Bumpers - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > JK Jeep Wrangler Forum > JK General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 12-23-2013, 09:01 PM   #1
Jeeper
 
Join Date: Dec 2013
Posts: 77
Bumpers

Hi Folks,

New to the forum. Been a jeep owner for 30 years. just became a 2014 JKUR owner a week ago. Been researching upgrades and my current conundrum is bumpers. In reviewing this and other forums it appears that there are numerous misunderstandings about bumpers and crush cans in particular.

Many seem to feel that the crush cans are some federal safety mandate, which indirectly they are I suppose. No one expects the airbag to go off at low speed. However, there is more to the story.

There is a requirement that a 5mph or less collision does not cause significant damage to the vehicle. Unfortunately with a heavy solid mounted bumper, if you happen to hit it at the frame mount (or anywhere if it is a stiff enough bumper), the stiff load path to the rest of the vehicle can cause a significant shock to the vehicle and set off the airbags. In the JKs this would represent significant damage, as several interior parts will need replaced along with the airbags themselves.....$$$$$

I have seen posts saying that the crush cans offer no such protection if you hit the center of the bumper. This is actually true, but also irrelevant in many cases. On the stock bumper and the rather thin AEV stamped bumper if you hit the middle of the bumper it is no where near as stiff a load path and will not transfer the same energy to the frame of the vehicle. The crush cans really are there in the unfortunate case that you impact something at the bumper frame interface and otherwise not active.

Realistically, with the associated cost, inconvenience and potential injury with airbags, no one should want them to go off unless they will actually offer increased protection, which typically means increased speeds.

All that said, my questions are :

1) Anyone have the airbags deploy and know the cost of replacement in both money and time?

2) Anyone seen the difference in impact speed that will cause airbag deployment with ANY aftermarket bumper over the stock one?

Thanks,
hbski

hbski is offline   Quote Quick Reply
Old 12-23-2013, 09:11 PM   #2
The Bad Guy

WF Supporting Member
 
daggo66's Avatar
 
Join Date: May 2009
Location: NJ exile living in Baltimore
Posts: 22,079
Bumpers have nothing to do with air bag deployment. They do not go off based on impact. They deploy based on the sudden deceleration as a result of the impact. If you want to know how much an airbag costs to replace contact your local body shop.

Do you plan on being involved in a frontal collision? Do you not carry insurance?

__________________
Tom

"I've got two things in this world, my balls and my word and I don't break them for no one."
daggo66 is offline   Quote Quick Reply
Old 12-23-2013, 10:24 PM   #3
Jeeper
 
Join Date: Dec 2013
Posts: 77
Quote:
Originally Posted by daggo66 View Post
Bumpers have nothing to do with air bag deployment. They do not go off based on impact. They deploy based on the sudden deceleration as a result of the impact. If you want to know how much an airbag costs to replace contact your local body shop.

Do you plan on being involved in a frontal collision? Do you not carry insurance?

Let's not be ridiculous here. Of course the answers to those questions are No and Of course respectively. Neither are the point. But hey thanks for NOT adding value to the discussion.

If I have to choose between a nuisance crash triggering my airbags at 4.5mph or 6mph, I will choose the 6mph hour for many reasons. And since it is a matter of a few hundred dollars at most between a non-crush can bumper and a crush can bumper it really is just a matter of whether I want to deal with the potential injury and hassle of the airbags going off in a less than ideal situation. In the simplest case the bumper only needs replaced, not my entire upper dash and steering wheel which I'm guessing are more expensive than the bumper to replace AND more of a hassle.

While yes, the bumper is not directly connected to the sensors which trigger airbag deployment, the airbags deploy based on the sensors reading which is very much influenced by the structure being contacted and the entirety of the vehicle dynamics at the time of impact. Vehicle dynamics are directly influenced by the structure of the vehicle including the bumper and to what is attached. Crush cans are designed and placed, so that if the bumper happens to contact something at the stiffest point relative to it's attachment, some energy can be dissipated by the deformation of the crush-can rather than being directly transferred to the frame of the vehicle and thus decreasing the likelihood of airbag deployment.

