Ahrma has announced a new 100cc class for moto-cross.
Lew Mayer
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.)
It's Ahrma. 'Nuff said [?]
It's listed in their "News Flashes".
Thank goodness, we've got Teddy in there.
Lew Mayer
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
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.)
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
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
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
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
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
HEY, I better get my 1970 Berkshire 100 ready !
Dwight
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
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
AHRMA stinks and always has...I stopped racing their events years ago.
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
This new class is great. I can remember 100cc classes with 30 to 40 bikes on the line. It's an art keeping these little bikes moving. As for the rules I'm sure Dick, Robert and the others will see the light soon and make proper class adjustments.
By the way was there any negative feedback regarding the Sachs D model motors staying in the classic class?.
Dirk
I would rather have a AHRMA race to go to no matter how bad they might be than to have no race to go to at all. Racing any race is better than staying home whining and crying { yeah stay in your garage and just look at the bike on its stand}[:0][B)]:D;)[:o)] race them all support the sport !!!
Larry,
As the rules are written now for the new 100cc mx class you have no choice but to stay home and stare at your Penton 100 6 speed Berkshire.
I am sure the decision makers over at AHRMA will realize there Hodaka partisanship mistake and allow manufacture's 100cc six speed sachs engined bikes.
I would not go rushing to swap your 100cc6/B motor for a 100cc 5/A
the change will have to come.
As my friends in downtown Los Angeles say "No justice,No peace":-)
Paul (socal)
Good morning guys,
The 100 cc class was a surprise to everyone. This seemed to be a last minute thought that happened at the Ahrma meeting while at Barber. To my knowledge no one had a heads up on this at all. Please trust me when I tell you that there are some Hodaka folks that have been in contact with some of the more knowledgeable Penton folks to try and figure why the six speed bikes would not be allowed. No one I have spoken to has any idea why this would be.
There seems to be some confusion with some of the other rules but the six speed issue is by far the largest. There also is a bunch of Hodaka folks that are working behind the scenes very hard to lobby the Ahrma rules committee to please change that six speed rule right away.
It has been a long windy road to get this 100cc class to come alive and now I hope that most guys will come out and ride it once we get the six speed rule reversed. Not one of the Hodaka guys I have spoken to want to see this as what has been called on the internet " A Hodaka Super Rat class". So please be patient and let's see if this rule will be changed before the first race in Arizona. I hope to race against the Penton's and any other brand in the 100cc class
as long as it is a fair playng field for all of us.
I will have to take off the 34mm forks and extended aluminum swingarms off my 100cc racers as I read the rules but that's racing. I hope that it will be fair to everyone and a success. It has taken a long time to get this far and I really hope it get's by this bump in the road. Thank you for the space.
Paul
Paul,
Thanks for your post. Your Character and Integrety is unquestioned as far as I am concerned. For those who wish to think of the class as a "Hodaka 100 Class" just aren't in tune with the big picture. I am happy for the 100 class and if someone has to build a 5 speed 100 Penton so be it. There is give and take on both sides. Weight verses CMF frame verses horsepower and on and on. I hope it is a class where people have fun and bring out some of the old 100 bikes. It is still a racers game and probably the best riders will be at the top of the score as ususal, but there is always room for new good riders.
Ron Carbaugh
Ron my friend, as the rules are now I can't put a sachs 5/A engine into my 1974 Penton 100 Berkshire.
f) Engine/frame combinations must be as manufactured; no mixing-and-matching of engine and chassis into "specials."
My Penton was manufactured as a 1006/B. As of now my bike will remain as pitbike. I am realy not the right size to race a 100cc bike I just love giving the Hodaka boys a hard time:-)
Paul knows I keep an eye on the Hodaka hords, someone has to keep them in line.
This is FUN..........
Paul(socal)
Paul, I believe I am the one who first said "call it the Hodaka Super Rat class". I did not mean to say that the Hodaka guys did this by back room lobbying I just pointed out the fact that as it currently stands it is in effect a Super Rat class. I believe you guys dont care about 5 speed or 6 speed, but the rule is there.
Pablo brings up another part of this rule that is not clear. It actually says bikes must be
"88-100cc two-stroke and 88-120cc four-stroke production motorcycles manufactured as up to 1974-model-year machines, and like-design. All motorcycles in this class must have been manufactured 100cc or smaller-displacement bikes.
and
Engine/frame combinations must be as manufactured; no mixing-and-matching of engine and chassis into "specials."
