off-road racing and large tires


swynx

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been to a fair share of off road races over the past few years, every year more and more events pop up around the nation. over the years the average tire to run has gotten bigger as we all know. my question is, how large is too large?

its not like 44's or even 54's are anything new, they were ran 10+ years ago in many events. now days the norm seems to be a 40"-42" sometimes 43"-44" for a trail truck/ weekend racer build. but ive seen at events where a rig with 42s have lap for lap beat a truck with 54s. some times its in the driver mod, sometimes its in the build quality.

all be it in the above said race, the truggy on 42's had a rear mount 6.2 with bling everything, and sold for like 70k, and the truck on 54's was a 1000 hp ttc blazer thingy, but even then so that ttc truck still got beat out by a toyota on 47s with a 22re, who was a close match for the truggy on 42's.

i know that the majority of radials size stop at 40's i suspect in the near future almost every brand will have a 42" tire.

i also have also seen where the small tire class is 40's and smaller, in my mind 40's are no small tire, but possibly its the day and age where 40's arent "hardcore" any more.

for offroad racing, where would you think the optimal tire size would be at?
 


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bobbywalter

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i think the optimal tire is 37 inches....


buuuuuut...

It's nice to have a street-able driver that runs the fat bastard tires......

I have been built to be on 42-44 in tires since 07 or so for certain trail work. Mostly recovery. for mud and most Michigan terrain its easy to do. steering is not a huge concern in soft environments....flotation is.

I never set up for rock work with the massive tires...or racing...due to the fact my vehicle is still used as transport and all around truck stuff ....

I have most of the stuff needed to beat on rocks, but the weight and complexity of the required steering was not needed till recently because I have not had the need to visit such fun things.......my son will use it now that he is beginning to come of age....so i need to drag out the drawing board and see if what was wrote on it is still good enough for today...

when going to hard obstacles, which I have been away from for years....due to time mostly.....I just don't have any time in lengths to allow extended trips these days.....but when i do go to harder stuff, I generally run conservative 35 to 38 in tires.

Since 2006 or so, when going wheelin where I know it's ruthless, I run military 37's as it is easier on my rig for difficult stuff.

now to the big tires taking over....terrain and challenges dictate this for the most part....and of course event rules.

Bigger tires in abusive situation cost huge in parts to support them for serious use....this is an easy correlation to surmise.

but it is not that simple in the competitive realm...

even running 33-35 in tires becomes an issue once you add hydro assist... the hydro assist allows you to exact a level of abuse that would normally be impossible to execute for most people.

you dont realize it until your all of the sudden destroying knuckles, inner c's and spindles which further require more welding and beefing ...or aftermarket solutions..... the fickle whore of incrementalism is what i call it....it is never satiated...


So yeah.....changes are coming to my rig based on this topic. You need them big tires to stay competitive now. i needed them to stay out of trouble extracting others from misfortune. but now adventure is returning to my agenda....so i need to step up a few increments....


the 2500 dollars for tires is the cheap part....the initial 1000-2000 in parts to use the big tires and countless hours of rebuilding and re-engineering the failure points is where the true cost is....going big is a pain in the ass on the best of days....but fun as hell even on the worst....


obviously the shit we do to pass the time is endlessly nuts...

so go ahead....call me crazy.
 
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swynx

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i run 37's now and i find them about perfect for weekend wheeler duty. alot of the community is still on 33's and 35's, i think alot of it has to do with the cost of handling large tires as you said.

one thing i do notice when i am on the trail is that the side by side world has changed the trails alot. they have an incredible amount of clearance, so im finding holes that i used to crawl thru, i am dragging the diff, even with the damn wheels firmly planted on the ground.

i do have a few friends that have ran 40's and 42's and since downgraded to 38's/37s depending on what they can get.
 

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one thing i do notice when i am on the trail is that the side by side world has changed the trails alot. they have an incredible amount of clearance, so im finding holes that i used to crawl thru, i am dragging the diff, even with the damn wheels firmly planted on the ground.
I'm running 28s on my SxS and have over 14" of ground clearance right down the center. When I switch over to 30s and portals I'll have around 19-20".
 

bobbywalter

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I'm running 28s on my SxS and have over 14" of ground clearance right down the center. When I switch over to 30s and portals I'll have around 19-20".

Change is constant.....never satiated.

All I wanted to do was keep up with Toyotas and pass jeeps on climbs.

That damn thing I am driving so far is the result.

In hindsight....all I needed was a welded rear and d35 swap with 488 gears....a sawzall.....and 35 inch swampers.


What a waste.
 

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I think it depends on what class and what type of race you're talking about. I have competed three times in the stock/mod class (basically a more or less "stock" vehicle with limited modifications allowed) and ran 31's the first two races and 235-75-15s this year. Most of the other trucks in the class have tires up to and including 33's or slightly larger.

Honestly I think for most race applications, ground clearance from tire height is important but low on the priority list. KOH/Ultra 4/etc type rigs are where you see the real big tires come into play simply because they have the ability to add a lot of horsepower to turn them with no restrictions.
 

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Change is constant.....never satiated.

All I wanted to do was keep up with Toyotas and pass jeeps on climbs.

That damn thing I am driving so far is the result.

In hindsight....all I needed was a welded rear and d35 swap with 488 gears....a sawzall.....and 35 inch swampers.


