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.

This would probably be a good place to start for ID.
https://www.parktool.com/en-us/blog/...&area%5B%5D=47

Which side is the "inlaid pattern?

It's the same on both the drive and non-drive side. If you imagine looking at a regular bottom bracket, you would see a depression which fits the splines laid into the end of the bracket housing. Instead this one has an inlaid shape that looks like it fits a tool with 6 square shaped lugs.

it's a low end-ish taiwan/china bike company still loosely based in England.

are you saying it has notches that a hook spanner will fit into, on the outer edges of the ring? many use a punch to loosen those...

there are hook spanners in various sizes for such parts...

if the 6 indents are in the FACE of the cups... i'd contact them about the tool to remove the BB. remove the bad part in a fairly destructive manner, then get a more normal BB to replace the junked one.

search: "Ridgeback Bicycles" and email them. if you're in England, they have a network of "Stockists" scattered about.

the biggest variety of special BB tools available that i know Does NOT show a 6 point BB tool, other than an external notch type. they sell about thirty or more sockets and wrenches for BBs.
search: "Bikehand.com. catalog"
they even sell special sockets for the bosch mid drive e-motors... those are 7 notch design, mostly....

Campagnolo makes a external 6 notch BB ... Park has the BBT-4 tool for those... not sure of the OD on those cups though.
the Chinese Love to copy other designs, so it may be what you are dealing with... ?

Thanks for looking. It's not external notches, it's an internal pattern that looks like the tool would be pretty much the same size as a regular splined removal tool but instead of having many small splines it would just have 6 large square shaped 'splines'.
I've also spent hours looking at pretty much every tool stockist on the net but no one has anything like it. I will phone the bike company and hope they have some tech person who's been there for 20 years and can remember.
I already tried to loosen it in a mildly destructive manner but it's not budging easily!

So you're basically saying the opposite of this?

Stop by a bike shop with the bike. If their head mechanic can't identify it, ask for a referral to another shop (probably to a long-established shop).

Or do an image search with your description. Or take a photo and do a Google Lens search.

You CAN post pics of the annoying BB to a Gallery forum here, under your handle, then someone can post that pic here... happens frequently... the "Ten Posts" rule is to reduce spammers and such....

So tool like this?

https://simplybearings.co.uk/shop/pr...xoCZD0QAvD_BwE

Thanks for all the advice guys. I've now posted a picture to an album called unusual bottom bracket. Please can someone copy it to this thread. As you'll see none of the suggestions quite match it.

Thanks for transfering the file. Any ideas who makes / made this?

Yikes, it looks like more issues than just the bottom bracket. not positive from the picture, but it looks like a crack where the seat tube joins the bb, along with significant corrosion.

That’s mud

might be this one

Possibly a pin spanner could get that out if not too tight

​​​​​​https://www.harborfreight.com/adjust...YaAhGWEALw_wcB

it's too tight, rusted in place.

ok.. after seeing that thing, i'd say your only course is to Email the Company and hope that they have a socket for that oddball BB.... Or go pyro and heat that sucker up and get out the 3 ]b. sledge and a punch, and SERIOUSLY Lay into it this time...
or go full-on crazy destructo and start by drilling holes in the cups, in three lines, at 120* intervals, then go at the cups with a big chisel and hammer to crack the thread area. some additional cutting with a rotary burr (Dremel or better) may be needed too...

but before all of that... Is the frame WORTH all that effort?

like i posted earlier.. it'a low -ish quality Taiwan/China bike sold by a Company in England... from the look of the one weld i'm seeing, the frame is steel, not good steel, and it was poorly welded to begin with... What derailleurs are on it? are the handlebars steel or aluminum? is the stem steel? is the fork suspension or rigid? what is the seat post style? are the rims single wall, or double wall?

look up "Ridgeback bikes for sale" their nicest Aluminum DH frames, with a long travel coiler shock, are for sale for under $75, in England. their Touring bikes seem to be more valued on the used market... 250 to 600 quid. a bare dirt jump-ish, Aluminum, hard tail MX35 frame with Disc mount on the rear is on Ebay at 30 quid... that's a typical specialized hard rock price....
Quick guess... the rare tool will cost about $40-50, and shipping is usually stupid-spendy, from England.

If you can get the other cup out & remove the spindle, then try Sheldon's method-
https://www.sheldonbrown.com/tooltips/bbcups.html

look at about 4 o'clock on the pic that looks like major rust with even a piece coming up

I would say this frame should be trashed ...... or of OP binned

Yeah, that's the right answer, but if I'm feeling jiggy, I would sacrifice a cheap 1/2" drive deep socket to the grinder and hit it with the impact wrench, but yeah, not worth the effort.

It could just be fibrous debris (plant material or from a rag) stuck on with oil and mud.

i start every repair or rebuild with a good Cleaning and Full Inspection of the machine.

I can see why you would say that but I dunno, the rest of the paint looks too good.

Couldn’t link the tool I thought might fit earlier because it has some controversial letters in the URL but search for this on tredz

Cyclo Bottom Bracket Remover Campag

that fits the external BB cups that the Park BBT-4 also fits...
here's the BBT-4 fit description: "Fits six-notch threaded bottom bracket tool fittings with a major diameter (outside of notches) of nominally 44 mm and a minor diameter (inside of notches) of 38 mm"
the BBT-4 is an external cup, external flat wrench.. i have one. i also have one of the Campy BBs it fits.

so... nope, it won't fit the "unusual BB".