I am travelling from Chiang Mai to Bangkok. Just need to know if Bus takes Mountain Bicycle as a luggage and how much they usually cost?

Cheers

In short yes. You may encounter a space problem in the baggage area if the bus is using LPG/NPG because that's where the tanks are installed. The may also ask you to remove the front wheel. I've taken both my MTB and touring bike on buses in Thailand and over to Laos on several occasions in the past. They normally ask me to remove the front wheel to make loading easier.

I've done it a few times, a lot depends on size of the cargo area in the bus. When buying the ticket just tell them you have a bike and if they will tell you if it'll fit or not. The cost it usually 100 baht.

I have on two occasions transported bicycles from Arcade,Chiang Mai ,to Suphanburi ,with Sombat Tour .

Each time i was charged an additional 200 baht over the ticket price.

the train is way safer if it is running and it does for sure take bikes, 100 baht, I was told no way on a bus once. but an agency said i could if i compacted it. - iffy

I bussed at night and the driver fell asleep at the wheel. almost crashed.

I agree about the train. It takes longer but you can get up and walk around or hangout in the restaurant car if you want. Plus it drops you off in central BKK which the busses don't.

Yes you can, there is no extra charge, its just the driver trying it on. If you tell him that the person at the counter has already told you that there is no extra charge, or ask for a ticket/receipt, they will quickly retract their demand in my experience.

I took a large bus and was not charged at all for my bike box. the website said it needed to be under 25 lbs, or something like that. didn't matter, they didn't weigh the bike box. and neither did the airline company I used. when I bought my ticket I didn't tell them about the bike box, since I already went to their site and checked; however, when in doubt, act dumb and they will usually not confront you regarding belongings. smile, keep walking.

I put a motorcycle on a bus from Sangklaburi to Kanchanaburi a few years back. It was a local bus with a baggage area down the back on the passenger level (few seats rows removed), as well as underfloor storage. It cost B100 for the trip.