Fabricators for a bespoke Rear Swing-away...?

[Chris]

Lorin, just a couple of thoughts here that might work in the overall design - I'm not saying copy this - they're just design concept ideas that might trigger part of the solution.

I was thinking about the carrier spec for big heavy spares - I had 37's on mine. If you look at the Arctic Trucks 80, they angle the spare in. It's not a lot, but it does move the weight in-board a bit more.

Secondly, they had a carrier that dropped down. No idea how this would help, it's another interesting design. Have the bikes on a swing out and the tyre on a drop down?

Now, last thought -and I am just thinking out loud, is that you have pictured the vehicle then the wheel then the spare. What if the bikes went against the tailgate and the spare was on the outside? No idea if that would help / work, but it's a bit of lateral thinking.

Could the carrier for the bikes go up and over perhaps? With springs, rams, cables for example, and bikes being not that heavy, it might be possible to push them up.

I appreciate you have a plan in your head, just chucking things in. I think if I was trying to do what you were doing, I think I'd be looking maybe at two separate moving components. No, not a double carrier, left and right, but rather than hang the bikes off the spare carrier, something differently articulated?

 

[Higgy]

I like the Idea of the drop down for the spare... Any idea how they secured it when folded up Chris... Nice and simple Idea that!

 

[Chris]

Not a Scooby I'm afraid Higgy. I just screen grabbed the shots off the Iceland video. The wheels are huge and probably very hard to lift into place.

 

[Higgy]

Not a Scooby I'm afraid Higgy. I just screen grabbed the shots off the Iceland video. The wheels are huge and probably very hard to lift into place.

No worries.. Like the idea tho,

 

[Lorin]

Lorin, just a couple of thoughts here that might work in the overall design - I'm not saying copy this - they're just design concept ideas that might trigger part of the solution.

I was thinking about the carrier spec for big heavy spares - I had 37's on mine. If you look at the Arctic Trucks 80, they angle the spare in. It's not a lot, but it does move the weight in-board a bit more.
View attachment 153831



Secondly, they had a carrier that dropped down. No idea how this would help, it's another interesting design. Have the bikes on a swing out and the tyre on a drop down?

View attachment 153832

Now, last thought -and I am just thinking out loud, is that you have pictured the vehicle then the wheel then the spare. What if the bikes went against the tailgate and the spare was on the outside? No idea if that would help / work, but it's a bit of lateral thinking.

Could the carrier for the bikes go up and over perhaps? With springs, rams, cables for example, and bikes being not that heavy, it might be possible to push them up.

I appreciate you have a plan in your head, just chucking things in. I think if I was trying to do what you were doing, I think I'd be looking maybe at two separate moving components. No, not a double carrier, left and right, but rather than hang the bikes off the spare carrier, something differently articulated?

Interesting ideas Chris. The angling in bit is a very common design element that will likely be incorporated if the tyre is mounted high enough. The problem with mounting the tyre high and angled in is it makes it much harder to lift on and off. My XZLs are absolutely NOT a light tyre, so as much as possible I want to ensure any lifting is minimal.

The drop-down carrier idea simply doesn't work if as I do, you live out the back of the truck when camping. It would also be impossible for my wife to access the back if I wasn't there. Trying to incorporate any 'lift-assist' mechanism would just add an uneccessary failure point IMO.

One consequence of mounting a heavy spare out the back is it upsets the balance of the truck. To minimise this you want to keep it as close to the body as possible. Mounting the tyre outside of the bikes would not only accentuate its affect on balance, but would also require a lot more metal/Fabrication to support it. This would just add complexity and weight for no benefit.

My setup involves a roof tent and a 270 awning. Therefore, for the bikes to be on some sort of separate lifting mechanism, it would need to be roof mounted just to clear the awning. Again, this is getting into a world of untested complexity for no real benefit.

Swing-aways are a proven concept. Admittedly, there is the issue of sourcing a pivot strong enough to support the weight for a single pivot design, but everything else is design and fabrication along a well worn solution route. With a well designed swing-away the pivot will only support the weight when open, when closed the weight can be supported across the bumper/chassis. Mounting the tyre on a single swing-away that also incorporates something like the ISI bike rack would mean one single mechanism for accessing the back and no need to remove the bikes when setting up camp.

Our travels will include some large distances on badly corrugated roads, together with sections of very technical terrain (e.g. like in Russia). Therefore, this design needs to be robust enough to cope, meaning that there is likely great benefit in making simplicity a core attribute.

 

[Lorin]

Have you measured or mocked up what you've sketched and know for sure there is enough space? Seems like quite a lot of free space for a 37!

I have now. The sketch below is reasonably to scale. If I keep the tyre dead central, I can fit a 6kg gas bottle in the gap as illustrated. If I wanted an 11kg gas bottle, I'd need to move the tyre off-centre toward the drivers side by a minimum 5cm. The basket I'd intended to fit the other side is actually too small to be worth the hassle or weight of including, so I'd just go with a tyre mounted trash bag instead. The bikes will be far enough away for this to work.

 

[StarCruiser]

I like Chris’s idea of mounting the bikes above the spare as there is a natural hollow between the bike wheels and doing this would allow the tail lights to remain visible simplifying things as well.

Here’s a thought.

If you were to partly cut away the rear chassis cross member in a curve, and fit a curved closure plate, somewhat like the old Nissan Terranos had, that would get the wheel lower down. The swing away needn’t follow this but could go straight across. My major concern is the amount of torsion there will be with the wheel wanting to twist the frame backwards and this would help lower this.

