Wilde
Registered user
36 42 here too. Planted!
Wilde and Insane
Wilde and Insane
2010 GSA Tyre Pressures
- Thread starter The Moose
- Start date
Bendy toy
Registered user
Tyres change all the time so it makes sense to use the tyre maker's recommendations rather than something written years ago when the bike/car was built.
Another vote for 36/42 here.
If you want to know what Valentino Rossi would recommend try asking AndyB or Newboy who ride similarly -just ask any Mountie.
If you want to know what Valentino Rossi would recommend try asking AndyB or Newboy who ride similarly -just ask any Mountie.
I would have to agree, just had a pair of standard tourances fitted, before I refitted the wheels I checked the pressures, 42/36, dropped them to 36/32 and it's feels great to me, just been hauling through the picos in Spain fully loaded and they feel superb even on wet roads
The Moose
Registered user
Interesting what you and mpgscott have said.
Yesterday was fucking disgusting after I adjusted the pressures on the way home, but was out on it again today. I went to 36F/42R.
On the way home last night, I had a bit of a wiggle moment from the front end on a country lane - I assumed I'd just hit a patch of shit in the middle of the road...which I probably did do, however I hadn't experienced the same thing previously.
Today at speed (70-100) on the motorway the front end didn't feel as planted and the bike didn't inspire the same confidence.
Previously I was running 32F/32R, so I'm going to go back to 32F and a touch more in the rear - probably 34-36R and see what I think from there. I don't know if it makes any difference, but I have the Wilbers shocks. On the way in was on Sport, on the way home Comfort and got the same wiggle.
I will update the thread just incase anyone is interested in my tyre pressure ramblings.
(I understand most people don't find it particularly interesting, but having spent a bit of time racing cars, I find it fascinating)
36 front 42 rear
An interesting article copied verbatim from an old MCN.
It goes someway to explain why BMW suggest one tyre pressure when riding a bike solo, two up, with luggage, slow and fast.
It's important to be pumped
Tyre pressures are a crucial factor in determining how your bike handles and how
quickly you wear out your (not exactly cheap) tyres.
There are lots of myths and misconceptions about what pressures you should run in
the wet, on track days or when you're loaded with luggage. Usually you'll find someone
propping up the bar who knows better than the manufacturers' recommendations. To
find out how close they are to being right we talked to a genuine expert - a man who
should know tyres if anyone does.
Leo Smith spent years as chief development tester at Avon tyres. He is now
motorcycle product manager. He said: "We probably get asked more about tyre
pressures than about any other aspect of a tyre”. There's so much bad information
kicking about that people can't separate the truth from fiction."
Smith says that is largely the fault of tyre companies themselves. Several years ago,
different tyre companies recommended different pressures for different tyres and
different bikes. But around 10 years ago, a decision was reached between the
companies to standardise pressures so that most bikes can run on the same no matter
what tyres they're on. That standard is 36psi at the front and 42psi at the rear.
There are some exceptions, like some 400cc grey imports which run 29psi at the front
and 36psi at the rear. Another notable exception is the Kawasaki ZX-12R - which is
meant to run 42 front and rear. But if you've got a modern, mainstream bike,
chances are you should be running the 36/42 standard.
That 42 figure in particular will have a lot of the gentlemen at the bar shaking their
heads. But it is not a figure chosen at random. Pressures determine how your tyres
deflect. The lower the pressure, the more the tyre will flex. That may make for a
comfortable ride when you're cruising in a straight line, but the tyre will flex too fast at
speed and make your bike unstable. The bike will feel vague going into turns and feel
like it's going to tip into the corner suddenly. This is because the tyre isn't "strong"
enough and it's literally buckling under you.
The bike will also feel wallowy through turns and it'll weave under acceleration.
Conversely, if you over-inflate a tyre, the flex will be slower but that will make your bike
more stable at high speeds. The ride comfort and the tyre's ability to absorb shocks will
be lost and your wrists and backside will take the brunt of it. The bike will feel so harsh
that many people will think they have a suspension problem.
Cornering won't feel as bad as when pressure is too low, but you will again lose feel
and feedback from the tyres. For example, if you ride over a stone, an over-inflated
tyre cannot absorb it and the tyre breaks contact with the road. Smith says the classic
myth about tyre pressures is that you deflate them for wet-weather riding. He says
most grip comes from the tyre's compound and the contact patch - and the shape of
the tyre where it contacts the road is everything.
