Felony Felony rear tires

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Jeremymx236

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Im sure im not the only one who has already burned through a set of tires on the felony, looks like we wont be seeing them in stores or online for about a month. Does anyone know of a aftermarket option for tires?
 
I did a half-hearted search on Amazon and the closest I found were 112mm diameter.

I have 3 sets of factory rears on backorder with HH so we’ll see when they show up.
 
Im sure im not the only one who has already burned through a set of tires on the felony, looks like we wont be seeing them in stores or online for about a month. Does anyone know of a aftermarket option for tires?

Sorry about that.... this is exactly why I have not run mine it sat in the box for a week+ and just now changing diff fluids and tuning it to keep from running it...

I tell myself I will gently run it.....right! I bash the Infraction v1 so I know it will be hard not to on the Felony. I too have tires on backorder with HH so who knows when those will come....
 
The duratrax bandito buggy tires are 107mm.. only issue is you will need to add offset hubs to get the wheel set out further.. they are only 42mm wide as well which should not be an issue for a temporary set..

Edit) I better add this in) they are obviously not belted so these cant be run at super high speeds.. ?
 
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Im new to this whole thing, how would you add offset to the hubs?


You would need to buy hub extensions, or offset hubs.. you would need to add 10mm

The video above is gold right now
 
So I been doing some calculations to try and figure out what tire sizes you could get away with in the front/rear and first I was thinking that maybe you could run GRPs in front (98mm) and standard Hoons in the back (100mm) and that might be enough offset to work. To check this we need to do some math to calculate the rollout. So just to be clear in the math part of things I want to restate that because arrma made the tires in the felony larger in the rear the rear diff ratio is different than the front diff ratio.

Per Arrma website:
Felony F/R Diff Ratios: F=2.8, R=3.21
Felony Tire Diameter: F=100mm, R=107mm

The tire rollout of both F/R should be close to the same, but to my surprise per my calculator app it showed that the fronts are turning 2.61mm more per RPM of the motor, this means the front wheels spin 7% faster overall than the rears with stock Felony tire setup.

I thought maybe my calculator math was wrong so I checked the diff drive ratio published on the Arrma felony specs page against my app, a website based calculator, and of course normal manual division and everything added up correctly of 2.8 ratio front diff ratio and 3.31 ratio rear, so that variable is fine. So then I took it a step further and calculated the final drive ratio in both my app and on the website calculator and found that both the app and website agreed on the math, but the published ratio by Arrma did NOT match.

Anyways so both my calculator and a separate calculator website agreed on the math and with that it definitely show a different rollout number between the front and rear with front wheels spinning about 7% faster than the rears. And even if I use the final drive ratio published by Arrma (F=8.58, R=9.43) and manually calculate the rollout ((Tire Diameter x Pi) / Final Gear Ratio) the math is even worse showing the fronts turning 3.3mm further per motor rpm than the rears which is a 9% difference in speed.

Anyways my head hurts now so someone please check my math and let me know if something I did was wrong, or let me know if there's a factor I'm missing like maybe the 7/9% difference is negligible and center diff action is where that offset is balancing out or something.

InShot_20200831_130107922.jpg


InShot_20200831_130242800.jpg



***EDIT*** Assuming my math is correct, if you used the V2 rear diff in the front (3.21) and used a V1 diff in the rear (3.31) and stick with the stock felony tire setup (100mm front/107mm rear) the rollout in the rear is 1.28mm more than the front (+4% more speed in rear).

Using the same diff scenario but using GRPs in the front (98mm) and stock Hoons in the back (100mm) the fronts will have only .35mm more rollout in the front. So basically in terms of straight math, sticking the V2 rear diff in the front, and then using a V1 diff in the rear and using 98mm GRPs in the front 100mm normal Hoons in the rear will put the wheel speed of the front/rear within 1% of eachother, but at that point you might as well just get matching diffs and tires.
 
