Cab Mount Chop - Food for thought?

Nope....that mount is designed for one thing, to keep the cab from falling off of the frame. It's NOT designed to prevent wheel intrusion into the cab.

 

Why does everyone hate on chrome?!? I seem to be the only one to not mind my chrome grill, and rear bumper.

 

Chrome looks a lot better on the 2nd Gen, it just flat out looks bad on a 3rd Gen.

 

I don't mind the chrome ring around the grill, but the rear caps look nasty. I still wouldn't remove the rear chrome caps.

 

Ok. I didn’t know I was talking to an engineer from Toyota.

My bad!

 

Some reading from the 1st link posted below:

“Small overlap frontal crashes primarily affect a vehicle's outer edges, which aren't well protected by the crush-zone structures. Crash forces go directly into the front wheel, suspension system and firewall. It is not uncommon for the wheel to be forced rearward into the footwell, contributing to even more intrusion in the occupant compartment and resulting in serious leg and foot injuries. To provide effective protection in small overlap crashes, the safety cage needs to resist crash forces that aren't tempered by crush-zone structures. Widening these front-end structures also helps.”

https://www.iihs.org/iihs/ratings/ratings-info/frontal-crash-tests

The article below is full of mis-translated words (rocket instead of rocker etc) but maybe explains why Toyota puts the cab mount as close to the wheel as it does (screwing all the guys wanting 33”s). The smaller the gap between the cab mount and the wheel, the more likely the vehicle will be deflected away from the impact “glancing off”, which decreases the chance of serious injury. A large gap behind the wheel is not desirable. Not that a 1/2” taken off to CMC is likely a huge factor, but at least there is rationale to the Toyota design (if I am understanding what is written correctly).

https://www-esv.nhtsa.dot.gov/proceedings/24/files/24ESV-000244.PDF

 

^^^^FTMFW^^^^^

I'm not sure why people are worried about hacking up their truck. Who cares about crash protection (don't get into an accident) or resale value (I'm never going to sell it) so I can drive around the mall with my big ass tires.

I get the guys that are doing it that actually have a need for it and accept the risk but there is no way I'm going to put a family member in a modified framed vehicle driving on the street.

 

Every modification changes the design specification of the truck. None of the aftermarket designers do anything near the level of testing Toyota does. They also attempt to eliminate their liability by marking their parts "off-road only." Since we have no actual data any discussion is so rife with speculation that it doesn't even rise to the level of supposition.

The vehicle is very carefully designed to meet NHTA standards. I will leave it up to the reader to decide if those standards are the best way to increase occupant safety. Every modification alters the crash performance of the vehicle.

We do it anyway though because we want to. It's a calculated risk. I personally don't understand limiting suspension articulation with giant tires. I understand putting 17" wheels since for some reason very few off road tire choices are available in the stock size.

 

285/70/17, 5100's w/887 springs, camburg UCA's. No CMC, no rubbing.

 

I put on the straight black ones that match the flairs on my OR. When I got done and looked at the new ones....I kinda missed the chrome ones lol. But it was the only chrome on my truck and kind of stood out.

 

A gusset could be made and welded on the backside of the cap mount while doing the CMC to add strength beyond the original design, if you are concerned.
Rock sliders also have an effect on the strength of that area and chance of glancing when in a small offset frontal impact.

or if you are really concerned about safety....put in a roll cage (there is a lot of mall crawl cred in a nicely painted cage).

 

@Stocklocker I think it’s a valid point, worth thinking about and discussing. How much of an effect a CMC would have on crash safety is likely less than the addition of the larger tires, and even the suspension lift, but that’s my off-the-cuff guess. A bigger tire closes the gap to the cab mount back to near stock distance after all, and the increased angle after the CMC would deflect the tire outward even more, in my opinion. And yes, material is removed from the mount, weakening it, but is it weaker to the point it would fail? That’s the million dollar question.

You could say similar things about the hidden winch mount that was on my Tacoma when it met it’s fate, or plate bumpers... I think the best idea is to make an informed decision about modifications, being aware of potential risks and deciding if the benefits outweigh them. Which is why I like your topic.

 

Looking at this picture ^^ again, it becomes pretty obvious that the cab-mount is not simply for mounting the cab, as some have suggested. If the purpose of this frame protrusion was solely to provide a mounting support for the cab, there would be no reason whatsoever for the additional metal that sticks out past the resilient mount (bottom of the photo). I don’t think the pointy-bit of the cab-mount would be required to simply support the cab, so I assume there is a dual purpose to this part of the frame. The second function is likely to keep the wheel out of the cab in an impact, which is why the protrusion is longer than it might otherwise need be.

As Landphil has pointed out, maybe the mods done to this part during a CMC don’t make a quantifiable difference, but I would argue running a chopped cab-mounts, without some sort of plate welded on to return some strength to the part, is foolish.

 

I would think a CMC could also almost help in a way. A lot of the companies producing these plates use high quality, thick (3/16”) steel. As long as it is welded properly I feel that it could reinforce the cab mount. The cab mounts are made of a relatively thin piece of metal.

 

With this logic, running bigger tires is a safety plus. If you're worried about cab intrusion, wouldn't it be more difficult for a larger tire to intrude too, since the force is displaced over a greater area?

Sounds like a good arguement for me to go tell the wife I need to sell my 31s and get 33s with a cmc

 

If you want to drive safe anyways, slow the fuck down. Check out the curve for braking distance vs speed. It's not linear, the faster you go, the more space you need for braking by a substantial factor. This can be misleading, and easily result in accidents. https://en.wikipedia.org/wiki/Braking_distance#Total_stopping_distance



If you want to experiment with this, go on an empty highway and stand on the brakes at 65. Now do the same at 85. It takes almost twice the distance and time to stop.

 

I know that these tests are needed and all... but I still hate watching a perfectly good Tacoma meet its bitter end...

 

This one had a shifty transmission and a weeping diff.

 

In that case I hope its burning in hell

 

If you got in an accident that bad a cmc wouldn't matter cause the truck would be totalled