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I have a beloved but well used front wheel built around an old Mavic 500 hub whose bearings are finally starting to give up the ghost. If you hold the axle and spin the wheel you can feel it grind through a few spots in the rotation as well as hear a nice few clicks as the bearings stick in the cartridge's raceways. I'm pretty convinced they need to be replaced.

There is however a lock ring that is preventing me from getting the bearings out. There is a special tool (the Mavic 670) that looks like similar to a bottom bracket tool except it has six pins that fit into each of the six little holes on the hub's lock ring. I found a few of them on ebay for the reasonable price of $90. Needless to say I would like to try to get the lock ring off without purchasing the "rare and vintage Mavic Key 670 Bottom Bracket and Hub Assembly Tool".

I gave it a try with a spanner wrench but only succeeded in stripping out one of the soft aluminum holes.

Does anyone know if the lock rings are reverse or regular threaded? Any advice for trying to free them without using Mavic's proprietary tool?

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2 Answers 2

Try carefully using an adjustable pin spanner, or the Park variant. If not, I believe current Mavic hubs use the same pin pattern, so the plastic tools that come with Mavic wheelsets is plentiful and may be strong enough for your use.

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I've been researching the same thing. Even built my own tool of sorts by drilling two holes through a wrench and inserting drill bits to act as pegs. The wrench is about 6" long and there's no hope in hell either of the "washers" are going to come off. My experiment didn't mess up the holes but I'd say there's a good reason for 6 pins on the Mavic 670 key.

@unworthy1 has a better answer to this question here.

Apparently the washers have a fine thread and screw off. Since @unworthy1 didn't mention the direction of the threads I would assume that means they're standard counter-clockwise. @unworthy1 gives advice on how to free them, and later on says the 6-pin 670 is the only tool for the job.

I think it's pretty safe to assume aluminum corrosion is on the outer parts of the threads binding it up and some kind of anti-seize lube is required.

EDIT ---- Oh, if anyone is ever lucky enough to get the washers off, the bearing is a standard 6001. I've been looking into the SKF e26001/zz-c3 E2 deep groove ball bearings. You don't need E2 bearings, but make sure they're deep groove to handle the side loads on the hub from cornering. Especially if you do fast downhill switchbacks :)

EDIT ---- I found this advice on a machinist's forum by @Patch. In a nutshell, place the wrench on under light tension, tap it with a small hammer, reverse the tension, tap again, and repeat. Of course, that may only work with the Mavic 670...

I wouldn't recommend sodium hydroxide or heat as suggested later in that page if your bearings are in any kind of serviceable condition. That way if the washers still won't come off you can use the wheel. Heat will just melt the grease and I'm pretty sure you don't want to leave NaOH anywhere inside your hub.

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