Intersesting, a little Bridgestone-heavy, but good info. I don't know
the source other than what it claims below, so take it for what it's

As you probably know, there is more rubbish talked about tyres than any
other motorcycle product - I've lost count of the amount of riders I've
spoken to who know more about what makes a bike handle than our
development riders, some of whom are former GP riders! Some of the
threads that I've read on various sites over the years have left me
amazed - some of the claims that owners have made for Brand-X tyres in
comparison to Brand-Y tyres go completely against all in-house and
independent testing that I have the results of. So I thought I'd try
and clear a way through the clutter and give you the definitive,
official Bridgestone UK line on our motorcycle rubber. If you abide by
this information you will have no handling problems, if you listen to
the bloke down the pub who thinks he knows better, you will have
problems. Trust me when I say that if the information the bloke down
the pub gives you differs from this information, he does not understand
tyres and how they work.
Choose the correct tyre:
I'll start with the one thing that many riders overlook - just because
a tyre is available in the sizes to fit your bike it doesn't
necessarily mean that it will suit your bike...not all tyres are
suitable for all bikes. For details on this see my comment below about
the BT-010 and the FZS1000. The BT010 is the UK's, if not the world's,
most popular sports tyre, and if we don't approve it's fitment on the
FZS1000 there must be a good reason. The same goes for other tyres in
our range - the BT-012SS fast road/track day tyre is too "full-on" for
the FSZ1000, the new BT-012 gives more than enough grip for this bike,
even for track day use. None of the major tyre manufacturers approve
the fitting of their entire range of tyres for every bike, and this
stands to reason - why should we expect an extreme-performance tyre to
offer its best when fitted to a bike that was developed for general
all-round riding? It's more important to choose the tyre that best
suits your needs and the bike's purpose. E.g. If you're going on a
European jaunt the BT-020 sports touring tyre would be a better choice
than the BT-010 or BT-012 sports tyres. If you use your bike for
transport as well as fun the BT-020 would again be the best choice. But
if all you use your bike for is fun and the occasional track day you
should probably choose the BT-010 or BT-012.
Don't worry about the grip available from your tyres. This may not be
something you're used to hearing, but grip isn't something you should
beworrying about - let us do that for you. The grip level available
from the latest sports touring tyres, such as our BT-020, is comparable
with full-on sports tyres of just five years ago. So don't worry about
grip, we've already got that sorted, concentrate more on what type of
tyre suits your purposes, and for that information see above. And don't
focus too much on the compound - there's a lot more to how a tyre grips
the road than just the compound.
If your tyre slips, don't automatically blame the tyre. Think about
where it happened - was the road surface contaminated, was it on a
greasy roundabout,was the road surface worn out? If the road surface is
not contaminated modern tyres give plenty of warning before they slide
and if you've ignored those warning signs you can't really blame the
Running tyres in:
Running tyres in takes approximately 100 miles and involves more than
simply scrubbing-in the tread surface of the tyre. When tyres come out
of the mould they have a smooth surface and to obtain optimum grip
levels this smooth surface needs to have it's entire surface
scrubbed-in and the best way to achieve this is not to rub the surface
with emery paper, but to go for a ride. The first few miles should be
spent riding upright so that you have a broad band in the centre that
has been scrubbed-in. You can then start increasing your angle of lean
while always keeping a portion of the scrubbed-in area in contact with
road. Scrubbing-in can be achieved by an experienced rider in as few as
10 miles, but this does not mean that your tyres will be fully run-in.
Running tyres in also involves seating the tyre on the wheel, and this
is not achieved simply by fitting the tyre to the wheel. Running-in
also allows all of the components of the tyre to seat in against one
another - by overheating a new tyre you can cause lasting damage that
means the tyre may not achieve its optimum mileage. While running-in
new tyres you should not subject them to hard acceleration or braking
One final point:
ITS MOTORCYCLE TYRES. New tyres feel slippery because they are very
smooth when they come out of the mould - see above. Riders who crash on
new tyres often try to blame releasing agent for the accident, but if
we don't use releasing agent how can this be? Actually, very few people
crash on new tyres, most riders are conscientious when running-in their
new tyres, but the vast majority of those who do crash on new tyres
usually admit to leaning their bike over at low speeds - junctions and
slow roundabouts are the most popular places. Think about it: when
traveling at low speed and leaning over there is very little force
acting upon a tyre to help it grip the road. Add in a brand new, smooth
tread surface and you have a recipe for a sudden slide.
