After reading the reports on fitting Bridgestone T31 tires on K-bikes, I bought a pair.  I'm now in the process of changing them out for their replacement.  I liked their performance; they made the bike handle as if it had lost 100 lbs.  However, they have surprised me in ways I never anticipated.  The front and rear tire wear at virtually the same rate.  In the past I've replaced two rear tires before one front was knackered.  That was my experience on other motorcycles. Now, at about 10 k miles I am again fitting T31 tires on both ends of the bike.  Is this typical of this tire?  A second surprise is the wear pattern of the front tire.  It's badly cupped.  Any thoughts on what caused that condition?

I have used BT45 and not familiar with BT31 but the front would scallop very quickly unless run at higher pressures, I runt the front at 38 psi and its ok at that.

10k miles is good but the front wear rate suggests its a dual compound or softer tyre meaning you might need to look at the pressure you run it at.

What pressure are you running the front at?  38psi is what I run all my front tires at, and have never had a cupping problem.  I'm pretty sure that is the pressure listed in the owner's manual.

I use 38/42psi. front/rear. 
In the more remote parts of Arizona that I rode through in October there were significant stretches of what approaches "washboard."  I found the forks did a pretty good job of taming that, but maybe the front tire suffered.

I've run lots of T30/EVO fronts at 35-36 front and 40 rear and the front tread wears just fine without cupping.

And the rears do wear faster but that may have something to do with how I ride.

An out of balance tire will have strange wear patterns(cupping and flat spots).  I have found that my wheels do not have the heavy spot at the valve stem.  Installing tires with the red dot oriented with the valve stem has led to weird balancing and odd wear issues.

I now check the bare wheel for the heavy spot before I mount the tire.  Makes balancing a lot easier, and the tires seem to run smoother with less vibration.  I've found that my three spoke wheels have a heavy spot about 60 degrees from the valve stem and can need as much as an ounce of weight to balance.

brickrider2 wrote:I use 38/42psi. front/rear. 
In the more remote parts of Arizona that I rode through in October there were significant stretches of what approaches "washboard."  I found the forks did a pretty good job of taming that, but maybe the front tire suffered.

I run the same pressures and have Ks going back 10 years and found these are the best too.

I doubt very much that incorrect tire pressure is the reason for the cupping of the front Bridgestone tire.  It's more likely that the balance was not the best.  However, that theory has it's own problems, as an out of balance tire can be felt by the rider, but the bike ran very smoothly.  As I mentioned, I've replaced it with a second T31.  It'll be interesting to see if the second one wears any differently.  It could very well come down to the formulation of the rubber and the condition(s) of the roads I travel.  We shall see.