You really do need the pin and bearings to be as strong as possible as Chris has said. It doesn’t just do it’s work when it’s swung out. A decent pin the other end would be essential. I’d say at least 25mm diameter maybe more. Dynamic forces are going to be far more than static. Probably in the order of 5 to 10 times. There’s probably a formula somewhere.

 

[Chris]

Hey Lorin, thanks for taking the time to respond to that load of ramble. No need dear chap. Just ideas to dismiss or make you go "hmmm..."
Personally if I could do without a rear carrier completely I would. My 35's won't fit underneath but if I was on 33's I'd stick it on the OEM carrier as I have the small subtank. I did think about just carrying a spare tyre carcass with no wheel as I have the kit to change tyres on board. That would then go on top of the JB.
You're in a sort of double jeopardy situation with wanting a wheel and bikes.

 

[Higgy]

Is it not practical to try and mount the spare on the Bonnet,(Land Rover style).. ? Has anyone ever tried it...It would certainly get it out the way.. to free up space and time to think about the other stuff... I dont know if its possible, Just a thought.. I know landcruisers have Gas struts but an old style Stay would not be hard to fit...

 

[Ian Rubie]

I'm going to approach this from a different angle and am fully prepared to be shot down. I know how strong a 255/100 XZL is, it is far far stronger than something like a BFG MT for example. I don't believe Toby or I ever had a flat when using them, I'm not sure if you have or not Lorin? How about forgetting the whole idea of carrying a spare and fit beadlock wheels with run flat inserts instead?

 

[Chris]

And chuck an inner tube in the spares box too.

 

[Ian Rubie]

I have no idea on the price but these look like they might be a solution

http://www.runflatcbr.com/dvd-demonstration/

8 hours of off road driving on four flat tyres.

 

[StarCruiser]

Is it not practical to try and mount the spare on the Bonnet,(Land Rover style).. ? Has anyone ever tried it...It would certainly get it out the way.. to free up space and time to think about the other stuff... I dont know if its possible, Just a thought.. I know landcruisers have Gas struts but an old style Stay would not be hard to fit...

Now this thought did occur to me but I decided the periscope needed to see over the thing might be a bit tricky to mount. Granted Lorin isn’t short but I decided the vision it would blot out would make it highly dangerous. You could have a mini in front of you with Bo Derek leaning out of the rear window and be blissfully unaware.

 

[StarCruiser]

I have no idea on the price but these look like they might be a solution

http://www.runflatcbr.com/dvd-demonstration/

8 hours of off road driving on four flat tyres.

I think that has got to be worth a look and in my view is a fantastic idea Ian. It literally knocks spare tyres out of the equation. Let’s face it, if you get a puncture in two tyres in quick succession you’re stuffed unless you can repair one. You could literally drive over a bed of nails with these in and carry on. Plus you’ve saved a huge amount of weight and construction and there are simple bicycle swing aways or even detachable carriers on the market.

Good call Ian.

 

[nick_the_fish]

These run flats look really interesting. Although presumably they can’t be deflated for sand driving and the like? Interesting option tho. I for one will be looking at them as an alternative to rear wheel carriers

 

[Jon Wildsmith]

I'd move the spare to the drivers side a bit to give more space for the gas bottle, the weight of that should more or less offset the tyre weight being off centre. £1k is a bit much for the bike carrier! No matter how well the swing out is clamped there will still be a lot of load on the pin but something like the Slee pivots that I've copied and used and I think are what Chris is referring to and I'm sure others have should handle it just fine.

 

[Chris]

Correct Jon. I copied your design seeing as I somehow acquired a lathe.. I have one half made on the bench at the moment. If you think about a Cruiser stub axle and how tough they are, a carrier pivot needs to be a similar sort of duty

 

[Lorin]

I'm going to approach this from a different angle and am fully prepared to be shot down. I know how strong a 255/100 XZL is, it is far far stronger than something like a BFG MT for example. I don't believe Toby or I ever had a flat when using them, I'm not sure if you have or not Lorin? How about forgetting the whole idea of carrying a spare and fit beadlock wheels with run flat inserts instead?

You absolutely right to remind me of this! I had lost sight of the fact that a key reason I wanted XZLs was so I didn't have to carry a spare. It is a hard decision to commit to as the established 'wisdom' suggests you need at least one spare, often two are recommended in more remote areas. In January last year I spoke with Marcus of http://www.tuckstruck.net/ about his experience of running the same XZLs. Over a period of 5 years he has done over 60,000 overlanding miles in an Iveco Daily 4x4 and has had just one tyre failure. I've had none and have not found any reports of them puncturing.

I did previously consider beadlocks but the cost for a proper set of doubles is pretty significant. I've also looked at beadlock inserts before but they are not well reviewed. However, the runflat/beadlock insert you linked to look very well developed and may actually make it viable to omit the spare. I'll get a price and see where it leaves me. I would be really quite pleased to not have to carry a spare. Although, I still need to swing the damn bikes away so I don't have to unload them every time I want to access the back!

 

[Lorin]

I have no idea on the price but these look like they might be a solution

http://www.runflatcbr.com/dvd-demonstration/

8 hours of off road driving on four flat tyres.

So, I got a price. Brace yourself.....

£355 per wheel plus VAT!

They also do a cheaper option for £250 per wheel plus VAT but not really suited to the XZL.

 

[Ian Rubie]

That is a bit steep, might be worth looking for some other kind of run flat insert from elsewhere.