new 100 cc Class

[Lew Mayer]

Ahrma has announced a new 100cc class for moto-cross.

Lew Mayer

[brian kirby]

That is good news, but its very odd considering the Board just rejected a rules proposal this year to start a 100cc class.

Brian

'72 Six Day (on loan from Ernie P.)

[Lew Mayer]

It's Ahrma.   'Nuff said [?]
It's listed in their "News Flashes".
Thank goodness, we've got Teddy in there.

Lew Mayer

[jj]

What's up with rules for this new class?

100cc Motocross: 88-100cc two-stroke and 88-120cc four-stroke production motorcycles manufactured as up to 1974-model-year machines, and like-design.

a) Engine displacement can be increased to class limit, plus allowable overbore.
b) Engines must have no more than five gear-box ratios.
c) Electronic ignitions and reed-valves are allowed.
d) Maximum carburetor size is 28mm.
e) Aftermarket frames are limited to those listed, pending approval of the Rules and Eligibility Committee.
f) Engine/frame combinations must be as manufactured; no mixing-and-matching of engine and chassis into "specials."

This makes mid 72 and up Pentons ineligible, but a 74 Super Rat is allowed??? Why don't they just make it easy and make all Pentons ineligible?

I still may to give it go since the year guide shows that early 72's still came 5 speeds. I have Nov 01 produced CMF Berkshire with a missing motor ID plate, so I should be able to get it through. Anybody ever put a reed valve on a Sachs motor?






John J Slivka

[brian kirby]

John, as with most classes this class has a "like design" rule. This means any year Penton Berkshire or Six Day should be legal as long as it has a 5 speed Sachs engine, it shouldnt matter if it came with a 6A originally. They do this in other classes, for example, a '73 Yamaha AT3 which came with a reed valve, is legal in Classic 125 (no reeds allowed) as long as you put an AT1 piston port cylinder on it. Since the Sachs engine Pentons were identical save for the bore size, any of them with a 5A 100cc engine should be legal.

Brian

'72 Six Day (on loan from Ernie P.)

[Ernie Phillips]

From AHRMA

>>Pull out those hot-rod 100s. You wanted it and now AHRMA announces the new 100cc Motocross class. The new class includes all 100cc machines up to 1974 (and like-design) that were manufactured as 100cc bikes. As a rule, the 100s will start in the second gate, behind the Classic 125s. The new class takes into consideration the machines currently up-and-running and the desire to retain the trailbike atmosphere.<<

I'd like to build and race a 100 Penton but as stated above, 100s will be gated behind Classic 125 so I can't race two bikes at the same time.   As far as trailbike atmosphere some of these bikes may  have started life as trailbikes but  in our area, the 100s were the most heavily modified bikes out there!   The 100 class always had the most riders.  I raced a "stock" Rat but soon the reed and down pipe and extended swing arm and Betor forks were added.   That  Super Hodaka was untouchable (when it ran).  By eliminating the 6 speed gearbox, Hodakas will have the performance edge (power & weight) but the Penton will be durable.  I hope some POGers will build a few.  After all, it is the rider that wins races.  Heck, it would be fun to build a 100cc Steel Tanker with an Iron Barrel and put a 140 pound kid on it.  Hey Brian, are you available [:I]?


Ernie P.
Chattanooga, TN

[SouthRider]

I am currently restoring a 100 Penton that has a Dec 72 frame (thus a 1973 model) with a B motor. It seems silly to disallow 6 speeds that are otherwise period correct.

I ended up buying 3 very rough bikes in order to build one - but the other bike has had a reed valve installed on it. Haven't pulled it down yet to look at it, and had initially blown it off as AHRMA ineligible.

Maybe I need an "A" motor to slip the reed valve cylinder onto, and install in my restored chassis for MX races only.

Something to think about.....


Clark




1979 SERA Louisiana State Champ

[Bryson Williams]

I'm building my Monark 100.  If I have to put a five speed in it, no worries. I seem to remember someone talking about simply blocking out first gear.  Is that possible?.

 If so how is that done.  Anybody got some killer top end port spec's for the 100's.

Viva Washougal!

Dirk Williams

[Ernie Phillips]

Dirk,  Better study the rules -- your Monark is NO-NO

from AHRMA:  
>>Ineligible are:

Any machine or major component manufactured as/for a 125cc motorcycle.
Six-speed gearboxes of any type.
Rickman frames originally manufactured for Zundapp engines.
Monarch frames. <<

Why is the Monark excluded?  Oh, wait a minute:  "Monarch" is excluded, not "Monark"  -- go for it!

.

Ernie P.
Chattanooga, TN

[Dwight Rudder]

Personally I think 100cc machines should  be allowed with the 6 speed as long as they are piston port engines. Reed Valve engine should be restricted to 5 speeds. HEY, Kawasaki G5 / KE100 bikes will be legal !  Rotary Valve engines. I wonder if you can stick one of these in a Hodaka frame ?
Dwight

[Dwight Rudder]

HEY, I better get my 1970 Berkshire 100 ready !
Dwight

[Ron]

Why would a 5-speed Monark be any different than a 5-speed Penton?
I understand the limit on 6-speeder's, but why single out Monarks?
BTW, wish I had one.
RonW

[Bryson Williams]

Gosh I wonder why no Monarks.  I own 14 of the little rippers.  Actually only 7 are runners the rest are projects.

Anyway I've got other places to race my 100cc Monark. To be honest with you,I no longer care what AHRMA does.  I'm fortunate I have several NON AHRMA races I can attend year round here in Oregon/Washington/California.

Dirk

[socalmx]

AHRMA stinks and always has...I stopped racing their events years ago.

[sixdazed]

Hey Greg-tell us how you really feel!Seriously,the no 6 speed rule doesn't make sense to me at all.Didn't later Berkshires come with 6 speeds?Why should you have to modify a stock bike to race it?I don't get it-am i missing something?AHRMA is goofy!
                                              Ric

ric emmal