My New Rear Bumper

[Craisy Daisy]

It was on XOC after Schlud posted a question about the Calmini bumper. It's a picture of the rear spare tire location and the back of the bumper right at the receiver.

[ned946]

I'm not an engineer, so I'm not sure about what you are referring to in terms of box section mounting to the bumper, but....

It (the tube section that the hitch slides into) is double welded (front and back) and on the inside of the bumper has a gusset from the hitch tube back to the bumper (a triangular piece like all the rock sliders have that reinforce the extensions) and a huge massive piece that goes back to where the tire hand winch thing mounted. I'd feel okay pulling a stump out with the thing. And, I know Steve was incredibly hesitant to place a class III until he was happy(his original design called for a class II due to his strength concerns)...he is BIG into OVERBUILT!

8 bolts hold the thing onto the X.

I have pics (of the SIMA truck too), but I don't have my synch cord. I'll have it on tuesday and I'll post pics. If there are specific detail shots you want, please post and I'll try to get it.

-Ned

PS- the triangular gusset I am referring to is NOT the one next to the hand in that link, it is similar but goes directly from the box tube to the back of the bumper.

[ChuckH]

Originally posted by Schludwiller
Yes, Chuck.

The Calmini bumper does not have box supports going into the frame. I raised this cocern with Steve at XOC and he pointed out the middle piece (hitch part, which he said attached to the crossmember) as being enough support when used with the two L-beams on the sides.

I dunno. I like things a bit overengineered myself, especially when I'm messing with pulling 4,000 lb things with tow straps, etc.

I guess we'll see.

If built right the "L" brackets to the frame would be plenty strong. What I'm seeing though that is a curiosity is that it appears that the "L" brackets attach to the bumper skin and there is no box section backbone going crosswise between the two frame brackets. Having a box section backbone behind the bumper skin adds a tremendous amount of strength and rigidity and I don't understand why it is missing unless Calmini was just trying to save weight. I think that's odd that receiver is only mounted to the skin of the bumper and to the crossmember above the spare, which isn't even one of the beefy crossmembers if I remember correctly. It kind of reminds me of the Class II hitch I had on my Audi that was mounted to the trunk well at one end and the rear suspension subframe at the other. That was fine on the Audi, but I wouldn't want to do it that way on an Xterra.

Anyway, I'm sure that tying it in that way is fine, but box section steel is better. The box section stiffens the whole bumper and gives a spot to mount the receiver to without adding a center bracket. I imagine the Calmini will bend easily in between the receiver and the outer frame mounts, where there is no box section reinforcement.

BTW Schlud, your bumper with all 12 bolts and the long inserts didn't even shutter when you pulled Bryan up the hill!

So that's what I see and think and if anyone disagrees with me well then :finger:

Hehehe!!!

[Schludwiller]

Originally posted by ChuckH


BTW Schlud, your bumper with all 12 bolts and the long inserts didn't even shutter when you pulled Bryan up the hill!

Hehehe!!!

Damn well better not. I spent enough time messing with that damn thing.

[ChuckH]

Originally posted by Schludwiller


Damn well better not. I spent enough time messing with that damn thing.

Ahem, don't forget the money and my time!

Now we just gotta get the pinholes filled and get that bad boy finished up!

[ned946]

Originally posted by ChuckH

If built right the "L" brackets to the frame would be plenty strong. What I'm seeing though that is a curiosity is that it appears that the "L" brackets attach to the bumper skin

I see your point now, kinda like the "bullet proof" bumper ad, right? Like I originally posted, I'm no engineer, just a tinkerer....but I'll throw in my two cents.

To start, describing it as a skin might be misleading, cuz that is think stuff. I would assume that the "skin", with its multiple bends, is the structural component (cross piece). You might note that the ARB, with its many bends and WAY thin "skin" is rated for a 9K winch. What I'm getting at is that a sub-frame may not be necessary (course it wouldn't hurt either).

I'll be sure to take close up shots of the welds. That is one of the most impressive things about Calmini, is the welding. Steve just walked around and picked up random parts at different stages of completion and every weld is a perfect bead. Those welds, I think, further decrease the need for a sub-frame.

