Tyres - crossply versus radial

Post by **d_harris** » Fri Aug 06, 2004 11:03 am

I believe that it is acceptable to the MOT man to have 2 radials on the front and 2 crossply on the back. or the other way round. Perhaps its worth having a look at Technical tips on the main section of the website, I seem to remember something about crossplies/radial combos and the legal situation. May be wrong tho

Post by **rayofleamington** » Fri Aug 06, 2004 11:14 am

I think that you were not meant to mix them on the same axle
I remember the government TV adverts from the 70's showing (i think) a red Austin 1100 that drove along a road then some tyre screetching noise then the car miracurously ended up on its roof - (using Dr.who stylie special effects [ie - none])

Realistically you shouldn't mix them at all as it is not worth the risk.

Post by **Cam** » Fri Aug 06, 2004 11:31 am

Dr.who stylie special effects [ie - none]

Watch it!!

Post by **pskipper** » Fri Aug 06, 2004 11:39 am

Dr.who stylie special effects

Surely that would have been them inverting the colours and making it flash! (Although people could have become confused and thought that mixing tyres led to Dalek attacks)

Post by **d_harris** » Fri Aug 06, 2004 11:41 am

I think that you were not meant to mix them on the same axle

Thats what I was getting at!

Post by **Alec** » Fri Aug 06, 2004 11:43 am

Hello all,
if you have a mixture of cross ply and radial ply, then each axle must be the same and radials can only be on the back axle. The other way round doe sgive "interesting handling" i.e. rapid oversteer.

Alec

Post by **Pyoor_Kate** » Fri Aug 06, 2004 12:40 pm

Aye, it's an 1100 that ends up on its roof. Although you don't get to see the transition from right way up to upside down. I have the advert on my DVD of public information films.

Incidentally, don't watch 104 public information films in a row, it does bad things to your head.

Post by **Cam** » Fri Aug 06, 2004 12:45 pm

I have the advert on my DVD of public information films.

VERY cool!

Post by **d_harris** » Fri Aug 06, 2004 12:46 pm

They should have got basil and his branch to demonstrate what happens when you mix tyres.

if you can find a better quality one, stick it on for me please?

Post by **Cam** » Fri Aug 06, 2004 12:48 pm

Post by **d_harris** » Fri Aug 06, 2004 12:51 pm

Yeah, I just found that exact one. I searched for fawlty towers austin rather than fawlty towers car.

Post by **Cam** » Fri Aug 06, 2004 12:57 pm

I searched for Austin 1100

Post by **Willie** » Fri Aug 06, 2004 7:38 pm

ROSIETHEMORRIS....You should fail the MOT if you have
radials on the front and cross plies on the rears as it is ILLEGAL,
(and lethal) Swop fronts to rears or better still buy another
pair of radials (or three if your spare is a cross ply). What you
are driving is a car with excellent grip on the front and very
poor grip by comparison at the rear so you will ,sooner or later,
find yourself spinning out of control.

Post by **Leyland** » Sat Aug 07, 2004 12:03 am

All you folk out there running on Firestone radials, are you using inner tubes or just running on the tyre.
There appears to be mixed views about this.
Any furhter comments would be helpful.
I have now ordered myself some Firestones.
Ty

Post by **Kevin** » Sat Aug 07, 2004 9:30 am

TY you are right when you say there is a division on wether tubes should be fitted or not, the owners club orginally said they should be fitted as thats what the rims were designed for but that has now changed as they have had to agree that modern radials are designed to run without tubes and the inside surfaces are rougher than crossplies and could cause problems with the tubes getting abraded by the inner surface.
Personally I prefer the tubeless method due to the above reason and recently I had a slow puncture on my saloon and when I took it into my local tyre place it had a tube in it (no I not noticed before as all the others havent)
and the source of the leak appeared to be an area not far from the valve itself with a very slight rub mark so it appears there is some truth behind not having a tube with radials and in the couple of months since having the tube replaced with a valve there have been no problems.
I know some say that with radial rims they have a lip that retains the radial better than the minor rim and this could cause a problem but I think if you wack a kerbstone or similar you are not doing the rim any favours any way, also within our branch many are running tubeless and so far I cannot rremember a single problem, the only thing is that the inner rims may need to be cleaned up a bit if they look tatty, well thats my pennyworth I am sure others will comment.

Post by **Willie** » Sat Aug 07, 2004 3:56 pm

Yes this is a common topic on here. The Minor rims are not
designed for tubeless tyres, but,provided that the inner edges
are in reasonable condition you are unlikely to suffer any problems
from going tubeless and it makes you safer in respect of the fact
that if a nail penetrates your tyre it will not deflate rapidly,if at all,
whereas, if you had an inner tube it would deflate immediately.
The Minor was not designed for Radials for the sole reason that
they were not available until near the end of production. It is
significant that the workshop manual includes details of fitting
tubeless radials because they were made available as a factory
option towards the end of production.

Post by **rayofleamington** » Sat Aug 07, 2004 4:23 pm

an area not far from the valve itself

splitting near the valve is quite common on old tubes - however as its a few inches from the tyre it makes me wonder why you think the inner edge of the tyre caused it.
I've had a number of problems using old rims without tubes and it's usually solved by fitting a tube (or by scrapping the rim if I had a spare one around). The sealing edge of the rim is prone to corrosion, and once it is corroded it makes slow deflation inevitable if you are tubeless.
To avoid it, you need a good rim that has been well prepared and painted with the tyre off, or fit a NEW tube - don't bother with old tubes.
Never leave the tyres deflated (with or without a tube) as this allows water down the side of the rim and yet more corrosion.

Post by **aupickup** » Sat Aug 07, 2004 4:55 pm

i hjave been running without tubes for 6 years in my mogs and no problems

Post by **rayofleamington** » Sat Aug 07, 2004 5:36 pm

Out of 10 moggies I've had in the last 17 years I've had at least 4 wheels where the pressure leaked via the rim (one more if you include one that I was given because it was leaking). Most were fxed by using tubes and 1 or 2 were thrown away as the tyre wasn't worth the effort.

I'm 100% sure loads of people have no trouble without tubes, however some rims will need them.

Post by **Willie** » Sun Aug 08, 2004 5:57 pm

Yes, as RAY knows(because he supplied me with a replacement
wheel) I have had ONE tubeless failure in over thirty years due
to the fact that the rim was badly corroded around the valve area.
It is worth noting that if you have leakage around the rims the
tyre fitters should have a pot of 'special brew' which they slap
on the rims as they fit the tyres. This seems to sort most problems.