Racing: the 4-stroke class

GoldenMotor.com

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
Ya know there is a reason why they are allowed to race up to 550cc 4-strokes in the 250cc Super-Cross races. What it boils down to is you need to double the dissplacement of a 4-stroke to equal the power of a 2-stroke of any given size.

I've got a couple of 46cc 2-stroke engines that 49cc 4-stroke could never touch......not even come close. 2 and 4-strokes should only come together in the unlimited class and the trophy dash. Just my opinion of course.

dnut

I just put one of those pocket bike motors (from Dax) on my bike with a Staton friction drive. After breaking it in, I staged a drag race. The competitors were as follows.

1. Beach cruiser. 50cc pocket bike motor, Staton 1.5" friction drive 250lb rider
2. Beach cruiser, 35cc Subaru, Staton axle mount 165lb rider
3. Mountain bike, 50cc Honda, BMP 1.25" friction drive 225lb rider
4. Beach cruiser, 35cc Honda Golden Eagle (stock gear) 225lb rider

First race: 1 block, #2 won by a bike length
Second race: 2 blocks, #3 won by a bike length #4 was right on his heels
Third race: 3 blocks, #1 won by 3 bike lengths.

I have driven all four of these combinations. I feel that they are all about equal. The pocket bike engine definitely has the best top speed, but doesn't have the best acceleration.

MB racing on a go-kart track isn't about top speed, it's more about who can accelerate the fastest and who has the guts to take the turns fastest....

I stick to my reccomendations.... 0-50cc, 51-135 and unlimited engine size. Regardless of 2 or 4 stroke.
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
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SoCal Baby!!!
www.facebook.com
Well all of this discussion has led me to think that we do need two 4-stroke classes and I think it most fair for them to be < 100cc & 101cc and larger. I don't think a stock Whizzer (136cc) should be allowed in the < 100cc class because it is larger than 100cc and how will you know it is stock without tearing the engine apart?

And it is now time to build a race specific bike as the competition demands this.....I love this stuff!
1)There is going to be a 50cc and under 4 stroke class.

2)A mid range 4 stroke class which may be mixed with 2 strokes.

3)The up to 11 hp class which includes Morini's.

4)Unlimited class which is anything over 12 hp or outside of the other
few rules.

slow smokey 2 stroker, your toaster-oven powered electric, or your evel knievel huffy cranbrook/snake river jumper,
All those bikes are welcome and have classes to suit with just a few rules.
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
That all sounds good Neil......me likes!

dnut

1)There is going to be a 50cc and under 4 stroke class.

2)A mid range 4 stroke class which may be mixed with 2 strokes.

3)The up to 11 hp class which includes Morini's.

4)Unlimited class which is anything over 12 hp or outside of the other
few rules.


All those bikes are welcome and have classes to suit with just a few rules.
 

SoSauty

New Member
Feb 4, 2011
147
0
0
Bako, CA
Worthy discussion,

Neil/Scotto, I understand this is the general idea:
?possibly class #2) <100cc4stroke combined w/ <50cc2stroke or whatever gets decided on.

A step toward classes based on 1st power & 2nd engine size. Whereas present classes are based 1st on engine type & power being a 2ndary consideration.

A perfectly fair system is a lofty goal, yet this idea further equalizes MB racing without killing racer fun. The big 2 stroke class gets split off as well; IMHO that means simpler logistics for every race event.
 
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scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
Worthy discussion,

Neil/Scotto, I understand this is the general idea:
?possibly class #2) <100cc4stroke combined w/ <50cc2stroke or whatever gets decided on.

A step toward classes based on 1st power & 2nd engine size. Whereas present classes are based 1st on engine type & power being a 2ndary consideration.

A perfectly fair system is a lofty goal, yet this idea further equalizes MB racing without killing racer fun. The big 2 stroke class gets split off as well; IMHO that means simpler logistics for every race event.
Yes, and without worry, there will always be "sand baggers", such is life and I don't plan to be one of them. I would hate to see this little sport turn to NASCAR rules and regs.....it would take the wind right out of my sails. You can't please everyone, you can only try.

dnut
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
109
63
SoCal Baby!!!
www.facebook.com
Yes, and without worry, there will always be "sand baggers", such is life and I don't plan to be one of them. I would hate to see this little sport turn to NASCAR rules and regs.....it would take the wind right out of my sails. You can't please everyone, you can only try.
Hey scotto-
Do you want to be on the SoCal Motor Bicycle Racing board?

There will be a website soon at SoCalMotorBicycleRacing.com

The current SoCal Motor Bicycle Racing board members are:
agk
BigBoy
msrfan
Samford&Son
Strotter
SoSauty (eBike advisor)
 
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