Mini gear issues / questions

17/62 sounds like a small 1/4 track. We used to run a local stock car track and ran 17/62 with the flatheads and an 18 or 19 with animals depending on where the racing line ended up (typically at the very bottom of the track clear down on the flat in the corners.) We had small rear sprockets back then (Rocket Sprocket Accelerator series) and found the larger gears faster on large tracks. Again, that was with the flathead...that said, I understand the results with the ohv engines vary today. I'd look at a similar ratio, (14/51) then move 2 teeth from there and see if you picked up any lap time. That seems to be the current trend anyway.


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Brian Carlson
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Are you on a clone or a Flathead… I did not see an advantage on a Flathead so we only run the standard gears on a Flathead … with the clone I am usually 3 teeth lower on the clutch driver with the mini gears..
 
I fought it for the better part of the past 4 months, but switched my junior driver over to minis and probably won't go back. 1st night out and it proved to be very effective! Hitting on things mentioned already but found chain does need to be a bit tighter than I had been running on the big gears, helps to shorten chain (basically putting the motor in the spot i tend to have it and adjusting chain from there), ratios are ratios but on minis I found us to be on a smaller ratio and its not about peak/max RPM any more...so it does take some adjustment to understand how to use them. Only 1 race in but liking what I've seen and half his class has switched to minis, when we weren't on them they were beating us... on them and we were right there with them and nothing else tire or setup wise has changed.
What do you mean when you say it's not about peak/max rpm anymore? What are you looking at instead? Just lap times? Do you find that your peak/max rpm on the mini gears is lower than what you would typically be shooting for on standard size gears, assuming they are both in the sweet spot?
 
If it were me and I couldn't find anything binding and the larger gears gained .3 or .4, I would just put on the regular gears and not look back. In fact I have I have a full set of Rocket Sprockets that have been sitting in my cellar, unused, for about twenty years. Did I give them a fair shot? Probably not.
 
If it were me and I couldn't find anything binding and the larger gears gained .3 or .4, I would just put on the regular gears and not look back. In fact I have I have a full set of Rocket Sprockets that have been sitting in my cellar, unused, for about twenty years. Did I give them a fair shot? Probably not.
Wanna sell them?
 
What do you mean when you say it's not about peak/max rpm anymore? What are you looking at instead? Just lap times? Do you find that your peak/max rpm on the mini gears is lower than what you would typically be shooting for on standard size gears, assuming they are both in the sweet spot?
Its all about what RPM you come off the corner at. At most tracks if you come off the corner at the right RPM, your RPM at the end of the straights will be right. Once you figure out how to utilize this info, then the mini gears become advantageous.
The 1st time actually i heard about the mini gears was at the Dirt Track at Charlotte, the track that holds the World Finals, when Nitro first made some. For Scott Heath that day he dominated and as they say the rest is history.
 
What do you mean when you say it's not about peak/max rpm anymore? What are you looking at instead? Just lap times? Do you find that your peak/max rpm on the mini gears is lower than what you would typically be shooting for on standard size gears, assuming they are both in the sweet spot?
Pretty much what @SoCo Tire Treatments just said, our focus is off the corner RPM and less on the Peak RPM... We let Peak be what it is, as long as the off the corner RPM is where the engine likes it, we go with that to determine any gear changes. We also tend to stay as close to 50 as possible, running both Jr3 and Adult. Wouldn't go back to regular at this point, focus more on tires...you'll spend too much time thinking .3 to .4 tenths is all due to gearing.
 
Pretty much what @SoCo Tire Treatments just said, our focus is off the corner RPM and less on the Peak RPM... We let Peak be what it is, as long as the off the corner RPM is where the engine likes it, we go with that to determine any gear changes. We also tend to stay as close to 50 as possible, running both Jr3 and Adult. Wouldn't go back to regular at this point, focus more on tires...you'll spend too much time thinking .3 to .4 tenths is all due to gearing.
I just switched over to the mini gears, having raced them for the first time last weekend. I chose the Sharp Quick Change mini gear hub, mainly to save time, when changing gears between races. So far so good. I will need more time on them to know for sure, but it seemed like they helped me with my starts. I have struggled to attach myself to the karts in front of me, on 95% of my restarts. I did not have that problem this past weekend. Might be a coincidence, might not be... We shall see.

