Can a 235/75 be used in place of a 31/10.5

Thanks for that, looks like another good idea bites the dust.
Thanks,Geoff

Shaker caravan axles are not drive wheels. Why do they have to be the same size

All the van wheels are braked so I assume that could cause some problems if the diameters are different.
Geoff

Doesn't have to be drive wheels, would you like to steer with a 2" tyre diameter difference?

Actually having wheels of different diameters will not affect steering. The main issue is a different height.

Think about tractors, the front of the tractor doesn't run away from the back. The bigger wheel will just turn more slowly. The brakes on the smaller wheel would definitely work harder though, and it's not something I would do permanently.

I looked into this a lot for my camper. I have the same wheels and tyres as the tow vehicle and 1 or 2 spares on that. When I put my bigger muddies ( 33 vs 31 inch) on, I wanted to just carry one spare most of the time and have tried it, it works fine. Tracks true. Having said that, I would only do it till I get to a tyre repair location though.

Tractors don't have different size wheels/tyres on the same axle.
Anyway, regardless of what you say or do, the law says wheels & tyres have to be the same on each axle!

Thanks for the legal advice Shaker. I am just commenting on the fact that it does work without steering problems. I have done it. If there is no diff and connection, there is no relationship between the wheel speeds and sizes at all, even if on the same axle.

So are you suggesting that you could put a 28" & a 33" on the front of your vehicle without affecting the steering?
Try it without power steering!

I reread my post 5 times and don't recall mentioning putting a 28" and 33" on the front of any vehicle. Or any vehicle.

Seriously Shaker, get a grip... of something else!

You have no idea what you are talking about. Best this for you to do is to remain silent, then you look smarter. LOL

I am alluding to the fact that there must be a cut off point where it does affect steering.
As far as your personal attack, what about your dumb reference to tractors?

Maybe I'll mention at this point, I signed RWCs in Victoria for 11 years & you can't have different size or construction tyres on the same axle, you can only have different tread pattern.

Good on you Shaker. Go for it man. You are obviously always right yeah?

Lets get one thing straight.

The 50mm increase in tyre size limit as discribed in VSB14 and in force on most states applies to motor vehicles and not trailers.
AS far as I have been able to establish.

The rules are far more lax for trailers.

As long as the tyres are otherwise compliant ( clearance, condition, so forth) as long as the tyres are larger ( greater diameter and or greater width) and of a higher load rating than specified on the tyre plackard if there is one....you should be fine.

NOW

start with ......is there a tyre plackard on this caravan or there is a tyre size specfied on the VIN plate....if there is, as long as the tyre is larger and of a higher load rating than specified on the plackard AND the tyres are the same size and profile..you should be fine.


235/75R15s will be smaller in diameter than 31x10.5R15s and narrower, they may however be of a higher load rating.

SO start with what is specified...if at all for that trailer.

If nothing is specified and or there is no tyreplackard...as long as the tyre is of sufficient load rating you should be fine.

There are complications like going considerably larger..like stepping from 14 inch rims to 15 inch rims associated with the de-rating of the axle for the larger wheels.

235/75R15s and 31 x10.5R15s are often run on similar sized wheels.

cheers

Yes tyres have to be run in pairs as same size and profile on the same axle.

cheers

Just to throw the cat among the pidgeons, what about those spaver tyres. How can they be legal?

wizzer

oh for an edit button. I meant pigeons and space saver tyre.

wizzer

There are specific rules & limitations pertaining to the use of space saver spare wheels.

You will find that space saver spare tyres are limited in the speed they can be run at and the distance that can be run.....and that distance is not far.

like 80kmh and 200Km is common.

cheers

I measured across the tread and its the same on both tyres, 235mm but the diameter is different as above.
Thanks, Geoff

G`day Rosco,
Mate, my 60 series L/C (March `85) has had Yokohama 31-10.5-15`s on 7" X 15" wheels since new, 350,000 klm with no problems.
Look up a tyre chart and I think you will find that a 7" width is listed for that size tyre.

Scrubby.

You are correct of course. Serious brain fade here. I'm running stock 265 on stock 7" rims ..... doh!!

........ and an even sharper eyed insurance assessor!

Legally bald is tread depth less than 3mm or approximately one-match head thickness, in the old rough and ready measurements.

If the tyre has tread depth markers - as many do today, then the markers level with the tread indicate 100% worn.

I see what you are saying, but a tyre is either legal, or not legal, bald is not legal. If it is past the markers it is illegal, if it not past, it is not legal.

NOW I have heard everything!

Thanks Penchy, I like a laugh every day and now I have already had today's.

Glad to help out the simple folk.

Ah-ha! - but you can do things that are illegal, but still safe to do.

Or you can do things that are unsafe, but not illegal.

When I chided an old mate about doing something illegal with his truck one day - he said - "I've been illegal all my life!! - and I'm not about to start becoming legal, now!! LOL