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Thinking of moving down to a newer 250f

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So right now I have an 07 KX450F that is a retired race bike. I have very little money in it. It was owned and raced by a friend so I know the history. Im a woods rider, and I've been without a bike for a couple years. I got a chance to pick this thing up to trail ride when he moved to a new blue bike. After 2 rides I've been bitten by the bug again. I want to start doing regional hare scrambles here in the southeast. The bike saw 4 seasons doing just that. I am 5'10 170lbs and fairly quick in the woods for someone who hasn't competed in HS or Enduro. This bike is sprung and valved for someone almost 100lbs heavier than me. You can imagine how that feels. It has a lot of good mods already done and had a new top end put in before I bought it. Valves are in spec. No weird noises, pulls hard, etc. It has an aftermarket triple clamp, cut down bars, an 18" rear wheel, MRD exhaust, its jetted correctly, new stator etc.

It needs fork seals. If I keep this thing I will have to have the suspension redone. Other than that it is ready to go.

This is the first 450 I've owned and used in the woods. I know the 07 is among the lightest and most violent of the kx450's put out as far as power delivery. Between that and the clapped out forks with springs from a geo metro I feel like the bike is riding me in the gncc style trails and lets not talk about the super gnarly single track. He had a rekluse in it when he raced it. That might help some but I've never been a fan of the auto clutchs. I rode observed trials for a couple years and I can't wrap my head around the idea of feeling disconnected like that.

So I was thinking about selling this thing and getting a newer 250f. I shortly contemplated 2t's but 4t's suit my riding style better. I had an 06 WR250F for a year and loved it in the woods. I had much more fun because I could push the bike a lot harder. I did all of the free mods and it was no slouch sfter jetting and a pipe. I never had the suspension done though. This 450 feels like a battle tank in the tight stuff. It feels top heavy and does not inspire confidence. I know some of that is the suspension. Here is my dilemma. I want something lighter and more flickable with a more controllable power delivery to race.

Then I looked up the weights. :o

2007 kx450f is listed at 243lbs curb weight.

2014 kx250f is listed at 234lbs curb weight with less fuel.

Dimensions are basically the same. Having ridden trials I know 9lbs is a lot, but is it worth switching bikes over? I know somw of the added weight is from the FI which will help with the power delivery so it is a catch 22. The 2007 250f was just over 200lbs dry.

So TT, should I spend the money on a suspension refresh on the older modded 450 or pick up a new or lightly used 250f and mod it myself? I hate to dump money into the 450 suspension and still not feel comfortable on it. Since it matters I will make money if I sell the 450 so I wont be taking a bath on a swap.

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i would keep the 450 and just add a flywheel weight on it . you can use the 450 to ride mx ,woods, trails,and hare . when i had the same issue this spring i asked a couple of dealers what bike would be the best choise for me (250f or 450f ) they all sad 450 becouse its power can be smooth and its pretty easy to fix ,but if you have a 250 and want more power its much more expensive ,

i live in Sweden 48years (young ) stopped racing at 1999 and now picked it up again , i use my bike in the woods ,mx, and just go out riding like trail or so , and offcourse when the winter comes i will get me some studded tyres and go out on the lakes and blast past all 250s :-)

but thats me at 95kg 48years young  and a 2012 kx450 only mod so far is a 51 rear sprocket and a xtrig triple clamp and offcourse the suspension ,and i dont regret my choice of bike (i just love it ) and with a flywheel weight you wont ether

 

Jorgen

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I hear what you're saying but I have to say you'd regret getting rid of the 450! If you're riding it with the suspension set up for someone 100 pounds heavier than you can't really judge how the 450 is in the woods at all. If you get the 250f I think you'll spend more in the long run. At 170 pounds, you'll need the suspension done for your weight anyway. Pay to have the suspension setup on the 450 to suit you, then take it out and see what you think. 9 pounds of bike weight isn't much when you have the power of a 450 to carry it along.

 

Like lappenator said, get a flywheel weight. Go up 1-2 teeth in the rear and make sure the bike is caught up on maintenance. I felt the same way when I rode my 450 but now I'm glad I have the extra power when I need it.

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I like the crf450r in the woods. Weight is an issue but, compared to the bikes I was riding in the past, the weight is not much different. Saw on TT today a thread to cut weight. Over an lb in just a seat is quite a bit and in a high position. Do a little more research. You may be able to wash the weight and have the extra power. Hear a rumor the 450 runs lower rpm and is easier on valves compared to the 250. The 450 may be a better fit if issues like this are considered.

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I hear what you're saying but I have to say you'd regret getting rid of the 450! If you're riding it with the suspension set up for someone 100 pounds heavier than you can't really judge how the 450 is in the woods at all. If you get the 250f I think you'll spend more in the long run. At 170 pounds, you'll need the suspension done for your weight anyway. Pay to have the suspension setup on the 450 to suit you, then take it out and see what you think. 9 pounds of bike weight isn't much when you have the power of a 450 to carry it along.

Like lappenator said, get a flywheel weight. Go up 1-2 teeth in the rear and make sure the bike is caught up on maintenance. I felt the same way when I rode my 450 but now I'm glad I have the extra power when I need it.

