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Does a flywheel weight make an MX bike woods worthy?

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Its time to retired my DRZ400 and its headaches. I want a 450 class bike and its lighter weight than what I have in the DRZ. Trying to find a good used 450 factory woods bike is tough but there are tons of MX bikes out there in mint condition.

my question is, if I put a heavy flywheel weight on a 450 MX bike, will it tame it enough to make it a good woods bike?

I am a very capable off road rider, I want the 450's power but also want to be able to put it to the ground. I dont ride MX.

Any thoughts are welcome. Thank You!

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A flywheel helps prevent low RPM stalls. Appropriate final gearing helps too. Getting the power to the ground varies depending on rider ability, engine tune, terrin and tire choice.

Going from a DRZ to a 450MX bike is going to be a larger case of headaches. A lot more maint. and a less forgiving bike. No more estart too. But it will be lighter and tons more power (could ber good or bad, depending on how good a rider you are), potentially better suspension.

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i know that on the wrs and yzs there are some very small engine differences like the timing chain is retarded 1 toth on the wr the th yz. but i think the big difference is suspension

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Depending on your terrain, suspension mods can go way farther in making an MX bike rideable in the woods than anything. Motocross bike in stock form is a deflection animal in rocks and roots, and will just flat wear you out.

FWW will help a little, but is far from being a magic bullet to turn an MX bike into a compliant woods bike.

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Its helps for sure. Well at least it helped on my 05 450. That bike was a beast would go up any hill I could find only problem was sometimes the damn thing left me at the bottom and I had to go up after it.

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IMO (and its based off of what i see the pros using) the ultimate off-road 450 is an MX bike.

Its not hard to build, you take said MX bike, then add the following:

#1 Revalved/sprung suspension

#2 Rekluse auto clutch

#3 Slip-on pipe that gives increases low-mid range

#4 Hand Guards (bark busters)

#5 Chinese Oversized Radiators (they are cheap and sturdy).

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There are a few significant differences between an MX bike and trail bike. Compare YZ's and WR's as well as CRFR's and CRFX's (or any other color bike).

Trail bikes have:

more flywheel weight for reduced low speed stalling

milder cams for better low rpm torque

a wider ratio transmission

18" tires to absorb sharp hits

higher output stators wired directly to headlights

suspension tuned softer for trails

larger gas tank

radiator overflow tank

electric start

kick-stand

But,

They are heavier, feel bulkier, and have less peak horsepower than MX bikes.

So, if you ride predominantly MX tracks and occasional trails, a modified MX bike might be the right choice. However, if you ride predominantly trails, a modern WRF or CRFX (or KTM trail version) is a great choice.

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If your not going to be riding open areas, just get a 250F. Plenty of power. I rode a stock yz250f (suspension done) for many years. As said get a KTM they are all ready. It's what I have know.

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There are a few significant differences between an MX bike and trail bike. Compare YZ's and WR's as well as CRFR's and CRFX's (or any other color bike).

Trail bikes have:

more flywheel weight for reduced low speed stalling

milder cams for better low rpm torque

a wider ratio transmission

18" tires to absorb sharp hits

higher output stators wired directly to headlights

suspension tuned softer for trails

larger gas tank

radiator overflow tank

electric start

kick-stand

But,

They are heavier, feel bulkier, and have less peak horsepower than MX bikes.

So, if you ride predominantly MX tracks and occasional trails, a modified MX bike might be the right choice. However, if you ride predominantly trails, a modern WRF or CRFX (or KTM trail version) is a great choice.

I think it depends on your riding style. If your playing on the trails then the WRF and CRFX are great, if youre racing you would be better suited to convert a race bike.

The real GEM of the WRF and the CRFX for trail riding is the gear ratios. It just sucks that you have to get detuned motor and heavy crap along with it.

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IMO (and its based off of what i see the pros using) the ultimate off-road 450 is an MX bike.

Its not hard to build, you take said MX bike, then add the following:

#1 Revalved/sprung suspension

#2 Rekluse auto clutch

#3 Slip-on pipe that gives increases low-mid range

#4 Hand Guards (bark busters)

#5 Chinese Oversized Radiators (they are cheap and sturdy).

