Tire sizes

slvrbullet

Well-Known Member
Joined
Jul 15, 2012
Posts
206
RDC Crypto
98
Location
Middleton, Idaho
I know everyone is about big tires big shocks. However I'm wondering on these golf carts if we a pushing them to far. Currently I'm running a 32" tire however I'm thinking of going back to a 30". IMO performance went to crap when I went to a larger tire. I look at guys like Ryan Piplic and he has been killing it on a 30" tire. With how light these cars are and the amount of travel they have I have to wonder if a 32-33" tire is really the right direction to go. Sure it makes the holes smaller and will give you a light top end speed increase, but is it really that big of a difference especially with the additional wear and tear and performance loss from rotating mass? I race in northern NV deserts so we race on a lot of technical courses, a few big holes and at most maybe 1 mile long whoop sections with at the most 2-3' tall whoops. The rest is sand and gravel, washes and tight twisty hill climbs.

Thoughts
 

Total Loss

Well-Known Member
Joined
Jun 5, 2006
Posts
1,356
RDC Crypto
856
Location
Prescott Valley, Az.
I left my 30s.
No breakage...handles great...clutch right on.
I am not racing...don't need bigger...
Brother broke a bunch of stuff on his XX with 32s...never got the clutch right.
Sold it.
 

Steve0

Well-Known Member
Joined
Jul 15, 2005
Posts
1,329
RDC Crypto
854
Location
Temecula, Ca
I missed the make of your ex’s. Run 32”. Tune your clutch and put 1000s miles on your machine.
 

Owyhee

New Member
Joined
Feb 15, 2021
Posts
2
RDC Crypto
1
Location
Owyhee County Idaho
2022 will be my first full race season in my own car, a XX. I will be running 30" tires. I have been told by many to run 32's. The reasoning generally revolves around "trophy truck ruts". For me I will run 30" tires until it proves to be a problem. Sometimes I have to learn the hard way. If my data tells me 30" is a problem that is solved by a 32 or 33" I will make the move.

I pitted for a XX team at the Baja NV Legacy race this summer. They run 32" tires and always fighting clutching and ultimately destroyed a primary at mile 450. Their fuel mileage is also terrible compared to what mine has done while racing. I do not have data to p rove its due to tire size but it can be safely assumed that it did not help with drivetrain stress. With ~120hp and stock drivetrain I don't think the larger sized tire is a problem solver. Perhaps a problem changer, so we can decide what problem we would rather risk having.
 

GageFamilyRacing

Well-Known Member
Joined
Aug 23, 2017
Posts
95
RDC Crypto
124
Location
Lancaster
I would say it totally depends on the course and how your car is built. If you are racing after trucks and buggy's with 40"-37" tires you will be dragging your skid plate everywhere you go so the added ground clearance definitely helps. When I raced a smaller UTV only series I used 30" tires and I would agree the overall performance was better especially because I was racing a somewhat stock NA car. My current car could run 35's so a 33 seems small.
 

apseagle

Member
Joined
Dec 8, 2020
Posts
22
RDC Crypto
52
Location
Boise, ID
2022 will be my first full race season in my own car, a XX. I will be running 30" tires. I have been told by many to run 32's. The reasoning generally revolves around "trophy truck ruts". For me I will run 30" tires until it proves to be a problem. Sometimes I have to learn the hard way. If my data tells me 30" is a problem that is solved by a 32 or 33" I will make the move.

I pitted for a XX team at the Baja NV Legacy race this summer. They run 32" tires and always fighting clutching and ultimately destroyed a primary at mile 450. Their fuel mileage is also terrible compared to what mine has done while racing. I do not have data to p rove its due to tire size but it can be safely assumed that it did not help with drivetrain stress. With ~120hp and stock drivetrain I don't think the larger sized tire is a problem solver. Perhaps a problem changer, so we can decide what problem we would rather risk having.

