“tyres out of shape” MOT failure

Well that’s a new one on me, plus the fronts are both worn handily on the inside apparently, so four new tyres to pass MOT yet nothing mentioned when serviced elsewhere less than 1 month & 1200miles ago…

Don’t pay for the tyres until you’ve had a look yourself? The wear is easily checked just by turning the steering to full-lock and having a look. The shape (sounds like a Maxxis MTB tyre) can be checked by (carefully) jacking up a corner and spinning the wheel

On all four? If so what have you been doing to them ?

A lot of places won’t look at the tyres for a service. They will just do the required service items and that’s it!

As Mashr says, get a check/second opinon. Easy enough to check tyre wear – have they clarified what they mean by out of shape?

have they clarified what they mean by out of shape?

Do these tyres exist in an obesogenic environment?

I just had my car serviced two days ago and the guy said my rear tyres were worn (down to 2.5mm on edges) and ‘out of shape’. He reckoned it would be an MOT failure as well.

I’ve had a tyre “egg” before on a car – nothing much you can do, just need another to replace it.

Don’t pay for the tyres until you’ve had a look yourself?

This then becomes one of those cases where the MOT rules deviate from what’s sensible and what might get you in trouble at a vehicle checkpoint.

The MOT manual says the tread has to be measured in the main circumferential grooves.  So if the blocks on the inside / outside edge wear off it’s not an MOT fail right down until the chords are exposed.

The inner edge of an asymmetric tyre is doing the bulk of the water clearing (the outer edge is there with bigger blocks for cornering grip) , so if those grooves disappear then water clearing is inhibited.

DVSA checks on the other hand can be stricter they measure the actual width of the tyre and then check the depth ~12.5% in from each edge.

TINA that 12.5% in from the edge is the correct limit, but anybody inspecting a tyre will usually only check the centre, unless there is a reason to check nearer the edges.

The comment about main circumferential grooves, is because that is where you measure the tread depth. Any grooves across the tyre are rarely at full depth, and don’t count for tread depth.

If you’re ever in any doubt as to where it should be measured, look for where the tread wear indicators are moulded into the main tread.

Out of shape is fairly specific, and should only apply to obvious tread deformities, which would indicate the tyre carcass is failing. Uneven wear isn’t out of shape.

Hitting potholes/kerbing a tyre can easily cause it to go out of shape.  Run your hand round the sidewalls see if you can feel any lumps.

Google “tyre sidewall bulge” and you’ll see what you’re looking out for

have they clarified what they mean by out of shape?
Do these tyres exist in an obesogenic environment?

That only pertinent to Spare Tyres isnt it?

Well the fronts had the weirdest wear pattern on them, both almost like the inner shoulder had been gouged out & the rears are fairly old anyway, so at that point I just booked them in for 4 new all seasons + balancing & tracking.

Thought I’d been pretty good at checking them too, obviously need to check the inners more thoroughly – fronts were cheap ones the garage put on them when I bought the car so can’t complain too much.