Driving on a temp spare?

[euromodder]

IIRC, Continental made LRR tyres for the Loremo in 105/70 R14 .

Dunno if they would be happy to sell a few of them to you. Nor at what price.

[todayican]

Did a quick search, that size isnt horribly uncommon as a temp spare, I wonder... is it one in the same? :-)

[redpoint5]

I have used spares fairly extensively. I went up a very rough and long logging road in my Legacy and had a flat. The spare held up on the punishing decent, and then kept on going for another thousand miles before I got new tires.

A spare should easily hold up for your light loads, and I should think they are very fuel efficient considering the higher than normal PSI (about 60psi if I remember correctly).

The main reason people are advised to not travel far on a spare is because having different diameter tires stresses the differential. Further, the handling characteristics of a car will be adversely affected by the smaller, thinner tire.

[todayican]

Ta da! a real tire that will work for my project :-)
135R15 FIRESTONE F560 BLACKWALL TIRE

[morphector]

At least if you're heading to junkyard to get spare tire try to get them not too old because I wouldn't drive too much on a 15 year old tire

[redpoint5]

Originally Posted by morphector

At least if you're heading to junkyard to get spare tire try to get them not too old because I wouldn't drive too much on a 15 year old tire

Old spare should be fine since it doesn't get much UV exposure. The sun is really what kills a tire. I rode my dad's motorcycle in 2000, and it had tires from 1976. 24 years old and they held up just fine.

[CapriRacer]

Let's start at the beginning:

15" car tires on a 15" motorcycle rim: I hope everyone realizes that this is an incompatible combination. 15" motorcycle rims are build at 15.080", while the tires are designed for a 14.968" diameter rim! That may not seem like a lot but when the beads are seated, the bead has to go over a safety hump. That increase in diameter can result in tires exploding when they seat - very dangerous.

Temporary spares (for cars) are designed to a standard with a lower margin of safety than the standard for regular car tires - as are the rims. That's the main reason for the warnings.

Further, temporary spares are manufactured to minimal quality standards - for obvious reasons.

While it it may be hard to believe, wider tires are frequently more efficient. Here's the background on that:

Barry's Tire Tech

Lastly, temporary spares are not designed nor manufactured with any consideration for fuel economy. If fuel economy is the goal, then a better bet would be to use a car tire that has been designed for fuel economy.

TodayICan: I realize this throws a monkeywrench in your planning, but I would suggest that you rethink the use of motorcycle rims with temporary car tires.

[todayican]

Well Capri, I have good news and bad news... :-)

I found "proper car tires" over at Coker tire 125-70r15 so Im liking that

On to this rim size mismatch thing...

with it being a couple of hundredths off, are we talking "be a little more careful mounting it" or "are you #$@&%ing crazy??"

Any ways to make the process easier / safer? putting the tire in ice water to contract it a touch?

Dunno, stabbing in the dark, it sure would be a toughee to figure out how to make a car wheel do what the motorcycle wheel can do so easily.

[todayican]

Im wondering, is the rim size mismatch consistant over other MC rim sizes as well, 16" 17"?

[Ryland]

Avon SM Mark II motorcycle tires are sold as a suggested tire for use with side cars on motorcycles, side cars do not lean, they are also labeled for use as a rear tire on a motorcycle, they have a 5" by 16, a 4" by 18" a 3.5" by 19" and a 4" by 19" listed in the motorcycle parts catalog in front of me, otherwise checking to see what is sold as OEM on Urial motorcycles might be a way to go as well as they tend to be sold with side cars as well.
I've only mounted motorcycle tires on motorcycle rims but the sizes are close enough that I would personally give it a try but you are either going to want to take the risk your self and mount them your self or give the person mounting the tires fair warning! but with the rout you are going the car tire is going to be going on a rim larger then it was designed for, if it was the other way then it seems like everyone would be in greater danger, but your first test is to see if the tire will even stretch over the motorcycle rim.