Mixing tyres:
There is absolutely no point in mixing tyres on the same bike. e.g.
BT-010 front with BT-020 rear.
In the case of FZS600 owners, many did it because the 110/70ZR17 BT-020
was not available until early 2003 and if they wanted to use a BT-020
sports touring tyre on the rear they had no other choice. The problem
with fitting this mixed pair on this particular bike is that stability
is not as good as with a matched pair of BT-010s or BT-020s. And this
just highlights the possible pitfalls when fitting mixed tyres on any
bike - if one type of tyre is designed as a smooth handling, totally
neutral sports touring tyre and the other is designed as a rapid
steering, ultra responsive tyre, why should we expect them to work
together? If a bike doesn't handle when fitting mixed tyres it's not
going to be the tyre's fault.
But the main reason why riders fit mixed tyres is to supposedly benefit
from having a grippier tyre on the front while getting sensible mileage
from the rear tyre. Well...we kinda know this. We are, after all, the
biggest tyre manufacturer in the world and we really do know what we're
doing. We know that the demands placed on a front tyre are different to
the requirements of the rear tyre, and that is why the compound of our
front tyres is different to the compounds of our rear tyres. So the
front BT-020 compound is different to the rear BT-020 compound and the
front BT-010 compound is different to the rear BT-010 compound, etc.,
etc., all the way through our various ranges of tyres. Now that you
have this information you can see that it's pointless mixing tyres,
Bridgestone is already giving you what you want when you fit a matched
pair of our tyres.
Bridgestone approves the repair of it's motorcycle tyres in conjunction
with BS159f, which precludes the repair of punctures in Z-rated radial
tyres. Punctures are unfortunate and it doesn't help when the vast
majority happen in the more expensive rear tyre. This is usually
because the puncturing object, which was lying in the road, is kicked
up by the front tyre into the path of the rear tyre. I know that it
upsets a few riders that Bridgestone doesn't approve the repair of our
tyres, but we have valid reasons for this. As soon as an object
penetrates the tyre a steady progression of road contaminants starts to
enter the hole. By road contaminants I mean diesel, oil, chemicals
dropped by farm vehicle and trucks...all of the bad stuff that can
seriously effect the construction of the tyre. If, as is likely, these
contaminants settle between the tread strip and the carcass, a process
called delamination can start. Delamination is the separation of the
tread strip from the carcass and the first visible sign is a bulge in
the tread. If this bulge is not noticed the delamination process will
continue until a catastrophic failure occurs. Unless you're very
skilled or very lucky this usually involves crashing the bike as the
tyre disintegrates.
If you notice during your regular tyre checks that the tyre has a
penetrating object and you decide to have it repaired, do you know how
long the object has been in the tyre? If the delamination process has
started, plugging the tyre will not prevent it continuing.
If you get a puncture and the tyre gradually deflates as you are
riding, the chances are that the tyre is ruined beyond repair by the
time the bikes poor handling alerts you to the situation. An under
inflated tyre runs very hot and this can lead to invisible internal
damage. If the tyre deflates fast enough so that by the time you bring
the bike to a standstill the tyre is flat, the sidewalls will have come
under such strain that the heat generated will have ruined the tyre.
But just because Bridgestone doesn't approve the repair of our Z-rated
tyres, it does not prevent you having your tyre repaired by your local
fitter. If you are satisfied that the repair that they make will be
good enough then that is up to you. But I have to make it clear that if
the tyre has been repaired, Bridgestone will not guarantee any further
claim you may make on the tyre and neither will we guarantee the
quality of the repair.
Personally speaking I would never repair any motorcycle life
is worth more than the cost of a new tyre.