That car you pitted for is now mine. I re-did the entire interior to make it much more pleasant as a recreational car yet keeping it's racing ability. One of the things I did was to go through the clutching system fully working closely with Speedwerx, who went above and beyond to help me get it dialed. The failure he had was due to a bad bushing in the clutch. I would also highly suggest installing the Speedwerx PTO shaft. It is hands down worlds better than the race clutch that was in it. Highest belt temp I have seen was 220 on a very hot day running pretty hard. Still running the 32" Tensors, but will probably switch to the ITP race tires which are a direct competitor mainly due to the $100 savings per tire.

The larger the tire, the smoother it travels and rolls through ruts, wash boards, holes, logs, rocks, etc. But, as you noted, it does take power to roll the larger tires, so keeping them as light as possible is critical. I do not think that 2" in diameter is a killer as long as you run light tires/wheels and properly dial in the clutch.

As far as fuel mileage goes, I have been averaging 12.5-13.5 mpg at brisk trail paces. This is not full on race pace, but gives you an idea. My speedometer has been re-calibrated so it is accurate for the larger tires, so my numbers are right (gps verified).

I think I am local to you, so let me know if you ever want to get together and bench race....
 

Total Loss

Well-Known Member
Joined
Jun 5, 2006
Posts
1,356
RDC Crypto
856
Location
Prescott Valley, Az.
That car you pitted for is now mine. I re-did the entire interior to make it much more pleasant as a recreational car yet keeping it's racing ability. One of the things I did was to go through the clutching system fully working closely with Speedwerx, who went above and beyond to help me get it dialed. The failure he had was due to a bad bushing in the clutch. I would also highly suggest installing the Speedwerx PTO shaft. It is hands down worlds better than the race clutch that was in it. Highest belt temp I have seen was 220 on a very hot day running pretty hard. Still running the 32" Tensors, but will probably switch to the ITP race tires which are a direct competitor mainly due to the $100 savings per tire.

The larger the tire, the smoother it travels and rolls through ruts, wash boards, holes, logs, rocks, etc. But, as you noted, it does take power to roll the larger tires, so keeping them as light as possible is critical. I do not think that 2" in diameter is a killer as long as you run light tires/wheels and properly dial in the clutch.

As far as fuel mileage goes, I have been averaging 12.5-13.5 mpg at brisk trail paces. This is not full on race pace, but gives you an idea. My speedometer has been re-calibrated so it is accurate for the larger tires, so my numbers are right (gps verified).

I think I am local to you, so let me know if you ever want to get together and bench race....
I know my brothers 32" tire XX handled way differently than mine on 30s and stock wheels...as far as steering...he did have 4/3 wheels I think...that makes a huge difference.

His suspension setup was also way stiffer than mine...that also changes characteristics.

Figured mine worked great so leave it.
 

slvrbullet

Well-Known Member
Joined
Jul 15, 2012
Posts
206
RDC Crypto
98
Location
Middleton, Idaho
2022 will be my first full race season in my own car, a XX. I will be running 30" tires. I have been told by many to run 32's. The reasoning generally revolves around "trophy truck ruts". For me I will run 30" tires until it proves to be a problem. Sometimes I have to learn the hard way. If my data tells me 30" is a problem that is solved by a 32 or 33" I will make the move.

I pitted for a XX team at the Baja NV Legacy race this summer. They run 32" tires and always fighting clutching and ultimately destroyed a primary at mile 450. Their fuel mileage is also terrible compared to what mine has done while racing. I do not have data to p rove its due to tire size but it can be safely assumed that it did not help with drivetrain stress. With ~120hp and stock drivetrain I don't think the larger sized tire is a problem solver. Perhaps a problem changer, so we can decide what problem we would rather risk having.
What series are you racing? I see your also in ID! I race the pro stock class and the guy with little 2.0 shocks and 30" tires won the championship so I'm thinking for the racing I do it makes sense. We race on pretty virgin land up in North NV that only gets used during V2R so it recovers pretty quick. I race the Vorra series and we dont have alot of unlimited cars, a few class 1's and 2-5 6100 trucks so huge ruts really arent a concern. Not to mention since going to a bigger tire I cant get the clutch buttons to stay in the clutch and clutching has been a nightmare until I worked with Speedwerx and G3 Motorsports the last race, but still not as good as when it was stock with stock tires.