All that said, given the free availability of information these days why wouldn't I try to inform myself as to all of the potential risks and factors associated with upgrading my vehicle. Unfortunately my search thus far has not produce a definitive amount of information to overwhelmingly influence the decision, AND brought to light many common misunderstandings as well.

AND, I certainly understand deciding to have a certain bumper over another based on utility, or just because you REALLY REALLY like it......if safety and or cost were my only concern, I wouldn't have chosen the JKUR in the first place.

Regards,
Hbski
hbski is offline   Quote Quick Reply
Old 12-23-2013, 11:48 PM   #4
Jeeper
 
atreggie's Avatar
 
Join Date: Aug 2013
Location: West Linn, OR
Posts: 164
I'm guessing the difference in deceleration based on which JK bumper you have is minimal at best so what most people consider is utility and looks. Based on your rather lengthly comments it sounds like you have a pretty firm understanding of what you're looking for, but the differences between bumpers and air bag deployment are probably so small that most people don't factor that into their decision.
__________________
1977 CJ7 Golden Eagle 'Limited Edition' <-- I miss her
1998 TJ Sahara <-- Sold
2013 JKU Rubicon <-- DD
atreggie is offline   Quote Quick Reply
Old 12-24-2013, 10:53 AM   #5
Race Car Dave

WF Supporting Member
 
NFRs2000NYC's Avatar
 
Join Date: Nov 2011
Location: NYC
Posts: 6,927
The airbags will not deploy because of the bumper, but rather, the deceleration force. You are 99% going to hit (if you ever hit anything) something soft (like another vehicle) in which case, the crush cans won't matter. They MAY slightly decrease the impact force if you hit something solid (Oak tree, K rail, etc) but that would literally be a 1-2mph difference at best. The odds of crush cans assisting in retarding enough force to keep the sensors from triggering would be astronomical...so don't worry about it. Run whatever bumper you like. The more solid the bumper, the more it will prevent damage to the jeep.
NFRs2000NYC is offline   Quote Quick Reply
Old 12-24-2013, 11:27 AM   #6
The Bad Guy

WF Supporting Member
 
daggo66's Avatar
 
Join Date: May 2009
Location: NJ exile living in Baltimore
Posts: 22,079
Quote:
Originally Posted by hbski View Post
All that said, given the free availability of information these days why wouldn't I try to inform myself as to all of the potential risks and factors associated with upgrading my vehicle. Unfortunately my search thus far has not produce a definitive amount of information to overwhelmingly influence the decision, AND brought to light many common misunderstandings as well.
Simple, you prefer to talk instead of listen. You prefer to use 10 words instead of 5. Less writing, more reading.
__________________
Tom

"I've got two things in this world, my balls and my word and I don't break them for no one."
daggo66 is offline   Quote Quick Reply
Old 12-24-2013, 11:31 AM   #7
Jeeper
 
Chrimbler's Avatar
 
Join Date: Jan 2012
Posts: 417
Quote:
Originally Posted by daggo66 View Post
Simple, you prefer to talk instead of listen. You prefer to use 10 words instead of 5. Less writing, more reading.
Chrimbler is offline   Quote Quick Reply
Old 12-24-2013, 11:56 AM   #8
kik
Jeeper
 
kik's Avatar
 
Join Date: Dec 2008
Posts: 4,371
Images: 1
If you're that concerned about it, which it is your choice to be, go with the Mopar off road front bumper. I have one with a winch and "I" like it. It might not be a popular choice but that's not a concern of mine. Mine does have crush cans but because it does didn't enter into my decision. With any steel off road bumper, if you come into contact with another vehicle their's will be significantly "crushed" so you don't have to worry about having cans.
kik is offline   Quote Quick Reply
Old 12-24-2013, 05:42 PM   #9
Jeeper
 
Join Date: Dec 2013
Posts: 77
Quote:
Originally Posted by daggo66 View Post
Simple, you prefer to talk instead of listen. You prefer to use 10 words instead of 5. Less writing, more reading.
Apparently everyone needs to read more. I asked specific questions in the original post, but while many have chimed in, no one presented even anecdotal evidence to help out with my questions. Nor have I seen them answered in other bumper threads and why I posed them in the first place.
hbski is offline   Quote Quick Reply
Old 12-24-2013, 05:56 PM   #10
Jeeper
 
