Stolen Specialized Rockhopper - Cardiff Central

On monday my bike was stolen from Wood St, just outside the Cardiff Bus ticket office in Cardiff central, it was locked to a bike stand, I actually saw the guy breaking the lock but as I was a distance away I shouted and ran towards him, but he jumped on the bike and rode off down a back street, I gave chase but obviously was unable to catch up. A Cardiff Bus memeber of staff outside the back entrance of the ticket office tried to grab him when he realised what was happening but he didn't quite manage to get a grip! The police were able to look on CCTV cameras in the area and have seen the incident but cannot get facial ID>
The bike was a Specialized Rockhopper in blue, I did make a note of the ID number but of course...have lost it!! It had a sticker on the cross bar covering a chip which said 'REEF' it also had the metalic sticker of the shope I bought it from - Summit Cycles in Aberystwyth. This incident shook me because I caught him in the act, and it was so frustrating to come so close to stopping it from happening!! ARRRhhhgghhh!!!! The guy looked like a typical junky, police were pretty good, drove me around for a while trying to see if we could ID him and the bike but no good! Any information is good, but I guess I can kiss the bike goodbye..... :-(