Clone Gear torque range.

Krtrcr47

Member
Happy Independence Day. .

I would like to elaborate. My flathead back in the day my motor builder very reputable had me turning as low as 5400 rpms. If it ever got to 6000 plus like others it would flatten out. Kind of like the predator hitting govonor not as bad of course. Flathead flatfooted. Now my animal by a very reputable builder was on 6800 to 7100 but my animal would gear bind had to watch it. Had to do with torque curve and rpm and hp curve. My animal wanted the tall gears on the back my flathead wanted small gears on the back. Many wins championships to prove it. It seems clone and animal are similar.
 
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paulkish

old fart
The 15/59 gets to desired RPM quicker, so you drop 1 rear tooth to keep your top end speed.
That's a reply to print and pin to the inside of your trailer, no matter what you race !

It's one of those things where your driver will come in and say with ease and relaxation, "it's better".
 

paulkish

old fart
Happy Independence Day. .

I would like to elaborate. My flathead back in the day my motor builder very reputable had me turning as low as 5400 rpms. If it ever got to 6000 plus like others it would flatten out. Kind of like the predator hitting govonor not as bad of course. Flathead flatfooted. Now my animal by a very reputable builder was on 6800 to 7100 but my animal would gear bind had to watch it. Had to do with torque curve and rpm and hp curve. My animal wanted the tall gears on the back my flathead wanted small gears on the back. Many wins championships to prove it. It seems clone and animal are similar.

Remember very well having to sometimes change racing strategies against built low end flatheads.
They were a pain being able to put themselves in the way mid corner off.
But IMHO remembering back they most always would fade late race or higher rpms would win out by the next entry.
Always figured somehow they were cheating but in the end they were not a points issue.
Made things fun though.
 

WPaul

Member
A 17:66 VS 15:59 will be a better test.
It’s simple, really !
The bigger both gears are the less the chain links bend, less friction puts more net torque to the ground. The 3.88 gear will accelerate quicker and of course have a higher top end.
Best, WP
 

alvin l nunley

Site Supporter
A 17:66 VS 15:59 will be a better test.
It’s simple, really !
The bigger both gears are the less the chain links bend, less friction puts more net torque to the ground. The 3.88 gear will accelerate quicker and of course have a higher top end.
Best, WP
"The less the links bend" looking at it that way, it appears your correct, but what about the other variables? I would like to see the difference the longer chain makes. There is a difference in gear ratio in your example, not much, but it's there. Just assuming that you could have more "top end" may not be a good assumption. You can't just assume you'll turn the same RPM. It all depends on the torque curve. In the end, your assumptions may be correct, but I wonder.
 

WPaul

Member
Al what we found over and over again, the larger diameter gears would allow you to pull a slightly taller gear ratio and still maintain your target RPM.
The length of the chain had no affect. Note; at speed the links are bending very fast almost 90 degrees on a small driver and accumulatively this adds up.
So it's my opinion, for the proper gear ratio for the conditions at hand, always use the largest diameter gears you can.
Best, WP
 

paulkish

old fart
Normal expected reply.

"Somehow I find your testing results ∆hard to believe∆"
"I'm still waiting for someone to show real proof".
"My spread sheet indicates otherwise".

I'm right and your wrong. Nanny Nanny boo boo
 

alvin l nunley

Site Supporter
Al what we found over and over again, the larger diameter gears would allow you to pull a slightly taller gear ratio and still maintain your target RPM.
The length of the chain had no affect. Note; at speed the links are bending very fast almost 90 degrees on a small driver and accumulatively this adds up.
So it's my opinion, for the proper gear ratio for the conditions at hand, always use the largest diameter gears you can.
Best, WP
Chordal angle. I have a chart somewhere that shows just how much the chordal angle decreases as the tooth count on the sprocket increases. The number is pretty big for the 9 – 10 – 11 tooth sprockets, but gets increasingly smaller as a tooth count goes up. Look it up on the web, maybe Wikipedia. I don't know where my copy is, I have a big hard disk with lots of files.
Don't know for a fact, but as little as the angle changes between the bigger drivers and axle sprockets, I wonder how much difference it could make. I think, just a theory, that the changes in chain speed have more to do with it.

I'm kind of wondering why nobody has done a definitive study on this phenomena? I'm pretty sure it could be measured with the proper equipment.
 

Krtrcr47

Member
Al what we found over and over again, the larger diameter gears would allow you to pull a slightly taller gear ratio and still maintain your target RPM.
The length of the chain had no affect. Note; at speed the links are bending very fast almost 90 degrees on a small driver and accumulatively this adds up.
So it's my opinion, for the proper gear ratio for the conditions at hand, always use the largest diameter gears you can.
Best, WP
Man I have to say I like this reasoning. I want to try the 17 66. I think you are right if keep rpms I'll be faster.
 

WPaul

Member
Normal expected reply.

"Somehow I find your testing results ∆hard to believe∆"
"I'm still waiting for someone to show real proof".
"My spread sheet indicates otherwise".