I understand this to mean no putting Yamaha engines in Penton chassis or a Sachs in a Rickman Hodaka frame. I dont read that to mean that you can not put a 5A engine in a '74 originally 6B frame since the Sachs CMF bikes are a classic example of the "like design" rule. I also dont see where Paul would have to take the bigger forks and extended swingarm off his Hodaka unless they came off a 125. It doesnt say the chassis has to be stock as manufactured, it says you can not use parts off a 125, it says nothing about using parts (forks) off a bike bigger than 125 so as its written Hodaka 250 forks are legal. If I build a Yamaha (which I might) as its stands I can use a 90 or 100 frame and use a CT1 175 forks and swingarm since its not a 125.
Poorly written rule in many ways. If I was going to write a rule for this class it would read:
"100cc class bikes will follow Classic 125 rules except reed valves are allowed and carburetors are limited to 28mm"
How easy is that?
Brian
'72 Six Day (on loan from Ernie P.)
Hmmmm, The only aftermarket frame eligible is the Van Tech. Correct me if I am wrong. But wasn't the Van Tech frames used mostly for Hodakas:-) ??????
Pablo (socal)
Pablo & Brian,
Sorry to step on your toes....I was just recognizing Paul and his discussion. I won't let it happen in the future.
Ron Carbaugh
Ron, you didnt step on my toes at all, I value our opinion and I want to hear what you have to say even if you disagree with me.
I am not upset with you, or the Hodaka guys, I am just bewildered at the reasoning and loopholes in the 100cc class rule.
Brian
'72 Six Day (on loan from Ernie P.)
Instead of riding Penton 100 6 speeds in the pits. Take some time and write a letter or call AHRMA. Remember the sachs "D" motor rule? If you write or call I think they will change the rules. So write or call today and with enough people doing this, I do think the rule will change. Just my thoughts Later Gary
No the Van Techs were made for any 100 motor Honda,Bridgestone etc.Van Tech made all the motor mounts where they could make engine brackets and mount almost any motor in it.
It just happened that the Hodaka motor was way more reliable than the Sachs [:0] and others,that is why you see them in most Van Tech frames.Seems like your Hodaka bias is showing again.[}:)]
Bojo Stults
I think that 6 speed piston Port engines should be allowed. As for the modified swingarms and oversized forks these are major frame components. and should be close to as manufactured.
IMO,
Dwight
Paul,(socal) race one of those 100 zundapp's I sold you. LG- some say -"BURN BABY BURN"
Dwight, I agree that major frame components should be as manufactured, but that it not what the rule says, it only says "Any machine or major component manufactured as/for a 125cc motorcycle" is ineligible. That is a loophole big enough to drive a truck through. As written, if you were so inclined , you could put Maico forks on a Hodaka as long as they didnt come off a 125 Maico.
I can tell that the intent of the rule was to keep the bikes as close to stock as possible to original, but that is not what it says.
Brian
'72 Six Day (on loan from Ernie P.)
BTW, I think I've beat this horse to death so I wont harp about it anymore.
Brian
'72 Six Day (on loan from Ernie P.)
O.K. this will be my last post also about this. Sorry guys I did not mean to stir up a hornets nest. I was only using this great forum to state that the Hodaka guys are with you and support having six speed Sach's motors eligible. Cool we all agree I think ?
Ron thank you ! What you say means more than you will ever know. I truly appreciate that.
Brian after looking through posts on Vinduro yes I do see where it was you that came up with the " Super Rat class " and I can see where you were coming from in light of the rules. No worries on my end at all.I would just want all to know that "Hodaka" did not know of this until the decision had been made for the class.
Brian you spanked all of us in the MX at the ISDTR this year and I could only hope to try and chase you on a bike in the 100cc class this year. Your ability sure shows and I hope I can keep up. Let's get you and all the other guys out there on whatever bike but let's race. Being a brand new class there has to be rules or ideas that need to be tweaked. I do not think any of us are smart enough to have all the answers first shot so if we can communicate with " Ahrma" this will be a positive thing.
Like Gary said send emails , send letters but DO contact Ahrma and let them know politely how you feel and ask maybe why this rule was placed in effect. Gary how is your shop coming ?
Paul I absolutely understand where you are coming from also. I love the fun you poke at us Hodaka guys like "putting DDT in your tank to fumigate the pesky Hodaka's at the ISDTR " or something like that. Dang that was a GREAT line and I loved it as did all the other guys :-) I as the rest of the guys know you are just having fun and when this sport get's so serious that we cannot have fun I for one am out .
