So if you find yourself in Chiang Mai or planning to go there, here is my few tips on renting something to drive with.
Finding a place to rent
If you want to rent a scooter its easy, they are everywhere but some can be a really good place or can be bad experience. When i live there i use Zippy Motorbikes. I had really good experience with them.
They have mostly 125cc scooters, but they are cheap and good conditions on the agreement.
I payed 150 baht a day to test(150 Baht a day was the cheapest i found with good condition), then i payed for a week, but i upgraded for a month. It cost me 2300 baht a month which was a really good price.
Renting a Big bike
Its a more tricky one, but possible. I used Mango bikes for a couple of days and those bikes was in good condition and everything went smooth.
Driving on the roads in Chiang Mai despite what you read elsewhere, its not that bad and i have not seen a single crash while living there. People can sometimes drive drunk, not watching, or videocall on the phone, but not to worry, never seen them have any accidents either.
Ok, so you have a bike, do you need a helmet and driver license? Short answer: yes, but you can still drive without a license and helmet if you wanna feel the wind and dont have the driving permit in order. If you get pulled over when you dont wear helmet and no lisence, the easy way is 1000 baht fine, but official rate is 500 baht fine, 200 for no license and 300 for no helmet, but you have to pay at a police station.
Speed limit is there for fun, the real speed limit is how fast the traffic are.
Other than that its just to learn how to drive like a ant walking home, all the ant are walking in line and in sync.
Using the turn signal is a must if you wanna avoid crashes, because all people there use it, unless you drive on a turn marked road, then you dont need to.
Doing a road trip with a motorcycle, since its alot of mountains its good to have a 200cc+ motorcycle. The small 125 can stall in uphill turns and then a car driving fast will crash into you if you have a bike not moving in a turn.
Good luck driving and have fun