Thread: What did you do on your Perentie Today.

Picked up the County from the panelbeater - has had nothing done to it.

John

Changed my first flat tyre.

BTW, *why* cant you mix radial and cross-ply tyres on the same axle?

And if you have no choice, how many km can you travel before the vehicle explodes?

image.jpg

Originally Posted by DBT

Changed my first flat tyre.

BTW, *why* cant you mix radial and cross-ply tyres on the same axle?

And if you have no choice, how many km can you travel before the vehicle explodes?

image.jpg

The reason you can't mix the tyre type is that the adhesion characteristics of the two types of tyre are very different, so you will find very different handling depending on whether you are turning left or right. Few drivers are good enough to manage this safely.

How many kilometres you travel before the vehicle explodes will depend on what you hit when you leave the road, and how far you travel before leaving the road will depend largely on how much of a surprise the new handling is. I am sure quite a few people have gotten away with it without damage or injury, but in the event of an accident, you would be likely to find your insurer (and also the local plod) rather unsympathetic, especially if someone is injured or killed.

John

Well, i did make it home. Just.

However my actions had clearly upset a divine Authoriteh.

Huge thunderstorm pounded me all the way home. Thunder cracking. Trees exploding. Soft top leaking. Sound of driving rain making the (3) Hi-Milers sound like Eco tyres, by comparison.

Pulled into the driveway just as the house lost power.

As the engine cooled, the storm gradually receded to the horizon, where it watched to see if i dared venture forth again with the abomination of mis-matched tyres.

I didn't.

My apologies to the Universe.

Originally Posted by DBT

Changed my first flat tyre.

BTW, *why* cant you mix radial and cross-ply tyres on the same axle?

And if you have no choice, how many km can you travel before the vehicle explodes?

image.jpg

Probably no worse than driving with a spacesaver tyre, just go a bit slower.

Jeff

space saver tyres come with legal speed restrictions.

Different construction tyres on the same axle are grounds for a defect notice or a fail at a roadworthy, but if you had just fitted the tyre with your spare and were on the way to the tyre service, most coppers would not give you a ticket or canary the vehicle.

It was just to get home.

So while I am planning to send my sick Hi-Miler to the repair shop (can't see any evidence of a puncture), I have 2 Olympics and 2 Hi-Milers to keep things going.

I assume the Olympics would be best mounted up front?

Would make sense, As the spare Olympic is on the back and I'm a lazy ****, so there's more divine punishment for me right there.

So. Olympics up front and Hi-milers on the back.

After a day of driving I can say there definitely is a big difference in these two types of tyres.

Under steer has reduced drastically.

However, now the front end feels a bit ... skittish ... in a straight line.

First thing I did was pull over and check wheel nuts and tyre pressures. All were ok.

So now I'm wondering if I have excess free play in my steering box. And maybe the cross ply tyres were masking this somehow?

My theory: the cross-ply tyres are reluctant to change direction, thus they increase under steer. They also may "dampen" steering free play for the same reason. The radials give me cornering ability that is pleasantly surprising. Unfortunately they seem to like cornering so much, they want to do it all the time.

Maybe it was always there, but with more responsive radials everything is happening faster than before?

Driving today reminded me of that aviation design adage: You can have stability, or you can have performance.

Doesn't really make sense for road vehicles though.

Hmm.

So ... is my ball and nut stuffed?