Took a motor cycle taxi from Asok to go to Pratunam market last Sunday. The guy asked for 120 Baht and I paid it. While coming back took the yellow/green cab and paid as per the meter, which was just 65 Baht!!! to my surprise. I thought the motor cycles are cheaper option. Looks like not necessarily. Any advice when to take motor cycle taxi and when not to?? Does one need to negotiate with the motor cycle taxi operators upfront??

It's called haggling.

Haggle it out man, haggle it out!

A motor cycle taxi will usually only take a fare from a particular place. So if he takes you a long way, he needs to go back to his base to get his next fare.

A motorcycle taxis are for short trips, less than 2 kms. They will charge between 10-40 baht for that.

I am pretty sure the following fares are accurate:

80b from King Power (so 1/2 km. beyond Pratunam) to T21 (corner of Asok),

60b from King Power to Bumrungrud (Soi 3).

So 120b from Asok to Pratunam is steep but not extortionate. Fares are usually on a chart at every motosai station but in Thai. If you pick one up ex-station then, of course, the fare first quoted will be high. Negotiate.

As a previous poster says motosais are cost-effective for shorter rides. For longer ones they are not, though they will no doubt get you there quicker than a taxi (and at a significantly greater risk to life and limb).

Motorcycle taxi's have gone up.But yes same as tuk tuk,you need to talk about how much baht before you get on.

I use motor bike taxi from phrom pong to pantip plaza cost 140 baht cause here the motor bike can not take any client outside his number batch area.