Back on the road after holidays in Sihanoukville

Happy New Year 2012!
I spent the last couple of days together with friends from Singapore at Phnom Penh and Sihanoukville. At the latter we celebrated New Year's Eve together and had a relaxed boat trip the day after.
Yesterday, I hit the road again and rode all the way from Sihanoukville to Siem Reap. This is the last touristic destination of my road trip through Southeast Asia.
Unfortunately, I couldn't discover Cambodia as much as I wanted because my rear tire and my front brake pads are (almost) used up and thus, I had to reduce the mileage. All attempts finding a on/off-road tire in size 140/80-18 at Bangkok, Pattaya and Chonburi - thanks to Kitty, a Thai motorcyclist who helped me a lot - were in vain.