Morris Minor Owners Club

Im just cleaning up some rostyle wheels from an MG midget to fit to my minor, and I am wondering can I use the same wheel nuts as the original minor wheels?? Also what tyre width would give the best grip?? As I have read about as the tyres get wider they dont squat down so much and the contact area gets less... but I think that is only if you fit tyres that are much too wide. The rostyle rims seem wider than the minor ones.
help much appreciated,
Tim

Check the angle of the taper on both sets of wheel nuts, if they are the same then you should be able to use the minor ones, although a capped nut would look better as the nuts are now in clear view. I'd go for 165/175/60 section tyres.

Offer the Minor nut up to the wheel and look at it very carefully - but since they are from the same era I think they should be ok. I think Minors look slightly odd with 13" wheels - the wheel arches are too big and open. Using 60 section tyres will be too small - the rolling radius will be well down and the gap around the tyre in the arch will be even more obvious. I would go for 175/70 x 13.

so would 175/70R13 tyres be more or less the same rolling radius as the 14" wheels with crossplies?? As I would like to be able to keep the standard spare wheel in the boot and be able to use it.

If the others are radials, I don't think you'd be advised to use a crossply as a spare - not to mention the fact that it's illegal

Yes and scary to drive like that in the wet

Ok good point, so the crossply is out, and finding a fifth rostyle 13" wheel is no good because it wouldnt fit in the slot in the boot due to larger width. What size radial would I need to get for the 14" spare? has anybody else who uses non standard wheels come up with a good solution to the problem of not having a spare wheel?? or do you just do without one? I did find a rolling radius calculator thing on the internet somewhere but I cant find it now... many thanks for everybody's input so far,
Tim

picky,
let me know your email adress by PM and I can send you a simple excell file that'll let you calculate tyre sizes by yourself.
The calculation isn't difficult but laying it out on excell is a nicer way to compare a load of different options all together.

rayofleamington,
PM sent...
Tim

file is on its way

Tim,
This may be the tire calculator you mean.

http://www.miata.net/garage/tirecalc.html

Its certainly very useful.
Ian.

Just run a tape measure round each tyre and compare the result. A 145x14 radial fits in the spare well ok - in fact - so does a 155x14! I reckon 175x70 will still be slightly smaller rolling radius - but reasonably near.
Ian - what size 13" tyres did you use ? And what does a tape read round the inflated tyre ?

many thanks for the link and rayofleamingtons excel gadget, the diameter of the 14" 145 standard tyre is 587mm and the diameter of a 13" wheel with a 175/75 tyre is 592mm which according to the tyre calculator website makes the speedo 0.9% too slow... I dont think I will notice the difference in speed somehow! and I think that If I do need the spare it will drive ok if I buy a new 145 radial tyre for my spare wheel?? hopefully will be more comfortable and less shakey than the 10 year old crossplies...

Tim

Erm you're running on 10 year old crossplies? You're pictures suggest you're running a tuned motor as well?!

I know... and im getting sick of practically stopping before going round a corner just to stop it sliding all over the place. Yes the motor has all the tuning parts fitted and it does run but it needs a rolling road as its much slower than it should be.

So the 13" wheel with 175/70 tyre (you say 75 - is that a typo because I don't think there is sucha profile ??) is actually slightly larger diameter than the 14" with 145/80 radial ??

well the tyre size calculator link has a drop down list an 75 is on it, whether you can buy tyres like this I dont know! if you put in 175/70 then it says that the speedo will be 2% fast... so there is not much in it really. however a 185/70 tyre on the 13" is almost exactly the same as the 145 14" wheel.. only 2mm difference in diameter.

Some commercial vehicles and 4x4 use 75 hight. Normal cars don't.
No offence to the LCV drivers though

What exactly have you done to engine?
Ian.

That isn't a 'common' tyre size but they do exist if yuou loom around vey hard e.g. : Simex 175/75-13 85H
185/70 is much more common, but obviously you'll have to check lots of other things as well as overall diameter, whichever tyre you choose.