There are a few significant differences between an MX bike and trail bike. Compare YZ's and WR's as well as CRFR's and CRFX's (or any other color bike).

Trail bikes have:

more flywheel weight for reduced low speed stalling

milder cams for better low rpm torque

a wider ratio transmission

18" tires to absorb sharp hits

higher output stators wired directly to headlights

suspension tuned softer for trails

larger gas tank

radiator overflow tank

electric start

kick-stand

But,

They are heavier, feel bulkier, and have less peak horsepower than MX bikes.

So, if you ride predominantly MX tracks and occasional trails, a modified MX bike might be the right choice. However, if you ride predominantly trails, a modern WRF or CRFX (or KTM trail version) is a great choice.

Both of these posts pretty much hit ALL the good points.

I dont ride woods, but do a lot of single track, and I used to race open expert class desert series. I have found the best setup for a singletrack bike (which I would say is identical to a woods bike minus the narrow handlebars).

I have ridden all kinds of bikes over the years and your 400 is pretty heavy and lethargic generally speaking. When I ride single track I will usuallu borrow my wifes CRK250X, it weighs about the same as my CRF450R, but I can ride the 250 much faster, the 450 IMO seems to be far more than I need since I am in no more that 3rd gear. IMO the best woods bike would be this:

250f (the motocross version to cut down on weight and they are not too hard to start)

Heavy Flywheel

Softer suspension (depending on your weight springs and revalve)

Hand guards

Overflow tank (for coolant)

Kickstand (I have them on 2 of my bikes as I am only 5'6" tall and need it to kickstart my bike sometimes, lol)

A Rekluse auto clutch (its pricey, but you will love it, I know I do!!)

Radiator guards

IMO this will be the bike that will be IDEAL in what your doing, or thats what I would build for myself...if you weigh much over 220lbs, I would recommend a 450

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Yes a FWW can help in trail conditions. It does two things, 1. Helps the motor stay running when lugged at lower RPMs, 2. It slows the rate of acceleration., i.e. the motor revs up slower.

If these features help you trail ride, then the FFW will be a help.

As mentioned by others, a FWW will help, but by itself it won‘t turn an MX bike into a trail bike.

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As mentioned before, if you're not open desert racing/riding and just doing trails and single track then seriously look into a 250. You may be surprised by what you can do with them. The biggest hurdle is your ego

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I think it depends on your riding style. If your playing on the trails then the WRF and CRFX are great, if youre racing you would be better suited to convert a race bike.

The real GEM of the WRF and the CRFX for trail riding is the gear ratios. It just sucks that you have to get detuned motor and heavy crap along with it.

I agree , too bad the first gear on MX is machined into final drive axle so a wide ratio atleast on my 04 CRF450R will never be like the X ..... I have road my R model on trails for years an now am finally puting flywheel on it.... It's was in my ability to make it work with offroad valving and stiffer springs but do get the flywheel !! I can actualy drag my bike back onto a trail if needed and I am thankful for it's lighter weight..... Huge difference in performance too ! You can make the MX capable of anything terrain can throw at it.... And better than the X or WR ....... The DRZ is a great trail bike with a good carb ....

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I ride an 06 CRF450R on trails and singletrack and love it. It has a 450X tank, full skidplate, Unabiker rad guards, a 13oz. Steahly, 18" rear wheel, Powerbomb and Q2 exhaust and a CRF250X suspension. I have revalved the stock suspension for woods, but not installed it yet. Narrowed Twinwalls and Barkbusters get it through tight singletrack with room to spare.

The beauty of these "R" bikes are how the "X" components fit perfectly and are dirt cheap on ebay. I have not found a trail that cannot be conquered by it and it's very light, forgiving and tractable yet with bottomless power. The abilty of a rider to abuse the clutch in first gear and wind it out in fifth are what makes MX bikes great in the woods; the lighter weight of an MXer makes a lot more sense to me than e-start and granny gears.

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My 07 YZ450 has both a heavy FW and Rekluse Pro and I love it in the woods. I wouldn't have anything other than a MX bike for the woods.

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