Pinion size question

[PKMSM]

The manual for the ET48 has this handy table for pinion sizes to go with different motor Kv ratings. I am using a 2200Kv Castle motor and I am trying to decide on the pinion size.

The table says that a combination of 2200Kv motor and small track is “not advised”. Why is that?

I’m a noob who just want to do some bashing. I‘m assuming either a 14t or 15t pinion would be a good starting point?

 

[Looping67]

Disclaim : I'm from France so i'll use the metric system(even if i use daily knots and feet i am not used to mph, lbs and other inches, i let you make the conversion), please don't hit!
Those recommandations are for racing where you set your gearing for about 65 km/h on the track(maybe sometimes less in the US where the tracks have more jumps et more tight turns). You can gear for more speed on bash but you have to be cautious with heat(bigger tyres means higher speeds and weight, so more heat in the end). On 1/8 scale, with buggies/truggies, you can almost approximate +/-100kv=+/-1 theeth on the pinion=+/-4 to 5km/h. It changes a bit if you use bigger/smaller tyres. I personnaly use a speed calculator(the link i give is in French but you should find something similar in US English http://www.nitropassion.fr/aide-astuce/09-calcule-de-vitesse/).
If you use Backflip 4S which are 154mm diameter you find this with a 2200kv on 4S(calculated at 3.7V(and no ballooning of the tyre so more in real) : 15t 72km/h, 16t 77km/h, 17t 82km/h.
The ET48.3 i have has the same ratio and after testings i use a 4274 2000kv with 17t(Backflip 4S as well) which gives me 75km/h. It doesn't overheat with a fan, i probably could gear up 1t or 2 (for bash only where you're not just accelerate/brake) with no issue but it's good for me like that.(i will try soon 1500kv/6S 16t-17t)
So i suggest you start with 15t, check the temps, and if ok gear up 1t or 2t to try and check again.

 

[MAVERICK]

The manual for the ET48 has this handy table for pinion sizes to go with different motor Kv ratings. I am using a 2200Kv Castle motor and I am trying to decide on the pinion size.

The table says that a combination of 2200Kv motor and small track is “not advised”. Why is that?

I’m a noob who just want to do some bashing. I‘m assuming either a 14t or 15t pinion would be a good starting point?

View attachment 7945

I also run a Castle 2200kv in my ET and I am happy with 15t pinion for a small track

 

[PKMSM]

Disclaim : I'm from France so i'll use the metric system(even if i use daily knots and feet i am not used to mph, lbs and other inches, i let you make the conversion), please don't hit!
Those recommandations are for racing where you set your gearing for about 65 km/h on the track(maybe sometimes less in the US where the track have more jumps et more tight turns). You can gear for more speed on bash but you have to be cautious with heat(bigger tyres means higher speeds and weight, so more heat in the end). On 1/8 scale, with buggies/truggies, you can almost approximate +/-100kv=+/-1 theeth on the pinion=+/-4 to 5km/h. It changes a bit if you use bigger/smaller tyres. I personnaly use a speed calculator(the link i give is in French but you should find something similar in US English http://www.nitropassion.fr/aide-astuce/09-calcule-de-vitesse/).
If you use Backflip 4S which are 154mm diameter you find this with a 2200kv on 4S(calculated at 3.7V(and no ballooning of the tyre so more in real) : 15t 72km/h, 16t 77km/h, 17t 82km/h.
The ET48.3 i have has the same ratio and after testings i use a 4274 2000kv with 17t(Backflip 4S as well) which gives me 75km/h. It doesn't overheat with a fan, i probably could gear up 1t or 2 (for bash only where you're not just accelerate/brake) with no issue but it's good for me like that.(i will try soon 1500kv/6S 16t-17t)
So i suggest you start with 15t, check the temps, and if ok gear up 1t or 2t to try and check again.

Ne t’inquiète pas, je connais bien le système métrique !

And thanks for the very detailed explanation. This is very helpful.

 

[Looping67]

Ne t’inquiète pas, je connais bien le système métrique !

And thanks for the very detailed explanation. This is very helpful.

Your French is perfect.
Actually i do know pretty well the conversion for mph, lbs, inches, US gal, just not used to use them. But, when talking about acres or yards for exemple i'm lost. One day i asked to an English friend of mine how much is an acre and he had some difficulties to tell me. I stay measuring with meters and multiply them to have square meters.

 

[PKMSM]

Your French is perfect.
Actually i do know pretty well the conversion for mph, lbs, inches, US gal, just not used to use them. But, when talking about acres or yards for exemple i'm lost. One day i asked to an English friend of mine how much is an acre and he had some difficulties to tell me. I stay measuring with meters and multiply them to have square meters.

Grew up in Montreal, went to French schools.

Ultimately whatever system you learned and are used to is the easiest. I learned the metric system and for the first few years after I moved to the US I converted mph and deg. F to kph and deg. C until they became second nature to me. That said, I still measure everything in the metric system. Finding the half way point between two segments of 24-3/32" and 14-5/64" is a little too much non-value added work when I can just add two even numbers and divide them by two...

In university we were introduced to imperial units, and I remember thinking why make things so difficult when you can simply multiply and divide common units by 10 (have you heard of "Slugs"?). But then again, whatever you are used to is the easiest.

 

[Klappars]

Disclaim : I'm from France so i'll use the metric system(even if i use daily knots and feet i am not used to mph, lbs and other inches, i let you make the conversion), please don't hit!
Those recommandations are for racing where you set your gearing for about 65 km/h on the track(maybe sometimes less in the US where the tracks have more jumps et more tight turns). You can gear for more speed on bash but you have to be cautious with heat(bigger tyres means higher speeds and weight, so more heat in the end). On 1/8 scale, with buggies/truggies, you can almost approximate +/-100kv=+/-1 theeth on the pinion=+/-4 to 5km/h. It changes a bit if you use bigger/smaller tyres. I personnaly use a speed calculator(the link i give is in French but you should find something similar in US English http://www.nitropassion.fr/aide-astuce/09-calcule-de-vitesse/).
If you use Backflip 4S which are 154mm diameter you find this with a 2200kv on 4S(calculated at 3.7V(and no ballooning of the tyre so more in real) : 15t 72km/h, 16t 77km/h, 17t 82km/h.
The ET48.3 i have has the same ratio and after testings i use a 4274 2000kv with 17t(Backflip 4S as well) which gives me 75km/h. It doesn't overheat with a fan, i probably could gear up 1t or 2 (for bash only where you're not just accelerate/brake) with no issue but it's good for me like that.(i will try soon 1500kv/6S 16t-17t)
So i suggest you start with 15t, check the temps, and if ok gear up 1t or 2t to try and check again.

Very helpful reply. The US equivalent site would be this:

https://www.radiocontrolinfo.com/information/rc-calculators/rc-car-calculator/