How Important Is Ramp Travel Index (RTI)?

Humvee4us

Member
Which setup would be preferred for rocks and deep ruts, 35" tires with a ramp travel index (RTI) of 700 or an RTI of 832 but only 33" tires?
 

jadmt

ignore button user
articulation is nice but belly clearance is also important. depending on the tires some times there is a bigger difference than simply what is marked on the tires for actual size. ie with some 35's are are close to 35's say true 34.5 where some 33's might really be 31.5 so you end up with a 1.5" more ground clearance. Also when airing down you lose clearance which of rock crawling you want to do.
 

Smileyshaun

Observer
Rti numbers are for car shows and bragging rights , you could have two rigs with a 700 rti score but at that point one could be on the verge of tipping over and the other could keep driving up the ramp with a tire dangling and still feel stable .
 

1stDeuce

Explorer
I too think your question is loaded... Are we talking about running bigger tires in the mud or snow? Then bigger tires will get you farther than smaller ones no matter what your RTI is. Rock crawling? I'd probably go with better RTI over tires with 1" more clearance.

RTI does count for something, at least at the extremes, as it is a measure of the vehicle's ability to flex and accomodate obstacles without lifting tires. If you're in a vehicle with really poor flex, you're lifting tires all the time, and a tire in the air is one less tire making traction. Given two otherwise identical vehicles, the one with better flex will obviously do better offroad...

Want to look cooler while offroad? DEFINITELY go with the bigger tire and less flex. Lifting tires makes the trail look hard and makes for cool photos.

I built my TJ for Moab originally, before the damn side by sides and rock buggies tore it all to hell. My buddies all had YJ's. We all did the same trails, but they had tires in the air all the time. I don't recall ever managing to even lift a tire hardly. Same line, same obstacle, their pics are "cool", mine look lame. For the most part, we all went the same places though. I just made it look easy, and with less pucker factor. And smaller tires... :)

FWIW, I found that my tires rubbed hard enough on the front fenders at full stuff to bend the inner lip, especially if I was turning. Instead of limiting travel, I chose to keep my travel and put a 3/4" body lift on the Jeep, along with a 1" motor mount lift. Now I have no rubbing, 1" more clearance under the oil pan, and very nice suspension geometry. Perhaps you can think outside the box and get 35's to fit without limiting up-travel... ??
 

billiebob

Well-known member
Which setup would be preferred for rocks and deep ruts, 35" tires with a ramp travel index (RTI) of 700 or an RTI of 832 but only 33" tires?
Are you rock crawling with a dedicated rock crawler and zero camping stuff?
Or overlanding with an RTT, food, cooler, and camping stuff.
Or will you drop a trailer at base camp.

Cuz as soon as you throw an RTT and rack on the roof, the last thing you want is a high ramp score. You want stability.
Ramp Index indicates all 4 tires are in contact making traction limiting wheel spin.
2 selectable lockers on anything will do the same thing.

But if you want good answers, you need to tell us what you are doing and where.
Deep ruts say ground clearance.
Rocks say articulation.
 
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As Scooter

Observer
Well, we can pit it another way. Some people have a blood sugar that may normally run at 150, which is considered prediabetic, but is a concern, yet they live their life normally and are quite athletic. Others can run 100 and be morbidly obese. The numbers are just indicators of performance. There are guys out there that can take an IFS with minimal travel on a trail that guys with high flex jeeps cannot accomplish.
 

Kraqa

Member
coming from the rock crawling world and ultra4 racing. RTI has little impact on vehicle capability.

flex is needed...but too much flex can be a bad thing. the real test is compare a vehicle with open difs and a HUGE RTI number.......to a vehicle with lockers and a very low RTI. Lockers will win nearly everytime.
 

dvdswan

Member
Lockers are the way to go for sure. Keeping the tires on the trail helps too. But on a side note, a winch is also needed. It's not fun digging for hours to get a locked vehicle unstuck. Just my .02.

15886852_large.jpg
 

nitro_rat

Lunchbox Lockers
RTI is a meaningless number by itself. It's only usefulness is to factor out wheelbase advantages when comparing the ramp travel of a short wheelbase vehicle such as a CJ-5 to that of a long wheelbase vehicle such as a Suburban. A Suburban with less travel than the Jeep can go farther up the ramp than the Jeep can simply due to its longer wheelbase. The "RTI" makes the Jeep look better in a ramp travel competition in a magazine when it's competing against anything else. That's why RTI even exists.

It's a useful number when comparing the results of modifications back to back to see how much travel you gained.

RTI usually can't be compared directly because the angle of the ramp also plays a factor. All ramps aren't the same angle so #'s from one ramp to another can't always be compared (unless of course you know the two ramps are the same angle).

Leave RTI where it belongs, in the magazines...
 

CrazyDrei

Space Monkey
Which setup would be preferred for rocks and deep ruts, 35" tires with a ramp travel index (RTI) of 700 or an RTI of 832 but only 33" tires?

Humvee4us,

Would a Focus or Prius climate control knob look better when the car is covered with a foot of snow?

What exactly are you asking? Keep in mind that a John Deere tractor with an RTI of 100 will most likely be coming to get you out of any rocks or ruts your RTI 700 or 832 will be stuck in.
 

RoyJ

Adventurer
All else being EXACTLY equal? Sure, more RTI the better. Now show me 2 rigs, identical down to center of gravity and dimension, that only differs in RTI.

H1 / Humvees have an RTI of like -300...Look up those New Zealanders (I think) crawling one up a huge rock step where a fully locked solid axle Patrol had tremendous trouble.
 

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