Tread patterns stop water from building up under the tyres - which could cause a bike
to aquaplane. Smith says: "A good front tyre chucks enough water out of the way to
enable the rear to get the power down. If you reduce the tyre pressure, the tread
becomes compressed so it can't clear as much water." If anything, Smith recommends
you increase the rear tyre by 2-3psi in the wet but leave the front as it is.
Another widely held misconception is that the psi recommendations are the maximum
the tyre can take. They're not. The figure only tells at what pressures the tyres were
tested at for all-round use. You could actually safely inflate a type up to around 50psi if
you really wanted to, although it wouldn't do you much good.
But the biggest area for debate has to be track days. If you've ever been to one it's
almost certain someone has told you you'll be best off reducing your tyre pressures.
You get more grip that way, they tell you. Smith has radically different advice.
You should leave them alone, he says. "Racing tyres are of a totally different
construction and stiffness to road tyres so they need less pressure to maintain the
carcass shape. That's where the rumours and bad advice comes from. "If you drop the
psi in road tyres you will get more movement in the tread pattern. They will heat up too
much and that will eat into tyre wear. You'll almost certainly ruin a set in a day without
gaining any advantage in grip."
Smith says he's known people to drop their rear tyre to just 22psi when heading for the
track. His advice is to leave your tyres alone, saying a good tyre at standard pressures
will give more grip than you need on a track day because you almost certainly won't be
going as fast or for as long as racers. Track surfaces offer much better grip than the
road, too - another reason for leaving your tyre pressures the same for the ride to the
track as for the ride around it.
Many people also ask the experts at Avon if they should increase psi to take pillion
passengers. Again there's no need. The manufacturers' agreed pressures of 36/42
were arrived at after testing with pillions, luggage, cold tyres and every other
combination you could think of.
One of the few cases when Smith does recommend you change your pressures is
when your tyres wear. A worn tyre has lost a lot of its strength as the shape and
flexibility levels have changed. That means it will handle differently to a new tyre. Try
increasing the tyres by 2psi when you're down to around 40 per cent tread depth. It will
only make a marginal difference, but it should improve your bike's handling a bit.
You may not have to keep changing your tyre pressures, but you do have to maintain
them. Smith recommends that you check them once a week as an absolute minimum
but to be extra safe, you should really check them every day because a tyre can
change by as much as 3psi on its own just because of changes in the weather.
You should always measure your tyre pressures when they are cold. A few bikes are
now coming with tyre pressure gauges in their under-saddle tool kits. If you haven't got
one it's worth buying one. They only cost a few quid and take up about as much room
as a pen. Forecourt gauges are notoriously inaccurate.
An interesting article copied verbatim from an old MCN.
It goes someway to explain why BMW suggest one tyre pressure when riding a bike solo, two up, with luggage, slow and fast.
It's important to be pumped
Tyre pressures are a crucial factor in determining how your bike handles and how
quickly you wear out your (not exactly cheap) tyres.
There are lots of myths and misconceptions about what pressures you should run in
the wet, on track days or when you're loaded with luggage. Usually you'll find someone
propping up the bar who knows better than the manufacturers' recommendations. To
find out how close they are to being right we talked to a genuine expert - a man who
should know tyres if anyone does.
Leo Smith spent years as chief development tester at Avon tyres. He is now
motorcycle product manager. He said: "We probably get asked more about tyre
pressures than about any other aspect of a tyre”. There's so much bad information
kicking about that people can't separate the truth from fiction."
Smith says that is largely the fault of tyre companies themselves. Several years ago,
different tyre companies recommended different pressures for different tyres and
different bikes. But around 10 years ago, a decision was reached between the
companies to standardise pressures so that most bikes can run on the same no matter
what tyres they're on. That standard is 36psi at the front and 42psi at the rear.
There are some exceptions, like some 400cc grey imports which run 29psi at the front
and 36psi at the rear. Another notable exception is the Kawasaki ZX-12R - which is
meant to run 42 front and rear. But if you've got a modern, mainstream bike,
chances are you should be running the 36/42 standard.
That 42 figure in particular will have a lot of the gentlemen at the bar shaking their
heads. But it is not a figure chosen at random. Pressures determine how your tyres
deflect. The lower the pressure, the more the tyre will flex. That may make for a
comfortable ride when you're cruising in a straight line, but the tyre will flex too fast at
speed and make your bike unstable. The bike will feel vague going into turns and feel
like it's going to tip into the corner suddenly. This is because the tyre isn't "strong"
enough and it's literally buckling under you.
The bike will also feel wallowy through turns and it'll weave under acceleration.
