running behind ok lagi..

but once it's on my left side, i kecut bola. i can understand dogs are guarding their territories, but when they are still charging at you from across the road, damn, that makes it still pretty dangerous and scary.

nope. headset bearing sold seperately and installed myself..

can refer here for tutorial
http://handsonbike.blogspot.my/2013/05/how...et-for.html?m=1

You don't really need the specialist tools if you do once in a while. What you can do is go to a hardware shop or better still a 'nut and bolt shop' , get a 20mm x 8 inch nut with 2 corresponding bolts. Also since the headset of the Dahon is 44mm in diameter, get 4 washers with 50mm diameter which the nut can pass through. That's the tool that is needed.

First, set the nut with washer on top of the headtube (install the bottom one first) , then align the headset bearing mount (take out the bearings first, off course) at the bottom of the headtube. The 8 inch nut will be protuding from below and put on the washer and bolt it with hand first until it is about to get tight. Then realign everything. Start bolting the nut and bolt tighter and this will press the headset into the headtube. Once done, unscrew everything and do the same with the top headset mount.

Before I use this way, I used to hammer in the headset mounting with rubber mallet. Works too but the nut and bolt way is safer and more assured.

i bought used groupset (complete), much cheaper than new one.

if u buy a whole used groupset, u got complete. lets say u buy the 5700 105 10speed groupset. all u can use accept for brakes (if u cant u cbrake) and the shifter (can sell it and buy new flatbar shifter with brake lever)

But if after 1 ride and found cycling is stupid… cheap bike and expensive bike are all junk bike... Yes, this happens most of the time.
Throw away a 500buck bike, you loose 500
Sell away an expensive bike you loose 500 too + the hassle of selling…