RoadGlide's Avatar
 
Join Date: Dec 2012
Location: Way north of Texas
Posts: 6,592
Quote:
Originally Posted by hbski View Post
Apparently everyone needs to read more. I asked specific questions in the original post, but while many have chimed in, no one presented even anecdotal evidence to help out with my questions. Nor have I seen them answered in other bumper threads and why I posed them in the first place.
i see some specific questions, but i might point out that the best way to get people here to answer your questions might be to not start off with telling us that we have misconceptions...

...and then later calling us ridiculous...and accusing one of not adding value to a discussion...

i have found that this forum has a wealth of knowledge to offer, and does so readily...humble questions will get 10 if not a hundred answers...citing your knowledge base and trying to impress the people you are asking questions of...well...might not get you the intended results...

welcome to the forum...enjoy...
RoadGlide is offline   Quote Quick Reply
Old 12-24-2013, 06:53 PM   #11
Supporting Member

WF Supporting Member
 
HunterTheBeagle's Avatar
 
Join Date: Jul 2012
Location: Central Pennsylvania
Posts: 609
Quote:
Originally Posted by hbski View Post
Apparently everyone needs to read more. I asked specific questions in the original post, but while many have chimed in, no one presented even anecdotal evidence to help out with my questions. Nor have I seen them answered in other bumper threads and why I posed them in the first place.
If many have chimed in yet your question has not been answered, then maybe the question is unclear.
__________________
2012 Crush JK Rubicon. Teraflex 2.5" coil w/fox shocks & 1" rear TF spacers. TF monster front and rear track bar. 315 75r16 duratracs on level 8 zx wheels. LOD armor lite mid w/engo 10000s. Lots of other goodies.
HunterTheBeagle is online now   Quote Quick Reply
Old 12-24-2013, 08:47 PM   #12
Jeeper
 
Join Date: Dec 2013
Posts: 77
Quote:
Originally Posted by HunterTheBeagle View Post
If many have chimed in yet your question has not been answered, then maybe the question is unclear.
1) Anyone have the airbags deploy and know the cost of replacement in both money and time?

2) Anyone seen the difference in impact speed that will cause airbag deployment with ANY aftermarket bumper over the stock one?

they seem pretty clear to me
hbski is offline   Quote Quick Reply
Old 12-24-2013, 08:49 PM   #13
Sponsoring Vendor
 
JPi1's Avatar
 
Join Date: Nov 2011
Location: So Cal
Posts: 4,542
Insurance is the answer.
__________________
32215 Dunlap Blvd.
Yucaipa, CA
92399
877-795-JEEP
Www.jeeperformanceinc.com
www.facebook.com/Jeeperformanceinc
JPi1 is offline   Quote Quick Reply
Old 12-24-2013, 09:01 PM   #14
Jeeper
 
RoadGlide's Avatar
 
Join Date: Dec 2012
Location: Way north of Texas
Posts: 6,592
Quote:
Originally Posted by hbski View Post
1) Anyone have the airbags deploy and know the cost of replacement in both money and time?

2) Anyone seen the difference in impact speed that will cause airbag deployment with ANY aftermarket bumper over the stock one?

they seem pretty clear to me
again...you are demanding answers...last i looked nobody here is paid to answer you...

loose the attitude friend or prepare to be ignored...
RoadGlide is offline   Quote Quick Reply
Old 12-24-2013, 09:04 PM   #15
The Bad Guy

WF Supporting Member
 
daggo66's Avatar
 
Join Date: May 2009
Location: NJ exile living in Baltimore
Posts: 22,079
Here ate your clear concise answers.

1.) No

2.) No

As I stated in my first post, you can get the replacement cost from any autobody shop.

