cons of front bumper replacement

[y-knot]

You guy's are putting way to much into this subject. If you want the stupid front bumper then just go get it and bolt it on, if not don't. But don't try and drag all these areas of concern up and pretend your a engineer. I personally don't see wear the heavy front bumper would hurt any of the trucks built in safety functions. The posters before me were correct, the bumper is fastened to the trucks frame and is completely independent of the radiator support, or anything else mounted up front. One thing installing the Buckstop bumper will do is tie the front frame rails together. They supply mounting brackets that are fab'd out of 1/4" steel, these brackets bolt to both the frame rails and the front cross member. The addittion of these braces realy strengthens the front of the truck, it ties both frame rails to the crossmember and then to the bumper. Yes the bumper will probaly hurt who ever it hits, much more then if it was stock. But, isn't that the reason for it's purchase? And yes, I do believe the frame is at risk for more damage in the event of a frontal impact, it has been tied together to form a very solid structure, and while it will provide more protection to the occupants, it will also take more of the load. I for one do not care if the frame gets bent, if I am in an accident I just want to survive with the least amount of personel injury, the truck can and will be replaced.

If you do decide to get the bumper, yes 200-250 lbs of extra weight hung on the front of any vehicle will create more load for the front suspension components to handle. And if you want you front to stay at the same height, you might have to make a few adjustments. After a month or two, when the front end has adjusted to the weight, you might want to switch front shocks, springs, or install a spring spacer, it just depends on the truck and your needs. Most that have bought the bumper, have add another 100lbs by installing a winch hiden in it's front, this may or may not be a route you wish to partake? I did with mine, and really never lost any height. Good luck

 

[RustyJC]

If you want the stupid front bumper then just go get it and bolt it on, if not don't.

I believe I said that, didn't I?

But don't try and drag all these areas of concern up and pretend your a engineer.

Why would you think I'm pretending?



Rusty

 

[thejeepdude]

You guy's are putting way to much into this subject.

Funny, your reply was one of the longest yet!

 

[fkovalski]

Great thread! This is why I enjoy the TDR. I almost bought a BuckStop in the group purchase a while ago but the pocket book did not agree with me. Eventually I will get one as I do believe this it is safer all around especially when protecting the body from big game. Obviously smaller cars will take a greater brunt of an accident, but as stated before- survival is the key.

With all the info being presented here everyone has neglected the primary, main and utmost important factor that has not been mentioned... What color is it!?

 

[DPelletier]

Interesting thread;



Advantages of aftermarket bumper;

- no worries about small dings and scratches from shopping cart buggies, kids bikes or whatever.

- much less chance of damage in low speed impacts

- look cool (subjective)

- most allow for easy mounting of aux lights, winches, etc.



Disadvantages of aftermarket bumper;

- heavier which translates to less payload.

- more weight on front suspension/increased wear

- aerodynamic issues

- may negatively impact engineered safety systems in the event of a major crash.



I think that about covers it. Rusty's comments are valid, whether or not they reflect a real world concern for you is something you need to decide. Personally, I have decided to leave the factory bumper in place after weighing the above issues. If I get into a low speed accident or some other minor front end damage, I will probably wish I had replaced it with something stronger. I'm at 11,555 lbs GVW on 12,000 lbs GVWR without my wife or kids in the truck with my camper loaded. Once my trailer tongue weight is added and passengers get in, I suspect I'm a few hundred pounds over as it is, so the factory bumper stays.



Cheers

Dave

 

[tbrudder]

But don't try and drag all these areas of concern up and pretend your a engineer.

Rusty beat me to it, but yeah--there's a few of us here.



Anyway, back to the kinematics--of course, if you have the same delta-v in half the space, your acceleration has to go up. But using the basic equation makes the assumption that you have a constant rate of acceleration. Now I'm not an automotive engineer, but I have to wonder--just how much energy does the stock bumper absorb? I'm guessing not much.



An example: Say I get a few empty cardboard boxes. Big ones--say refrigerator boxes. Now I duct tape all these together, and hook it to the front of my truck. Now, I have an extra 20 feet of crumple zone. If I drive into a retaining wall at 70 MPH will the boxes really help me? No. You might go from 70 to 69. 8 by in the 20' it takes you get to the bumper, then 69. 8 to 0 in the 2' or so the front end caves in.



Now apply this to the stock bumper. Lets say it gives you an extra 18" before the frame starts to deform. Does that mean that 3/4 of the energy is dissipated before then? I don't think so--I imagine you'll get rid of some of the energy, but not in the amount proportional to the extra distance traveled.



