It's really close to the same weight as a Trail Grappler but being that it's a 13.50 as opposed to a 12.50, it is a bit heavier.
At the same psi, it really shouldn't make a difference.
NEW Shoes for RUBICAT : 37x13.50R17 Cooper Discoverer STT Pro M/T Tires
- Thread starter wayoflife
- Start date
It's really close to the same weight as a Trail Grappler but being that it's a 13.50 as opposed to a 12.50, it is a bit heavier.
At the same psi, it really shouldn't make a difference.
Actually, you're in luck. I had taken measurements of the tread and this is what I can tell you. Brand new, the Nitto Trail Grapplers have an actual footprint width of 10". Fully inflated and measuring from the widest point on the shoulder lugs on both sides, you do get a 12.50" measurement. That being said, the 37x13.50 Cooper STT Pros have an actual footprint of 11.5". In other words, you have a full 1.5" wider tread. Fully inflated and measuring from the widest point on the shoulder lugs on both sides, you do get a 13.50" measurement as well.
Red Knight15
Caught the Bug
Like the look of these tires, going to 35s on mine. [emoji106][emoji106]
Speeddmn
New member
These are very high on the short list for our jeep when the Toyo's wear out. They are also on top of the short list to replace my current Terra Grapplers on my GMC 3500, only in a 295/70/18 due to towing reasons. Got a quote of 1240 mount/balance etc prior to getting a Military discount.
That's a hell of a good deal :thumb:
Bullwinckle
Hooked
Rubicats looks great with the new tires!
Eezybreezy08
New member
Damn good looking jeep. Like those tires
Exodus 4x4
New member
I should note that we were able to take Rubicat out for a quick spin and so far, here are our initial thoughts on the Cooper STT Pros.
1. They are a LOT quieter than we were expecting. I think being that our Renegade is a unibody, the sound from the tires translate into the cab a lot louder than a JK which has a body on frame and separated by body mounts that are really isolators. Of course, on our Renegade, we were moving from street tires to mud terrains and on Rubicat, we went from bigass Mud Grapplers to these Coopers.
2. Surprisingly, they are a lot rounder than I was expecting. In fact, I didn't notice any shimmy or roughness until I got to about 75+ MPH and even then, it was very slight. Based on the fact that I couldn't feel anything in the steering wheel, I have to think that the minor balance issue is on a rear tire. I have to say that it's almost not off enough to even bother getting them balanced but, I think we'll do it anyway just because we tend to drive on the 75 MPH range on a regular basis.
3. Right off the bat, we aired these tires up to 30 psi and being that they are Load Range E tires, we can definitely feel it. At least, we can feel every stone and crack in the pavement but, that's nothing new to us. We'll be bringing them back down to about 26 psi and I suspect that will help out.
I will be sure to post up more as I think about it. If any of you have any questions, please let me know.
After driving mine for a few hundred miles I have to agree that these are a lot quite than I was expecting. I was picking up a slight vibration around 65 that wasn't too bad until I push it to 75, and mine also feels like it may be a rear tire. Now all I need to do is find a shop that will balance beadlocks.
Back when I was living in SoCal, my local Discount Tire was willing to balance my bead locks. Of course, every shop is different even if they are owned by the same company. My current Discount Tire won't do squat for me.
GraniteCrystal
New member
Can you explain this more? It sounds like there were things you wanted to do but couldn't when running 40s and now you can with 37s. Bigger tires not always better?
Exodus 4x4
New member
Ended up finding a mom and pop this morning that didn't even flinch when I said beadlock. They all balanced out pretty well with a few ounces with the exception of one of the rears needing 14.5 oz.! Pretty sure it's the wheel, and not the tire. I seem to remember one of them having a significant amount of weight on it when I broke them down. Now I'm heading out to trail test them tomorrow!
LOL!! Big is good but not always better especially if you're not built for it. Cindy and I like to bomb across the desert and big heavy ass 40x15.50s can be really hard on an axle, even if it's a 60. Also, we are unfortunately now running 5:38 gears and in a 44, the pinion is really small. The odds of us breaking it are really high even with 37s. Of course, that's just us - I know there are a ton of guys who will tell you how they run 40s on a Dana 30, wheel really hard all the time and without any issues.
GraniteCrystal
New member
Gotcha. Thanks for the explanation!