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So I been doing some calculations to try and figure out what tire sizes you could get away with in the front/rear and first I was thinking that maybe you could run GRPs in front (98mm) and standard Hoons in the back (100mm) and that might be enough offset to work. To check this we need to do some math to calculate the rollout. So just to be clear in the math part of things I want to restate that because arrma made the tires in the felony larger in the rear the rear diff ratio is different than the front diff ratio.

Per Arrma website:
Felony F/R Diff Ratios: F=2.8, R=3.21
Felony Tire Diameter: F=100mm, R=107mm

The tire rollout of both F/R should be close to the same, but to my surprise per my calculator app it showed that the fronts are turning 2.61mm more per RPM of the motor, this means the front wheels spin 7% faster overall than the rears with stock Felony tire setup.

I thought maybe my calculator math was wrong so I checked the diff drive ratio published on the Arrma felony specs page against my app, a website based calculator, and of course normal manual division and everything added up correctly of 2.8 ratio front diff ratio and 3.31 ratio rear, so that variable is fine. So then I took it a step further and calculated the final drive ratio in both my app and on the website calculator and found that both the app and website agreed on the math, but the published ratio by Arrma did NOT match.

Anyways so both my calculator and a separate calculator website agreed on the math and with that it definitely show a different rollout number between the front and rear with front wheels spinning about 7% faster than the rears. And even if I use the final drive ratio published by Arrma (F=8.58, R=9.43) and manually calculate the rollout ((Tire Diameter x Pi) / Final Gear Ratio) the math is even worse showing the fronts turning 3.3mm further per motor rpm than the rears which is a 9% difference in speed.

Anyways my head hurts now so someone please check my math and let me know if something I did was wrong, or let me know if there's a factor I'm missing like maybe the 7/9% difference is negligible and center diff action is where that offset is balancing out or something.

View attachment 97493

View attachment 97492


***EDIT*** Assuming my math is correct, if you used the V2 rear diff in the front (3.21) and used a V1 diff in the rear (3.31) and stick with the stock felony tire setup (100mm front/107mm rear) the rollout in the rear is 1.28mm more than the front (+4% more speed in rear).

Using the same diff scenario but using GRPs in the front (98mm) and stock Hoons in the back (100mm) the fronts will have only .35mm more rollout in the front. So basically in terms of straight math, sticking the V2 rear diff in the front, and then using a V1 diff in the rear and using 98mm GRPs in the front 100mm normal Hoons in the rear will put the wheel speed of the front/rear within 1% of eachother, but at that point you might as well just get matching diffs and tires.

I've been racking my brain as well! Didn't want to explode with the math !! Besides I figured the front would need to spend a fraction above the rear to prevent the motor from overworking also causing all kinds of hit and traction problems. So I decided to find the tires closest to diameter. Like you I figure the grp's are the best option for the front. For the rear the closest in diameter i could find are the pro line avengers which are 106mm and a soft compound. With 17mm hex hub extenders it should be fine. Will run a medium hard compound up front so that the traction up front is not to great as to allow the set to work effeciently

Screenshot_20200830-063116_Chrome.jpg


Screenshot_20200830-063116_Chrome.jpg

So I been doing some calculations to try and figure out what tire sizes you could get away with in the front/rear and first I was thinking that maybe you could run GRPs in front (98mm) and standard Hoons in the back (100mm) and that might be enough offset to work. To check this we need to do some math to calculate the rollout. So just to be clear in the math part of things I want to restate that because arrma made the tires in the felony larger in the rear the rear diff ratio is different than the front diff ratio.

Per Arrma website:
Felony F/R Diff Ratios: F=2.8, R=3.21
Felony Tire Diameter: F=100mm, R=107mm

The tire rollout of both F/R should be close to the same, but to my surprise per my calculator app it showed that the fronts are turning 2.61mm more per RPM of the motor, this means the front wheels spin 7% faster overall than the rears with stock Felony tire setup.