I'm right and your wrong. Nanny Nanny boo boo
Entertaining PK. Question,, how much dirt does your spread have on it ? Just asking,, my race notebook is quite dirty.
Best, WP
 

Krtrcr47

Member
My entire thoughts on this entire post comes from riding bikes and crane gear boxes. I'm seriously considering try to figure out a way to make a bike with the 2 diffrent gears. I want to feel how drastic the difference is. If a ratio was a ratio gear boxes wouldn't be 4 to 1 multipliers. In other words I feel like to me there is way more to this than meets the eye. It's 1 peice of multi peice puzzle so this will not be only factor in win. But this can make you lose.
 

paulkish

old fart
This common discussion has its disagreements because of mixing two completely different functions and uses of physics together.
They can be averaged to get a common result but function and use of each separately are different.

1. The only need to move towards smaller gears is to try to ease both low and/or top end acceleration restrictions. IMHO period !
2. The only need to move towards larger gears is to try to enhance your ability to maintain momentum. again IMHO period !

Each is used and/or averaged depending on on track racing needs.
 

WPaul

Member
Chordal angle. I have a chart somewhere that shows just how much the chordal angle decreases as the tooth count on the sprocket increases. The number is pretty big for the 9 – 10 – 11 tooth sprockets, but gets increasingly smaller as a tooth count goes up. Look it up on the web, maybe Wikipedia. I don't know where my copy is, I have a big hard disk with lots of files.
Don't know for a fact, but as little as the angle changes between the bigger drivers and axle sprockets, I wonder how much difference it could make. I think, just a theory, that the changes in chain speed have more to do with it.

I'm kind of wondering why nobody has done a definitive study on this phenomena? I'm pretty sure it could be measured with the proper equipment.
Al I think this is akin to Wrap Angle in belt driven torque transfer. With the SAME set of pulleys, moving them further apart increases the WA on the small pulley and decreases it on the large pulley. On a chain driven system the increased tooth contact on the small sprocket may account for increased friction, being the small sprocket is spinning faster than the larger sprocket.
Just my thought,, I think the heat generated in the chain is when it bends around the small sprocket. And heat in the chain is energy from the engine being wasted.
Remember what happened to the chains on 9 tooth sprockets before the advent of the Space Chain ?
Best, WP
 

Krtrcr47

Member
Let's wake this back up......

The mini gears. So a little more than half way through the 2021 season I have really been studying the gear game. In predator and clone. This is now my pretty solid opinion on how and why what works.Then I'll see all of your opinions.

It's fine tune adjustment of a gear ratio. Clone most tracks start with a 4/1 ratio adjust from there. Go down on driver if I'm running out of rpm but only by like 50 rpms. You all follow. Then predator start with 3/1 then adjust. It's easier to explain with predator. Say you run a 19:54 but today track got fast and you are hitting govonor but only just barely just entering corner. Rather than go down to a 53 what I'm doing with success is go down to an 18:51 for example. Or a little more than a 17:48. Basically you can micro adjust until you get to the ratio 2.79. So if you really know how a track reacts you can out gear people. So that is my conclusion. Micro gears are for micro adjustments. Can't be afraid to go from a 13 tooth driver to a 16 or visa versa(normally on clone for those drivers) if the ratio and track speed calls for it..

I have nitro gears for sale all sizes mini excel gears as well as regular 6 lug nitro gears. Message me if you are interested.
 
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Let's wake this back up......

The mini gears. So a little more than half way through the 2021 season I have really been studying the gear game. In predator and clone. This is now my pretty solid opinion on how and why what works.Then I'll see all of your opinions.

It's fine tune adjustment of a gear ratio. Clone most tracks start with a 4/1 ratio adjust from there. Go down on driver if I'm running out of rpm but only by like 50 rpms. You all follow. Then predator start with 3/1 then adjust. It's easier to explain with predator. Say you run a 19:54 but today track got fast and you are hitting govonor but only just barely just entering corner. Rather than go down to a 53 what I'm doing with success is go down to an 18:51 for example. Or a little more than a 17:48. Basically you can micro adjust until you get to the ratio 2.79. So if you really know how a track reacts you can out gear people. So that is my conclusion. Micro gears are for micro adjustments. Can't be afraid to go from a 13 tooth driver to a 16 or visa versa(normally on clone for those drivers) if the ratio and track speed calls for it..

I have nitro gears for sale all sizes mini excel gears as well as regular 6 lug nitro gears. Message me if you are interested.
So what gearing would you recommend for clone 390 on 1/5th mile red clay track? I just got a clone engine kit and will be my first time running a clone class this weekend and I’m clueless as where to start on gearing.
 

1fasttiller

Member
So what gearing would you recommend for clone 390 on 1/5th mile red clay track? I just got a clone engine kit and will be my first time running a clone class this weekend and I’m clueless as where to start on gearing.
Adult unrestricted, I'd start at a 3.90-4.0 ratio and go from there.
 
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