What a waste.
All I'm trying to do is make it through this one mud pit I keep getting stuck in. 30s and 15% gear reduction/ 4" lift portals should do it.
And before you ask...
Yes, I'm willing to spend almost $4K on shit I don't need to go through a mud puddle I can just go around.
 

swynx

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I'm running 28s on my SxS and have over 14" of ground clearance right down the center. When I switch over to 30s and portals I'll have around 19-20".
with 37's on the dana 35 i have 13" at the diff. i believe my buddy with a dana 60 on 40s has 14" at the diff. 20" is incredible, starting to see alot of side by sides with 33's and 35's. almost not even worth building a truck any more :ROFLMAO:

I think it depends on what class and what type of race you're talking about. I have competed three times in the stock/mod class (basically a more or less "stock" vehicle with limited modifications allowed) and ran 31's the first two races and 235-75-15s this year. Most of the other trucks in the class have tires up to and including 33's or slightly larger.

Honestly I think for most race applications, ground clearance from tire height is important but low on the priority list. KOH/Ultra 4/etc type rigs are where you see the real big tires come into play simply because they have the ability to add a lot of horsepower to turn them with no restrictions.
most of the racing i have been to is pretty rough races. koh, insanity fab winter challenge, north idaho mud and crawl, to name a few.


been trying to figure out how big of a tire i want to go with when i install my tons, considered everything from 40's to 44's. 40's are pretty damn universal and theres alot of great options.
 

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i agree it depends on the class. and types of racing. for rock crawling and ultra 4 type racing where there is no real fender or body, youre basically just limited to what your hubs, axles can whistand. lots of trophy truck and 6100 teams have been running 39s and 40s and i dont think theyll go any bigger than that any time soon. the limiting factor there is the body. with the massive amounts of up travel the suspension has the tires can only get so big before they start hitting the underside of the hood/tops of bedsides. now with AWD technology hitting the trophy truck class teams are having trouble finding a balance between power and rotating mass to keep all the awd components together for a 500-1000 mile race.
 

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40's realistically are a huge tire. idk how many of you guys have tried to put a 40" tire and wheel on a vehicle but its no easy task. seems that 40" seems to be the sweet spot for racing, im thinking anything more than that and your not as much into go fast as you are brute force, because of the weight of axles and tires.
 

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Yes, huge, and heavy. I dismounted, and remounted on different wheels, a set of 40" Gumbo Monster Mudders years ago... by hand... with a high lift jack and tire spoons. If the tire height's not enough, the weight of those things alone will kill axle shafts real quick... they laugh at D44 parts.

That's the problem with big tires, you have to have the axles to support them, which are also bigger, sometimes making ground clearance a wash plus your adding that much more weight to your rig and decreasing your power to weight ratio. If you've got half ton or smaller axles and a stock engine it's almost better to stick with smaller, lighter tires.
 

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Yea the only way to really have 40s for a high speed racing application is a fabricated housing with a 10" center section and like jumbo 36 or 40 spline axles with big 2.5" hubs.
 

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What a waste.
Your truck is a f*cking work of (modern) art. The tail lights make it.

Like I've said: any machine that looks like it was being sent to the crusher, then murdered the crusher and used it for parts is one that I have massive amounts of respect for.

OK, back to tires.
 

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Your truck is a f*cking work of (modern) art. The tail lights make it.

Like I've said: any machine that looks like it was being sent to the crusher, then murdered the crusher and used it for parts is one that I have massive amounts of respect for.

OK, back to tires.
I am saving that for future.quote...

I have had similar things said before. Most people are just shocked it works at all.....let alone drive over their car ...

One of my favorites was after winning the ugly award and Max pull mini at a pulling event....."it's like a self propelled dumpster"......I used that for years.....



Like said though....tires are the cheap part of competing with 40 in or larger ....

Supporting hardware mantainaing it is prohibitive
 

swynx

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Yes, huge, and heavy. I dismounted, and remounted on different wheels, a set of 40" Gumbo Monster Mudders years ago... by hand... with a high lift jack and tire spoons. If the tire height's not enough, the weight of those things alone will kill axle shafts real quick... they laugh at D44 parts.

That's the problem with big tires, you have to have the axles to support them, which are also bigger, sometimes making ground clearance a wash plus your adding that much more weight to your rig and decreasing your power to weight ratio. If you've got half ton or smaller axles and a stock engine it's almost better to stick with smaller, lighter tires.
i think the ground clearance thing is pretty killer, i have 13" at the diff on 37's, asked my buddy he measured 14" with 40's under his chevy dana 60. made me think about portals, which are slowly coming to market, i dont think its quite there yet, plus what is out there is stupid expensive.

see alot of toyotas now days that still run a 22re so they dont blow up there toyota parts with 40's but they have to run them in double low to go anywhere, then they just dont have the wheel speed to make any real obstacle, with any lack of traction.

Yea the only way to really have 40s for a high speed racing application is a fabricated housing with a 10" center section and like jumbo 36 or 40 spline axles with big 2.5" hubs.
i wouldnt doubt that at all, if dudes are really beating there rigs, ive seen guys snap 40 spline chromoly axles with a 42 inch tire.

I am saving that for future.quote...

I have had similar things said before. Most people are just shocked it works at all.....let alone drive over their car ...

One of my favorites was after winning the ugly award and Max pull mini at a pulling event....."it's like a self propelled dumpster"......I used that for years.....



Like said though....tires are the cheap part of competing with 40 in or larger ....

Supporting hardware mantainaing it is prohibitive
that is true tires are the cheap part, even if they are 2 grand, after you figure in actually building a set of tons or whatever it may be, you can easily be at 10 grand for 2 axles. assuming you only want to build them 1 time.

speaking of your truck bobbywalter, what ever happend to your build thread thing. i thought i had started reading one, and lost it?
 


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