I know my brothers 32" tire XX handled way differently than mine on 30s and stock wheels...as far as steering...he did have 4/3 wheels I think...that makes a huge difference.

His suspension setup was also way stiffer than mine...that also changes characteristics.

Figured mine worked great so leave it.

I have my suspension pretty well dialed but the car (XX) is just not as agile as it was on 30's.

That car you pitted for is now mine. I re-did the entire interior to make it much more pleasant as a recreational car yet keeping it's racing ability. One of the things I did was to go through the clutching system fully working closely with Speedwerx, who went above and beyond to help me get it dialed. The failure he had was due to a bad bushing in the clutch. I would also highly suggest installing the Speedwerx PTO shaft. It is hands down worlds better than the race clutch that was in it. Highest belt temp I have seen was 220 on a very hot day running pretty hard. Still running the 32" Tensors, but will probably switch to the ITP race tires which are a direct competitor mainly due to the $100 savings per tire.

The larger the tire, the smoother it travels and rolls through ruts, wash boards, holes, logs, rocks, etc. But, as you noted, it does take power to roll the larger tires, so keeping them as light as possible is critical. I do not think that 2" in diameter is a killer as long as you run light tires/wheels and properly dial in the clutch.

As far as fuel mileage goes, I have been averaging 12.5-13.5 mpg at brisk trail paces. This is not full on race pace, but gives you an idea. My speedometer has been re-calibrated so it is accurate for the larger tires, so my numbers are right (gps verified).

I think I am local to you, so let me know if you ever want to get together and bench race....
Did you buy Dick's car?

I would say it totally depends on the course and how your car is built. If you are racing after trucks and buggy's with 40"-37" tires you will be dragging your skid plate everywhere you go so the added ground clearance definitely helps. When I raced a smaller UTV only series I used 30" tires and I would agree the overall performance was better especially because I was racing a somewhat stock NA car. My current car could run 35's so a 33 seems small.
I race the pro stock NA class, stock width, stock drivetrain etc. We do sometimes race after the big boys but inthe Vorra series it's mostly a buggy series with a few 6100 trucks and 1-2 class 1's.
 

BRINGTHERUCKUS

Nimrod de PMC
Joined
Apr 28, 2005
Posts
8,033
RDC Crypto
644
Location
Parker, Arizona
I think 35's will be the tipping point of too big without major improvements, billet hubs, etc. unless they get the weight down.

33's aren't bad, but like mentioned before, depends on the track. a 31 or 30 would be great at Silverstate or Baja Nevada, but terrible at the Mint. Have a clutch set up for both.

Piplic's set up intrigued my this last year, loved the smaller tire, I did notice he has a massive trans skid on his XP. A must with the small tire.
 

Total Loss

Well-Known Member
Joined
Jun 5, 2006
Posts
1,356
RDC Crypto
856
Location
Prescott Valley, Az.
I have my suspension pretty well dialed but the car (XX) is just not as agile as it was on 30's.
You have a 72 Speed setup...correct?
Do you run the stock offset wheel?
That definitely makes a difference. If you noticed...Robby always ran the stock KMC's on his race cars.
We went through this in a previous thread...changes the SAI? May look for that thread.

Anyway...my stock (64) car handled way better than my brothers 64 on 32s, 4/3 wheels and full shock package..
Now at speed in the nasties, he would walk away from me.

