Morris Minor Owners Club

Dumb question time

Okay, so I recall that bulges are bad - my current set of Firestone's don't (as yet) appear to have developed the bulges that one of the last lot had, but at least two of them (it's currently raining, so I'm not completeing the service I was doing) - appear to have, well, indents.

They're about 3/4" wide and run vertically out from the rim to the outside, and only appear to be on the inside wall of the tyre. They're probably about 1/12" deep, if that (when cold), but once you know they're there they're quite noticable.

I have been getting vibration at about 70-75 mph, could this be the cause, and have I got a cruddy batch of Firestones? Or is it nothing to worry about.

I don't yet know if they get worse (indent / bulge wise) when hot.

1/2" deep!! that is definitely not right and sounds like a potential
accident, I would take an example to the nearest tyre depot and
ask their opinion. If they are 'indents' then you would expect them
to decrease as the tyre warms up but they should not be there.
Were they supplied by one of the Minor specialists??

Not half an inch... no. 1/12 of an inch! Well, between 1/12 to 1/16th of an inch - but this is when cold. I've now checked and it's the same on all 4 that are on the car. In the same place on each tyre too.

I've now checked and it's the same on all 4 that are on the car. In the same place on each tyre too.

Sometimes a bad indent can be caused if the inner bead has not seated evenly on the rim. However for a small indent, it may be just uneven joining of all the braiding (not nice though) - especially as it is the same on alll wheels.
If you jack the wheel a few mm off the ground and rotate it, you should be able to spot if the tyre circumference is miss-shaped.
If the circumference is affected then this can be related to your bad vibes.

For bulges, one common cause is that the steel braiding is disintegrating! Therefore a tyre with a bulge is an accident waiting to happen.

OH, sorry, but relieved, I have a brand new set of Firestones in
my garage, i will inspect them as soon as possible.

KATE, just for the record and as you would expect, I have checked
my set of unused new Firestones and there is absolutely no sign
of any indent on the side walls.