wich size do you think i need to used
my height is 5'6
right now i am riding a 19.5 ht
thanks!

Anywhere between a 14" and a 19" but definitely not a 19.5".

I'd say a around a 15" for most mormal riding applications. I rode with a friend the other day thats around 5'7" and he rides a 19 in bike. Looks like the most uncomfortable position ever.

OP is using a trailing stem design.

it sort of depends on the bike, some bike's ride smaller or larger, depending on the geometry and how they are set up. For example, i'm 5'5", i would normally ride a 16" frame or so, but on the new Rocky Mountains, i fit quite comfortably on a much larger frame, which made no sense at all, but there i was and i was comfy. it also depends on if you have long legs and a short torso, or short legs and a long torso. at 5'6" you need a "medium" bike, i would say around the 16-18 range.

my bike is a trek 9.8 but i was looking to the access frame but they only have 16.5 and 18
i always looked that the guys from uci xc race small frames
im almost equal from the legs and my torso
i think my legs are longer because the thing on this frame that affects me is the size of the top bar

I'm 5'7" and ride a medium frame (17") for a 26" bike but depending on the brand, I'll ride a small frame for some 29ers.

Top tube fit is more important IMO. I like small frames with long TT's , this makes for a nimble flixable frame .

i want to buy the frame this week so i will try one frame from my friend!
what do you think about the fork?
is a cheap fork

https://cgi.ebay.com/New-SR-Suntour-1...ht_2581wt_1139

this is the link