Dont know if anyone has mentioned this already....

For those riding bikes around the loop. Just after the Mae Rim turn off from the Hangdong - Samoeng road, road construction is under way for 1-2km. Apart from hard packed earth there are very thick layers of loose gravel. Take it carefully!

I've noticed it too, treacherous.

We discovered it the hard way... No accident, but mighty close. You'd think that they would mark the fact that there was a road grader blocking the entire lane just around the blind curve, but TIT. Unfortunately, there was 8" of loose sand and gravel to climb over while making a too-fast swerve into the opposite lane. Not fun on two wheels... Fortunately there were no cars coming the other way or we'd be just red road coloring.

If you are fit enough to ride the loop on a bicycle, and I am not, there is the alternative to ride down into Samoeng and then ride up to North Samoeng towards Mae Pa and then up to Mae Khi and then its all downhill to Mae Rim from there. Look at the GT-Rider Samoeng Loop map for details.