I've seen quite a few car wrecks (four years in EMS), and a few with heavy-bumpered trucks. They definitely came out ahead of the lesser equipped vehicle (as the bumper sticker I once saw says, "YOU are my crumple zone"). Driving into a wall would be a bit of a different story, but I believe that in a serious collision like that, the armor isn't going to give you that much more of a jolt (haven't seen an example of this, though).



And just to nitpick--it won't affect the airbags. If they're programmed to deploy at 5G (just a guess), they'll come out at 5G, regardless of the vehicle setup.



Interesting discussion, nonetheless (at least for some of us)



--Ty

 

[TBrennan]

Excellent points all tbrudder, and is exactly what I was pointing out. You saved me a lot of typing as I was going to use the same type of example (I was thinking styrofoam :-laf ).



Oh, and, count me as the third engineer to weigh in on the matter, although I confess my expertise is software and systems, not mechanical.



One other point I would make is that I believe if you research accidents you'll find the number one reason for serious injury with a properly secured passenger is intrusion into the passenger compartment. With air bags all around (I have the side curtain air bags also), that's the biggest concern.



There's a reason you can watch a 180 mph collision on a NASCAR track and watch the driver walk away usually. It's that "heck for stout" roll cage, it sure ain't the paper thin sheet metal. Go try that with the highest rated passenger car for frontal collision and see how it compares.

 

[JoshPeters]

OK guys. I've got a BHAB (Big Honkin @$$ Bumper) Mine came about due to my truck being parked and hit by a semi at low speeds. $4200 in damage. Do I want to fix all that again. No way. The way I see it is this. That stock front bumper crinkled like cardboard when that semi hit it. Sheet metal is not a bumper. I can pick up my stock bumper with a brush guard, with one arm... and walk around with it. Easily... not really, but can be done. The bumper I have now... . I used a cherry picker to install it. Bolt it to the frame... . nope... welded. Should I do something stupid and crash my truck. I deserve it. If some idiot pulls out infront of me and I hit them..... They deserve it.

The government has taken natural selection away. I'm just trying to help by putting some back! There are WAY to many stupid people in this world!



Josh

 

[RustyJC]

There's a reason you can watch a 180 mph collision on a NASCAR track and watch the driver walk away usually. It's that "heck for stout" roll cage, it sure ain't the paper thin sheet metal. Go try that with the highest rated passenger car for frontal collision and see how it compares.

To overgeneralize once again, the cell around the driver needs to be stiff. Everything else needs to be soft. The energy is dissipated in deformation of the soft stuff which also increases the "s" (distance) factor involved in deceleration. As NASCAR has learned, stiff chassis are what killed Petty and Earnhardt - the peak g forces fractured the base of their skulls as their bodies (being strapped to the car) slowed at the same rate as the car while their heads (sans HANS devices) kept going at Vo, even though the car or the crash didn't look that bad (in Earnhardt's case).



If you go back and read my post wherein I offered the textbook formula for calculating acceleration given velocities and distance, I believe I offered the disclaimer that the peak acceleration will be higher than the average acceleration value that the equation yields. The deceleration forces in a collision aren't constant or even linear, and I never postulated that they were, but the formula I offered was intended to provide a tool for non-engineers to play with the numbers and see how reducing crush space increases the deceleration experienced in a collision. Please forgive me if I oversimplified.



Rusty

 

[RustyJC]

... but I have to wonder--just how much energy does the stock bumper absorb? I'm guessing not much.



An example: Say I get a few empty cardboard boxes. Big ones--say refrigerator boxes. Now I duct tape all these together, and hook it to the front of my truck. Now, I have an extra 20 feet of crumple zone. If I drive into a retaining wall at 70 MPH will the boxes really help me? No. You might go from 70 to 69. 8 by in the 20' it takes you get to the bumper, then 69. 8 to 0 in the 2' or so the front end caves in.

Ty,



I understand what you're saying, but trust me, the front ends of modern vehicles are engineered for controlled rates of crush. These engineers design for stuff like the NHTSA 40 MPH offset frontal crash tests, etc. You or I may not think that much kinetic energy is dissipated by the crumpling sheet metal, but those engineers have designed and tested it to a gnat's eyelash, I promise you! And tbrennan - they are using styrofoam on racetrack guardrails just for this reason!



Rusty

 

[EBottema]

However, if you get into a major accident, the force might not be distributed as evenly as the truck was designed to from the factory!

Did you rear my whole paragragh?



Doesn't the bumper act as a frame crossmember?



