Motorcyle class question

[Johnny KCK]

I read the '08 SCTA rule book, but I have a question about the class regulations concerning motorcylces.
O.K. Here it goes:
I understand that if I run a stock unmodified Harley Sporters frame it will put me in the P- class and if I run a stock 1200cc sportster engine the engine would be classified as PP. So together it would put me in the P-PP 1350 class. At least I hope I got this right.
Now to my question. If I keep the engine stock as per the rules for a PP (production pushrod) engine but I lower the suspension and lenghten the swingarm a few inches this would put me in the A- class, for modified production frame, now per the rule book all engine classes are legal in this class except UG, UF, and omega, correct? So if I keep my engine stock as per the rules for a PP engine would this put me in A-PP 1350 class or which class would I be running in? The reason why I'm asking is that I can't find a A-PP class in the rule book or the SCTA web site, I can find A-PG or A-PF. But since the engine will be unmodified as per the rules for PP would I still have to run in A-PG  class or would I be running in a class that hasn't been established yet, such as A-PP? Or am I just talking nonsense here?
My plan is to see how far (fast) I can push the production Evo Sportster engine and lowering the bike and extending the swingarm will help with highspeed stability and traction in my opinion, plus it will cut down on drag since my frontal area will be smaller.
 Any and all help will be appreciated!
-Johnny-

[ol38y]

Welcome Johnny.

Let's see if I can answer some of your questions. First, PP does not necessarily mean stock. It means more like stock appearing. You can do any internal modifications you want as lang as it appears stock, including boring to 1350. But, you must also have stock mufflers, carb, air cleaner, frame and ride height. If you lengthen the swing arm you will be in the M class. In M you are limited to 10% over stock wheelbase. Once you move out of Production class to M you also move to PG class. So, with your described mods you would be 1350 M-PG.

On another note, there is no M-PG class at El Mirage. You're either P or A. The 1350 A-PG record is a pretty good one. There's a couple of us running at it.

As everyone says, keep reading the rulebook, then read it again. Good luck and see ya out there.

Larry

[isiahstites]

The 1350 A-PG record is a pretty good one. There's a couple of us running at it.


Larry

Yep, those pushrod records are no joke...........

[VeeTwin]

You guys gave good info but didn't answer his actual question.

So if I keep my engine stock as per the rules for a PP engine would this put me in A-PP 1350 class or which class would I be running in? The reason why I'm asking is that I can't find a A-PP class in the rule book or the SCTA web site, I can find A-PG or A-PF. But since the engine will be unmodified as per the rules for PP would I still have to run in A-PG  class or would I be running in a class that hasn't been established yet, such as A-PP? Or am I just talking nonsense here?

Production engine requires production frame and vice-versa. So there's no A-PP and likewise there's no P-PG.

My plan is to see how far (fast) I can push the production Evo Sportster engine and lowering the bike and extending the swingarm will help with highspeed stability and traction in my opinion, plus it will cut down on drag since my frontal area will be smaller.

Extending the swingarm generally trades off traction for stability. By moving the rear wheel back, you put less weight on it, and more weight on the front. This can be compensated for adding weight to the swingarm. You'll see that most guys with extended arms also hang some weight on them.

[Johnny KCK]

Welcome Johnny.

 The 1350 A-PG record is a pretty good one. There's a couple of us running at it.

As everyone says, keep reading the rulebook, then read it again. Good luck and see ya out there.

Larry

Yeah the record in 1350 A-PG is some thing like 166 mph. Wow! Looks like I'll be going for the 1350 P-PP record, last I checked it was 146 mph. I think I could have a chance at it. I'm sure I won't get it on my first try, actually I'm certain I won't get it on my first but that won't keep me from trying.

[Johnny KCK]

Extending the swingarm generally trades off traction for stability. By moving the rear wheel back, you put less weight on it, and more weight on the front. This can be compensated for adding weight to the swingarm. You'll see that most guys with extended arms also hang some weight on them.

Yeah I guess you might be right with the traction thing, I was thinking in terms of dragracing. I've built some fairly potent dragbikes and extending the swingarm helps traction, but that is under hard acceleration.
On the lake I won't be accelerating hard enough to load the real wheel I guess.

Thanks to you guys for the info and help.

               Johnny

[VeeTwin]

I know drag racers who have put a lot of work into figuring out what length swingarm works best, making different lengths and trying them. Longer costs traction on the dragstrip, too. It's a trade off between traction and keeping the front wheel down.

[Johnny KCK]

I know drag racers who have put a lot of work into figuring out what length swingarm works best, making different lengths and trying them. Longer costs traction on the dragstrip, too. It's a trade off between traction and keeping the front wheel down.

True, to long is worse than keeping it stock, it all has to do with the amount of power your making, your center of gravity, if you have a slick or a street tire, total weight of bike, a lot of things come into play.

[ratt2y]

I am in the same boat but i had my motor bored and stroked to 85.31n..exhaust not stock.(drag pipes)
where would I fit in?Is there a 1400cc M-PG CLASS? 1976 Harley sportster ridged frame.

[fredvance]

Anything over 1350 puts you in 1650 class

[Seldom Seen Slim]

M/PS/PG (or F if you don't run event gas) 1650.

Modified

Partial streamlined

Pushrod

Displacement between 1350 and 1649.999 cc

[wobblywalrus]

Johnny, some comments in longer swingarms.

Mo'sickle stability, or lack thereof, was a big problem with the Triumph.  The rake angle was reasonable, so that was kept standard.  A set of real strong billet triple clamps were made with as little offset as possible without making it difficult to steer.  The bike is used on the street and it needs to turn.  Then, the swingarm was extended only a few inches.  The front end work eliminated the need for a long extension and the traction problems associated with it.