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Sierra Towbar
Posted: Fri Feb 23, 2007 8:15 pm
by CWBYUP
Just wondering if a H/D hayman reece towbar is strong enough to use a recovery point ?
Dont have time to do chassis mods at this stage but will in a couple of months so was thinging of getting the towbar cause I think it will be stronger than the original tow hooks on the rear.
Any thoughts guys ?
Cheers Nick
Posted: Fri Feb 23, 2007 8:27 pm
by ofr57
i got a tow bar on my lwb zook when i brought it .... but i was to change it to the hayman reece sorta way to tuck in it more
i would just see your local engineer
thats what I'm going to do
Posted: Sat Feb 24, 2007 7:34 am
by Highway-Star
My Sierras got a hayman reece towbar (Beets me if its Heavy Duty or not), but I intend top use as a recovery point if i have to. I've still got the original rear 'tow point' on the car, and the towbar beats it hands down.
BTW, my intention would be to wrap the strap around the bar and put the d-shakle back onto the strap itself, does this sound a decsent way of doing it?
Posted: Sat Feb 24, 2007 7:47 am
by Gwagensteve
Yes, a hayman reece bar is fine as a recovery point.
Highway star, re the strap around the bar, that is a way of doing it, but I would only do this in an emergency. It puts lots of load on the strap and is far from ideal. If you must do this, I would run the strap through itself so the strap goes through its own eye. This removes the need for a shackle at your end and less shackles always make for a safer recovery.
I would cut down the tongue on your hayman reece and drill it for a shackle, or just fit a shackle through the existing towball hole (these can sometimes be too long really drag offroad, which is why I suggested cutting it down)
Or buy a short piece of steel bar and make a new tongue just to take a shackle.
Steve.
Posted: Sat Feb 24, 2007 6:09 pm
by Bad JuJu
Gwagensteve wrote:Yes, a hayman reece bar is fine as a recovery point.
Highway star, re the strap around the bar, that is a way of doing it, but I would only do this in an emergency. It puts lots of load on the strap and is far from ideal. If you must do this, I would run the strap through itself so the strap goes through its own eye. This removes the need for a shackle at your end and less shackles always make for a safer recovery.
Bad - you exert much more load on the strap by doing this.
likley to snap just before the eye of the strap
Gwagensteve wrote:
I would cut down the tongue on your hayman reece and drill it for a shackle, or just fit a shackle through the existing towball hole (these can sometimes be too long really drag offroad, which is why I suggested cutting it down)
Best solution, you should be able to fit a 4.7 t shackle pin through the towball hole from a std 50mm tow ball. This is what I do - I have a H-R tow bar.
Gwagensteve wrote:
Or buy a short piece of steel bar and make a new tongue just to take a shackle.
Steve.
Bad, you wont make it beefy enough, or use a suitable grade of steel.
Posted: Sun Feb 25, 2007 8:21 am
by Highway-Star
OK, thanks for the those answers, I can see why my idea was flawed. My tonque has already been 'trimmed' a bit to fit triangle drawbar trailers with little room between the hitch and the draw bar front. I'll go see if my d-shackles will fit, but i don't think they will.
As for the tonque being too long, no. I took it off one day when i went wheeling, and ended up bending my rear bumper, with the tonque on it acts like a short skid plate (about 200mm). (It's a bit like the trench crossing theory used on the Renault FT-17 tank if you know them).
Thanks guys.
Aaron.
Posted: Sun Feb 25, 2007 8:46 am
by Highway-Star
My D-shackles fit through the standard towballl hole, with only some slop. They are 3.2T ones.
Posted: Sun Feb 25, 2007 1:22 pm
by Gwagensteve
Bad JuJu wrote:Gwagensteve wrote:Yes, a hayman reece bar is fine as a recovery point.
Highway star, re the strap around the bar, that is a way of doing it, but I would only do this in an emergency. It puts lots of load on the strap and is far from ideal. If you must do this, I would run the strap through itself so the strap goes through its own eye. This removes the need for a shackle at your end and less shackles always make for a safer recovery.
Bad - you exert much more load on the strap by doing this.
likley to snap just before the eye of the strap
Maybe, but I have done it like that for years when necessary and have not had a strap break at the eye. I agree, there is the potential for the eye to be spread a bit by the force, but remember that where the eye passes through the strap is double thickness. Is it harder on the strap? sure, but if there is no other usable recovery point, This is my preference. I will not add additional shackles into a recovery unnecessarily, and will only use this method on the stuck car, never on the recovery vehicle.
Bad JuJu wrote:Gwagensteve wrote:
I would cut down the tongue on your hayman reece and drill it for a shackle, or just fit a shackle through the existing towball hole (these can sometimes be too long really drag offroad, which is why I suggested cutting it down)
Best solution, you should be able to fit a 4.7 t shackle pin through the towball hole from a std 50mm tow ball. This is what I do - I have a H-R tow bar.
Gwagensteve wrote:
Or buy a short piece of steel bar and make a new tongue just to take a shackle.
Steve.
Bad, you wont make it beefy enough, or use a suitable grade of steel.
You don't need to insult our intelligence. I am more than able to use a length of bar the same thickness and thickness as a towing tongue and would assume that highwaystar could too. What do you know about metallurgy? Is there something about the grade of steel used in hayman reece bars that we don't know about? I'm pretty sure it is just Grade 250 bar. In any case, it is bolting to a 2.5mm thick chassis... a 20mm thick bar, regardless of the grade, will have a massive factor of safety, and that's just the way H-R design it.
I'm not having a go, I just think that the chances of shearing a piece of 80mmX20mm flat bar with a sierra are effectively nil, and the towbar would pull through the chassis long before the tongue went.
Steve.
Posted: Sun Feb 25, 2007 7:32 pm
by Highway-Star
I don't know whether BadJuJu was insulting our intelligence Steve, they may be just allowing for an unknown level of 'feel' for the physical world and mechanics etc. I known some very inteligent poeple, who don't have the slightest bit of common sense when it comes to vehicles, manufacturing etc.
And Yeah I think I could figure out what size bar to use if need be (but what I got seems good), as I'm starting third year mechanical engineering tomorrow. When I designed my slider bars I coped abuse from everyone around me for 'over-engineering' them. Just thought I would defend myself a bit.
I Also believe that the rear end of the Sierra Chassis and the hayman and reece towbar can take a greater load than the max Sierra tow rating, even if the car itself probably couldn't tow the mass safely. I rekon the first point of failure if not the recovery equipment would be the four bolts which bolt the bar to the chassis. The wouldn't break but maybe bend, as the towbar does seem prone to being twisted on its mounts.
I don't no where I'm going with this so I'll leave it there.
Aaron.
Posted: Sun Feb 25, 2007 7:40 pm
by Gutless
Highway-Star wrote:
I Also believe that the rear end of the Sierra Chassis and the hayman and reece towbar can take a greater load than the max Sierra tow rating, even if the car itself probably couldn't tow the mass safely.
Not really related to the discussion at hand, but most tow ratings are based on a combination of thingsww, such as suspension design and load carrying ability, length of wheel base, brakes, engine size, chassis strength and towbar mounting integrity etc...
Having said that, I have snatched a 3t patrol wagon from a sticky, swampy bog hole ( took a dozen goes to get it out) doing about 30kph each time, and the only damage done was to my neck the next morning ( read: whiplash

)
A standard towbar will be sufficient for any zook recovery needs
JMO
Pete