You are not getting the responses you seek because aftermarket bumpers are simply not a factor in abnormal air bag deployment. We are Wrangler owners. This is not the testing center for comparison of airbag speed deployment of stock vs. aftermarket bumpers.
__________________
Tom

"I've got two things in this world, my balls and my word and I don't break them for no one."
daggo66 is offline   Quote Quick Reply
Old 12-24-2013, 09:12 PM   #16
Jeeper
 
Join Date: Dec 2013
Posts: 77
Quote:
Originally Posted by RoadGlide View Post
i see some specific questions, but i might point out that the best way to get people here to answer your questions might be to not start off with telling us that we have misconceptions...

...and then later calling us ridiculous...and accusing one of not adding value to a discussion...

i have found that this forum has a wealth of knowledge to offer, and does so readily...humble questions will get 10 if not a hundred answers...citing your knowledge base and trying to impress the people you are asking questions of...well...might not get you the intended results...

welcome to the forum...enjoy...
Hi, thanks for the welcome and the advice.

I find it hard to believe that most people don't find these questions just a bit ridiculous:

"Do you plan on being involved in a frontal collision? Do you not carry insurance? "

And certainly not helpful, and my response was only to the person making the ridiculous statement.

As for my knowledge, yes I have a bit in the area of structural mechanics and dynamics, however, I wasn't trying to impress anyone. I was trying to be helpful about the link between vehicle dynamics and airbag deployment and how bumpers can indeed influence the speed at which your airbag(s) will deploy. How much I do not know as I don't have any supporting information on that. However, it is likely not a trivial difference or they wouldn't bother putting them in stock bumpers and the few available aftermarket ones with them either.

The crush cans are a protection feature designed to reduce unnecessary shock to the vehicle frame and as such are placed right at the frame connection which is the stiffest load path from the bumper to the frame. Hitting this point without the cans transmits the impact energy directly to the frame and hence the rest of the vehicle, including passengers and the airbag sensors. That's not my knowledge, that's just the laws of physics.
hbski is offline   Quote Quick Reply
Old 12-24-2013, 09:14 PM   #17
Jeeper
 
Join Date: Dec 2013
Posts: 77
Quote:
Originally Posted by RoadGlide View Post
again...you are demanding answers...last i looked nobody here is paid to answer you...

loose the attitude friend or prepare to be ignored...
how exactly did I demand?

How many other posts do people make were several people say, hey OPs question was........please get back on topic????
hbski is offline   Quote Quick Reply
Old 12-24-2013, 09:47 PM   #18
Race Car Dave

WF Supporting Member
 
NFRs2000NYC's Avatar
 
Join Date: Nov 2011
Location: NYC
Posts: 6,927
Quote:
Originally Posted by hbski View Post
Apparently everyone needs to read more. I asked specific questions in the original post, but while many have chimed in, no one presented even anecdotal evidence to help out with my questions. Nor have I seen them answered in other bumper threads and why I posed them in the first place.
I answered your question VERY specifically. If you chose to ignore the answer, that's on you. Crush cans do nothing unless you are hitting a solid object. Unless you hit a solid object fast enough, it will not transfer enough energy to trip the airbag sensors. If you do hit the object fast enough, then the crush cans don't matter.
NFRs2000NYC is offline   Quote Quick Reply
Old 12-24-2013, 09:55 PM   #19
Race Car Dave

WF Supporting Member
 
NFRs2000NYC's Avatar
 
Join Date: Nov 2011
Location: NYC
Posts: 6,927
Quote:
Originally Posted by hbski View Post
1) Anyone have the airbags deploy and know the cost of replacement in both money and time?

2) Anyone seen the difference in impact speed that will cause airbag deployment with ANY aftermarket bumper over the stock one?

they seem pretty clear to me
1) Airbags run approximately $1000 a piece, and the installation cost+new dash will probably run close to the same amount.