Erik

 

[Jetson]

I'm not an engineer. I can't see the stock bumper providing much crumple zone. It bolts to the frame with two steel struts that protrude about 6" where they attach to very thin flat metal (the bumper). The only thing to crumple seems to be the attaching struts. I wonder about the significance of that.



I'm sure I don't have to worry though, since my bumper is made out of beer cans, it should crumple just fine.

 

[thejeepdude]

I think this would be a good test to put the final word on all this hypothesizing:



1. Get 2 identical RAM 3500's

2. Keep one stock and install a BHB (Big Honkin Bumper) on the other.

3. Get two rednecks to run head on into each other with the cruise set at about 45mph.

4. The safest truck is decalred by the quickie mart employee after observing which driver is able to run into the store the quickest and down a case of Pabst.



I want to be in the truck with the BHB.

 

[Cummins Pilot]

My front end only dropped about 1/2 an inch after I installed my Buckstop with a winch. My mileage hasn't dropped any. Hand calculations and the trucks computer don't show it. I know there is a drop but not noticable. The front end of my truck now weighs in at 4889#. I'm sure the track bar, ball joints, tie rods, tires, bearings, and everything else will wear faster but I'll take that. The added benifits of having a winch enclosed and aux lights also enclosed are wonderful. Also the hitch reciever in the front will come in handy. My truck also sees a fair amount of off road work. From logging to playing once in a while or rescuing someone it was needed.



Plus I think it looks really good. And the best part of all is that the better half thinks its cool.

 

[tbrudder]

I understand what you're saying, but trust me, the front ends of modern vehicles are engineered for controlled rates of crush.

Perhaps I should have been a bit more careful in my analysis--I understand the design philosophy behind crumple zones, and I never meant to imply you were wrong on this point. My thinking, though, is that in a collision severe enough to warrant the crumpling of the front end, it will crumple regardless of the bumper.



The frame itself has to be designed to crumple along with the sheet metal---otherwise, the stock bumper and radiatior would be destroyed with very little energy dissipated, then the frame rails would come in contact with the wall/heavy thing/etc. , and then we're back to your stop-in-a-hurry scenario.



In a low-energy collision (such as a deer-strike), the superbumper prevents the impacted object from deforming weak body panels by deflecting it. In a mid-energy collision (guy in the Honda not paying attention), it does the same thing by causing the other vehicle to crumple more than it would otherwise (his vehicle dissipates your energy by crumpling into nothing). In a high-energy collision (look out for that wall), the frame begins to deform, along with the front end of the vehicle.



At least that's my take on it. Again, I'm in the airplane business, so I'm theorizing on the finer points of this discussion, and if someone actually knows better...



I know there's plenty of fire/EMS guys on here--anyone seen a truck like this hit something solid? I'd be interested in what it looked like and what condition the people were in for a bit of empirical evidence. I've seen plenty of small cars crushed by SUVs, a few vehicles run under semitrailers, and a half-ton Chevy t-boned by a freight train (hint: CSX won that fight), but in general, people driving heavy trucks seem less likely to run head on into solid objects than other drivers, in my experience.



--Ty

 

[TBrennan]

You provide two examples (Earnhardt and Petty) where the system fails and we can witness 1 or 2 week for the last 20 years where it worked. Take any of those catastrophic wrecks and replace the vehicle with the best engineered Volvo and you have a dead driver 90% of the time.



I could agree that there are certain fairly rare (high speed impact, immovable object) types of collisions where more trauma could in theory be caused by the heavy duty front bumpers, but I feel quite certain in stating that in the majority of all accidents seen by the average driver we are much better off with a heavy duty bumper than with out. Even air bags kill people, but they save more people than they injure.



I see tbrudder has responded while I type this, lol. Once I again I agree with his conclusions.

 

[EBottema]

I'd also like to add... The California Highway Patrol runs Ford Expeditions with a reunel front bumpers. I dont think they would be running those if they felt the officers were in danger since they dont want any lawsuits from dead officer's families.



Erik

 

[John - K5AWO]

This has been one awesome thread.



I wish to congratulate all of the correspondents for providing the pro and the con, AND keeping it all in a civil protocol.



I do wish all threads were so neatly tucked with info for consideration by those of us who want to learn more.

 

[rbattelle]

An interesting thread. Personally, I think the debate is purely academic. An accident bad enough to damage the frame and crush any crumple zones with or without a Buckstop is going to cause so much carnage that the liklihood of a total loss is high.



-Ryan

 

[JCrockett]

Very good thread, only thing I want to add is I love MY BHB!!!