That was my whole dilemma. Thr FI 250f's weigh almost what the older 450's weigh. I know there is more mass higher up on the 450 but I don't see how it could be a huge difference.

I've got a 52 on the rear right now. The P/O had a rekluse in it so he was running the stock gearing. I wish the 250f's were lighter. The majority of the hare scrambles in the southeast are nothing more than alternating sections of tight single track and ATV width "road course" like open sections where you make a flat or off camber corner, accelerate out and immediately brake hard to turn the other way. Im not saying they are all like that because the mountainous areas are different. The more open stuff that I have ridden keeps me in 2nd or 3rd gear the whole time at usually no more than 1/3 throttle with a 2 second burst towards wide open here or there. It seems like overkill because I'm hardly using the bike.

I know I'd have way more money in a 250f but I would have a new bike too. I can still get a 13' for about $5600 OTD. I guess I'll get the suspension done and give it another chance. If I sell it I'll eat the bill.

Does anyone have a recommendation for a suspension shop that is good at valving these forks/shocks for woods riding?

Edited by fmx05

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no love for the older 450's huh lmao!! ...psst my 06 smokes way newer 2t's...all day . lmao.. I get the whole weight issue and i just like to chime in on something you hinted on . The 06 and 07 have very abrupt power and what Ive come to realize is the torque & smoothness of these older 450's is really effected by the rear lower linkage . The flywheel weight is a good idea but I have ( believe Numroe too) added 2011 rear linkage and it really made the 450 much easier to handle the power. just fuel for thought . Sounds like a nice modded 07 .... I wouldnt sell that for 2t ...

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I had considered a kx250f as well as a replacement to my 450, but I wanted to ride off road and felt the electric start would be too important to not have, but it was very tempting and I would really like to ride one some day. My 450 while very fast is tiring and stall prone in tight stuff, but a 250 mx model may not be much better, but I have heard they were.

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Can you go for a test ride on a fresh 250F? I think you have to do that. I bet you'll want one. If you road a smooth broad 2 stroke, you might want one of those too. ;) When it get's twisty a 300 2 stroke in race trim feels lighter than any 250F.

 

Your 07 could be a lot better with the forks reworked! Also it's great for agility to lower the whole bike. Just let the forks come up in the clamps and get a 2010 or later linkage with the longer optional 135mm tie rod. I like my forks up 13mm in the triples, but then I use stiff springs for my weight also with 3mm of preload. 

 

Next time I pull the shock out of my 06 I'll measure up the shim stacks and post here. I bought it lightly used and it's a great shock setup. I dunno if the tuner got lucky or was a genius, but it works great.

 

Keep your 07 light. Especially the wheels and up high.  So Tubliss rear. Lightish rear sprocket. Good tires. No heavy crap on the bars.

 

The motor will put the low RPM power down a lot better with a more restrictive exhaust. Which might need leaning out on the jetting.

 

If you think you have "4 stroke riding style", then I don't see why you'd not like a Rekluse z-start pro clutch. I have one in my KX450F. Setup for very low RPM engage it's excellent for any type of riding. The trick is to set the pro clutch up to engage right where the power hits. For your 07 that means just above idle, so the softest spring and the "hard hit".  It gives great stall resistance, but you also retain just enough feel on the manual clutch lever override to meter the power out effortlessly and oh so smoothly with one finger. If you pull the lever in and blip the throttle and release the clutch, it grabs harder than any full manual clutch. Clutch lifespan is incredible with the pro because assuming you're not abusing the slip RPMs all the time, the clutch is a locker and you just cannot burn out your clutch. I'm a real heavy clutch user by habit, but I've got about 250 hrs out of some Honda fibers in my KX450F. In comparison in my YZ295 I've just killed a set of fibers after 40 hours, and I use the clutch in the same way - just to smooth out the bottom end hit of the motor in tight corners. The pro clutch locks while the manual clutch burns up. Same oil.

Edited by numroe

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I read up on that linkage and some other things. There is no oversized tank for the new kx250f yet. That kills it for now because it hold just over a gallon.

I called factory connection and they are sending me a box. After pulling these forks they look pretty clapped out. I won't know exactly what they need until FC gets them apart. Sending the shock too.

Hopefully with the right springs and some luck they will get it pretty close for me. I don't expect perfection. If they do get it close and I lower it in the clamps a bit, put the long link on, and get the sag set right it should be 100x. Better than it was. I ordered an 11oz fww from steahly to help smooth it out some.

I'm definitely keeping the weight down. I need a set of bars with a different bend. It already has the excel talon/takasago combo front and rear with a 110 on the back. I just put a renthal ultralight rear sprocket on with an X ring chain. It already had Cv4 hoses, rad braces, works connection full skid plate, tm designworks chain guide, 21.5mm clamp, and a few other things I listed in the first post. As long as the bottom end holds together for me I should be ok. I'll give it a season and evaluate how bad it has beaten me up then go from there.

 

 

 

Edit: Something I couldn't find on the linkages... Are 2011+ all the same?  I found a 2012 and I can't seem to figure out if it is the same as the 11' everyone seems to love.

Edited by fmx05
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2010 and later are the same linkage. Check part numbers. Up until 2010 Kawi kept improving it. Then they found a winner. 06 to 14 are interchangeable.

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