12in wheel for a spare?

[asianflava]

I want to get a spare tire for the IRG trip. I was thinking about just getting a 12in trailer wheel and tire from HF or Wally World. I think that it will be considerably smaller than the 175/75-14 tires that I'm currently running. I'd like to use the smaller tire so that it doesn't take too much room in the car.

I guess I also have to find out how much smaller they compared to the setup I currently have.

Are there any dangers, or harm that can happen from doing this?
.

[SteveH]

Rocky,

Obviously it will sit lower on that side if you have to use it, but as long as nothing drags the ground, I don't see why it wouldn't work. I carry one of the small temporary spares, and it's a lot smaller than the ones on the trailer. I did use it once on a boat trailer, and while pulling it I couldn't tell the difference.

[angib]

A 175/75-14 will have a diameter of about 24.5" and a 12" will have a diameter of 21" (4.80-12) or 22" (5.30-12), so the side with the spare will ride about 1.5" lower than standard. It shouldn't present any sort of problem although the trailer will be trying to track a little to one side (due to camber thrust) - this probably won't even be noticeable in the tow vehicle, but it is a reason why you shouldn't go too far or too fast in this condition.

Incidentally, a UK motoring TV programme did a fascinating piece recently on space-saver tyres. As we've all got them but have never used them, they tried them out on a race circuit. They demonstrated that the 50mph speed limit is for real - they will blow up if abused above that speed, but we're talking about sliding the car sideways to do it. They ended on a good laugh by fitting four space-saver spares to an old Civic and then thrashing it round the circuit - its ability to stay on the track was somewhat limited, but it looked like fun!

Andrew

[Kurt (Indiana)]

I want to get a spare tire for the IRG trip. I was thinking about just getting a 12in trailer wheel and tire from HF

Are there any dangers, or harm that can happen from doing this?
.

AF I ran my 12" spare for about 65 miles with out a problem. My normal set up is P195 15.

It worked OK for me.

[hammer & tongs]

On my new build I plan on carrying a 12" wheel as a spare...while the trailer wheels will probably be 15"ers.
As long as nothing drags...shouldn't hurt anything.

Many automobiles (some costly) use those little cheapie "sausage spares"...and they are meant for either the driving or idling wheels, even though the size differential between spare and regular tire is great .