I really can see where you guys are passionate about how you feel and what you believe. Let's all work together please to at least see this rule change through and possibly get better clarification on other rules. Gary's idea was perfect.
Bobby I think and that is a big think that Van Tech also made kit's for Yamaha and others too. I have a brochure someplace in the shop but cannot find it at the moment.Been to busy raking leaves. Do you know you cannot get a high school kid to rake leaves anymore ?? Anyone of us came from a time when we would rake leaves all day for 50 cents an hour. Where did those day's go ?
I guess my point is please let's all work thought this together. the Hodaka guys all want a level even playing field and want this class as it seems you guys do too. It might take a few weeks but with effort and hope we will succeed.
Thank you
Paul signing off.
I will only bring this up this once. I promise. You guys can work through this if you wish but remember what I have to say on this as there is a pattern to it like the D motor thing and it will come up again.
It would be good to know WHO at AHRMA proposed the 6 speed portion of the rule. If you could get to the bottom of it my money says that it is the same source that ran the D attempt and that person wishes to exclude Pentons. They are NOT a friend. What else does this rule really eliminate?
By the way, in 1974 when the only venue for a National 100cc Championship played out it was a 100cc six speed Berkshire special that stood on top. Coincidence? I don't think so. AHRMA is the only real game for Vintage on the National level but in all honesty they STINK!
Larry P
Well..I'll admit - the class sounds interesting, especially to a guy with a 16 yr. daughter that wants to go racing for the first time. AHRMA/ACRMX scene just seems like a great place for her to give it a go, and do the family thing.
First question - minimum age IS 16 in AHRMA, right? Second - gosh, just what bikes would meet the rule that were manufactured thru 1974? Of course the Hodaka models, and I know that Yamaha made an MX100 (yellow) in 74, but did Suzuki make a TM 100?
BTW, while I'd love to have a Berkshire in the "stable", the reality is this year will be a learning year for maintaining my own "brand new" 72 125 SD, and two Pentons might prove a bit much for now. : - )
God I love the passion on this site...a 100cc class is announced and there's three pages of discussion. BTW - I do think the letter-writing campaign is a great idea. Heck - give me the address. I'LL WRITE a letter!
Finally - the tree is in, and outside decorations are up. Cross those off the honey-do list. Next up - screen print the POG items page and let Santa know I want a 2008 calendar and the JP Story. Happy Holidays to the members of this board!
AHRMA is using a Performance Index of the bikes. To try and keep the playing field as even as they can ,(or they think they are ? ).[8D]
Just a side note for some of the newer members of this site and POG.
Larry Perkins was the 1974 School Boy National 100 Expert Champion on a 100 Penton in the Astrodome. He beat all comers including the highly modified DG and FMF Suzukis, Hondas and Yamahas bikes. I hope this new 100 class is as fun as it was in the early to mid 1970's. Larry still has that bike and it still as beautiful and as fast as it was on that day back in 1974. I believe this is the last National MX Championship that was won on a Penton. Please correct me if I am wrong[8D].
Ron Carbaugh
Sounds like Larry has some first hand experience with Hot 100s. Who was his tuner?
Brian
'72 Six Day (on loan from Ernie P.)
"Hot rod 100 or trail bike class?" If one examines the racing up to and including 1974, there is no basis for a "trail bike" class. The 100cc class was a full-blown racing class. Which one will ARHMA rules support? Photo of my hot-rod 100 (Hodaka) circa 1972-74. Betor leading axle forks, lower/lengthened frame, custom swing arm, long girlings, reed/ported, down pipe, alloy tank... sweet!
(http://pictures.aol.com/galleries/ephilride/07a0VYncF0aeVwF6fYqMxVXvy*DIl2TYcWlVv4xQp5Fd3Ig=)
added new link:
http://pictures.aol.com/galleries/ephilride/07a0VYncF0aeVwF6fYqMxVXvy*DIl2TYcWlVv4xQp5Fd3Ig=
http://autos.ph.groups.yahoo.com/group/Hodaka/photos/view/5ed1?b=1
National Champ 100 Penton -- way to go Larry!
Ernie P.
