I am rebuilding a 1980's road bike made by Zebra Bicycle Co. of Japan. Specifically, I have to relube all the bearings and I have to loosen the BB cup. It's about 36mm diameter and the raised flats are 16 mm across. Attached is the pic. A regular open box wrench won't do it.

Any idea if there is an off-the-shelf tool I can get to get this job done. I guess I will have to fabricate a tool otherwise.

Thanks much for help.

When you tried to remove the BB cup with the 16mm flats did you first loosen the lock ring? The lock ring acts as a lock nut clamping the cup is a specific amount of insertion (this is the long way around the bush to say "bearing adjustment"). There are bike specific lock ring tools like the Park HCW-5 but a well handled flat blade screwdriver and a hammer also works. Do you have an instructional manual to follow? Andy

Yes, I loosened the lock ring first. In the past I have worked on a '91 Miyata's BB and have several repair manuals. I was able to use Park tools for that bike. I'm thinking the ideal tool for the Zebra BB cup would be a socket with a 16 mm wide notch across the end facing the cup.

I think there is a "tool" for that.


https://www.bikeride.com/bottom-bracket/

I think often if the lock ring is removed, the bottom bracket can be easily removed. But, if not, what I usually would do is take a large adjustable wrench (I have some big ones), and put it on it. Then I'll build up a few washers so that I can tighten my wrench down onto the bottom bracket and hold it in place with the bottom bracket bolt/nut so it won't slip.

Zebrakenko

That kind of tool might well work. I assume the issue is that however you are trying to grab the cup the tool slips off the flats or you can't apply enough torque. Yes/no?

There are all sorts of ways to jam a couple of 16mm cone wrenches against the flats using a crank arm bolt and washers/spacers to fill the gap. I just used the Park HCW-11 today at the city bike recycler fixing up bikes for their give aways. Nice tool but two cone wrenches with good clamping can be just as effective. If you still can't get the cup out change lanes and pull the guts from the drive side. Then use a cup vise for the still in place "adjustable" cup. Andy

Wow, that bottom bracket and everything pictured looks brand new!

Yes. Also there is enough play that the 16 mm wrench flats mostly bear on the opposite corners of only one of the raised areas. I think you have given me some good ideas to try and I appreciate your help very much. I was thinking the socket I mentioned could be made to attach to the axle but your ideas are simpler and don't require a special tool.

BTW, I'm repurposing the bike to encourage a 15 year old boy to start broadening his fitness interests. I hope it takes root and perhaps will help him to put some of his baggage in the right compartment, so to speak.

Yes. other than 35 years of dusty grime this bike is practically new. My first wife bought this before we were married from a small bike shop south of DC.

Thanks CliffordK. That tool is perfect. This site is fantastic. Thanks a million.