It actually isn't all that 'little' as it took me >3 hours to bike around the perimeter.
Most folks are aware of 'Big' Koh Chang off Changwat Trang but me & the missus headed out to Little Koh Chang where it's more rustic.
Little Koh Chang is off Changwat Ranong just north of Phayam Island which is more developed with motorbikes to rent etc.
We stayed at a resort called 'Context' towards the north end of the island that sports a dozen or so 'bungalows' situated just above the high tide level. This is your basic backpacker place and very laid-back. Excellent paved trails throughout the island and great biking although there are some steep hills in places. Giant Hornbills sweep in at dusk at the restaurant to scarf down bananas.
Being a 'laid-back' place, electricity wasn't on 24/7 but that really didn't detract much although, 2 days of reliving my backpacker roots was enough. You can either take a high-speed boat (300 THB) out from Ranong or a long-tailed boat which takes an hour for 150 THB.
We might check out Phyam Island next time which hopefully isn't quite as 'rustic'