IROK Bias vs. Radials When Rockcrawling???

[Craig T]

How much rockcrawling performance would I lose going from 36" Bias ply IROK's to 37" IROK radials?

What other off-road drawbacks are there to the radials?

My rig is 80% trailered to trails and 20% street.

Thanks,

Craig

 

[bmc69]

I can only speak to the radials..the 39.5 IROK radials are the most awesome improvement I ever made to my rig as far as both road manners and rock crawling capability..coming from 16/38.5 TSLs..then 12.50/38 TSLs before that, both of those being bias ply tires.

The radial IROK sidewalls are reportedly weak..and they look like they are. I have not messed one up yet though.

 

[SaddleUp]

The radials are probably only minimally better in the rocks than the bias tires. (Yes, I turned that around as I think it is backwards) The softer sidewalls help the tire wrap around rocks better but as mentioned above it also makes the sidewall weaker. If you drop the air pressure too low then you risk pinching the sidewall between the rocks and wheel which can punch a hole through the side. (I have one in the garage with a hole in the sidewall) The bias tires will allow lower air pressures but on the flipside they also need lower pressures to attain the same sidewall flex due to the stiffer sidewall.

While I do think the radial has a slight advantage I don't think it is really sufficient to worry about. If I had it to do over again I would get the Bias instead to save a few dollars.

 

[SecondChance]

Radials will be quieter going down the road, but you could just turn the radio up a little louder. The bias ply will definitly withstand more abuse.

 

[amc78cj7]

I used to run Bias Ply Super Swampers (I know, a step up from IROKs, but similar) and now run Super Swamper Radials (SSR). There is no difference in my opinion as to the trail/rock performance. The radials are a LOT more money though. The good thing about the radials is they wear much better on pavement. I figure I'll get at least double the miles out of mine which is a big deal since I currently flat-tow. If you have an exclusive trail rig that is a trailer queen I would get the bias ply and save yourself some cash. Trailer queens loose their sidewalls long before they loose their treads.

 

[GRIZZLY]

I've only had the radials. For you guys that have had both, do the bias plys seem like they flat spot more if sitting for a while?

 

[Kaw-Liga]

I've never had problems with flat spots even when I leave the Bronc at home for a few weeks while on trips. This set of TSL's is my 2nd set of bias swampers, first was 36x13.5 IROKS. amc, not trying to argue with you, but are you sure that radials last longer on the street...I've talked to many tire guys that deal w/ swampers and they have all said that the radials have the same soft tread compound as the bias ply tires, its just that they are steel belted so that there is less chance for tread separation. They have all told me to my face that radials and bias ply tires last about the same time on the street. Just want to know if I've been getting my leg pulled by my tire guys or not.

Rob

 

[z70what]

i'm with you on that Rob, i owned a set of MT Baja claw bias plys and my buddy got his Radial Claws at the same time i got mine (35x13.50) and we both had them on jeeps, and his seemed to wear just as fast as mine... and i still got quite a few miles out of them... Definitely going w/ Iroks as soon as i save some money..

Luke

 

[bmc69]

I had TSLs on my '69 before I went with the radial IROKS. I still have TSL-SXs (38.5) on my '78 Bronc for trail duty and run 35" Dunlop radials on that for street duties. I had 16/38.5 TSLs on my F-250 tow rig..have Parnelli Dirt Grip radials on it now. In all three cases, the radials behave hugely better in terms of not 'flat-spotting'. Wear?..the only valid data point I have is the F-250..and I'm getting almost 2:1 life out of the PJs than the TSLs. The TSL-SXs on my '78 wear quickly..but I wouldn't consider any comparision betwen them and the Dunlops vaild since the Dunlops are ATs and wear like iron (65K and counting..).

 

[Steve]

I've only had the radials. For you guys that have had both, do the bias plys seem like they flat spot more if sitting for a while?

Yes. It depends a lot on what air pressure you have in them when they're sitting; the lower the worse the flat spotting. I have personally seen several radials (SSRs and Iroks) tear sidewalls while rock crawling; I've never seen a TSL/SX with a torn sidewall.

 

[amc78cj7]

The bias ply SS had a balooning affect when filled (ie. the sidewall would baloon and there was less flat surface on the road) than the radials. This affected road handling. Also, my Jeep is not a daily driver and sat still in my garage for an entire winter - after which the bias ply had flat spots that made 65mph driving interesting. This is my first winter storage with the radials so I do not know yet if they will get flat spots, but they allegidly don't.

 

[68 Broncoholic]

I couldn't drive over 25mph with the SX's (ballanced) due to flat spotting. Once they heat up, then I could get up to 40mph if I was lucky. This didn't bother me so much as I trailered most places. It was a pain to trailer for local wheeling though.
The ride was very harsh off road even aired down and I also tore a side wall in one. Bias tires don't flex for crap aired down but are very strong. I noticed I had to air down to 6-8#'s to get decent performance. This will increase the chance of debeading a tire if you don't have bead locks.
Its a toss up in my mind whats best. I like Radials cause they run smooth on pavement, flex well and give a soft ride. If you go SSR get the unconditional warranty so the tire is replaced when you tear a side wall. If you are trailering only I'd stick with Bias for strength and longer lasting.