tyre question

[roversmith]

We have just picked up a 1955 107. the motor sounds healthy, but the tyres are very perished. I have some 235 85 16 tyres and the question is would it be over geared if I fitted them. It's running 7.50 16s on 5.5 rims at the moment, but the tyres are that bad that I'm not game to get it up to speed. Thinking of putting it on club plates and doing the odd trip just to remind us how far things have come.


Cheers Greg

[JDNSW]

The diameter of the tyres should only be about half an inch larger than the 7.50 tyres, but your problem is that the 235 is really far too wide for the 5.5 rims. You can probably get them on, but no self respecting tyre place will be prepared to fit them, and I would be reluctant to use them at any speed.

John

[roversmith]

Thanks John, I suspect that you are correct, even 7.50 should be on 6.00 rim. I was more interested in peoples opinion whether the 2 litre would pull top gear with this diameter tyre. I have plenty of 7.00 disco rims but that would just be uncool.


Cheers Greg

[slug_burner]

Should be ok on the 235 85 16 from a diameter perspective. 5.5" are what defenders came with on 750x16. A quick look up on a tyre manufacturer's web site will tell if the tyre rim combo is as per OEM recommendations.

[wrinklearthur]

Try find a tyre with the same rolling radius as the original 7.00 x16, have mercy on your very old half shafts.
.

[roversmith]

[QUOTE=wrinklearthur;2368208]Try find a tyre with the same rolling radius as the original 7.00 x16, have mercy on your very old half shafts.


Funny that you should mention that Arthur. I just happen to have a s1 109 full floater rear diff, and a mate in Melbourne that makes axles. Yet to be seen how adventurous we get.

[JDNSW]

Thanks John, I suspect that you are correct, even 7.50 should be on 6.00 rim. I was more interested in peoples opinion whether the 2 litre would pull top gear with this diameter tyre. I have plenty of 7.00 disco rims but that would just be uncool.


Cheers Greg

Perhaps someone should have told Rover about that when they started putting 7.50x16 on 5.5" rims in 1958 and ever since.

As pointed out by others, even 7.50 is asking a bit much from the 2 litre engine, although I was doing that in the early sixties, and don't remember seeing it as a problem, although that was in an 88.

John

[roversmith]

I think that I will us the scientific approach.


Suck it and see.


Cheers Greg

[Rick Fischer]

Reckon you should go for cross ply RTMs or similar, perhaps bar treads if you can find them.

Old xply cars really don't mix well with modern radials. Too much steering load. Some old "original" design radial Michelins might work.

The actual tyre design term is "Cornering Force" and radials have too much.

Cheers

RF

[gromit]

I've got 7.00 x 16's fitted to my Series I, I managed to get a set of new Road Trek Majors.
In 2008 I took it to Cooma and it could hold 50mph without any problem and it occasionally saw 55mph (speedo was checked with a GPS and is reasonably accurate).
There were a couple of hills approaching Cooma where I was down to second gear and it sat at 26mph, wouldn't go any faster but would just hold that speed.

The motor condition is unknown, vehicle is unrestored.

1956 Series 1 with PTO welder (home made)


Colin