Overall...my car was way more forgiving and fun IMO.
 

apseagle

Member
Joined
Dec 8, 2020
Posts
22
RDC Crypto
52
Location
Boise, ID
Did you buy Dick's car?
Yes I did.
IMG_20211016_160312208_HDR.jpg
 

Owyhee

New Member
Joined
Feb 15, 2021
Posts
2
RDC Crypto
1
Location
Owyhee County Idaho
That car you pitted for is now mine. I re-did the entire interior to make it much more pleasant as a recreational car yet keeping it's racing ability. One of the things I did was to go through the clutching system fully working closely with Speedwerx, who went above and beyond to help me get it dialed. The failure he had was due to a bad bushing in the clutch. I would also highly suggest installing the Speedwerx PTO shaft. It is hands down worlds better than the race clutch that was in it. Highest belt temp I have seen was 220 on a very hot day running pretty hard. Still running the 32" Tensors, but will probably switch to the ITP race tires which are a direct competitor mainly due to the $100 savings per tire.

The larger the tire, the smoother it travels and rolls through ruts, wash boards, holes, logs, rocks, etc. But, as you noted, it does take power to roll the larger tires, so keeping them as light as possible is critical. I do not think that 2" in diameter is a killer as long as you run light tires/wheels and properly dial in the clutch.

As far as fuel mileage goes, I have been averaging 12.5-13.5 mpg at brisk trail paces. This is not full on race pace, but gives you an idea. My speedometer has been re-calibrated so it is accurate for the larger tires, so my numbers are right (gps verified).

I think I am local to you, so let me know if you ever want to get together and bench race....
Good car and even better people.
 

slvrbullet

Well-Known Member
Joined
Jul 15, 2012
Posts
206
RDC Crypto
98
Location
Middleton, Idaho
You have a 72 Speed setup...correct?
Do you run the stock offset wheel?
That definitely makes a difference. If you noticed...Robby always ran the stock KMC's on his race cars.
We went through this in a previous thread...changes the SAI? May look for that thread.

Anyway...my stock (64) car handled way better than my brothers 64 on 32s, 4/3 wheels and full shock package..
Now at speed in the nasties, he would walk away from me.

Overall...my car was way more forgiving and fun IMO.

I'm running stock width after market front arms. Stock KMC wheels and valved shocks with all the goodies.
 

MTPyle

Well-Known Member
Joined
Oct 8, 2018
Posts
2,850
RDC Crypto
6,024
Location
Draper UT
We have to run 32” as that’s the only size Toyo makes. Was worried it would be too small but we have loved them. Have 2000 hard miles on a set and they look amazing. Most of that was in San Felipe and Cal City racing.

The smaller tire handles better for sure and less load on the systems.

Bigger is not always better. Yes I know I argue for 40” on our spec truck but that’s a different animal. With the UTV it’s more nimble and you can pick your lines better. The truck we just close our eyes and pin it.

Toyo is working on a 35” UTV tire but we won’t make that jump. Maybe a 33” but that’s max in my opinion.

Not sure I would want to go down to 30”

Mike
 

Total Loss

Well-Known Member
Joined
Jun 5, 2006
Posts
1,356
RDC Crypto
856
Location
Prescott Valley, Az.
We have to run 32” as that’s the only size Toyo makes. Was worried it would be too small but we have loved them. Have 2000 hard miles on a set and they look amazing. Most of that was in San Felipe and Cal City racing.

The smaller tire handles better for sure and less load on the systems.

Bigger is not always better. Yes I know I argue for 40” on our spec truck but that’s a different animal. With the UTV it’s more nimble and you can pick your lines better. The truck we just close our eyes and pin it.

Toyo is working on a 35” UTV tire but we won’t make that jump. Maybe a 33” but that’s max in my opinion.

Not sure I would want to go down to 30”

Mike
No way under 30...if I was racing in SCORE or BITD or Legacy, I would run 32s at least no doubt.
AVE or local stuff with no trucks and tighter finesse courses...30s are great.

For fun...30s are fine IMO.
Folks get tied up in the bigger is better IMO for recreation. Less breakage...unless 32 is stock like the new ProR.
 
Top