I am so big I would hate to have an old man pedalling to get me around it is just not right. though I admit I once took a samlor - in Kanchanaburi, when there were no taxis around and I had a bus to catch. it was just 1.5 km or so but still too much for my peace of mind. the old man was really really nice, he was actually around during the war, and spoke really good English too... I ended up giving a big tip.