Hi all, this is a first time build for me, which I just finished building. This will be a first introductory post to describe my experience. After spending numerous hours (including here on Chinertown) I decided on which bike I would build with the following primary parts:

Speeder SC-R49D (because of the aggressive geometry, and the aesthetics of the wheels "cutting" in the frame)
ER9 (as an entry level priced electronic groupset /  12 speed)
Elitewheels Pro 55mm disc (had good experience with rim wheels before / are friendly priced)
105 crankset
+ 105 power meter (comes from previous bike)

Good:
- the bike is exactly what I expected in to be in terms of aesthetics
- seemingly built well (although I will return here after I had plenty of km's on it)
- reasonably priced (1000 USD for frame, handlebar, headset, fork, seatpost and shipping)
- Speeder is OEM for Winspace
- standard position is VERY aggressive (which is exactly what I was looking for)

Medium:
- sticker on the box mentioned the frame in another size (thankfully the actual frame was correct)
- the communication was alright, although he could have been a bit more transparent in terms of producing / shipping times (only mentioned AFTER purchasing the frame: 3 months)

Bad:
- both headset bearings had a lot of play, which stressed me out as I thought I had a faulty frame. Thankfully, after finding one of patliean1 posts on headset play, I reduced it to almost zero with adding a couple of layers of tape in the socket of the bearings.

Open issue:
Now that the bike is fully built, I wanted to take it on a couple of rides. However, I can already feel it pedals very heavy and even backpedaling feels heavy as well. Both wheels spin very freely, and the crank set without chain also somewhat freely (my old bike was better in this regard).  I just tried pedaling back, and it seems like the cassette does not want to spin, as the chain will just lose tension and curl up.

Does anyone know how to resolve this issue? Thanks!