To sipe or not to sipe KM2s?

tmac

Adventurer
FWIW, 2 weekends ago I noticed Bill Burke has the 2 center rows siped on his KM2s. IIRC, he lives in Colorado snow country.

100_4464.JPG

Unless there is a different photo those tires are not siped. Those grooves in the center lugs are factory.
 

flyingwil

Supporting Sponsor - Sierra Expeditions
I'm not a fan of siped tires, we get bad enough chunking of tires with out siping, and adding the siping would just increase the chunking IMO. I know many are fans of siping, I am just not one of them.
 

1911

Expedition Leader
Unless there is a different photo those tires are not siped. Those grooves in the center lugs are factory.

+1, here's a photo with my factory, un-siped KM2's and you can see that they have the same factory grooves cast into in the center lugs:

IMG_3022.jpg
 

Simp801

New member
I have the KM2's on my Tacoma, and after a winter driving trip to southern Utah I had to get them sipped. They were horrible without the sipes in the snow. I had only the center lugs done, and they are holding up well. Much better traction in the snow now.
 

theicecreampeople

Adventurer
INTERESTING you say they were the best tire thereafter. Question is would you buy them again new & siped for snow country?

totally ,lived in bend for 10 yrs we had some good winters there ,i never owned chains or put them on ..i did use the star rated bfg a/t on wifes suvs ..they worked good ...i would have them on here in tex if i could find a place to sipe them ?they also did great on ice ,,,lol..thats part of moving from bend ,i needed to get warm ..lol.. ps never did any rock crawling there ,not sure full siping would be good for that ?
 
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bob91yj

Resident **************
I'm curiuous why all of you guys don't run an AT tire (at least in the winter) and be done with it? I gave up on MT's on a streetable rig years ago, switched to AT's and never looked back. Granted, I'm in SoCal so mud is rarely an issue, I've not had a problem when mud has been encountered. Having said that, I do run TSL/SX's on my rock rig, and have swapped them over to the LJ on occasion.
 

corax

Explorer
Unless there is a different photo those tires are not siped. Those grooves in the center lugs are factory.

Yep . . . but his are siped. The sipes are hair thin and barely visible from even a few feet away. As stated above:

yeah, it's hard to see and that's not really my picture (just for illustrative purposes, I guess). but he does have the center 2 rows of tread siped and recommended it on the KM2's for any kind of winter driving at his class at NW SarCon (Mt Hood, OR)
 
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doug720

Expedition Leader
Last winter I watched an 80 series LC slide sideways going around a very slow (10 MPH) off-camber turn that was almost flat with BFG MT's. You could see the truck just slip on the packed snow, not ice.

I was right behind him in my 60 with BFG AT's and had no problem, and even pulled him back onto the road sideways.

I don't know how much sipping helps, but it must help.

I have never had MT or KM/2's, just AT's. But spend time every year in snow and have little problem. Plus I have chains for all wheels when it's real bad...

Doug
 

Pskhaat

2005 Expedition Trophy Champion
I'm curiuous why all of you guys don't run an AT tire (at least in the winter) and be done with it?

BFG ATs IMHO is really not that good in snow | ice | winter. I prefer a studded MT in the winter well over an AT any day. The KM2s still come in the 255/86r16 size. That said, I think there are some interesting tread complexities with winter driving making the KM2 questionable.

Outside of Blizzaks and studded MTs with chains, best winter tire I ever had were (ready for the boos) the Goodyear AT/S :Wow1:
 

Box Rocket

Well-known member
Actually it can be pretty hard to tell whether a tire is siped or not. I had my KM2's siped at Discount tire when I bought them. For at least a couple months you couldn't even see the sipes. Now they are visible on the center lugs. I think the sipes helped a great deal last winter here in Utah. Also I just finished a trip to Moab this past weekend with lots of time in the rocks and the center lugs didn't chunk at all as a result of the siping.

Here's a photo the day I bought the tires. Can't see the sipes at all but they are there.
_MG_1444.jpg
 

4Rocker

Observer
After the first snow last year, my 255/85 km2s felt like ice skates compared to the bfg ats that i was used to. That night I spent an hour per tire siping the center lugs 3/16" deep with a specially ground utility knife. The difference was night and day! They felt like a completely different tire in the snow, almost (but not quite) on par with the ATs. I would absolutely recommend the siping on these tires.

On a side note, grooving and siping are two different things. Grooves are wide and are formed by removing material. Siping is simply the cutting of the rubber to provide more biting edges when the rubber flexes during acceleration or braking.
 

Buliwyf

Viking with a Hammer
I spotted a Dodge yesterday with 35" Kelly Safari tires that looked like really nice siped MT tires.

No idea if that's a good tire or not. Just pointing out that I don't quite get the sipe BFG MT idea. Why not just choose a different tire?
 

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