Cab mount chop opinions

Those of you who had to do the cab mount chop (CMC) what wheel and tire specs are you running that made you have to do it?

 

285/70/17 for me w/ 0 offset. I did ti as a precaution but at just the right angle I can tell I would have rubbed had I not did the chop.

 

Are you running a lift?

 

Best chance would be 33s on stock wheels because the offset is so high so the scrub radius is less. Otherwise if you wheel and stuff the tire it will rub the CM.

I did run a 255/80r17 on 17x8 0 offset with only a rare occurrence of rub on stock CM, basically it was safe for DD duty. I never did fully stuff that wheel though and it rubbed while turning and going over bumps that raised the wheel.

 

I'm wondering if a 3" lift would give you the clearance to go with a -6 offset. I have a feeling it'll be really close

 

I have the Dobinson GTS kit, got me around 2.5 inches.

 

Lift does not help clear tires. Alignment does

 

I'm new to this truck thing. So an offset of -6 would stick out farther than a 0 offset correct? That would mean that a -6 offset wheel would be farther away from the CM than a 0 offset wheel?

 

in theory yes, but -6 increases scrub radius which can lead to rubbing elsewhere. with these trucks -6 to -18 is a good place to be. again alignment is everything

 

I really appreciate the input! I'm trying to figure out if a 17x8.5 wheel with a -6 offset will cause me to hit the CM with a 285/70/17. I'm okay if there is rubbing elsewhere, like the mudflaps or the plastic wheel well. but I want to avoid the CMC at all costs.

 

with a good alignment you'd be okay, i didn't CMC for 33s

 

I see this sentiment occasionally, is there a reason you want to avoid it at all costs? I've had it done twice on older vehicles, never had an issue. Not doing it can create issues though.

 

Thanks again, I just ordered my wheels! I've heard from a few people with similar setups that I shouldn't have to do the CMC with a 17x8.5 -6 and a 285/70/17 so I'm just going to go for it. So we'll wait and see

 

For me to say (avoiding it at all costs) is an exaggeration. I want to avoid the extra costs if possible, and I don't want to deal with any potential warranty issues after cutting into the body.

 

So... how’d it turn out?

 

Perfect, no CMC needed.

 

Awesome. What UCAs are you running? And what tires did you buy?

 

SPC control arms with Wrangler Duratracs

 

personally, I think a CMC is a better plan than using alignment to compensate for tire fit. Alignment is regular maintenance, and you'll sacrifice handling (though admittedly you might not notice), and the next alignment service may have you rubbing again. I had a slight nuisance rub with 285's and an Icon stage 7 lift. the alignment shop helped, but the truck has a vague wandering feel at speed, and it still rubbed occasionally. Had SDHQ in phoenix chop it while they were putting in the gears, still need to get the alignment put back to spec.

alignment has a purpose, and it isnt tire fit.

 

What's your caster set at? I'm looking at nearly the same setup - 2.5 lift, SPC UCA, Methods w/ 0 offset, and currently running 265/75/r16. Looking to go to 285/75/r16. I don't want to do a CMC if possible.