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About crashreallyfast

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  1. he will be fine, it will just be a pain in the ass when he tries to pick it up
  2. crf250x was the best trail bike i ever road, handled like a dream. gave it to my dad to get a MX bike, miss it every time i hit the trail.
  3. sand paper would work, but i would imagine it would be like break pads, it might wear down after that. If you already have a new rotor on it, i would just toss the glazed one. no point in messing with it.
  4. or just put some gass on a rag, should come right off.
  5. thanks for all the explanations and help this should all help with my project
  6. ok i understand what your saying about the friction because its on the walls and not directly forced downward. However just to clarify, what i understand what your saying is that the when the gas and air mixture is compressed by the piston, its causes the molecules in that space to expand in a spread, and the force from the expantion pushes the piston back down right?
  7. I havnt gotten a chance to ride any of the new fuel injected 450's the newest 450 ive ridden was a 09 YZ. i imagine all of the 450 much more mellow now (excluding the ktm) you cant go wrong with either one. personally if you are willing to handle the weight (im not cause i only weight 150lb) you might be better off with the honda, just because they are so reliable. and if your shopping for new bikes, then a new 450 would probably work.
  8. thanks,for the tip, i can probably drag thoes numbers out of the service manual now that i think about it. but compared to what my other class mates are doing, im by far doing somthing more advanced. So as far as the variables of friction go, between a 32:1 and 40:1 gas to oil mixture, at an idle with normal running tempatures would be ideal for the friction, that being said, i can get a blunt number from the force of the explosion caused my the compression when its running.
  9. i second the RM250, but im 2-stroke bias, and dislike the 450's because of their weight (however never knew the rmz was that light). but i do aggree that you will most likely get board with a rmz250 at the track, and i think that the 450 will be a little much for you. either way you'll be getting a good bike.
  10. to be honest, if you want to ride a bike to its potential get a 250f or a 125. but in my opinion, that would be way to much of a downgrade in power from you 450 if you ask me, if you want a bike that is lighter, more managable, easier to maintain, get the 250 2-stroke (dont be too YZ minded. if i were you i would look into a honda 02 or newer, they say they are just unsung heros in the woods and i can belive it just riding some short trails around the track on my cr250, but in the long run, find the bike you think is best) that being said, my dad has a crf250x (2004) and that is the best damm woods bike you will probably ever ride. Use to be mine, definatly dont miss it out at the track, but really miss it in the woods. And a nice tip for you if you get a 2-stroke, if you dropp the bike and it gets flooded. If you pinn the throttle while you kick it, it will start right up.
  11. get the kx100, more tourqe, so its not as touchy as the 85 is. The suspension isnt as good at the track as an 85, but if he is a new rider it doesnt matter, pluss he will outgrow that 85 in an instant. the kx100 is by far a better trail bike too. i stepped off my kx100 and went to a crf250 when i was 5'5-5'6, (wanted a race bike though). he will be misrable on an 85, and probably a little to big for it to fast. so if i were you i would get him the kx100. its more beginner friendly, he wont already be to big for it. and he will have more fun on it in the long run.
  12. my 03 cr125 was a monster in the woods. the 1 thing you need to dow with a CR125 because it only has 5 gears is get the front sprocket 1 or 2 teeth lower than stock. (im not 100% sure if i remember, but i think it was 12 tooth) Anyways that sprocket made the bike better in the woods and on the tracks. the 2 rules to riding a 125 in the woods. Keep it in the power band (which is easy with a smaller front sprocket), clutch control, and take a gadorade bottle or 2 filled with gas incase you run out. when you run out whats nice (at least in the rocky mountains) is that when your running off your gadorade bottle, you can coast down the hill, and when you get to the bottem, shift into 2nd gear, let the clutch go, and the bike will start itself. the 125 is harder to ride in the woods than a 250f for sure, but if you want to learn how to race a bike and ride fast, your better off with a 125, i went from 250f to 125, i was way faster on the 125, and i would still be on that 250f if i never went down to a 125 (im on a 270 2-stroke now). 2-strokes are also way cheaper to maintain then a thumper. its your call. if i were you i would go 2-stroke.
  13. The 350 is ballzy. but still doesnt seem as crazy as the 450s if you ask me, never owned a 350, but ive rode a friends not to long ago. If i was in the 4-stroke market i would highly consider one. and it would be the number 1 bike i look at. Because i personally dont like how heavy the 450's feel when you ride them. and ive done my time on the small boar bikes (4-stroke and 2-stroke). the 350's still feel light and managable. that being said, ive turned into a die hard 2-stroke guy, so im not the most reliable sorce, ive never owned both a 450 and 350, but i have ridden both. but if i were in your istuation, i would probably lean twoards the 350. only issue i have with it is it being KTM and i dont fully trust their reliabilty (not trying to start any arguments, i still think they are still reliable, but i wouldnt trust one as much as a Big 4 bike)
  14. Hey, so i have a project in my science class were we take somthing apart and see how it works. I already rebuilt my bike so im just going to use what i have from that for the project. However i need to tie it into an eaquation. So i was wondering if any1 knew what the Coefficiant of friction is for the piston and cylinder wall (for a 250 2-stroke, but idc if it is for a 2-stroke or not, i would assume all pistons and cylinders would all be simillar and all very low) OR the amount of force in newtons produced by the blast when the piston compresses (it would be really nice to get the specific ammount for a 250 2-stroke). Either one of thoes would be awsome, dont really need both, because if i have one of thoes i can do the math to find the other. but the last thing i would like to ask; because i have no way of messuring, is the area of the compression chamber in the cylinder head in cm^3 (or m^3), (and again 250 2-stroke, cr250 to be exact) Again any1 of thoes 3 would be enough for the project, i just dont know what i to expect. And if anyone has an idea for an eaquation i could use, im all ears cause im sort of an over achiever when im actually intrested in this stuff lol. Thank you and please excuse my spelling, im sort of in a rush.
  15. might want to look at your suspension and race sag.