What about 500 vs 250 transmissions?

[Hillclimb#42]

 Well, hill was super slick and muddy, then dried to a heavy goop in the second round. Sunday was a mixture of soft sand-like wet powder on the breakers, and the inclines were hard and tacky, and was fairly dry by the second round. 14-47 stayed on thru all conditions and actually did better on slick and nasty on saturday. Pulled out a fifth, i think, and sixth on Sunday. Not my ususal, but my rear tire is toast. I've rounded all the nobbs that I have left. The rest are either torn or broken. I'm sure that played havoc on consistent traction, as well as previous gearing choices. A worn tire is supposed to help on a stock length swing arm, but it didn't at all. I did ride around a freshly groomed motocross track and really liked the way it rides and pulls the gears. 14-47 is a good choice. Any more tweaking will be a 45 or 49 on back.
  My 250 is sporting a new Kenda Washougal and threw down a 5.102 good enough for second. And I ran another good time in the 250 stretched class (5.2something) and got a 7th in a very tough class of twenty. The important thing that I did was beating the guys I needed to for the season points. I'll be ordering new rubber and probably ditchin the spacer for the state championships.
 I appreciate your input BDI, and I hear you that you have ridden on more than sand. I also agree that the little guys over in Japan figured out alot of things correctly. Thats a good reason to tweak changes and not make leaps and bounds. You just have to hear half of the strategy and plans that I hear, to appreciate my positive headway. Last year was my first season at hillclimbing, where most everyone else has been at it for years.
 I see first hand the difference in gearing. One of my buddies rides a 750 triple and a 800 triple in 250 chasis. He has to gear down to get traction or it spins too much. Same thing on slick mud or extremely steep or rough conditions. Gear up for easy hills, good traction, big hills or sand. too tall will be hard to keep the front end down, where under gear is way too slow. No matter what though, I need fresh rubber to gauge where I stand, in my opinion of course. Thanks for the help and info for future tweaking!!!!!!!!!

[BDI]

I ran a IRC 130 soft teraian tire one time It was the closest thing to a paddle tire with knobbies I have ever ran. It was the direct reason I found my self on my but twice. When I say It hooked up thats no joke. sorry you did not do better .

[don46]

We typically run a IRC M5B 140, and geared as high as you can pull. You could also run a tereaflex, it's even bigger. If it was hard and slick, a used tire may have been better than a new tire, if there's nothing for the knobs to grab to they may not help. On really hard packed surfaces I've wondered about siping, to try to get as much rubber to contact the ground

[Hillclimb#42]

 New tire, new results. Got the Kenda Washougal on the k5. It hooks up ALOT! I had trouble coming out of the hole without the bars in my face. I had to move out of the rut and try to keep the bike straight. Also set the timing back a tick to the retarded side. That made a noticable change to max rpm's. Pulled out a 2nd  place finish in the Illinois State Championship. The hill was a man-made hill that resembled a volcanoe. It's back side was as high and almost as steep as the front with only about 20 feet of flat on top. The 500 never saw flat ground and was landing near the bottom of a 150 ft hill.  I was shakin so bad, that it was hard to get calmed down for the next round.
 On the 250 I wound up 4th in 400 stock and 5th in 250 stretched class. Again I'm racing these guys with a stock length swingarm and riding trails around the event, just having fun. I think they are nuts and I guess they feel the same about me. Gearing choice is sweet and so is the new rubber. New tire was a little tough to break loose off the log, but I made up for it in the middle of the hill. The majority of the riders were seperated by only 3 tenths of a second.  Thanks for your input guys, and if anyone is trying to figure out gear ratios, I believe that I'm on to something.

[BDI]

Good job did you change anything other than the tire from last time?

[Hillclimb#42]

 Well, I left the 14 on and also turned the timing back a tick. Retarding the timing was supposed to help pull more r's according to another thread about lengthening the power band of the k5. Its true. And its not like other changes, where you get help in one place and lose it somewhere else. I still am going to drop the reed spacer, but haven't pulled it apart, yet.

[don46]

New tire, new results. Got the Kenda Washougal on the k5. It hooks up ALOT! I had trouble coming out of the hole without the bars in my face. 

Have you thought about using a MX holeshot device? I have, and think it would be the ticket in certain situations, it would keep the bars out of your face and allow you to accelerate up the hill.

[Hillclimb#42]

 Against the rules here Don. So is the new slipper clutches. You're right though, they work. Guess thats why guys protested them and made the rule.