2) That would require a single person to have TWO accidents, so that's unlikely. Crush cans are used to minimize damage to a vehicle. The federal safety standard FMVSS215 was created to minimize the cost to the consumer in minor impacts. Crush cans were designed by manufactures to absorb the "damage" and lower repair costs for consumers/insurance companies. This used to be called the "5mph impact test." It has since been reduced to 2mph. Without crushcans, the impact forces would distribute into the bodywork, causing it to buckle, which violated FMVSS215

Quote:
Phase I and II refer to a two-phased rulemaking action on bumper requirements. Phase I of the standard became effective on September 1, 1978 for passenger cars beginning with MY 1979. It incorporated the FMVSS 215 safety criteria, and added new performance criteria which prohibited damage to all exterior vehicle surfaces. For MY 1979, the standard required that there be no damage to safety-related parts and exterior surfaces not involving the bumper system(e.g., sheet metal; lamps; and fuel, exhaust and cooling systems) with damage to the facebar and its fasteners at impact test speed of 5 mph front and rear impacts with barrier and pendulum; 3 mph corner impact with pendulum.
Quote:
The agency set the protection standard at 2� mph after studying the comparable repair costs of a 5 mph bumper that has higher energy absorption capacity along with additional cost and weight.
After public hearings involving all parties, including consumers and manufacturers, NHTSA concluded that the public is assured of the largest net benefits under a standard that requires 2� mph protection for both the front and rear bumpers.
Bumper Questions and Answers

In short, the crush cans have absolutely NOTHING to do with the safety of a vehicle, they are there solely to minimize the cost of minor collision damage.

Is that specific enough?
NFRs2000NYC is offline   Quote Quick Reply
Old 12-24-2013, 09:58 PM   #20
The Bad Guy

WF Supporting Member
 
daggo66's Avatar
 
Join Date: May 2009
Location: NJ exile living in Baltimore
Posts: 22,079
Bumper Questions and Answers

The car bumper is designed to prevent or reduce physical damage to the front and rear ends of passenger motor vehicles in low-speed collisions. Automobile bumpers are not typically designed to be structural components that would significantly contribute to vehicle crashworthiness or occupant protection during front or rear collisions. It is not a safety feature intended to prevent or mitigate injury severity to occupants in the passenger cars. Bumpers are designed to protect the hood, trunk, grille, fuel, exhaust and cooling system as well as safety related equipment such as parking lights, headlamps and taillights in low speed collisions.
__________________
Tom

"I've got two things in this world, my balls and my word and I don't break them for no one."
daggo66 is offline   Quote Quick Reply
Old 12-24-2013, 10:00 PM   #21
The Bad Guy

WF Supporting Member
 
daggo66's Avatar
 
Join Date: May 2009
Location: NJ exile living in Baltimore
Posts: 22,079
Ha! Great minds think alike!
__________________
Tom

"I've got two things in this world, my balls and my word and I don't break them for no one."
daggo66 is offline   Quote Quick Reply
Old 12-24-2013, 10:08 PM   #22
Race Car Dave

WF Supporting Member
 
NFRs2000NYC's Avatar
 
Join Date: Nov 2011
Location: NYC
Posts: 6,927
Quote:
Originally Posted by daggo66 View Post
Ha! Great minds think alike!
Must be the NJ water.
NFRs2000NYC is offline   Quote Quick Reply
Old 12-25-2013, 01:08 AM   #23
Jeeper
 
Join Date: Dec 2013
Posts: 77
Quote:
Originally Posted by NFRs2000NYC View Post
1) Airbags run approximately $1000 a piece, and the installation cost+new dash will probably run close to the same amount.

2) That would require a single person to have TWO accidents, so that's unlikely. Crush cans are used to minimize damage to a vehicle. The federal safety standard FMVSS215 was created to minimize the cost to the consumer in minor impacts. Crush cans were designed by manufactures to absorb the "damage" and lower repair costs for consumers/insurance companies. This used to be called the "5mph impact test." It has since been reduced to 2mph. Without crushcans, the impact forces would distribute into the bodywork, causing it to buckle, which violated FMVSS215





Bumper Questions and Answers

In short, the crush cans have absolutely NOTHING to do with the safety of a vehicle, they are there solely to minimize the cost of minor collision damage.

Is that specific enough?
Thanks. Good info there!

I will still say that I still would rather NOT have the airbag deploy unnecessarily. They can cause other injuries, plus as shown above incur significant cost and potential downtime for the vehicle.

Thanks again.


To everyone, I didn't come here to argue and if I stepped on anyones toes, my apologies.....MERRY CHRISTMAS & HAPPY HOLIDAYS folks!

