Change font size


Post a new topicPost a reply Page 1 of 2   [ 20 posts ]
Go to page 1, 2  Next
Author Message
 Post subject: Another rear-mounted wheel carrier (longish story)
PostPosted: Tue Sep 23, 2014 9:38 pm 
User avatar

I Say: very little. It always gets me into trouble ...
Vehicle: MY07 X MT

Posts: 450
Location: Perth
We had planned an extended journey in some outback areas, including a fair amount of corrugated gravel roads. So there was a purpose in carrying a second spare tyre externally (internal space is at a premium, and there's nothing funny about unloading a vehicle on a muddy or dusty road just to reach the standard spare under the luggage). Rather than carrying a roof rack/basket combo I explored the prospect of rear-mounting. The only promising system I found was Dell's one but that involved a bumper penetration, something I was keen to avoid as this Forester is a keeper, and this was to be realistically for that one extended journey. So after a long look at the side-swinging approach I decided to try a towbar-mounted swing-down system. The objective was to keep the wheel as close to the tailgate as practical, with the weight above the towbar (minimising static towbar rotation moment) rather than hanging rearwards like a bike carrier. To have the wheel studs facing backward would require a dog-leg bracket which would both raise the wheel and move it further away from the tailgate, so in this situation a mount with the wheel studs pointing forwards was simpler to fabricate - no doglegs or unnecessary bends.

The first part - and probably out of reach for most home handypersons - was the "replacement gooseneck". As the original gooseneck was ex 75x20 bar, that's what I preferred to use. Problem#1 was how to get it bent 45 degrees in two places to provide an upright post, and to drill the two mounting holes. When I finally found a steel fabrication shop that said "we can do that" I was delighted to hear Travis add "and we have 75x20 here if you don't already have some". Bingo!

Two days later the bar (*) is bent and drilled, exactly matching the profile of the 50x3 aluminium template I provided, and the length of the upright gave me the planned 10mm clearance for opening the tailgate. (Although this sets the wheel up somewhat from the "bumper", it gives the maximum height for the post and distance from the hinge for the latch mechanism.)

Image

Image

The design was based on using 50x50x2 box section for the hinged "T" (the upright and the horizontal element into the wheel mount itself), and for a possible spacer off the vertical "post" (the 75x20), and it looked like more 50x50 although that was dependent on the hinge system.

I set out with the intention of doing the cutting and welding myself, even though I was never a great welder due to lack of practice. But when I was explaining what it was all about, Travis offered to cut and drill a 150 diameter disc ex 6mm sheet to form the wheel "hub" - again a home-built part would be far less professional than that. I provided the setout dimensions for three wheel studs on the 5x100 pattern, and three HT bolts and wheel nuts as well as my spare spare (ex Bram). Done. Now I'm figuring that these guys (a) have all the steel sections, (b) are welding all the time, (c) etc etc, so now Travis and his team are building it in steps as the design/dimensions evolve in test-fitting sessions. Yes it may cost a fair bit (unknown at this stage) but it WILL be well-built and will certainly pass muster when Plod casts an eyeball over it.

The original hinge scheme was scrapped in favour of a 50 wide "flap hinge" from UES International. This produced about a 14mm gap between the two vertical box sections, so to maintain a comfortable wheel-to-tailgate clearance the "spacer" box became 75*50.

Image

Note the part of the T which extends backwards. This keeps the spare off the ground and makes it easier to lift as you can easily get your hand(s) under the furthest point. Lifting further in gets noticeably harder.

As the detail of this design evolved, one thing that kept me puzzling was how to secure the bracket in the "up" position with both anti-rattle and anti-theft measures. Bear in mind the hinged mass is about 25kg (the spare is nearly 20kg) so it had to be a decent arrangement. Having seen some of the goodies that UES carry, I researched the over-centre latches from one of their sources (OJOP). I settled on their 702L/C series in stainless (rated 3kN/300kg each), one each side because I'm anal/paranoid. If you get the right ones, these are lockable AND have a safety catch to prevent the handle ever slipping open. Some heavy rubber (like conveyor belt) and a layer with some "give" (both ex Clark Rubber) provides the anti-rattle pad and the amount of compression required for the latch over-centre action.

Image

Image

A bracket for the number plate and LED light and it's finished. Cable for the light travels down inside the swinging part and plugs into the trailer socket.

Image

The whole assembly was sand-blasted and primed, then finished with a couple of coats of rattle-can matt black.

The end result was simple and quick to gain access to the tailgate - pop the two latches off and swing down the wheel, all of about fifteen seconds at a leisurely pace. Even SWMBO found it easy to do. Obviously it took longer when the padlocks were fitted, but that was only practiced in "selected" parts of regional Australia where things move in the night.

The carrier performed flawlessly through 15,000 km across Oz and back, including about 1300km on the unsealed/corrugated Great Central Road (Laverton to Uluru) and Mereenie Loop (King's Canyon to Glen Helen Gorge).

Image

Some Q&A.

Would I recommend this approach to others? Absolutely.

