RadarRacing Posted December 18, 2009 Report Share Posted December 18, 2009 I would not build a 421 cheetah for a trail bike at all. That would be a poor choice IMO for a trail bike its still not gonna be much till revved up quite a bit and will cost at least $2000 just for the topend and crank. Cheetahs also take 250R intakes unlike cubs and stockers. Quote Link to comment Share on other sites More sharing options...
FrankieSquid Posted December 18, 2009 Report Share Posted December 18, 2009 Just like everyone else, i wouldnt shoot for a 421 cub as trail bike. Them motors are meant to go nowhere else but straight. Their HP gains are in the upper RPM range. You will need something with low to mid RPM Hp. If you are not going to be hitting 6thgear i would not get the 421. To be fast in trails you need a setup, suspension plays a big ass role when it comes to movin in and out of tight trails. They have different porting that will suit your needs. Quote Link to comment Share on other sites More sharing options...
SonOfSand Posted December 18, 2009 Report Share Posted December 18, 2009 I have a couple of thoughts, Maybe you are thinking cheetah because you want something that is still wicked fast, just in case someone wants to drag race, or you hit a long stretch, and maybe you don't believe the 4mill ported jugs are going to be much faster than what you have. If this is the case, you will be shocked to feel the difference between what you have now, and the 4mil. I feel confident in saying that the 4mil will blow you away, and most comers who want to race. The other thing is fuel consumption, do you go on long trail rides? I noticed a big difference in range after I built my 4mil, I am sure it would only get worse if it were a 421 cub. Quote Link to comment Share on other sites More sharing options...
WINDYCITYJOHN400 Posted December 18, 2009 Report Share Posted December 18, 2009 I have a couple of thoughts, Maybe you are thinking cheetah because you want something that is still wicked fast, just in case someone wants to drag race, or you hit a long stretch, and maybe you don't believe the 4mill ported jugs are going to be much faster than what you have. If this is the case, you will be shocked to feel the difference between what you have now, and the 4mil. I feel confident in saying that the 4mil will blow you away, and most comers who want to race. The other thing is fuel consumption, do you go on long trail rides? I noticed a big difference in range after I built my 4mil, I am sure it would only get worse if it were a 421 cub. GREAT POINT! A cub motor will DRINK fuel in a trail setting. I've got a 472 cheetah with powervalves and it doesn't matter what gear it's in, it won't hook in anything other than sand. 2-guys in my ride group found out the hard way that a 421 cub is junk for the trails. they took they're new 421 cub motors out for a day of woods/trail riding at the local off-road park and burnt thru a ton of fuel ($$ RACE GAS $$) doing nothing but spinning tires, and over reving motors. Stick with a stock type cylinder. Quote Link to comment Share on other sites More sharing options...
DallasGDub Posted December 18, 2009 Report Share Posted December 18, 2009 Not a good idea like everyone has advised. I also want to add that all that power will get you nowhere b/c traction on that motor will be hard to find in the trails. You will be getting walked on by smaller, torquey bikes as your tires spin in the dirt. Like Lim said, 2001Stroker's bike was not really built as a trail bike. He just happens to ride it like that. You can get a port job to match your pipes, and some bolts-on's for more than enough power to smoke people with, and kill in the trails. I ran a HJR Dune port on a trail banshee, and it KILLED. People hated playing cat and mouse with me leading. They just could not keep up. IMO, for trail bikes, the bulk of your cash should go into the bike, not the motor. A trail bike should focus on suspension, and handling. (shorter swinger, front and back shocks, +4axle, +3 arms, taller stem, beadlocks, nerfs, skids, ext....) The cost is not much different. Rather it be a trail, dune, or drag bike. If you build each bike the right way, they get costly either in parts, or in the motor. Takes the right tool for the right job. Quote Link to comment Share on other sites More sharing options...
robert0762 Posted December 19, 2009 Author Report Share Posted December 19, 2009 Just like everyone else, i wouldnt shoot for a 421 cub as trail bike. Them motors are meant to go nowhere else but straight. Their HP gains are in the upper RPM range. You will need something with low to mid RPM Hp. If you are not going to be hitting 6thgear i would not get the 421. To be fast in trails you need a setup, suspension plays a big ass role when it comes to movin in and out of tight trails. They have different porting that will suit your needs. Not a cub but a cheetah . i was thinking the pv's would help me out I have a couple of thoughts, Maybe you are thinking cheetah because you want something that is still wicked fast, just in case someone wants to drag race, or you hit a long stretch, and maybe you don't believe the 4mill ported jugs are going to be much faster than what you have. If this is the case, you will be shocked to feel the difference between what you have now, and the 4mil. I feel confident in saying that the 4mil will blow you away, and most comers who want to race. The other thing is fuel consumption, do you go on long trail rides? I noticed a big difference in range after I built my 4mil, I am sure it would only get worse if it were a 421 cub. exactly my thoughts and intentions. Finnally someone actually reads before they post . Neway i think I will just go with the hjr port work on stock cylinders. maybe after I get this bike done I will do a cheetah motor and if I think its too much i'll just go all out drag with it Thanks for all the input guys u really helped me out Quote Link to comment Share on other sites More sharing options...
