What is the Best sprocket combo for a db30 with stock predator 212 ?

#1
I currently have a 70 tooth rear sprocket on the stock db30.
Installing a predator stock 212.
What are the best clutch tooth / rear sprocket combinations?
Thank you
 
#5
The stock rear sprocket and use a 12T clutch. When my son and I used to have DB-30s (years ago) that is what we had and it worked great.
Michael
 
#7
Thank you,
I will try the 12 tooth with the 70 rear sprocket and 6 inch tires.
As stated above the factory set up is good , It is the overall diameter of the tire that matters , there are speed calculators you can use , they factor in front sprocket , rear sprocket , rpms and rear tire diameter !
 

Triley41395

Well-Known Member
#8
Thank you,
I will try the 12 tooth with the 70 rear sprocket and 6 inch tires.
Your rims are 6" not the tire. 6 inch OD tires with a 212 is a recipe for a wreck. I have a bike with 4 inch rims and approximately 9.5 inch OD and I don't ride it. You get the death wobble going and it's over.
 
#10
If I remember correctly, the stock sized DB30 tires are around 35" in circumference. Circumference is what you need to know...not the height of the tire. With that tire size, I like a 12t clutch and a 66t rear sprocket, but the 70t sprocket that you have will be fine.
Here is a good calculator to use...
Racing Go Kart Gearing & Speed Calculator (eccarburetors.com)
Thanks,
I was using the rim size... i feel stupid, no wonder none of those calculations got me over 7mph...lol
 

SAS289

Well-Known Member
#11
If I remember correctly, the stock sized DB30 tires are around 35" in circumference. Circumference is what you need to know...not the height of the tire. With that tire size, I like a 12t clutch and a 66t rear sprocket, but the 70t sprocket that you have will be fine.
Here is a good calculator to use...
Racing Go Kart Gearing & Speed Calculator (eccarburetors.com)
Other speed calcs accept tire height (diameter) and do the math for you. Otherwise you do the math for circumference.
Mini Bike Speed Calculator (MPH) (csgnetwork.com)
 
#12
I like a 12t clutch and 60t-70t rear sprocket with a stock to stage 2 212 engine when running a newer 6" wheel bike.

Your rims are 6" not the tire. 6 inch OD tires with a 212 is a recipe for a wreck. I have a bike with 4 inch rims and approximately 9.5 inch OD and I don't ride it. You get the death wobble going and it's over.
My drag bike with a 6" rear and 10" front wheel is dead steady at 70+mph.

My CT200U is running 6" wheels and tops out right around 60mph. Steady as can be too.

My DB30 with the stock wheels will do maybe 50 and it's steady too. The brake is the sketchy part on that bike.

I used to have a bike with 5" wheels, that thing was scary at anything over 25mph. That's the last pic, started out as a Cat and got modified. A buddy still owns it and I want it back, he won't sell it.
 

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Triley41395

Well-Known Member
#13
I like a 12t clutch and 60t-70t rear sprocket with a stock to stage 2 212 engine when running a newer 6" wheel bike.



My drag bike with a 6" rear and 10" front wheel is dead steady at 70+mph.

My CT200U is running 6" wheels and tops out right around 60mph. Steady as can be too.

My DB30 with the stock wheels will do maybe 50 and it's steady too. The brake is the sketchy part on that bike.

I used to have a bike with 5" wheels, that thing was scary at anything over 25mph. That's the last pic, started out as a Cat and got modified. A buddy still owns it and I want it back, he won't sell it.
I understand what you mean but sometimes newer members think that your talking about tires. You say 10 inch front wheel but you mean 10 inch front rim. Sometimes when people talk about wheel size newer members think they are referring to the tire size.
 
#14
I understand what you mean but sometimes newer members think that your talking about tires. You say 10 inch front wheel but you mean 10 inch front rim. Sometimes when people talk about wheel size newer members think they are referring to the tire size.
A tire is a tire, a wheel is a wheel. A rim is only on a laced wheel that the hub is connected to with spokes. I refuse to call a wheel a "rim". Multiple piece wheels also have rims that the center section bolts onto. In that case you can refer to the rim or center section of the wheel. If someone doesn't know the difference between a wheel and a tire when used in a sentence I don't think they should be messing with minibikes, or anything motorized.

The attached pic someone made on the Camaro forum probably 15+ years ago still cracks me up.
 

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#16
A tire is a tire, a wheel is a wheel. A rim is only on a laced wheel that the hub is connected to with spokes. I refuse to call a wheel a "rim". Multiple piece wheels also have rims that the center section bolts onto. In that case you can refer to the rim or center section of the wheel. If someone doesn't know the difference between a wheel and a tire when used in a sentence I don't think they should be messing with minibikes, or anything motorized.

The attached pic someone made on the Camaro forum probably 15+ years ago still cracks me up.
Its 45" but Thanks for your 2 cents...
 
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