I gotta say that I don't think that pictures do the bumper justice......cuz we are all used to seeing ARB type heft and may assume the Calmini is of the same caliber.....which (for sure) it is not. Calmini is much heavier.

I don't want to say that it is better in terms of strength etc than your finished product, but I would gamble that upon close inspection, you would be more than satisfied that it would easily handle anything you could throw at it.

All, IMHO

[ned946]

Originally posted by ChuckH

I imagine the Calmini will bend easily in between the receiver and the outer frame mounts, where there is no box section reinforcement.

Just wanted to comment once again that I really don't think its even a remote possibility. Yes, a box is the strongest, but I would equate the Calmini as a "C" channel, with closed ends and a center reinforcement area and made out of some very think material. I'm also thinking that the function of the center mount in the 3 point mount would be to help reduce side to side sway of the hitch and the receiver while also helping out mounting strength.

[ChuckH]

Well, I guess someone in PNWX is going to have to buy one so I can get a good look at it! I'm also looking forward to seeing your pictures. I hope you take pictures from different views before it's on your truck so I we can see the back. BTW, I'm not trying to bash the Calmini bumper...some things just aren't clear to me.

Keep in mind too that I spent most of my life in shops that built stuff for Fire Trucks, so just about anything for a personal vehicle looks wimpy to me! That goes for the KMA too...there would have been more beef if I had built the whole thing from scratch. Uh, let's just say that in my world the only way the bumper could be pulled off the truck would be if the frame went with it. I'd also have battery compartments underneath, home made skids, my own sliders, a tow hitch insert in my ARB (with other ARB enhancements), a roll cage, and ......???Unfortunately I no longer have access to the tools and materials to do that kind of stuff.

[xoc]

Originally posted by Philosopher

How did you find that pic, and what the hell am I looking at ...? How confusing.

How simple.
On the right is the reciever hitch.
On the left it bolts to the cross member where the spare tire hangs.

[xoc]

Sorry Daisy, but that is the biggest POS I have ever seen. It makes the Frankenstein KMA crap look like they were built by NASA.

Does anyone here really think that looks cool, or good ?
Or that sawing a chunk out of the hatch is a good idea ?

[Craisy Daisy]

Originally posted by xoc
Sorry Daisy, but that is the biggest POS I have ever seen. It makes the Frankenstein KMA crap look like they were built by NASA.

Jeez Ian, tell me how you really feel

Just out of curiosity, is it

1. the bumper
2. the brackets
3. the fit
4. the fact that its not a Calmini
5. the notch in my hatch
6. or the way my truck looks now

that makes it a POS?

Like I said, I am just curious.

[ned946]

Originally posted by ChuckH
Well, I guess someone in PNWX is going to have to buy one so I can get a good look at it! I'm also looking forward to seeing your pictures. I hope you take pictures from different views before it's on your truck so I we can see the back. BTW, I'm not trying to bash the Calmini bumper...some things just aren't clear to me.

I know your not bashing Calmini (on the other hand I'm not paid by Calmini either )! I do agree, seeing it up close is the best. I too like to overbuild and I'm happy (if that means anything). I pitty the poor fool who might rear end me

I'm posting ASAP (likely tuesday) and I apologize for not being able to get the pics up sooner.

Again, if there are specific areas you want to see, I'll do my best to get it.

-Ned

[xoc]

Originally posted by Craisy Daisy
Just out of curiosity, is it

1. the bumper
2. the brackets
3. the fit
4. the fact that its not a Calmini
5. the notch in my hatch
6. or the way my truck looks now

that makes it a POS?

All of the above, except number 4. Bravo for attempting it, but seriously, take a good long look at it.

[Synchro]

uh...daisy? ....sorry man...but that thing is fugly. I don't even think I spent that much cash on my KMA and fixing it and it is better than that. sorry man, i just had to give my honest opinion.

[Strom]

CD, what type of lift do you have on your truck?
(sorry to be off-topic)