Chattanooga, TN
The 100cc class was considered a Trail bike class even then. I believe that AHRMA intention is to keep this class as close to stock and low tech as possible. I don't see what the complaining is about. I personally don't see a problem with piston port 6 speeds either. Another complaint is that the rules don't include smaller cc bikes. 73cc K80GS Sachs Boondockers went pretty good too. We even have a K50GS Hercules in our collection too. Why should they be excluded ?
I wonder also if they will open a 100cc class for Cross Country events too ?
Dwight
It would be nice to see a 100cc class in CC Dwight, but they dont usually have more than a handful of entries in Sportsman 200 and even less in Classic/Premier. I imagine that a lot of the Hodaka guys that currently run 125s in Sportsman 200 (Gary Copeland) or 100/125s in age classes (like Johnny Friedli, Leo Stinnett) might run a 100 class if they had one.
A 100cc class also seems like an ideal if one was interested in haveing a 12-15 yr old class, but that is just another pipe dream that AHRMA will never implement.
Brian
'72 Six Day (on loan from Ernie P.)
5 or 6 speed gearboxes should not matter IMO. One of the reasons I no longer participate is the fact that there was no 100cc class so we were forced to race with Huskies, CZ's and all the other bike bikes. While it is fun to go around the course nobody wants to get smoked!
At the Elsinore GP a few years ago the opened a 100cc class. I thought Hooray until a sleeved down(supposedly)honda Elsinore lined up next to me. The next year a couple of really trick Suzuki TM100's showed up and darn near lapped everyone.
I don't have answers for these situations. Maybe 72 should be the cutoff date but then you limit a small class even further. The technolgy jump from 72 to 74 was massive. In looking through my old Cycle news want ads from 74/75 there were all kinds of Pentons,dkw's and other euro bikes being sold and waiting lists at the honda-Yamaha-Suzuki dealers.
Dwight,
Not to argue but in 1974 in Texas at a MX race the 100 class was quite large and it was NOT a trailbike class. It was filled with many High Tech for the times, bikes. Highly modded Hodakas though lagging, Sleeved Elsinores, sleeved YZs, and a decent amount of Berkshires. There was even an Ultra-Fast Rotary Valve Bridgestone. If you ran at the front the crank was stuffed, it had a pipe, a bigger carb, small rotor ignition, and porting. There were complete bikes and mods from DG, FMF, E.C. Birt, and Banke. For a few months I even raced an E.C. Birt sleeved one-off Pursang that ran a Banke Snail pipe. There were trail bikes but they were WAY back.
AHRMA has a pattern of wanting to re-write History on one hand and then allowing some of the Hodakas and Huskys to run pipes today that are beyond 1974 thinking and technology. Please do not help them with what is mis-information that may not have applied everywhere. We are talking MX not woods! Perhaps Texas was unique but I do not think so.
Larry P
But, Larry, How modified were the frames and suspension on most of these bikes ? How big a carb were actually on these bikes ? Other than the rear shocks I bet the frames and suspensions were mostly stock. Tweek them a bit if you must but lets keep the spirit of vintage racing in this.
IMO,
Dwight
Quotequote:Originally posted by Larry Perkins
Dwight,
Not to argue but in 1974 in Texas at a MX race the 100 class was quite large and it was NOT a trailbike class. It was filled with many High Tech for the times, bikes. Highly modded Hodakas though lagging, Sleeved Elsinores, sleeved YZs, and a decent amount of Berkshires. There was even an Ultra-Fast Rotary Valve Bridgestone. If you ran at the front the crank was stuffed, it had a pipe, a bigger carb, small rotor ignition, and porting. There were complete bikes and mods from DG, FMF, E.C. Birt, and Banke. For a few months I even raced an E.C. Birt sleeved one-off Pursang that ran a Banke Snail pipe. There were trail bikes but they were WAY back.
AHRMA has a pattern of wanting to re-write History on one hand and then allowing some of the Hodakas and Huskys to run pipes today that are beyond 1974 thinking and technology. Please do not help them with what is mis-information that may not have applied everywhere. We are talking MX not woods! Perhaps Texa
s was unique but I do not think so.
Larry P
Look above at Ernie's "Super" Super Rat. The frame was modified, engine lowered in the chassis, it had a reed valve, square section lengthened swingarm, leading axle forks, it was trick and this was just out of a little shop in Pensacola, FL. Hardly the epicenter of trick stuff, but there it is. He has an article in the old Dixie Cycle News about his bike called the "$2000 Super Rat".
Brian
'72 Six Day (on loan from Ernie P.)