What did it cost? Steel fabricator (all material + labour) $150 (*). Sandblast/prime $40. Latches were "samples". Hinge I don't recall. LED light and 7-pin plug around $15. Bolts and wheel nuts ~ $12.

Would it be better to use a heavy duty towbar rather than a standard type? Not in my view. The standard Hayman-Reese towbar is rated for 75kg vertical load at the ball position. The whole assembly weighed around 32kg and the centre of gravity was actually slightly forward of the original ball position, so a bit less than half the allowable rotation moment for the towbar. Also (apart from one HD bar whose tongue was seized in situ) every single HD tongue I have seen/tested had significant slack/rattle in the fit. This wheel carrier assembly would thrash around on even minor bumps on one of those. The rigidity of fitting to the standard bar was impressive.

Would I do it differently if I did it again? Structurally, no. In terms of niceties:

(a) I'd ensure there was a hole to allow cable to the top of the T so a 10W LED reversing light and a reversing camera could be fitted.

(b) If one is completely paranoid and doesn't trust the hinge completely, a pin from the T to the post spacer would ensure the hinged part doesn't drop if the hinge fails.

(c) I'd make the bracket for the numberplate light a bolt-on rather than a welded job, as storage is easier without that "outrigger".

--------------------------------------------------------------------------------------------------
(*) Travis actually made TWO of the 75x20 bar posts, so I have a spare. Maybe I'll build another one and incorporate these features.[code][/code]


Last edited by zippo on Mon Aug 07, 2017 10:52 pm, edited 2 times in total.

Top
 Profile  
 
 Post subject: Re: Another rear-mounted wheel carrier (longish story)
PostPosted: Tue Sep 23, 2014 10:06 pm 
User avatar

I Say: Embrace the Grind
Vehicle: Regal Blue 05 XT Lux manual

Posts: 5490
Location: Perth
great writeup
is a trip report coming?


Top
 Profile  
 
 Post subject: Re: Another rear-mounted wheel carrier (longish story)
PostPosted: Tue Sep 23, 2014 10:07 pm 
User avatar

Vehicle: MY06 XT -Sliver

Posts: 108
Location: Australia
Good to see man! :)
Detailed! Love it.


Top
 Profile  
 
 Post subject: Re: Another rear-mounted wheel carrier (longish story)
PostPosted: Wed Sep 24, 2014 12:33 am 
User avatar

I Say: Remember, no-one is listening until you fart.
Vehicle: '11 S-Edition - '91 Liberty LX

Posts: 4639
Location: Launceston, Tas
Nice job :thumbs:

Baronia Towbars sells an anti rattle pin that stops that movement in the HD hitches. Your solution looks to work well and would be especially easy to remove with a cordless rattle gun.

zippo wrote:
(*) Travis actually made TWO of the 75x20 bar posts, so I have a spare. Maybe I'll build another one and incorporate these features.[code][/code]


Maybe you could look and see if there's a design that could house 2 spare wheels, one on either side???

_________________
dazzz168 wrote:
"Ain't no one got time to change gears these days :lol:"


Top
 Profile  
 
 Post subject: Re: Another rear-mounted wheel carrier (longish story)
PostPosted: Wed Sep 24, 2014 1:39 am 
User avatar

I Say: very little. It always gets me into trouble ...
Vehicle: MY07 X MT

Posts: 450
Location: Perth
BJM wrote:
Nice job :thumbs:
Thanks, appreciated.

BJM wrote:
Baronia Towbars sells an anti rattle pin that stops that movement in the HD hitches.
There are a number of those, but they all seem to work loose after some time, not what I wanted.

BJM wrote:
Your solution looks to work well and would be especially easy to remove with a cordless rattle gun.
As long as the rattler can crack wheel nuts, 'cos that's the amount of torque I used on the 16mm bolts that hold the tongue/post onto the bar. I use a 15" breaker bar to fit/remove them.

zippo wrote:
(*) Travis actually made TWO of the 75x20 bar posts, so I have a spare. Maybe I'll build another one and incorporate these features.

BJM wrote:
Maybe you could look and see if there's a design that could house 2 spare wheels, one on either side???
You get into issues with having to add supplementary lights, as that would block the 45 degree view of the lights. If you were happy to bang another 20kg onto it you could stack backwards I guess. For me, one readily accessible spare was enough insurance against a tyre failure (or bent wheel) in the middle of nowhere.

On serious 4WD's there are of course a number of those dual swingout carriers that can ahndle two wheels and a jerry etc. But they are serious $$$ and weigh a heap too. This was meant to be light, simple, temporary and cheap and it ticks all those boxes for me.


Top
 Profile  
 
 Post subject: Re: Another rear-mounted wheel carrier (longish story)
PostPosted: Wed Sep 24, 2014 8:38 am 
User avatar

I Say: Remember, no-one is listening until you fart.
Vehicle: '11 S-Edition - '91 Liberty LX

Posts: 4639
Location: Launceston, Tas
zippo wrote:
You get into issues with having to add supplementary lights, as that would block the 45 degree view of the lights. If you were happy to bang another 20kg onto it you could stack backwards I guess. For me, one readily accessible spare was enough insurance against a tyre failure (or bent wheel) in the middle of nowhere.

