Hi. I'm a reasonably competent DIY bike repairer. One of the family's bike needs it's bottom bracket replacing but the type is like nothing I've seen before. The bike is a Ridgeback mountain bike which was new in approx mid-2000s. I presume it is the original bottom bracket. After extensive searching on the internet I've found nothing that looks like it. Unfortunately this post is a bit hamstrung by the fact that as a newbie I'm not allowed to post pictures. So I'll attempt to describe it.

The axle appears to be fairly standard tapered square. But instead of the usual internal splines to unscrew the housing there is an inlaid pattern which looks like it would fit a tool with 6 square shaped lugs. There is no makers name visible on the bracket.

Does anyone have any idea what make this bracket is or the tool that would remove it? I'm out of ideas short of making my own tool to fit.

Thanks in advance for any help offered.