The 3 reasons Interco Thornbirds are a fail.

[CJim7]

There are exactly 3 reasons why the Interco Thornbird is not the tire it was originally hyped up to be.

#1. The hard compound of the tread makes it less then desireable for use on slippery conditions....rain, snow, ice. It also hampers performance of the tire in an aired down situation. The tread will not properly expand around obstacles.

#2. The center tread design offers very little void for self cleaning. Mud and snow build up inbetween the tread blocks and will not clean out at normal operation. The result is a doughnut shaped ball of mud which offers no traction.

TSL for comparison

Additionally, the center tread is extremely poor as an on-road design. Because the tread blocks are as big as they are, they do not provide the grip on ice that most other tires offer. Most of the tread runs front to back which, one would think, would be helpful in a situation where hydroplaning is eminent. Not so. The voids do not offer an ideal water repelling design but rather trap water and push it forward. This design also offers very poor performance on snow because of the heavy front to back lateral siping.


#3. Although they are unique and look cool, the raised side lugs are absolutely worthless in mud where they were (and still are) advertised as effective.
The problem with these lugs, is they do not trap mud. The trapping of mud is essential in many situations for traction. Wide voids and downward force provide compression of the mud which is where traction comes from. TSL Boggers are a great example of this. Even in high speed mud racing, this compression is critical. Although tires take on the impression of "floating" over mud, they are actually trapping and creating a surface in which to gain momentum.
The problem with the Thornbird is the side lugs are essentially "suspended" from the tire. This means they operate not in conjunction, but independently from the rest of the tread. Mud is in a decompressed state when the side lugs touch it and in that condition, no traction is offered.

 

[BajaEdition]

I did not know they still made those things. I have not seen a set in decades

 

[CJim7]

I did not know they still made those things. I have not seen a set in decades

Well, Im wondering if the Denman closure and the attempted outsourcing of Interco molds along with the eventual product continuation in Tennessee didnt finally kill off the design. That would have been the best opportunity to do so
...One could only hope.

I ran these things 20 years ago....for all of about a month.

 

[BajaEdition]

I had a set back when I was in the south and those things could not clear mud from themselves, which is real bad for a mud tire
never tried them on the rocks, but then I did not have rocks back in Louisiana,

 

[CJim7]

I had a set back when I was in the south and those things could not clear mud from themselves, which is real bad for a mud tire
never tried them on the rocks, but then I did not have rocks back in Louisiana,

The final straw for me was when I took them out on wet pavement. I thought I was going to die
I quickly went back to my set of TSL's and breathed a sigh of relief

 

[BajaEdition]

Jim I love Mickey Thompson Baja Claws in the rocks, they stick like glue and you can get over a lot of stuff, plus under heavy use you can get 2 seasons of rocks out of them

However, do not even think of going out in the rain with them

they have no street cred what so ever, and in the rain, well it is better to just pull over and wait it out

 

[CJim7]

Jim I love Mickey Thompson Baja Claws in the rocks, they stick like glue and you can get over a lot of stuff, plus under heavy use you can get 2 seasons of rocks out of them

However, do not even think of going out in the rain with them

they have no street cred what so ever, and in the rain, well it is better to just pull over and wait it out

I used to wheel with a guy named Mac...he was the owner of Dirtroad.com (Elwood blues knows him) and he ran the Claws very successfully in the rocks. I was impressed with them more then a few times. I cant remember if they were the radial or the biasply. At the time, they had just come out on the market. I dont know that I've ever heard a bad review on them.

 

[BajaEdition]

I ran them on my TJ exclusively

and that was probably my best Jeep I ever owned, but like most jeeps designed to to push the envelope, it ended up upside down, crumpled and I recovered the 50 grand plus investment by selling off the parts one at a time.

I am past the extreme Jeeping thing now, give me classic Iron and a medium to semi hard trail, I will show off a bit, lead the trail ride. teach and spot the newer jeepers, but in the end we all get back to camp under our own power.

Like most older Jeepers, I love to watch the extreme stuff, but I do not want to pay for those repairs anymore myself, now let me drive your Buggy, and I will show you some lines to fear, but you are paying for repairs.

I have pictures of me driving buggies at 85 degrees sideways, using spotting straps to keep me from flopping over just out of bowls I drove into.
I love extreme jeeping, I just do not enjoy the cost of it anymore.

 

[Darren9975]

Worst tires made. The only thing good about these tires are looks. Everything else sucks!

 

[derf]

My first thought when reading the title of the thread:

"Only 3 reasons?"

 

[BusaDave9]

Jim, thanks for the tire review. I have heard they were lousy tires. I never heard any reasons until now.
We have a section for tire reviews: http://www.jeep-cj.com/reviews/wheels-and-tires-5/
But there are zero reviews. Can a moderator move this post there? That way it will stay where people go to find out about what tires to get and to avoid.
Thanks again Jim
:rock:

 

[CJim7]

Can a moderator move this post there? That way it will stay where people go to find out about what tires to get and to avoid

That's a good Idea Dave. I fully approve