I thought maybe my calculator math was wrong so I checked the diff drive ratio published on the Arrma felony specs page against my app, a website based calculator, and of course normal manual division and everything added up correctly of 2.8 ratio front diff ratio and 3.31 ratio rear, so that variable is fine. So then I took it a step further and calculated the final drive ratio in both my app and on the website calculator and found that both the app and website agreed on the math, but the published ratio by Arrma did NOT match.

Anyways so both my calculator and a separate calculator website agreed on the math and with that it definitely show a different rollout number between the front and rear with front wheels spinning about 7% faster than the rears. And even if I use the final drive ratio published by Arrma (F=8.58, R=9.43) and manually calculate the rollout ((Tire Diameter x Pi) / Final Gear Ratio) the math is even worse showing the fronts turning 3.3mm further per motor rpm than the rears which is a 9% difference in speed.

Anyways my head hurts now so someone please check my math and let me know if something I did was wrong, or let me know if there's a factor I'm missing like maybe the 7/9% difference is negligible and center diff action is where that offset is balancing out or something.

View attachment 97493

View attachment 97492


***EDIT*** Assuming my math is correct, if you used the V2 rear diff in the front (3.21) and used a V1 diff in the rear (3.31) and stick with the stock felony tire setup (100mm front/107mm rear) the rollout in the rear is 1.28mm more than the front (+4% more speed in rear).

Using the same diff scenario but using GRPs in the front (98mm) and stock Hoons in the back (100mm) the fronts will have only .35mm more rollout in the front. So basically in terms of straight math, sticking the V2 rear diff in the front, and then using a V1 diff in the rear and using 98mm GRPs in the front 100mm normal Hoons in the rear will put the wheel speed of the front/rear within 1% of eachother, but at that point you might as well just get matching diffs and tires.
Screenshot_20200901-003819_Gmail.jpg
 
So I been doing some calculations to try and figure out what tire sizes you could get away with in the front/rear and first I was thinking that maybe you could run GRPs in front (98mm) and standard Hoons in the back (100mm) and that might be enough offset to work. To check this we need to do some math to calculate the rollout. So just to be clear in the math part of things I want to restate that because arrma made the tires in the felony larger in the rear the rear diff ratio is different than the front diff ratio.

Per Arrma website:
Felony F/R Diff Ratios: F=2.8, R=3.21
Felony Tire Diameter: F=100mm, R=107mm

The tire rollout of both F/R should be close to the same, but to my surprise per my calculator app it showed that the fronts are turning 2.61mm more per RPM of the motor, this means the front wheels spin 7% faster overall than the rears with stock Felony tire setup.

I thought maybe my calculator math was wrong so I checked the diff drive ratio published on the Arrma felony specs page against my app, a website based calculator, and of course normal manual division and everything added up correctly of 2.8 ratio front diff ratio and 3.31 ratio rear, so that variable is fine. So then I took it a step further and calculated the final drive ratio in both my app and on the website calculator and found that both the app and website agreed on the math, but the published ratio by Arrma did NOT match.

Anyways so both my calculator and a separate calculator website agreed on the math and with that it definitely show a different rollout number between the front and rear with front wheels spinning about 7% faster than the rears. And even if I use the final drive ratio published by Arrma (F=8.58, R=9.43) and manually calculate the rollout ((Tire Diameter x Pi) / Final Gear Ratio) the math is even worse showing the fronts turning 3.3mm further per motor rpm than the rears which is a 9% difference in speed.

Anyways my head hurts now so someone please check my math and let me know if something I did was wrong, or let me know if there's a factor I'm missing like maybe the 7/9% difference is negligible and center diff action is where that offset is balancing out or something.

[pics removed]
***EDIT*** Assuming my math is correct, if you used the V2 rear diff in the front (3.21) and used a V1 diff in the rear (3.31) and stick with the stock felony tire setup (100mm front/107mm rear) the rollout in the rear is 1.28mm more than the front (+4% more speed in rear).