Cheers,
Hbski
hbski is offline   Quote Quick Reply
Old 12-25-2013, 01:57 AM   #24
Jeeper
 
Jancie's Avatar
 
Join Date: Dec 2013
Location: Salt Lake City, Utah
Posts: 518
Personally I am not concerned with airbags deploying as I just totalled a vehicle going 70 mph hitting a big buck - tore off the entire right side fender, buckled the hood, extensive damage and my airbag did not deploy. Why? I have no clue as I hit the deer with the right side of my front bumper. Fortunately I was not hurt. Unfortunately the buck died.

I would much rather put on an aftermarket steel bumper and protect the front end of my jeep than depend on the plastic bumper that it comes with.

My 02. worth.
Jancie is offline   Quote Quick Reply
Old 12-25-2013, 09:06 AM   #25
The Bad Guy

WF Supporting Member
 
daggo66's Avatar
 
Join Date: May 2009
Location: NJ exile living in Baltimore
Posts: 22,079
Quote:
Originally Posted by hbski View Post
Thanks. Good info there!

I will still say that I still would rather NOT have the airbag deploy unnecessarily. They can cause other injuries, plus as shown above incur significant cost and potential downtime for the vehicle.

Thanks again.


To everyone, I didn't come here to argue and if I stepped on anyones toes, my apologies.....MERRY CHRISTMAS & HAPPY HOLIDAYS folks!

Cheers,
Hbski
So now we know what the REAL question is. The answer is that aftermarket bumpers will not cause your air bag to deploy unnecessarily. If it deploys, it's because it needed to. The whole injury from airbags thing is over-played. Any injuries that may happen due to airbag deployment would be much worse without one. Just like seatbelts that cause bruises and broken ribs, yet save your life.

It's been a while, but we have discussed the crush can thing ad nauseam here. You will find that direct question will get you direct answers. If you look back at the original post, the entire issue was based off of a misconception:

Quote:
There is a requirement that a 5mph or less collision does not cause significant damage to the vehicle. Unfortunately with a heavy solid mounted bumper, if you happen to hit it at the frame mount (or anywhere if it is a stiff enough bumper), the stiff load path to the rest of the vehicle can cause a significant shock to the vehicle and set off the airbags. In the JKs this would represent significant damage, as several interior parts will need replaced along with the airbags themselves.....$$$$$
Although the very first post in reply, which was mine, accurately answered the question, you dismissed it as "ridiculous." I'll let you slide this time.

You also mentioned that you have owned Jeeps for 30 years. What were they? Any pictures of them? The only surviving picture of my first is my avatar picture.
__________________
Tom

"I've got two things in this world, my balls and my word and I don't break them for no one."
daggo66 is offline   Quote Quick Reply
Old 12-26-2013, 01:48 PM   #26
Jeeper
 
Join Date: Dec 2013
Posts: 77
Quote:
Originally Posted by daggo66 View Post
..........They do not go off based on impact. They deploy based on the sudden deceleration as a result of the impact...........
actually you yourself indicated that it was as a result of the impact. The deceleration of the airbag sensor will be determined by the load path that causes the deceleration....including the bumper. And this was NOT what I was indicating was ridiculous.

Quote:
Originally Posted by daggo66 View Post
Do you plan on being involved in a frontal collision? Do you not carry insurance?
these were ridiculous questions.


Quote:
Originally Posted by daggo66 View Post
Bumpers have nothing to do with air bag deployment......
Is a false statement. Everything in the load path from the impact point to the sensor which signals deployment influences the conditions under which the airbag will deploy. REFERENCE: not me, but rather the laws of physics


As I mentioned earlier, there really is no need to argue the point anymore. no one has the information readily available. I wasn't looking for a definitive answer on bumpers, I was looking for supporting information which is apparently not available which is fine.

WHETHER an aftermarket bumper can alter the impact conditions of airbag deployment was not my question. IT CAN. What that difference is and the consequences were the basis for my questions. Obviously if given the same impact conditions for either bumper makes a trivial difference then it's not worth worrying about, but if for the typical fender bender it can make a difference of even a couple of mph (say 4mph vs 6mph for the otherwise same collision) then it is worth considering.

