages
20,304
Reaction score
1,717
Location
k town
that dyno result is the highest that I've seen for sure. found lots of results that are under 50 hp, 49.97 was the highest. crf dynos are anywhere between 50.9 to 55 for the high. guess we'll just have to line 'em up

dam straight! you ride my ktm and you'll be asking momma for a seond bike. lol . ive seen ktm380 dyno'ed at 58hp. torque is high to.
 

teeroy

Active VIP Member
Joined
Oct 7, 2007
Messages
9,149
Reaction score
14,426
Location
Roma, Alberta
dam straight! you ride my ktm and you'll be asking momma for a seond bike. lol . ive seen ktm380 dyno'ed at 58hp. torque is high to.
nah, if I get another 2 smoker it'll be a KX 500. would love to find a clapped out early 90's model with the inverted forks and go to town modding it out from the frame up. that or go with a RTR service Honda KXF chassis with a 2 stroke 500 stuffed in it. couple buddies here have the honda version, they are bad ass. ten grand tho
 

Marley

Active VIP Member
Joined
Dec 20, 2011
Messages
493
Reaction score
341
Location
SW Alberta & SE BC
Shane Watts won GNCC races on every one of KTMs engines. Even won ISDT on a 125 I believe...

dam straight! you ride my ktm and you'll be asking momma for a seond bike. lol . ive seen ktm380 dyno'ed at 58hp. torque is high to.
 

jbb

Active VIP Member
Joined
Aug 22, 2008
Messages
20,304
Reaction score
1,717
Location
k town
nah, if I get another 2 smoker it'll be a KX 500. would love to find a clapped out early 90's model with the inverted forks and go to town modding it out from the frame up. that or go with a RTR service Honda KXF chassis with a 2 stroke 500 stuffed in it. couple buddies here have the honda version, they are bad ass. ten grand tho

buddy of mine had one to. he sold it to buy my 450. he's been eye balling my 380 to. screw that..... he aint getting this bike, lol
 

takethebounce

Active VIP Member
Joined
Dec 10, 2008
Messages
5,193
Reaction score
8,750
Location
calgary
380 hmmm...might have to go on the "next bike" list :)


I don't see them listed on their website though?
 
Last edited:
Top Bottom