Tyres; those black round rubber things that through the contact patch of a business card, hold you and your precious little rocket ship to the road. Probably should put a bit thought into which ones you buy hey? Good Idea 
The 250 is fitted with wheels are designed to take a 110/70 front tyre and a 140/70 (or more rarely 140/60) rear tyre, although many people have put a 150/60 tyre on the rear (although it is designed for a wider rim that what’s on the 250.
There are a few opinions around on what size works the best, as nicked from the old thread.
“Some argue that the 150/60-17 rear tyre may suit the track better (with slower turn in but better stability), and also that a 140/70-17 rear profile may "tip in" quicker and be better for the street (less contact patch = less resistance = better fuel economy etc). I have used a 140/60-17 and I would recommend not getting it if you want to corner briskly, as it.. err, runs out of tread”
Moving to the 150 section rear however does open up a much wider range of brands to choose from, although many of the tyres are design for bigger bikes with more horsepower, and higher speed ratings (V:240kph, Z:240kph ,W:270kph) This poses a problem as the 250 may struggle to sufficiently work the tyre to maintain the proper temperature for optimum grip. So it is best to try and stick with a tyre that is H(210) rated and designed to work with bikes with less power.
There are 2 main ranges to pick in terms of usage, Sport and Touring/Commuting.
Sport tyres have a softer compound offering up more grip, at the expense of durability. Sport tyres also a more aggressive, V shaped or triangular, profile which lends itself to faster tip in speeds and more edge grip.
Touring tyres have a harder compound, or in many cases today a multi-compound rubber which provides added durability, whilst sacrificing the overall grip that a sport tyre provides. The profile on touring tyres tends to be more rounded which leads to a more docile handling (softer tip in speed and less rapid change of direction).
Now I’ve tried to keep my personal opinions out of the above size rant, now I’ll throw in my 2cents.
Personally I stick with the 140 section rear, The tip in and change of direction speed over that 150 is nice. And there is plenty of edge grip and stability even pushing them at the track.
I have found that using 150 section tyres pinched onto the rim of the 250 to work pretty well under most circumstances. However when pushing them hard at the track I have found that I’m not wearing them all the way to the edge of the tyre, even though my footpegs and fairings are slowly grinding themselves away. This seems to cup them out just short of the edge, which seems to diminish edge grip. (though I’m sure someone’s going to disagree with me)
So let’s throw up a list.
Sport- Bridgestone BT-090
[Comes in both 140 and 150 section rears]
http://mc.bridgestone.co.jp/en/products/battlax/bt090.html
Bridgestone’s small bike sport tyre, my personal favourite. Offers loads of grip, has a nice aggressive profile with leans the bike very quickly. These tyres can be a bit hard to track down as they are imported as a racing product, and most tyre places have never heard of them but racing suppliers should be able to get them no dramas. (At least this has been my experience)
Sport- Dunlop GPR-a10
[Comes in both 140 and 150 section rears]
http://www.dunlopmotorcycle.eu/dunlop_euen/mc/tyres/on_road/Sportmax_GPR_Alpha_10.jsp
Dunlop’s small bike go fast tyre. Loads of grip, a bit more docile on the handling that what the Bridgestone’s are but still a great tyre, can’t really go wrong.
Sport- Bridgestone BT-003 RS
[Comes in both 140 and 150 section rears]
http://mc.bridgestone.co.jp/en/products/battlax/bt003rs.html
Supposedly the successor to the above BT-090s, I’ve yet to see a set in the wild, so can’t really comment.
Listed as sport/middle sport on the Bridgestone webpage, along with the 090’s
Touring- Bridgestone BT-45
[Comes in both 140 and 150 section rears]
Offering a dual compound rear these tyres are durable enough to put up with constant long commutes without squaring off too rapidly, but with a softer shoulder that has no problems providing laps of knee down fun at the track.
A pretty standard tyre, any tyre place will be able to get them without issue.
Sport- Michelin Pilot Power
[Comes in 150 section rear only]
http://www.michelinmotorcycle.com/index.cfm?event=pilotpower
A long time staple bike tyre, has been used one everything at some stage or another. A few people on the forum have used Powers with success.
A pretty standard tyre, any tyre place will be able to get them without issue.
Oh Good God In Heaven Why- Dunlop GT501-Arrowmax
The Arrowmax, AKA Arrowstax, Rings of telfon, rings of wood, hey my tractor has tyres like that.
Ok to be just a touch fair, these tyres that come fitted on most bikes are proberly already 10+ years old and whatever oil was in them has long since buggered off down to the pub with its mates, leaving a lonley shell of rubber that has long since degraded into some kind of plastic that has the co-efficent of friction of astro glide. (astromaxs, perhaps?) Though since they offer next to no grip, they never wear out, burnouts have been known to create smoke out of the road rather than damage the tyre.
Even with this legendary hardness which is in the running to knock diamonds off the top stop on the Rockwell list. There have been reports of people getting their knee down on these tyres which in itself is impressive, but also been able to get it back up while still moving and not ending upside down in a ditch on fire.
These are the kind of tyres Casey Stoner wishes he had on his bike to at least give him a half decent excuse as to why he fell off this time.
Disagreement anyone?
Thatll do just for the moment, If anyone would like to do a quick little tyre blurb, feel free and I can throw it in here. Also anyone that has any questions on the black rings of life, shoot, I'll see if I can answer them and keep expanding this section.
The 250 is fitted with wheels are designed to take a 110/70 front tyre and a 140/70 (or more rarely 140/60) rear tyre, although many people have put a 150/60 tyre on the rear (although it is designed for a wider rim that what’s on the 250.
There are a few opinions around on what size works the best, as nicked from the old thread.
“Some argue that the 150/60-17 rear tyre may suit the track better (with slower turn in but better stability), and also that a 140/70-17 rear profile may "tip in" quicker and be better for the street (less contact patch = less resistance = better fuel economy etc). I have used a 140/60-17 and I would recommend not getting it if you want to corner briskly, as it.. err, runs out of tread”
Moving to the 150 section rear however does open up a much wider range of brands to choose from, although many of the tyres are design for bigger bikes with more horsepower, and higher speed ratings (V:240kph, Z:240kph ,W:270kph) This poses a problem as the 250 may struggle to sufficiently work the tyre to maintain the proper temperature for optimum grip. So it is best to try and stick with a tyre that is H(210) rated and designed to work with bikes with less power.
There are 2 main ranges to pick in terms of usage, Sport and Touring/Commuting.
Sport tyres have a softer compound offering up more grip, at the expense of durability. Sport tyres also a more aggressive, V shaped or triangular, profile which lends itself to faster tip in speeds and more edge grip.
Touring tyres have a harder compound, or in many cases today a multi-compound rubber which provides added durability, whilst sacrificing the overall grip that a sport tyre provides. The profile on touring tyres tends to be more rounded which leads to a more docile handling (softer tip in speed and less rapid change of direction).
Now I’ve tried to keep my personal opinions out of the above size rant, now I’ll throw in my 2cents.
Personally I stick with the 140 section rear, The tip in and change of direction speed over that 150 is nice. And there is plenty of edge grip and stability even pushing them at the track.
I have found that using 150 section tyres pinched onto the rim of the 250 to work pretty well under most circumstances. However when pushing them hard at the track I have found that I’m not wearing them all the way to the edge of the tyre, even though my footpegs and fairings are slowly grinding themselves away. This seems to cup them out just short of the edge, which seems to diminish edge grip. (though I’m sure someone’s going to disagree with me)
So let’s throw up a list.
Sport- Bridgestone BT-090
[Comes in both 140 and 150 section rears]