Quote:
Originally Posted by daggo66 View Post
It's been a while, but we have discussed the crush can thing ad nauseam here. You will find that direct question will get you direct answers.
not necessarily as i asked direct questions and many including yourself chose to essentially tell me they didn't matter and in fact did not give any direct answers.

ONE person answered about the airbag cost and no one answered about differing deployment conditions, but still chose to tell me bumpers don't matter.

I read many of the bumper threads and that is one of the reasons I chose to post. Because of the the misconception that bumpers don't influence airbag deployment. It MAY be trivial, I cannot say, but saying that they don't or can't is incorrect. NO ONE here has given proof otherwise either

Quote:
Originally Posted by daggo66 View Post
You also mentioned that you have owned Jeeps for 30 years. What were they? Any pictures of them? The only surviving picture of my first is my avatar picture.
Thanks for asking. I've owned 4 CJ-7s, an SJ, a XJ and still own my '85 CJ-7 and my '14 JKUR. No pictures at present of most. The '85 , as all CJs are, is definately a work in progress! Has the 6 cylinder and a Mopar MPI kit waiting to be installed in my garage......one of these days Ill find the time to do it. Did manage to find the time to finally put my 4" black Diamond lift on it (got one of the last ones I think) a few years ago along with cragars and 32x11.5 BF Goodrich M/T tires. Still have a couple of boxes of parts to install on it as well.....alot of polished stainless stuff, but currently has the rustic look, which I like, may just clearcoat the jacked up paint and sell all the polished stainless...LOL


No offense meant for any of the above, just simply answering accusations and questions lobbed in my direction. Hope everyone is having a wonderful holiday and has a Happy New Year!!!!
hbski is offline   Quote Quick Reply
Old 12-26-2013, 02:08 PM   #27
Race Car Dave

WF Supporting Member
 
NFRs2000NYC's Avatar
 
Join Date: Nov 2011
Location: NYC
Posts: 6,927
Quote:
Originally Posted by hbski View Post
actually you yourself indicated that it was as a result of the impact. The deceleration of the airbag sensor will be determined by the load path that causes the deceleration....including the bumper. And this was NOT what I was indicating was ridiculous.



these were ridiculous questions.




Is a false statement. Everything in the load path from the impact point to the sensor which signals deployment influences the conditions under which the airbag will deploy. REFERENCE: not me, but rather the laws of physics


As I mentioned earlier, there really is no need to argue the point anymore. no one has the information readily available. I wasn't looking for a definitive answer on bumpers, I was looking for supporting information which is apparently not available which is fine.

WHETHER an aftermarket bumper can alter the impact conditions of airbag deployment was not my question. IT CAN. What that difference is and the consequences were the basis for my questions. Obviously if given the same impact conditions for either bumper makes a trivial difference then it's not worth worrying about, but if for the typical fender bender it can make a difference of even a couple of mph (say 4mph vs 6mph for the otherwise same collision) then it is worth considering.



not necessarily as i asked direct questions and many including yourself chose to essentially tell me they didn't matter and in fact did not give any direct answers.

ONE person answered about the airbag cost and no one answered about differing deployment conditions, but still chose to tell me bumpers don't matter.

I read many of the bumper threads and that is one of the reasons I chose to post. Because of the the misconception that bumpers don't influence airbag deployment. It MAY be trivial, I cannot say, but saying that they don't or can't is incorrect. NO ONE here has given proof otherwise either



Thanks for asking. I've owned 4 CJ-7s, an SJ, a XJ and still own my '85 CJ-7 and my '14 JKUR. No pictures at present of most. The '85 , as all CJs are, is definately a work in progress! Has the 6 cylinder and a Mopar MPI kit waiting to be installed in my garage......one of these days Ill find the time to do it. Did manage to find the time to finally put my 4" black Diamond lift on it (got one of the last ones I think) a few years ago along with cragars and 32x11.5 BF Goodrich M/T tires. Still have a couple of boxes of parts to install on it as well.....alot of polished stainless stuff, but currently has the rustic look, which I like, may just clearcoat the jacked up paint and sell all the polished stainless...LOL


No offense meant for any of the above, just simply answering accusations and questions lobbed in my direction. Hope everyone is having a wonderful holiday and has a Happy New Year!!!!
Ok, if you are looking to get EXTREMELY technical.....

