If you are touring in Northern Thailand and need parts, I'd recommend Chaithawat Cycles. I had some trouble with Top Gear. They promised to buy a bike back for 60%-80% provided it was in good condition. I rode it for a month and a half, maybe 500 miles. They tried to tell me that the drive train was shot when I returned it, and offered only 40% of the purchase price. They showed me a chain wear indicator and freewheel wear indicator, but used them incorrectly. They also told me that they would have to replace the parts with Shimano components, even though the bike was stocked with cheap Chinese parts. There were a number of other problems as well. In the end, they gave me 55%, but only after a good deal of grief! They generally seemed more interested in money than customer satisfaction.

Chaithawat, on the other hand, was very professional, and offered bikes at about 20% less.