Using the same diff scenario but using GRPs in the front (98mm) and stock Hoons in the back (100mm) the fronts will have only .35mm more rollout in the front. So basically in terms of straight math, sticking the V2 rear diff in the front, and then using a V1 diff in the rear and using 98mm GRPs in the front 100mm normal Hoons in the rear will put the wheel speed of the front/rear within 1% of eachother, but at that point you might as well just get matching diffs and tires.

The only definition I know of for Final Drive / Final Gear ratio = engine turns / wheel turns. The published ratios by ARRMA must be incorrect, because a larger diameter tire needs a lower Final Drive ratio or you'll be tearing up your differential.

One thing I think you're confusing is Diameter. Diameter does not equal rollout, but maybe you just weren't explicit about that in your post (the 7% difference you mention is accurate). Rollout is circumference of the tire. Circumference is 2πr. Rollout of the rear tires is 2(3.14)(53.5) = 336mm. Front tires 2(3.14)(50) = 314mm. The 7% difference in rollout is made up for by the differential difference, though I still get a discrepancy like you did. The ring & pinion ratios would produce a 14% difference in RPMs at the wheels, with the fronts spinning 14% faster than the rears, although the rollout suggests only a 7% difference is warranted.

I'll have to take apart my Felony soon and see what the actual difference is in the differentials. If the front and rear ring gears (crown gears as ARRMA calls them) have the same teeth, the front and rear tires would have a 7% discrepancy in RPMs (7% more RPM front than rear, which matches the rollout). To me, this would make the most sense... you would not normally want one set of tires to rotate faster than another, or you'll end up burning up your tires or your differential unnecessarily, whichever "gives" first.

If the crown/ring gears are the same: 15 tooth pinion gear for front diff / 14 tooth pinion for rear diff = 1.07 (+7% RPM on front tires, as we'd expect to see based on rollout calculations.)

It will be really interesting (read: f'd up!) if the final drive ratios are actually different front to rear... that would explain unnecessary burnouts! Shouldn't require gear ratios/over-turning the rear tires to make this car break traction, if burnouts are your thing ;)
 
So I been doing some calculations to try and figure out what tire sizes you could get away with in the front/rear and first I was thinking that maybe you could run GRPs in front (98mm) and standard Hoons in the back (100mm) and that might be enough offset to work. To check this we need to do some math to calculate the rollout. So just to be clear in the math part of things I want to restate that because arrma made the tires in the felony larger in the rear the rear diff ratio is different than the front diff ratio.

Per Arrma website:
Felony F/R Diff Ratios: F=2.8, R=3.21
Felony Tire Diameter: F=100mm, R=107mm

The tire rollout of both F/R should be close to the same, but to my surprise per my calculator app it showed that the fronts are turning 2.61mm more per RPM of the motor, this means the front wheels spin 7% faster overall than the rears with stock Felony tire setup.

I thought maybe my calculator math was wrong so I checked the diff drive ratio published on the Arrma felony specs page against my app, a website based calculator, and of course normal manual division and everything added up correctly of 2.8 ratio front diff ratio and 3.31 ratio rear, so that variable is fine. So then I took it a step further and calculated the final drive ratio in both my app and on the website calculator and found that both the app and website agreed on the math, but the published ratio by Arrma did NOT match.

Anyways so both my calculator and a separate calculator website agreed on the math and with that it definitely show a different rollout number between the front and rear with front wheels spinning about 7% faster than the rears. And even if I use the final drive ratio published by Arrma (F=8.58, R=9.43) and manually calculate the rollout ((Tire Diameter x Pi) / Final Gear Ratio) the math is even worse showing the fronts turning 3.3mm further per motor rpm than the rears which is a 9% difference in speed.

Anyways my head hurts now so someone please check my math and let me know if something I did was wrong, or let me know if there's a factor I'm missing like maybe the 7/9% difference is negligible and center diff action is where that offset is balancing out or something.

View attachment 97493

View attachment 97492


***EDIT*** Assuming my math is correct, if you used the V2 rear diff in the front (3.21) and used a V1 diff in the rear (3.31) and stick with the stock felony tire setup (100mm front/107mm rear) the rollout in the rear is 1.28mm more than the front (+4% more speed in rear).

