Morris Minor Owners Club

What tyre pressures would you recommend for a car carrying 43 stone and pulling a trailer?

Hi Elaine..
What size tyres and what size rims? (eg 145 radials on standard rims)

That's right Ray, 145's on standard rims.

Thanks

Elaine

I would use about 30psi

To quote the man who's always right...

Radials ( 145X14) were an optional factory extra from around the end
of 1968. The recommended pressures were 24 front and 26 rear.

You may want a few extra psi for laden - ie 26/28.
The trailer should be loaded so the hitch weight isn't excessive, but you may want to take the rears up to 30 to compensate.

I use 26 all round just to make the steering a little lighter for Em... Works very well.
Matt at 30 unloaded I would think you are only running on about 3/4 of the tyre width & will wear the centre of the tread out....

It doesn't seem to it is wearing quite evenly (apart from the front n/s where the chassis leg is bent )

For the trailer... the maximum towing weight of the Minor is 600kg. Now, trailer noseweights in earlier days were worked out as being 7% of the total trailer weight. Taking 600kg as the maximum tow for a Minor, the 7% rule gives a noseweight of 42kg, so it could be wise not to go over this. You can test it by propping the trailer hitch up on a block of wood on top of your bathroom scales, if you don't have a proper noseweight gauge.

The other way to test 42 Kg is that it is heavy, but the average person can lift it.

The 40 to 50Kg maximum also comes from the idiots guide to logic. You need some hitch weight so it is not trying to unhitch all the time, but not so much that you can't unhitch it at the roadside in an emergency. (not that you're going to have an emergency).

So if you can't lift 42 Kg, make it a bit less ;-)

Don't trailers have jockey wheels...? I'm thinking caravans, here, but it might be the same for a trailer...

What I'm thinking is, that all modern cars have a maximum hitch weight... Some 4x4's have up to 150kg (a standard AL-KO hitch is rated at 100kg), but some japanese cars (Toyota Avensis for one) have a rating of about 45kg.

There is no such weight for a Minor, but using the 7% rule, it would be unwise to go over 42kg, as the towbar mountings and chassis were not designed for that sort of downward, (perhaps pivotal) force. You don't want the whole shebang to land in a heap at the roadside...

If you can't lift 42kg (I probably couldn't... ) then obviously logic comes into play, but without a documented maximum weight, I'd personally take that.

Yes a decent trailer will have a jockey wheel, but even if it does it's safer if you can unhitch without it in an emegency. (eg. for when you get stuck half way round a U-turn on a busy road and people get impatient )

Oh dear... that sounds worryingly like the voice of experience talking....

Gareth,
you should see my local tip on a Saturday lunchtime!!
Far too much trailer stress

Our local tips dont like trailers.... we take the traveller instead...

Our local tip doesn't like anyone...

and the 42kg..... I lifted the engine from the morris accross the garage so we could do something (but I cant remember what) with it

the maximum towing weight of the Minor is 600kg

I was glancing through my drivers handbook, and happened to notice it says the Morris Minor 1000's max. towing weight is 762kg. Is the 600kg a reccomended max. towing weight so you don't struggle on steep hills etc?

762 kg just happens to be the weight of a 2 door Minor - I guess that Morris thought it was OK to pull it's own weight.

600 kg is now the maximum (legal) weight of an unbraked trailer.

I've just had a look through my original handbook (for a '62 948cc with a supplement detailing 1098cc differences) and it doesn't mention it...

Maybe it's in my workshop manual - I shall have a look...

Thanks for all the advice, I'll pump up the tyres nearer the time.

The trailer is Andy's department so I will show him all the details later