Conversely, if you over-inflate a tyre, the flex will be slower but that will make your bike
more stable at high speeds. The ride comfort and the tyre's ability to absorb shocks will
be lost and your wrists and backside will take the brunt of it. The bike will feel so harsh
that many people will think they have a suspension problem.
Cornering won't feel as bad as when pressure is too low, but you will again lose feel
and feedback from the tyres. For example, if you ride over a stone, an over-inflated
tyre cannot absorb it and the tyre breaks contact with the road. Smith says the classic
myth about tyre pressures is that you deflate them for wet-weather riding. He says
most grip comes from the tyre's compound and the contact patch - and the shape of
the tyre where it contacts the road is everything.
Tread patterns stop water from building up under the tyres - which could cause a bike
to aquaplane. Smith says: "A good front tyre chucks enough water out of the way to
enable the rear to get the power down. If you reduce the tyre pressure, the tread
becomes compressed so it can't clear as much water." If anything, Smith recommends
you increase the rear tyre by 2-3psi in the wet but leave the front as it is.
Another widely held misconception is that the psi recommendations are the maximum
the tyre can take. They're not. The figure only tells at what pressures the tyres were
tested at for all-round use. You could actually safely inflate a type up to around 50psi if
you really wanted to, although it wouldn't do you much good.
But the biggest area for debate has to be track days. If you've ever been to one it's
almost certain someone has told you you'll be best off reducing your tyre pressures.
You get more grip that way, they tell you. Smith has radically different advice.
You should leave them alone, he says. "Racing tyres are of a totally different
construction and stiffness to road tyres so they need less pressure to maintain the
carcass shape. That's where the rumours and bad advice comes from. "If you drop the
psi in road tyres you will get more movement in the tread pattern. They will heat up too
much and that will eat into tyre wear. You'll almost certainly ruin a set in a day without
gaining any advantage in grip."
Smith says he's known people to drop their rear tyre to just 22psi when heading for the
track. His advice is to leave your tyres alone, saying a good tyre at standard pressures
will give more grip than you need on a track day because you almost certainly won't be
going as fast or for as long as racers. Track surfaces offer much better grip than the
road, too - another reason for leaving your tyre pressures the same for the ride to the
track as for the ride around it.
Many people also ask the experts at Avon if they should increase psi to take pillion
passengers. Again there's no need. The manufacturers' agreed pressures of 36/42
were arrived at after testing with pillions, luggage, cold tyres and every other
combination you could think of.
One of the few cases when Smith does recommend you change your pressures is
when your tyres wear. A worn tyre has lost a lot of its strength as the shape and
flexibility levels have changed. That means it will handle differently to a new tyre. Try
increasing the tyres by 2psi when you're down to around 40 per cent tread depth. It will
only make a marginal difference, but it should improve your bike's handling a bit.
You may not have to keep changing your tyre pressures, but you do have to maintain
them. Smith recommends that you check them once a week as an absolute minimum
but to be extra safe, you should really check them every day because a tyre can
change by as much as 3psi on its own just because of changes in the weather.
You should always measure your tyre pressures when they are cold. A few bikes are
now coming with tyre pressure gauges in their under-saddle tool kits. If you haven't got
one it's worth buying one. They only cost a few quid and take up about as much room
as a pen. Forecourt gauges are notoriously inaccurate.
Bendy toy
Registered user
Also get a 90 degree valve adaptor. Many garage air sullied won't work with bike tyres and especially not with solid valves like our TPS valves.
Nobody ever defines what a "cold" tyre actually means to the touch. But if the tyre just feels warm I pump it up anyway. 1psi low is better than 10psi low
Nobody ever defines what a "cold" tyre actually means to the touch. But if the tyre just feels warm I pump it up anyway. 1psi low is better than 10psi low
Italia-GSer
Registered user
Hey guys, Iv'e just taken off a very worn rear Bridgestone Trailwing which came with the 2003 1150 GSA (it was sliding a bit under braking) and fitted a new rear tourance inflated to 36 as it says in the book. I also took the front up to 31.9 as it was on 19!! Problem is that (and I know that the new rear has to be scuffed up to take of the new tyre surface) the bike now feels as if the road is made of sheet glass, with cooking oil on it! It just feels really unstable, whereas it was pretty chuckable before. Anyone got any ideas? Am I doing/have I done something dim!!??
Any thoughts much appreciated.
Dan
Any thoughts much appreciated.
Dan
Deleted account 190920001
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Try running the pressures that 95% of this thread recommends i.e 36/42 Your probably also feeling the affect of a new round tire which is going to tip in a lot quicker that an old squared off worn tyre.