Using the same diff scenario but using GRPs in the front (98mm) and stock Hoons in the back (100mm) the fronts will have only .35mm more rollout in the front. So basically in terms of straight math, sticking the V2 rear diff in the front, and then using a V1 diff in the rear and using 98mm GRPs in the front 100mm normal Hoons in the rear will put the wheel speed of the front/rear within 1% of eachother, but at that point you might as well just get matching diffs and tires.
The front diff is a GP5 so it's 15/42 and the rear is a GP6 14/43. So it's still not perfectly matched but it's probably the closest they could get, in order to make different diffs fit in the same diff case :)
Edit: Well that's confusing, some websites have the GP6 spur listed as 43T and some as 45T. 43T would make more sense but the Arrma site has listed it as 45.
 
One thing I think you're confusing is Diameter. Diameter does not equal rollout, but maybe you just weren't explicit about that in your post (the 7% difference you mention is accurate). Rollout is circumference of the tire. Circumference is 2πr.
I had to re-read everything again to remind myself in what I was doing and yes you are right about rollout commonly referring to a tire's circumference (can calculate using 2πr or D*π), but in rc gearspeed calculations it seems the term "rollout" is used in conjunction with distance of travel per 1 revolution of the motor and that is my intended definition of "rollout" , if there's a better term for this let me know, maybe "motor rollout" so there's less confusion?

If the crown/ring gears are the same: 15 tooth pinion gear for front diff / 14 tooth pinion for rear diff = 1.07 (+7% RPM on front tires, as we'd expect to see based on rollout calculations.)

Yeah this would be the mathematically best way to get the wheel speed 1:1 for front and rear. What you would call the gear set if you combined the arrma defined GP5 main diff gear (42T) with the Arrma defined GP6 input gear (14T)....GP5.5 maybe? Like you said that would be mathematically the best rear ratio (3.0) to offset it by -7% of the front ratio (2.8) and align with the +7% circumference/diameter difference of the rear tires. UGH MY BRAIN ASPLODE.

All this makes me want to buy a set of GP5 and GP6 gear sets with some felony rear tires to do some science experiments on my Infraction V1. I wish we could ask someone at Arrma why +14% ratio to the front instead of just +7% and if this was indeed intentional by design assuming the published GP5 gearing (42/15) and GP6 (45/14) is what was actually used.
 
So ignoring the math and all, what if I just put same circumference tires on the vehicle and did not change up the gearing. What could possibly happen? Go!
 
Im sure im not the only one who has already burned through a set of tires on the felony, looks like we wont be seeing them in stores or online for about a month. Does anyone know of a aftermarket option for tires?
So…..here’s what I’ve come up with. I’ve started buying the ZD Racing wheels and tires and so far so good!! Who woulda thought that something from Banggood would fix a major problem with the Armma Felony and Infraction?!! I also just picked up a couple sets of the NEW BSR Racing Foams. (Item#C8027 1/8 Buggy Red) I had to trim the body slightly and also the splitter but it’s definitely a good replacement for the more expensive and back ordered DBoots Hoons!! Hope that helps EVERYONE!!
 
Im sure im not the only one who has already burned through a set of tires on the felony, looks like we wont be seeing them in stores or online for about a month. Does anyone know of a
So…..here’s what I’ve come up with. I’ve started buying the ZD Racing wheels and tires and so far so good!! Who woulda thought that something from Banggood would fix a major problem with the Armma Felony and Infraction?!! I also just picked up a couple sets of the NEW BSR Racing Foams. (Item#C8027 1/8 Buggy Red) I had to trim the body slightly and also the splitter but it’s definitely a good replacement for the more expensive and back ordered DBoots Hoons!! Hope that helps EVERYONE!!
(Keep in mind that these are the same diameter front and rear so it can affect your car depending on how you have it geared.)


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