[bibby]

so this bullbar i have mounts to the chassis at the front and sits on the two bars coming out the chassis with 2x m10 grade 8 bolts thorough either side you can kinda see in this photo the mounting point but ill draw it too..
just want to know if i put D shackles through the circled bits in the drawing will it be okay to recover off


Hope that makes sense thanks guys

[Scrawny]

What car?

If you put a spacer in the chassis and bolted right through then it would probably be ok for small recoveries on a Sierra. Anything bigger you'd want a few more mounting points to spread the load.

[bibby]

yeah it does go the hole way through the chassis like the bolts do and its a lwb sierra ute

[alien]

IMO 2 bolts per side aint enough...

You'll want crush tube welded into the chassis, maybe even fish plate each side of the rail for extra beef?

[Joe]

bibby wrote:

yeah it does go the hole way through the chassis like the bolts do and its a lwb sierra ute

Yes but it will work some what betterer with some crush tubes added like these



Even then i suggest only using it as a recovery point if you really need too and only to recover your self don't recover Toyotas with it

[bibby]

mates tjm winch bar only has 2 bolts each side on a land rover? and the bloke before me ran this bar like this for ages but if you think that ill take your advise, would you be able to draw up an idea so i know what you mean

[Marko_SJ]

Use the bolt holes you have, with crush tubes.

[bibby]

Joe wrote:

bibby wrote:

yeah it does go the hole way through the chassis like the bolts do and its a lwb sierra ute

Yes but it will work some what betterer with some crush tubes added like these



Even then i suggest only using it as a recovery point if you really need too and only to recover your self don't recover Toyotas with it

okay dokie, where can you get that kinda tubing? i have old bmx bike bars could i use that round steel? haha

i wont any tiime soon

[bibby]

and that should be okay if i put the shackles through the bar then?

[Gwagensteve]

What's wrong with the standard loop on the front crossmember?

Yes, you can add crush tubes across the rails in order to allow the load to be shared across both sides of the box. Make sure you use heavy wall tube and it's cut accurately. Also ensure you torque the bolts to spec and use washers, preferably thick washers (you'll have to ask for these- you won't get them without asking.

I can't really see in your photo of the bar where you're going to put the holes for the shackles, but looking at the thickness of those plates I think I'd be doubling them up with a weld washer. That's what I'd do, but I don't need to because I use be stock Suzuki point on the front crossmember. I've been recovered very hard using that point and it's been fine. Critically though, if it fails, it isn't very heavy, and it bends a long way before it fails. This isn't like what you're proposing- if the chassis or bolts fail you're going to have a big heavy hunk of metal moving fast away from your car.

Ps, have a good look at the bumper mounting bolts on a land rover. The connection is well designed- the chassis is very strong in that location and the bumper sandwiches the chassis end. It's much, much stronger than the end of a sierra rail.

Steve.

[ChrisN]

Great example of the point that Steve makes in this video, at 10:30. http://www.youtube.com/watch?v=S8kwFNI45lM

It's a Samurai too.

[bibby]

Thanks heaps for all that steve i really apreciate it when someone takes the time to make a well thought about and knowladgeable response thanks mate
But to the point would you then just recomend the crush tubing and the 4 bolts holding the bar on and then for recovery points just use the stock ones? And the plate is 8mm thick if thats all good?
And i do have thick washers and m12 grade 8 bolts

[Gwagensteve]

I use the stock point, generally with some caution, but every recovery point should be used with some caution.

I'd still attach the bar with crush tubes.

Steve.

[bibby]

yeah right o got any idea of what i could use? just some thick metal pipe

[Gwagensteve]

Yes- heavy wall tube, of have some round bar bored.

Steve.

[ChrisN]

Should crush tubes be welded in place?

[Marko_SJ]

ChrisN wrote:

Should crush tubes be welded in place?

I think they can be free or tacked.

This thread reminds me I should do something about my (well actually the original, but I haven't changed it yet ) dodgy setup.

[want33s]

Cheap, easily available crush tubes are sold at Bunnings as cyclone rod joiners. Possibly not available in southern states.

[droverdave]

Short tubes in compression have enormous load capacity. So you don't have to go too overboard with the "heavy walled". Heavier than body steel sure, but I think boring solid bar is a bit overkill.

Also remember that the bolts in shear aren't all that what holds the bar on. The bolts hold the plates of steel together (the bull bar, and the steel on the car), holding the steel together creates friction between the steel. It is this friction that holds the bar on, not the shear of the bolts them selves. The shear strength of bolts is considerably less than the tensile strength, thats why you use the tensile strength to hold the steel together to create the for mentioned friction.

[AckerDackerly]

For those with limited fabbing skills or is tired of re-inventing the wheel, this product works great:

http://www.zuksoffroad.com/Heavy-Duty-Bolt-kit_p_56.html

I hope that this helps

[bibby]

Im in the NT so cyclone rod will be readily avalible ill go grab some when i have the chance

[Gwagensteve]

The reason a suggested heavy wall is it's easy to find tube that's really light wall (1.6mm or so) and I don't think that's ideal either- it will act like a cookie cutter on the rail. 2.5mm+ would be better IMHO.

Steve.

[Gwagensteve]

AckerDackerly wrote:

For those with limited fabbing skills or is tired of re-inventing the wheel, this product works great:

http://www.zuksoffroad.com/Heavy-Duty-Bolt-kit_p_56.html

I hope that this helps

Over $100 landed in Australia for four bolts and some tube looks pretty steep to me. (Even $30 looks steep for what you get)

Steve.

[jdk81]

Excuse the format and me not providing the link. Im on my phone.

Im assuming Steve was talking about heavy wall tube and thick washers as its more due to the area of chassis clamped together than the column length of the crush tube.
Heavy wall tube allows more area of the chassis to be sandwiched together.
With some deflection crush tubs can still tear out easily, due to how close it is to the end of the rail and only pulling on one side of the rail.

I think atari posted a pic of one for sierras which I really likge.
It was solid piece machined to slide inside the rail. It had a section machined to clear the xmember tube.
with the recovery point on the outside, a solid block inside and plate on the other side, is close to the best you can get.

it removes the deflection, which by default then removes the moment applied.
so keeps it al linear and more predictable.

[tanshi]

I personally like the the idea of ubolts around the crossmember tube. or big end bearing caps if you can find some the right size.

[Dcraw]

hey bibby theres another thread in the noob section where there is talk of crush tubes if you want to check that out as well. Handle bars are to thin you want some thing with a thick wall. In the other thread a 2.5mm minimum was recommended

[Dcraw]

Do you have any examples of u bolt setup tanshi? Is it the ubolts behind the crossmember then through some plate up front?

[tanshi]

a mate on here uses this setup.
basically bolts backward from the bar and sitting either side of the tube crossmember
then bearing caps from a hilux I believe around the tube and bolted up.

[Dcraw]

ahhh, ok so the bearing caps are holding it on the cross member and the ubolt forms the recovery loop? i got go find myself some bearing caps

[tanshi]

anything can form the recovery loop. its more a case of mounting the bar to something substancial.