robert0762 Posted December 19, 2009 Author Report Share Posted December 19, 2009 (edited) Just like everyone else, i wouldnt shoot for a 421 cub as trail bike. Them motors are meant to go nowhere else but straight. Their HP gains are in the upper RPM range. You will need something with low to mid RPM Hp. If you are not going to be hitting 6thgear i would not get the 421. To be fast in trails you need a setup, suspension plays a big ass role when it comes to movin in and out of tight trails. They have different porting that will suit your needs. Not a cub but a cheetah . i was thinking the pv's would help me out I have a couple of thoughts, Maybe you are thinking cheetah because you want something that is still wicked fast, just in case someone wants to drag race, or you hit a long stretch, and maybe you don't believe the 4mill ported jugs are going to be much faster than what you have. If this is the case, you will be shocked to feel the difference between what you have now, and the 4mil. I feel confident in saying that the 4mil will blow you away, and most comers who want to race. The other thing is fuel consumption, do you go on long trail rides? I noticed a big difference in range after I built my 4mil, I am sure it would only get worse if it were a 421 cub. exactly my thoughts and intentions. Finnally someone actually reads before they post . Neway i think I will just go with the hjr port work on stock cylinders, 4mill. maybe after I get this bike done I will do a cheetah motor and if I think its too much i'll just go all out drag with it Thanks for all the input guys u really helped me out Edited December 19, 2009 by robert0762 Quote Link to comment Share on other sites More sharing options...
THE GRIM RIPPER Posted December 19, 2009 Report Share Posted December 19, 2009 Hehe... Powervalved cub twister 421 stroker turbo nitrous 10mill, In the woods...... End up getting intimate with a tree. Call HJR, keep it simple, focus on geometry, suspension, and strength. And set all you controls up just right to avoid fatigue. Quote Link to comment Share on other sites More sharing options...
sandman81 Posted December 20, 2009 Report Share Posted December 20, 2009 I can pretty much say SonOfSand nailed it on the head. I got a 421 cub and I used it for trail riding. The only down side was fuel consumption, I could kill 5 gallon of race gas in like 5 hours and thats taking breaks in between. Another down side, my +5 swinger would make it hard to go into tight turns. so i would have to keep the revs right were the powerband would kick in so i could spin the tires and kick the bike sideways, but if i forgot what gear i was in or got tired and not keep the revs up and i would go into the trees. My shit would never hook, just too much power for dirt. but as for sand that thing is a wheelie monster and fun as fuck to ride. My opinion i think a 4mill for trials is not the best chioce just cuz i hate having too drive for my race fuel and then it only lasting one weekend of only 5 hours. Now i could make it run on pump gas but then that would just disgrace the cub. Good luck on your build. Quote Link to comment Share on other sites More sharing options...
NickisGod Posted December 29, 2009 Report Share Posted December 29, 2009 where can u get a 421 cheetah? does it use a 4mill crank and a 68mm bore? Quote Link to comment Share on other sites More sharing options...
robert0762 Posted December 29, 2009 Author Report Share Posted December 29, 2009 where can u get a 421 cheetah? does it use a 4mill crank and a 68mm bore? CPI Manufactures them in a lot of stroke a nd bore combinations. Trinity cab get them but I would try to got thruogh HJR or Fast before I went to trinity for it http://www.cpindinc.com/pub/part_list?manufacturer=3 Quote Link to comment Share on other sites More sharing options...
Tony T Posted December 30, 2009 Report Share Posted December 30, 2009 If u don't want the pv setup I'll take it stang3002@yahoo.com Quote Link to comment Share on other sites More sharing options...
2/2 many banshees Posted December 30, 2009 Report Share Posted December 30, 2009 I would think the best thing for you would be a RZ top end. The 421 cheetah is to much on the trail with out big suspension upgrades. If you have the $$ the cheetah with the suspension upgrade would be a hand full but bad ass. Quote Link to comment Share on other sites More sharing options...
NickisGod Posted December 30, 2009 Report Share Posted December 30, 2009 shit i have elkas all the way around. i wish i would of seen a cheetah kit when i was doing my top end. my only issue is id hate to have my case trenched, i remember seeing some guy on the forms a bit back blow his cheetah crank into a million pieces. Quote Link to comment Share on other sites More sharing options...
shogs Posted December 31, 2009 Report Share Posted December 31, 2009 My stock suspension really killed me in the woods. I'd be sweating and breathing heavy after just a little time in the woods. Then I got some dual rate elkas and i'm in the process of getting my rear works rebuilt. Suspension is definately the key before getting into the motor. Heres my setup and I really like it in the woods. My trails are pretty technical and sometimes I'll have to clutch it and give it a little bit of gas, but for the most part theres power waiting to be unleashed. Heres my setup. Aggressive trail port by hjr +4 timing and 20cc domes on high octane. +2+1 a-arms with dual rate elkas -2 swinger with works rear shock -Billet Impellar 2into1 carb really gives it that light switch effect some people are looking for. I'm sure the porting has a little to do with that as well . PTR mids I'm sure I forgot something but the main thing has to be durability. Unless you beef up the bike your gonna run into weaknesses. Good luck keep us updated. Quote Link to comment Share on other sites More sharing options...
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