AnswerID: 202446 Submitted: Thursday, Nov 02, 2006 at 06:59
Ian from Thermoguard Instruments
replied:
As you've noticed and others have said, the only way you're likely to get a 15' tandem is an expensive custom-built job. Can I ask why you're sure you need four wheels, if it's not for weight carrying?
A 15' poptop could easily be found or fitted with axles, bearings and hubs suitable for 31x10.5R15 wheels and that's quite a lot of contact area on the ground. Could even go to really big 33"+
tyres on 16" rims with a bit more work - plenty of soft surface flotation there.
For that matter, although I've never seen it done, I can't see any
technical reason why a single axle van couldn't be fitted with dual wheels, provded it was done with proper engineering certification and the relevant mods to wheel arches, etc.
So, what have you got in mind for this beast?
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Reply 4 of 6
FollowupID: 462109 Submitted:
Thursday, Nov 02, 2006 at 15:07
Lekkerkamp posted:
Now that's the kind of
feedback that I like. Now we can talk.
Bigger wheels won't help. It would lift the towhook to high and then the van will run nose down and shift to much weight onto the ball (>80kg's) So, 4x small 13" wheels will give similar surface area that big 33" muddies and it will fit into the storage space at my place.
Also, 4 wheels will give me the option to let the front 2 down when on soft sand to "level" the sand while I could keep the pressure on the back wheels to carry the load when the surface suddenly change.
I've only got a small car and don't need a big 17" or 18" van.
And while were on the topic 4 wheels are much more stable in high winds.
Yes you can fit another axle, but as soon as you talk mods the
bright blue eyes from those who would do the work just turn into $$ signs.
FollowUp 1 of 4
FollowupID: 462324 Submitted:
Friday, Nov 03, 2006 at 07:51
Ian from Thermoguard Instruments posted:
Hi Lek,
OK, I see what your getting at. I have to question a couple of your points through. Nose up or down attitude won't materially alter the ball weight (it doesn't alter the horizontal distance between ball and the axle by more than a couple of mm). Also many high clearance 'rough road' vans have a 'dropped' coupling to better line up with the tow ball and maintain a level attitude. Lastly, your ball weight target seems very low. I'd expect a strongly built 15' pop-top to come in at 1300 to 1500kg fully loaded so, according to the experts, you should have about 10% of that on the ball: 130-150kg. If you tow vehicle isn't rated for these sorts of figures, I'd rethink the whole thing.
Now, back to wheels and axles. When I said "dual wheels" I meant dual wheels on a single axle, like on a small truck, not single wheels on tandem axles. As I said, I've never seen it done and it would certainly be a talking point wherever you went. But I can't see why it couldn't be done with proper engineering certification. Plenty of small trucks and large delivery vans run dual 13' or 14' wheels, don't they? And I've seen a few dual wheel, single axle trailers behind trucks from time to time. Just trying a bit of lateral thinking.
Ian
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FollowUp 2 of 4
FollowupID: 462449 Submitted:
Friday, Nov 03, 2006 at 17:23
Ian from Thermoguard Instruments posted:
Hi Lek,
Camper trailer and van axles with stub axles suited to Landcruiser and/or Patrol hubs & bearings are pretty common so I'd start by seeing if that size stub axle was shared by something like the dual axle hubs of Coaster/Civilian buses perhaps? (But maybe not, because the Japs are famous for making just about NOTHING common between different models).
There was a series of Mazda vans than ran 12" or 13" duals a one time too - don't know if they might be around the right size/load capacity. Ford Transit, Mercedes, Fiat, Iveco etc. vans also run duals in some models but we might be talking exotic prices for parts here.
Let us know how this project pans out, OK?
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FollowUp 4 of 4
