Tyres. Front tyres.

No, not a "which one" thread. More of a "when?" thread.

Look, this is a little embarrassing...

OK, modern front tyres don't have a whole hell of a lot of tread to
begin with. And I have real trouble deciding what's legal, and what's
not when they get worn.

My front tyres tend to "feather" in that the individual tread blocks
wear on the leading corner, so I end up with a tyre that looks pretty
worn and pretty new at the same time.

So how do you judge when it needs changing?

 

Same as it ever was - if there's still some rubber covering the canvas
there's still some life left.

 

Canvas !

Pah !

 

As I understand it, only the part of the tyre that has a wear indicator
is measurable.[1]

So if the outer most edge is wearing, but all the treat indicators
still have plenty of wear left to go, you're okay. Unless you break
through to canvas and/or steel.

[1] if you look at some of the big, no, BIG, tyres for Lambos and the
like, they are virtually slicks on the outer 2 inches when new.

 

With the ZRX it's when the bars start to wiggle at 35mph because the
tyre is so scooped.

With the 10R it's when they're about half worn, because I transfered
the last half used front over to the ZRX and stuck a fresh one on.

 

I tend to have mine replaced as a set, and the rear always wears out
first. I know I could save a few quid by stringing the front along a bit
longer but it hardly seems worth the effort.

 

You understand wrong.

It has to be within limits for a continuous unbroken area covering 3/4
(I think) of the width of the tyre. That is to say it can't be within
wear limits for the 1/4 nearest the edge on one side and the whole of
the other side, but it can be fucked for the quarter nearest the edge on
one side.

 

Yebbut, these days they're all tubeless, innit?

 

So tell me how that works on this:

http://www.ziemasriepas.lv/images/upload/MichelinPilotSportCup/large_Michelin_SPORT_CUP.jpg

given

that there is no measurable tread on the outer 1/3rd of the tyre when new.

 

This ties in with the way I work it. A front will last maybe 50%
longer than a rear tyre but if the front is fucked when the rear is
still good you tend to ignore it until both need replacing. Not a good
idea.

 

I got 6k out of a front with 3 rears

 

That's a funny looking bike tyre, particularly for a front.

From the MOT manual for bikes, grounds for failure include:

"The depth of tread is not at least Imm throughout a continuous
circumferential band measuring at least three quarters of the breadth of
the tread"

But since you're now talking about car tyres, the grounds for failure
for a car include:

"The grooves of the tread pattern are not at least 1.6mm throughout a
continuous band comprising 1) the central three-quarters of the breadth
of tread, and 2) round the entire outer circumference of the tyre.
Note: Each side of the central band of the tyre can be devoid of tread
(ie. ?bald?) and still meet the pass standard although in practice such
tyre wear is unlikely to occur. See diagram below"

 

Using the patented Mavis Beacon "Hunt&Peck" Technique, ogden

Except...

The GTR seems to do roughly 1.5 front tyres to 1 rear.

 

I'm sure there are a number of reasons I get less life from a rear than
you, not least the ripsnorting motor and my prolific wheelying.

 

I already was, but I hadn't realised that WUN wasn't, IYSWIM.

So, my point that, the outer edge can be near as bald as it gets, as
long as the actual tread pattern (which is the bit with wear
indicators), was about right then.

Thanks.

 

My technique was to go along to a UKRM French Run, and wait for
someone to say "fucking hell, you ****, you desperately need new
tyres".

 

I hope you're very happy.

 

If you ignore "and 2) round the entire outer circumference of the tyre",
sure

Sounds pretty scientific to me.

 

Called "cupping" around here. Some is normal, but low tire pressure
exacerbates it.

I could care less what's legal. I change tires when I don't feel safe
on them. Or when I'm traveling and know it'll be a while before I can
get a new tire. If there is any part of the tire where the tread has
disappeared, it's time to change, but I usually ride past where the
wear bars say. I was very surprised once to see a tire had worn to the
cords in one area, but had plenty of tread on the rest of the tire. I
spin tires all the way round now when checking.

 

ogden wrote:

I tend to sell the bike before it needs tyres and buy something
different