I have a feeling Suzuki TM100's just doubled in value [:p]
ric emmal
Were the first YZ 100s five or six speads? I drooled over them so bad at the dealer back then with that down pipe and green tank [:p]
Dennis Jones
Dennis, you are talking about the green Yamaha LT2MX from 72 and 73, it was a 5 speed with a reed valve, also lets not forget the Kawasaki G31M and the HD Baja 100, got to luv the 100's !!!
Mike Gallagher, Camden County, NJ. - 70 + 71, 125 Steel Tankers, 72 x 2, 73 x 2, 125-6 Day's, 73 Jackpiner, 75 - 250 H/S, 74 1/2 Mint 400
Quotequote:Originally posted by Dennis Jones
Were the first YZ 100s five or six speads? I drooled over them so bad at the dealer back then with that down pipe and green tank [:p]
Dennis Jones
The YZ100 didn't come out till 1975 and it was a 6 speed monoshock. Historic class. The bike you are discribing is the LT2MX ( 1972 reed valve , 5 speed)
The 5 speed Yamaha LT2MX or the LT3MX and the MX100 were legal.
Dwight
Thanks for correcting me guys. It is the MX model I lusted after. I can't say that I have saw any for sale in recent years.
Dennis Jones
Guys there has been some very good communication going on about this class with some of the Ahrma guys. This may take a couple more days to shake out but hopefully by Friday there will be information available to answer everyone's questions. The Ahrma guy's are all working extremely hard on a variety of issues. I personally think everything will work out fine. Although as all of you know you will never be able to please everyone. I for one look forward to seeing a bunch of 100cc bikes at the races.:)
Thanks
Paul
Can you name thee most accomplished, renowned, and legendary (American) 100cc rider/racer ever ?
If you answered Dane Leimbach - then you'd be right. :D
You mean, Dane "the Bud Ekins Pioneer Award" Leimbach! I knew that!
With all the new 100cc class buzz, I'd like to hear from Dane, Billy U, Ron C, Larry ... Doug, on what unique qualities it takes to be successful in the 100 class. And, how much did they weight back then? :D
Ernie P.
Chattanooga, TN
Rob,
Hear hear! I agree! Did anyone win more Gold Medals at Qualifiers and ISDT than Dane on a 100? I doubt it. Some of the hills he had to climb with the little 100 had to be a trick. I and many others will always marvel at his 100cc feats.
Ernie,
In MX back in "The Day" 100cc success came through this formula-High horsepower over a narrow powerband usually accomplished with porting, head milling, big carb, pipe, crank stuffing, and small flywheel or total loss ignition. You had to combine this package with fancy clutch work to keep in the narrow meat of power, light rider weight, and talent. However, in my case you could obviously substitute heart, luck, and being a good start cheater for talent.[8D] As far as weight back then I weighed 145 pounds soaking wet. I am sure in the woods the formula was quite different but I did not find the woods till I was about 26.
On a side note on weight a couple of years ago I saw Our own Mike Lenz battle former great Mike Bell on 100's here in Missouri. Mike Lenz is a little over 200 pounds:D and he gave Bell all he could handle. So talent can also over ride weight. Pounds is generally ponies in small bikes, though. Hope my opinion helps a little. I am far from an expert. I just rode them and watched them be built. That is where the tricks were learned.
Larry P
Greg Holder 100cc Combs Ark. 2006
Thomas Carmichael
1970 125 Six Day
1976 250 Hare Scrambler
I always loved riding 100s back then. I even overalled a ISDT qualifier style event in 1980 over near Shreveport LA on a Suzuki RM100.
I liked riding 100s better than 125s. I won many H/S in the 100 class on my Hodaka Ace 100B+ . Not even a Super Rat. but a 10hp Ace. I had a blast on my K100GS Hercules at the last ISDTR. Too bad it is a 6 speed. I love play riding on my Kawasaki 100 even.
100s are just plain fun.
Dwight
PS: Back in the early 70s my heros were Dane L, Billy U, and Paul D. Later when I started riding the Nat'ls and ISDT Qualifiers, I was amazed on how fast my friend, Dane's brother, Teddy was on a Penton 100.
IMO the very best offroad racers on the WORLD started out on 100cc bikes. When do don't have power you must substitute skill. I remember reading about the ISDT or maybe a qualifier where Dane slid all the way down a hill still holding on to the handlebars keeping the engine running and remounting to climb it again. now that's skill!