Clone Roadrace gearing

G

GL4Stroke

New member
Hello.
I'm looking for some very general gearing for road racing a stock clone. I have a 15T (35 chain) clutch sprocket on the engine. What is a good, general axle sprocket number?
Thanks!
 
I have not run a clone at Daytona, but I would bet that you want to be in the 2.4 range. You are going to need a much larger clutch driver.

Larry
 
When we ran the Yamaha on Sprint sit up, we used a 13/68. We were turning just a little over 13,000 RPM. The stock Yamaha, with a pipe, produces right at 18 horsepower peak. At 13,000 RPM it's substantially less. I'd say the post before this is pretty close. There is no way that 15 tooth sprocket is going to work.

From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
 
Seem I remember with the 8mm belt drive setup, the Clone guys are in the 28 - 30 driver range. We use a 27 on an Animal and turn a bunch more rpm than the Clones. So figure a 30 and a 70 ( for instance ) is a 2.33 ratio. that may be a little high but should be close for starters. You should be good with 28 and 30 drivers and from 65 to 70 back pulleys.
 
When I raced at CMP and Summit Point I also used a chain but needed a sprocket someway between 21 and 25 teeth. With a 15 you won´t get the ratio you need for long road racing tracks. For most clutches you might not even find a sprocket, most drivers use a chain. What clutch are you gonna use?
 
We ran a 35 chain on two CIK bodied clone karts at Daytona in 2012. Going thru my notes, we ran a 25T front driver and a 71 rear gear. In retrospect we probably would have been better going up one or two teeth on the front driver. We hit 6600-6700 rpm and started getting into valve float on the back stretch draft. The chain was replaced daily. We now run the belt drive system and the difference is night and day. With your 15T driver gear you are looking at a 42-43T rear gear. I'm not even sure those are available. The best of luck at Daytona and please feel free to come to our garage ("Red Bull" 4-cycle) for any assistance we can provide.
 
You can get the small rear gears for #35 chain. Rocket sprocket makes them along with the hub to mate up with your axle. We ran them for a while when our switch from Flathead to Animal took place in 2006 just to experiment. With a 15 or a 16 driver, though, the chain makes such a sharp turn on the clutch at such a high rpm for such a long time ( 20+ minutes ) the belt is just so much better. But for now, I think there is a 23 tooth available for a Bully (??) which combined with a 53 gives you 2.30 to 1 ratio. Look for the belt drive system used at swap meets possibly, the pulleys don't wear out and belts last a good long time also ( buy those new though ). I have pulleys from 1992 that we still use today. No messy lubes all over the place either. Nobody can say that about a chain sprocket that is used constantly.
 
Now now guys don't go bashing a chain setup! lol With a good chain and xeramic chain lube you should have no problems going 3/4 a season on a chain road racing. I ran animal and limited mod and never go close to needing to change it daily.

Mike Stroik
 
One can win with chain as Mike has proven time and time again. I have gone through great effort to produce drivers and baskets for us four cycles so I'm all about belt.

One thing Mike and I agree on is Ohio State football, coming to play in the sunshine Mike?
 
DGE43 is correct, we did have to use the bully conversion kit to fit the larger gear driver. I think after you spend for the Bully conversion kit and the bigger gear driver you are most of the way paying for the cost of a belt system. I have a few rear belt gears to lend if you need them. I dont have any spare belt driver gears but if you can acquire one with a clutch then you just need a $20 belt and you are golden.

I hear only good things about the belt gears that B-Man produces, if you can visit him in the garage area you will be impressed by his craftmanship and precision.

If chain is your thing then definintely get the Bully converstion kit and 25+ driver and we will see you at the races.
 
:eek: Thanks for the complement, I'm making #26 thru #30 as I write this, well actually Berta is making them, I just tend to her needs.
 
If i didnt have any drums and drivers ---- These are second to none !!!!!!!!!!!!!!!!! They may cost a couple bucks more but "SECOND TO NONE " !!


Peewee MGM Fab
 
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