Dan, you mention a new rear tyre; did you also change the front tyre ? A worn tyre & a new tyre don't make the best combination.
Bendy toy
Registered user
I wear out two rear tyres to one front tyre and don't fuss if they are from different manufacturers. I run 36/42 and have no handling worries. I carry an angled tyre valve adaptor so no worries about garage forecourt air pumps not fitting.
My rear tyre is now (well) overdue for replacement. The bike has hardly squared it off at all, so I have very not much tread down the middle and more than 2mm on the shoulders, but apart from a diesel slick it was fine this morning on wet A Roads in Devon. My front is still legal but I will be fitting a new pair very soon indeed.
Don't forget that new tyres have manufacturing lubricated surfaces so they will slide until bedded in. I nearly binned my brother's CBR when took it for a new rear tyre. I wasn't used to its light handling and took a traffic island (slightly?) quicker than I should have.
For experimenting, 42psi on the rear wont do any harm so pump it up and see how it feels. If its not to your taste split the difference from your old preferred pressure and try again. That way you will notice the changes. Doing 1 or 2 psi at a time will not make any obvious difference and will take ages to find what best does the job.
Personally Ive used 36/42 on all my bikes from MZ 250 to 600 and 900 Yamahas an Aprilia and the Beemer. I'm happy with the tyre life and handling so no reason the change argue. I can also tell the difference when the rear gets to 38. One time on the Yammie 600, the front got to 20psi with a puncture before I realised there was a problem and it wasn't just greasy roads.
My rear tyre is now (well) overdue for replacement. The bike has hardly squared it off at all, so I have very not much tread down the middle and more than 2mm on the shoulders, but apart from a diesel slick it was fine this morning on wet A Roads in Devon. My front is still legal but I will be fitting a new pair very soon indeed.
Don't forget that new tyres have manufacturing lubricated surfaces so they will slide until bedded in. I nearly binned my brother's CBR when took it for a new rear tyre. I wasn't used to its light handling and took a traffic island (slightly?) quicker than I should have.
For experimenting, 42psi on the rear wont do any harm so pump it up and see how it feels. If its not to your taste split the difference from your old preferred pressure and try again. That way you will notice the changes. Doing 1 or 2 psi at a time will not make any obvious difference and will take ages to find what best does the job.
Personally Ive used 36/42 on all my bikes from MZ 250 to 600 and 900 Yamahas an Aprilia and the Beemer. I'm happy with the tyre life and handling so no reason the change argue. I can also tell the difference when the rear gets to 38. One time on the Yammie 600, the front got to 20psi with a puncture before I realised there was a problem and it wasn't just greasy roads.
Italia-GSer
Registered user
Thanks Marki. I will try that today as per the article
Italia-GSer
Registered user
Hi Martyn,
I only changed the rear as the front trail wing is in good nick. Having re-lowered what I thought to be the high BM booklet settings, the bike seems back to its old, planted self. I will try the pressures as per the article above, and keep you posted!!
I only changed the rear as the front trail wing is in good nick. Having re-lowered what I thought to be the high BM booklet settings, the bike seems back to its old, planted self. I will try the pressures as per the article above, and keep you posted!!
Italia-GSer
Registered user
Thanks Bendy! I am going to mess about with the pressures today as we have a hot sunny day coming up and I can experiment as you suggest. Have a good day chaps and i'll keep you posted!
Dan
Dan
Some people mention the 90 dgs extensions. I got the NN ones which I found useless; too big, they leaks, etc. which ones do you use? Cheers
(BTW 2.5 & 2.9 too)
Sent from my iPhone using Tapatalk
(BTW 2.5 & 2.9 too)
Sent from my iPhone using Tapatalk
Time Traveller
Registered user
I'd be interested in a recommendation for that too, please...
Bendy toy
Registered user
I got mine from eBay two for about £5. At that price duff ones are always possible but mine both screw on and off fine with minimal leaks in the process.
Something like this.
http://pages.ebay.com/link/?nav=item.view&alt=web&id=281516622070
NZRalphy
Registered user
I'll put money on it that the TPS will be spot on.
The system includes a temperature monitor inside the tyre. What a TPS does is ALWAYS display the tyre pressure as if the tyre and air inside were at 20degC. It does a funky bit of maths.
The system includes a temperature monitor inside the tyre. What a TPS does is ALWAYS display the tyre pressure as if the tyre and air inside were at 20degC. It does a funky bit of maths.
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