1990kdx

Member
Nov 9, 2010
13
0
would my 90 kdx 200 have eough power for a 8 paddle, paddle tire? i have got my bike up to 70 mph on a flat road in a half a mile. thanks for your help
 

dirt bike dave

Sponsoring Member
May 3, 2000
5,349
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Might be fun to give a paddle tire a try, but I'm skeptical that a KDX has enough power to make it worth while.

Maybe a six paddle would be better?

Rolling down a paved road at high speed and digging into deep sand are two different animals.

If you do it, be on the watch for any signs of overheating.
 

motopsycho87

Member
Dec 26, 2010
152
2
What exactly are you trying to do? I'm guessing sand cause anything else I would imagine you might just hurt yourself! Any bike can run a paddle tyre, but I wouldn't expect an extreme desert racer out of the KDX unless you hop it up like hell :D
 

mudpack

Member
Nov 13, 2008
637
0
motopsycho87 said:
What exactly are you trying to do? I'm guessing sand cause anything else I would imagine you might just hurt yourself! Any bike can run a paddle tyre,
phycho87 is quite right, on all counts.
 

Joburble

Bring back the CR500
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Jul 20, 2009
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Hmmm... A paddle tyre on a KDX200. I would not be surprised if you have found the way to kill the KDX200. If it's deep sand my bet is that you'll kill it (the motor). I could be wrong, but that's my guess. I think it will overheat as the work load is just going to be too high. Like I said I could be wrong, I have been wrong once before, but only once ;)
 

mudpack

Member
Nov 13, 2008
637
0
If a paddle tire in sand will harm the KDX, then riding fast on asphalt will also. Traction is traction....regardless of the surface.
If paddle tires in sand killed motors, Glamis would be littered with smoking shards of aluminum and steel.
 

dirt bike dave

Sponsoring Member
May 3, 2000
5,349
3
Ride to a sand dune. Turn your motor off. Now push the bike up the dune.

Ride to a nearby road. Turn your motor off. Push the bike down the road.

Which one makes you work harder? If neither, I guess traction is traction, lol.
 

_JOE_

~SPONSOR~
May 10, 2007
4,697
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Right.....sand has much more rolling resistance than pavement. It's not the paddle tire that makes the bike work harder it's pushing the front tire through the sand.
 

dirt bike dave

Sponsoring Member
May 3, 2000
5,349
3
Bottom line is you will be on the gas harder, use more power and generate more heat riding deep sand than any other type of riding.

There's a reason you find mopeds and scooters on the road and not in the deep sand. They simply don't have enough power for the sand.

Does a 21 year old KDX have enough power to be fun and reliable pulling an 8 paddle tire in the sand?

I think so (crosses fingers), but if it were my bike, here is what I'd do:

1) Make sure the cooling system is working properly
2) Mix more oil than usual to improve lubrication, maybe go 24:1, or even 18:1 or 16:1.
3) Go at least one step richer on the main jet
4) Drop the clip to one lower groove on the needle
5) Consider putting in a spark plug one step colder than you run for the trail.

After 1/2 tank of fuel, if it shows no sign of overheating or straining too hard, go back to your stock plug heat range and consider putting the needle clip back to its original position.

All this costs you is the price of a new main jet and spark plug and few $ in oil, but you have added a big cushion in terms of protection from excess heat and poor lubrication.

Oh, and bring lots of gas. You'll need it. Plan on hitting reserve in about 1/2 the miles and time it would take on the trail.
 

Joburble

Bring back the CR500
~SPONSOR~
Jul 20, 2009
417
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mudpack said:
If a paddle tire in sand will harm the KDX, then riding fast on asphalt will also. Traction is traction....regardless of the surface.
If paddle tires in sand killed motors, Glamis would be littered with smoking shards of aluminum and steel.
I did not say "paddle tires in sand killed motors", I was talking specifically about the KDX200. I have ridden many bikes in deep soft sand and have found that the KDX200 unless ridden 'balls to the wall', 'hard on the stopper', flat knacker', 'WFO' has a hard time doing the work at any decent speed. The key words here are "Deep Soft Sand", and unless your bike has power to spare which the KDX200 does not, then it'll be VERY VERY hard work on the motor. Now, I appreciate that what we expect in regard to performance in the sand will differ depending on how we ride, but as a general rule I'd say she's under powered. Be kind to the bike and you'll still have a lot of fun, but expect it to go hard all day and I think that's where you may have a problem. In regard to "traction is traction", simply not so. Even a quick thought about the contact patch difference between deep soft sand and a road surface should alert you to that. (On re-reading that it sounded a bit harsh Mudpack, I didn't mean it to be offensive).
 

1990kdx

Member
Nov 9, 2010
13
0
the dunes im going it is not like the oregon dunes. its sand mixed with ash, dirt, gravel. its the moses lake sand dunes. i been there once before without a paddle tire it did good when it got up to 20mph. it was spining out alot that is why i want a paddle tire also to go faster
 

Feanor

Member
Aug 10, 2004
144
0
Both sides of the argument "seem" correct...

That sand has greater rolling resistance than pavement of course is true, and the motor will use more power to move the bike thru sand.

That the motor will suffer and fail with a paddle tire in sand may also be true, depending...

The truth is, you can blow up your kdx in sand with a normal knobby as well because your traction will be so low and your rolling resistance so high that you'll constantly need to be turning very high rpm to get into the rpm range to need to spin the tire fast enough to produce enough thrust to gain enough speed to get on top of the sand... Etc etc... Riding fast in sand is all about developing enough speed to become stable and efficient to get over the threshold beyond where your front tire is plowing.

Because a normal knobby rear has little tracrion on sand it is akways spinning madly and the engine screaming often to build up that thrust. Very high rpm + low speed and airflow = bad for motor

On the flip side, a six paddle rear (8 is almost too many even for a 220) has far more traction and thrust develops much faster with lower rpm, however, because the rear spins in the sand so much less than a knobby, you can never get out of the lower gears very fast and the "window" for optimal speed vs rpm vs gear is very very narrow... You'll spend far more time and effort hunting for that necessary perfect situation with a paddle whereas a much wider range of rpm, gear, speed and traction will "work" with a knobby...

The best solution? Leave the paddles to the quads and 4stroke bikes, and use a soft terrain or sand knobby... Michelin S series rear work great! Very soft terrain knobbies are essentially low profile paddle tires with 50 paddles :) the knobbies are arranged in "walls" rather than staggered like a harder terrain knobby. The rear will spin up to allow you to get into an rpm band early while having enough thrust to get the bike up to speed where it starts to float over the sand in a gear that allows you to build up enough speed efficiently to become stable, all with adequate airflow generated for cooling to keep the motor happy.

This description above is not based on any scientific theorizing, but just on many hours at Pismo Beach with different kinds of rear tires on an 04 KDX 220 :)

Sand is fun! Sea water corrosion is not! :(
 

1990kdx

Member
Nov 9, 2010
13
0
hey guys thanks for the help. i got back from the dunes 2 weeks ago. i had a great time my kdx did awesome. it got up to about 45 mph it did not over heat. got stuck 3 times going up steep hills. fouled the spark pulg, but it did great. i was very happy with it. next time i will have the 13/50 sprocket ratio
 

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