On serious 4WD's there are of course a number of those dual swingout carriers that can ahndle two wheels and a jerry etc. But they are serious $$$ and weigh a heap too. This was meant to be light, simple, temporary and cheap and it ticks all those boxes for me.


I know weight is an issue the Land Rover guys are having with their new vehicles once they add a long range tank, bullbar and wheel carriers. They are having to limit what they can carry in the back.

_________________
dazzz168 wrote:
"Ain't no one got time to change gears these days :lol:"


Top
 Profile  
 
 Post subject: Re: Another rear-mounted wheel carrier (longish story)
PostPosted: Wed Sep 24, 2014 10:57 am 
User avatar

I Say: very little. It always gets me into trouble ...
Vehicle: MY07 X MT

Posts: 450
Location: Perth
BJM wrote:
I know weight is an issue the Land Rover guys are having with their new vehicles once they add a long range tank, bullbar and wheel carriers. They are having to limit what they can carry in the back.
Even worse, a lot of the BT50/Ranger type crewcab vehicles have quite an overhang from rear axle to their tow point. When they load up their HD bar with the max downforce with a 23ft van, they (of course) upgrade the springs and sometimes put airbag suspension helpers in. All that does is stiffen the whole suspension so the overhang causes bending. Any load in the tray compounds the problem as the axle is waaaay forward of the tray centre. There are a heap of traps between the listed on-road mass and the limit.


Top
 Profile  
 
 Post subject: Re: Another rear-mounted wheel carrier (longish story)
PostPosted: Wed Sep 24, 2014 11:11 am 
User avatar

I Say: very little. It always gets me into trouble ...
Vehicle: MY07 X MT

Posts: 450
Location: Perth
lefty wrote:
great writeup
is a trip report coming?
Nah, it was really just touristy stuff right through the 8 weeks.

The Foz went like clockwork. Needed an oil/filter job in Brissie as by then we had about 10,000 since the one before we left. Tried Boxer Service in Brendale (Q) but they were booked up as far as. Subi Evolution in Brendale managed to squeeze it in nicely.

Overall for the trip (a fair percentage was cruise on highways) and running on 91, she averaged 11.8 km/l which is pretty decent. Worst figure was in the 9's in some twisty mountain stuff. Last tankful gave us 636 km (250 of gravel) before refilling - gauge showed about 1/8 and the light hadn't come on. Only ever saw it once, and never got more than 48 litres in even though I always filled it right up the neck.

Best part of 2000 km was gravel, yet nothing failed or came loose ... BUT the night after we got home a low beam popped. Presumably fatigued on all the corros.


Top
 Profile  
 
 Post subject: Re: Another rear-mounted wheel carrier (longish story)
PostPosted: Thu Sep 25, 2014 10:23 am 
User avatar

I Say: high and mighty!
Vehicle: MY06 XT CGM

Posts: 729
Location: Bundy, QLD
Excellent work and great idea mate, I like it. :thumbs:
I'm glad some how I'm part of the inspiration to have a go and design your own thing which suits you best.
Yeah!...Forester is just amazing vehicle for touring around Australia, they can tackle any road surface and thousands of kilometres without any hassle. :ok:

_________________
06 Forester XT - Team Raised - built for the rough stuff.
- Bullbar, Rear Bar w/ wheel carrier, Sidesteps, Sump Guard 6x Spotlights, King Springs, Strut Top Spacer(40mm), Safari Snorkel, BF Goodrich Mud Terrain 235/70 R16
& 1986 BMW 323i TC Baur Cabriolet & 1999 WRX...soon to be track car.


Top
 Profile  
 
 Post subject: Re: Another rear-mounted wheel carrier (longish story)
PostPosted: Thu Sep 25, 2014 11:04 am 
User avatar

I Say: very little. It always gets me into trouble ...
Vehicle: MY07 X MT

Posts: 450
Location: Perth
dellsfozzaxt wrote:
Excellent work and great idea mate, I like it. :thumbs:
I'm glad some how I'm part of the inspiration to have a go and design your own thing which suits you best.
You certainly were, and thanks for that. It was only the cosmetic considerations after removing it (remember, this is my town car) that steered me the way I went. Also as I'm not an ace welder, the dog-legs would have been a bit more of a test in terms of achieving structural potential.
dellsfozzaxt wrote:
Yeah!...Forester is just amazing vehicle for touring around Australia, they can tackle any road surface and thousands of kilometres without any hassle. :ok:
Ate up the corrugations across the back-blocks of WA as well as the best of them, and was more comfortable than a lot of 4WD's would have been. And the compact size certainly helps in city parking.

It's only a pity that FHI don't have an optional tailgate with the inbuilt wheel-carrier strength and mounts. Wouldn't sell many in Japan I guess, but US and here there would be potential sales.

Just looked at your location. We were in Bundy for a few days, if the penny had dropped then I might have looked you up ...


Top
 Profile  
 
Display posts from previous:  Sort by  
Post a new topicPost a reply Page 1 of 2   [ 20 posts ]
Go to page 1, 2  Next


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  


Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
"Takka LE" for phpBB3