How do you determine what rpm the engine likes to be at coming off the corner? Also, why as close to 50 as possible? I know you can run that gearing with standard size sprockets, do you notice a difference?
 
I just switched over to the mini gears, having raced them for the first time last weekend. I chose the Sharp Quick Change mini gear hub, mainly to save time, when changing gears between races. So far so good. I will need more time on them to know for sure, but it seemed like they helped me with my starts. I have struggled to attach myself to the karts in front of me, on 95% of my restarts. I did not have that problem this past weekend. Might be a coincidence, might not be... We shall see.

How do you determine what rpm the engine likes to be at coming off the corner? Also, why as close to 50 as possible? I know you can run that gearing with standard size sprockets, do you notice a difference?
If you have dyno sheet, peak horsepower is the ideal rpm to be coming off corner.

Reasoning

If you lose more rpm, hp is also dropping.

Edit

Maybe better put.

You are going as slow as you will be, your engine is producing maximum force to gain speed.
 
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If you have dyno sheet, peak horsepower is the ideal rpm to be coming off corner.

Reasoning

If you lose more rpm, hp is also dropping.

Edit

Maybe better put.

You are going as slow as you will be, your engine is producing maximum force to gain speed.
Unfortunately, I do not have a dyne sheet. Is there any other methods to find out the number, or at least get you in the ballpark?
 
Unfortunately, I do not have a dyne sheet. Is there any other methods to find out the number, or at least get you in the ballpark?
If you have data acquisition, watch acceleration off the corner.
If slight bog before best acceleration, rpm is below peak hp.
If best acceleration off corner, drop a couple teeth until have that slight bog.

Once you find that sweet spot, use that to define where you want to be.
 
I just switched over to the mini gears, having raced them for the first time last weekend. I chose the Sharp Quick Change mini gear hub, mainly to save time, when changing gears between races. So far so good. I will need more time on them to know for sure, but it seemed like they helped me with my starts. I have struggled to attach myself to the karts in front of me, on 95% of my restarts. I did not have that problem this past weekend. Might be a coincidence, might not be... We shall see.

How do you determine what rpm the engine likes to be at coming off the corner? Also, why as close to 50 as possible? I know you can run that gearing with standard size sprockets, do you notice a difference?
On the 50 - due to advice on this forum and due to what I've found works for the tracks we typically race at. For mini's, 48-52 and for regular 58-62, haven't strayed to far away from that as a rule of thumb.
 
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On the 50 - due to advise on this forum and due to what I've found works for the tracks we typically race at. For mini's, 48-52 and for regular 58-62, haven't strayed to far away from that as a rule of thumb.
For some reason, the clone motor just seems to like this range of gears, and i havent ever really heard a good reason but i have found this to be true.
 
Not at all, look at all my posts i have written about mini gears and you can see how advantageous they can be.
To be honest, I have, and was unable to find much in terms of reasoning or data to explain the differences. I understand the debate over "is a ratio a ratio", my question here is, what is the advantage of the mini gears, if you are running a gear combination, that is capable of being ran on a standard set of gears. For example... I can run a 13/52 on standard gears or mini gears... What is the advantage of the mini in this situation?
 
To be honest, I have, and was unable to find much in terms of reasoning or data to explain the differences. I understand the debate over "is a ratio a ratio", my question here is, what is the advantage of the mini gears, if you are running a gear combination, that is capable of being ran on a standard set of gears. For example... I can run a 13/52 on standard gears or mini gears... What is the advantage of the mini in this situation?
Fine tuning is what the mini gear brings to the equation at least that the way I interpret it.
 
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