http://mc.bridgestone.co.jp/en/products/battlax/bt090.html
Bridgestone’s small bike sport tyre, my personal favourite. Offers loads of grip, has a nice aggressive profile with leans the bike very quickly. These tyres can be a bit hard to track down as they are imported as a racing product, and most tyre places have never heard of them but racing suppliers should be able to get them no dramas. (At least this has been my experience)
Sport- Dunlop GPR-a10
[Comes in both 140 and 150 section rears]

http://www.dunlopmotorcycle.eu/dunlop_euen/mc/tyres/on_road/Sportmax_GPR_Alpha_10.jsp
Dunlop’s small bike go fast tyre. Loads of grip, a bit more docile on the handling that what the Bridgestone’s are but still a great tyre, can’t really go wrong.
Sport- Bridgestone BT-003 RS
[Comes in both 140 and 150 section rears]

http://mc.bridgestone.co.jp/en/products/battlax/bt003rs.html
Supposedly the successor to the above BT-090s, I’ve yet to see a set in the wild, so can’t really comment.
Listed as sport/middle sport on the Bridgestone webpage, along with the 090’s
Touring- Bridgestone BT-45
[Comes in both 140 and 150 section rears]

Offering a dual compound rear these tyres are durable enough to put up with constant long commutes without squaring off too rapidly, but with a softer shoulder that has no problems providing laps of knee down fun at the track.
A pretty standard tyre, any tyre place will be able to get them without issue.
Sport- Michelin Pilot Power
[Comes in 150 section rear only]

http://www.michelinmotorcycle.com/index.cfm?event=pilotpower
A long time staple bike tyre, has been used one everything at some stage or another. A few people on the forum have used Powers with success.
A pretty standard tyre, any tyre place will be able to get them without issue.
Oh Good God In Heaven Why- Dunlop GT501-Arrowmax

The Arrowmax, AKA Arrowstax, Rings of telfon, rings of wood, hey my tractor has tyres like that.
Ok to be just a touch fair, these tyres that come fitted on most bikes are proberly already 10+ years old and whatever oil was in them has long since buggered off down to the pub with its mates, leaving a lonley shell of rubber that has long since degraded into some kind of plastic that has the co-efficent of friction of astro glide. (astromaxs, perhaps?) Though since they offer next to no grip, they never wear out, burnouts have been known to create smoke out of the road rather than damage the tyre.
Even with this legendary hardness which is in the running to knock diamonds off the top stop on the Rockwell list. There have been reports of people getting their knee down on these tyres which in itself is impressive, but also been able to get it back up while still moving and not ending upside down in a ditch on fire.
These are the kind of tyres Casey Stoner wishes he had on his bike to at least give him a half decent excuse as to why he fell off this time.
Disagreement anyone?
Thatll do just for the moment, If anyone would like to do a quick little tyre blurb, feel free and I can throw it in here. Also anyone that has any questions on the black rings of life, shoot, I'll see if I can answer them and keep expanding this section.