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Dual-tyre rims

A margin of safety
  (+4)
(+4)
  [vote for,
against]

A tyre blowout at speed can spoil your entire day.

However, with new BorgCo twin rims, you can reduce your risk of a trip to the emergency room, or indeed the mortuary.

The new twin rim, instead of being designed for a single tyre, has a partition in the centre such that two tyres, of half the width, can be mounted on it.

There are separate valve stems so that each tyre is pressurized independently.

If one tyre fails, the other will still support the mass of the vehicle and allow a controlled stop.

The contact area is slightly reduced, but the central gap allows more efficient clearing of surface water.

If tyres wear unevenly, then the fault can be corrected and the affected tyre swapped into a new position to make best use of the remaining tread.

The rim is a swap-in replacement for the standard factory fitted rim.

8th of 7, Jul 03 2017

[link]






       A vehicle can always be brought to a controlled stop, even with a sudden front tyre blowout. The only nuance is whether it is the driver or the laws of physics that afford the control.
MaxwellBuchanan, Jul 03 2017
  

       Dual wheels for trucks are WKTE. This just complicates matters by having a single (rather than separable pair) wheel.
Also, some time ago, I came up with the idea of using dual wheels connected by a (planetary) differential. A bit of digging found that it was a very old idea (1950s), that never really saw the light of day.
neutrinos_shadow, Jul 03 2017
  

       // This just complicates matters //   

       No, it doesn't. It's simpler. No spacer plates, no real change in the unsprung mass - only the extra central web to support the two inner tyre beads. Dual wheels require an axle designed to take them; this can be retrofitted to any axle.   

       In order to take dual wheels, in a "one in, one out" configuration (the rims are identical, and mounted "face to face" then there needs to be enough depth behind the hub for the inner wheel, and enough inset so the outer wheel doesn't protrude outside the wheel arch.   

       This design gives you the fault-tolerance of dual wheels in a simple easy-fit format.
8th of 7, Jul 03 2017
  

       )
MaxwellBuchanan, Jul 03 2017
  

       [8th of 7]: fair enough.
neutrinos_shadow, Jul 03 2017
  

       So this is to be an alternative to the current run-flat designs? Looks doable so long as the sidewalls do not rub one another.
whatrock, Jul 03 2017
  

       What stops stones and general grot from accumulating between the two tyres?
MaxwellBuchanan, Jul 03 2017
  

       Whatever existing dual-wheel designs have. Many types of van, bus and truck have paired wheels, and they seem to manage OK.   

       When at rest, there will be a small gap between the tyres - that should ensure that any contaminants fall, or get thrown, clear.   

       [what], it's likely that there will be sidewall pressure during normal running, but it won't be a rubbing contact, so there shouldn't be any abrasion.
8th of 7, Jul 03 2017
  

       A waterbed baffle type system could implement this on the inside, retaining the cost of one tyre.   

       Actually an orange segmentation would mean pin prick fault tolerance but catastrophic failure is the same. Structure valves would inflate from the centre out through levels of teardrops to tire tread.
wjt, Jul 04 2017
  

       If the single tyre is damaged, or wears asymmetrically, then it's a total loss.   

       With the twin-tyre system - and the tyres would be standard, off-the-shelf sizes - the unit cost of a damaged tyre would be lower; and a part-worn tyre can be swapped to a new location on the vehicle without compromising roadholding.
8th of 7, Jul 04 2017
  

       So taking the 15" tyre as a common size, the widths available for normal, as in non-super thin space saver tyres, run from 165-295mm. I also assume you'd need say 10mm for sidewall bulge clearance. So The narrowest common sizes, 165+10+165 gives you 340mm. Which is quite a lot wider than the rear tyres on a 911 turbo. So which two widely available tyres are replacing which single widely available tire?
bs0u0155, Jul 04 2017
  

       // 15" tyre // What?? 15" is teeny!
MaxwellBuchanan, Jul 04 2017
  

       Perhaps, morealso, this idea could be extended to tanks. Twin treads.
MaxwellBuchanan, Jul 04 2017
  

       //15" is teeny!//

Not everyone drives a penny-farthing [Max]. My wheels are 15" and my tires are 33". My front bumper is approximately 3 feet off the ground and a blowout of a front tire at high speeds would be catastrophic. Interesting idea. [+]
LimpNotes, Jul 04 2017
  

       //15" is teeny!// Personally I roll on 26x1 3/8 or 17 55/180 but neither would benefit from side-by-side tyres.
bs0u0155, Jul 04 2017
  

       Pirelli Sport Demons
normzone, Jul 05 2017
  

       //My wheels are 15" and my tires are 33". My front bumper is approximately 3 feet off the ground and a blowout of a front tire at high speeds would be catastrophic.//   

       Sounds like you're compromising the on road ability of your vehicle to gain off road competence. May I recommend going to full tank tracks? Solves the blow out problem, extra cool on the trail.
bs0u0155, Jul 05 2017
  

       //full tank tracks//

No. Extra cool yes, but ramp travel index is too low.
LimpNotes, Jul 05 2017
  

       If you increase the size of the tank to which the tracks are attached, the ramp will collapse obligingly into a much more manageable obstacle.
bs0u0155, Jul 05 2017
  

       Don't think my car is quite as extreme as LimpNotes', but my sunroofs are two metres from the ground, and I can sit upright and rest my back against one chassis rail while welding on the other. My wheels are 16" and I think my rolling diameter is 33" too.
david_scothern, Jul 07 2017
  

       Mine is not extreme, but the terrain (on roads even) can be quite featured. I need the articulation, and it is big, but anything too big becomes cumbersome as well. It's a balance of brute-force and dexterity and collapsing the path into submission may leave me wishing I had installed wings instead.
LimpNotes, Jul 07 2017
  

       14" rims, 26.5" tires : Truck looks best with 31's, but I don't need them.   

       I'ma [+] it but I see two issues   

       a) unless there's a sizeable gap, stones will get stuck in between.   

       b) the sidewalls - as well as being 4 of them - will need to be thicker/better reinforced... maybe a higher tire pressure ?
FlyingToaster, Jul 08 2017
  

       //unless there's a sizeable gap, stones will get stuck in between. // That's what I thought, but [8th] pointed out that twin-tyre lorries manage OK.   

       [edit] OK, googling "why don't rocks get stuck between twin wheels", surprisingly, yielded a result. They do, and there are various ingenious ways of removing them. Alternatively, they can be left in situ until one of the tyres is punctured; this seems to work quite quickly.
MaxwellBuchanan, Jul 08 2017
  
      
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