The most common threshhold for the most commonly used airbag sensors are 7gs. For comparison sake, the fastest cars out there rocketing 0-60 will generate approximately 0.6gs. A top fuel dragster accelerating from 0-302mph will generate around 4.6gs. The worlds craziest rollercoasters will generate 4gs.

ON AVERAGE, to generate 7gs inside a motor vehicle, you would need to hit a SOLID OBJECT (like a 4 foot wide oak tree or a K rail) at 15mph, or a soft object (like another vehicle) at 25-30mph.

Now, adding a solid steel bumper would have zero effect on the soft object hit, but it WOULD have a minor effect on a solid object hit. Without actually running crash tests, it can only be estimated, but it would probably take 1-2mph LESS speed to achieve the 7gs...so instead of 15mph, you MIGHT trip the sensor at 14 or 13mph. If you hit a solid odject doing 16mph, then either the factory bumper or the steel bumper would transfer enough g's to trip the sensor, so the discussion is moot.

Having said that, BOTH incidents would still require you to hit that 7g mark, a force that the governing bodies deem suffient to require the use of an airbag. So even IF you tripped your airbag at 13mph rather than 15mph, your body doesn't care, as the load presented is still 7gs.

Finally, crashing is a game of chance and probability. The chances of you striking soft object like another vehicle are substantially higher (1000%+) than you hitting an oak tree. In those situations, steel will help far more than plastic (crush cans will be irrelevant, as we stated,they are not designed to reduce g forces by any meaningful amounts, but rather to mitigate damage.) The next most common crash (still a soft object) is an animal strike, and again, crush cans are irrelevant, and steel with proper stinger/pre-runner will not only save you from having the animal flop onto your hood, but it will also save your jeep.

IF the airbag deployed on a hit, it is because it NEEDED to. There is no such thing as an "unnecessary deployment" because the sensors work off gs...regardless of if its a 1mph crash or a 100mph crash...if there are sufficient G forces to cause bodily harm (and trip the sensor) they will pop....and crush cans have absolutely NOTHING to do with it.

You literally have a much better chance of having a 747 crash on top of your jeep than crush cans ever helping you.
NFRs2000NYC is offline   Quote Quick Reply
Old 12-26-2013, 03:10 PM   #28
Supporting Member

WF Supporting Member
 
iDream's Avatar
 
Join Date: Aug 2013
Posts: 32
I swerved my jk to avoid a kid on a snow saucer. My speed was from 8 to 15 mph. With my dog in the front seat we hit a street sign pole. I have the oem bumper and the airbags did not deploy. Cost to repair jeep $3300. I will pay the $250. deductible. Every accident is different. Insurance is the answer. I hate to think what could have happened if I had not ditched jeep.
iDream is offline   Quote Quick Reply
Old 12-26-2013, 04:03 PM   #29
Race Car Dave

WF Supporting Member
 
NFRs2000NYC's Avatar
 
Join Date: Nov 2011
Location: NYC
Posts: 6,927
Quote:
Originally Posted by iDream View Post
I swerved my jk to avoid a kid on a snow saucer. My speed was from 8 to 15 mph. With my dog in the front seat we hit a street sign pole. I have the oem bumper and the airbags did not deploy. Cost to repair jeep $3300. I will pay the $250. deductible. Every accident is different. Insurance is the answer. I hate to think what could have happened if I had not ditched jeep.
If you had a steel bumper, you would have scratched the finish on it, and thats it...total damage...$4 in touch up paint.
NFRs2000NYC is offline   Quote Quick Reply
Old 12-26-2013, 04:53 PM   #30
Supporting Member

WF Supporting Member
 
iDream's Avatar
 
Join Date: Aug 2013
Posts: 32
Your right... and so I will replace with a Hanson Bumper.

iDream is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



logo carid shop wrangler parts carid fender flares custom wheels store avs deflectors at carid
» Rates
Get low rates on auto insurance in Canada!

» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 05:08 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC