Hello,

I have a set of wheels with Deore XT disc hubs, model HB-M756. I want to clean the bearings and put in fresh grease. However, the existing cone wrenches I have, both sets, are too fat to fit in there to take the axle apart. How skinny do these have to be? Considering filing mine down until they fit. Anyone else have this problem? Solution? Thank you,

what cone wrenches do you have ?

The old Park Tool ones with the black oxide finish were pretty thin, IIRC.

I have a cheap set shown in black on the left side and this Torx set. In all honesty, I have used the cheap set so much the surfaces have mushroomed a bit, But neither set fits.

At the shops I've been in we would just grind down the wrench flats "mushroomed" bits. I've also done this to reduce the thickness to fit unusually narrow cone flats. Andy. (who wouldn't pick a file to use on a cone wrench)

get the Park Tool wrenches.. the new Black Oxide ones barely fit those hubs, as long as their jaws' working edges aren't flared out... i have to re-dress them occasionally, like mentioned above.
the old chrome Park wrenches were a touch too wide, and also required re-dressing.
i used their 13-15mm combo wrenches on those hubs, back then.... they are typically thinner, but shorter, and not as hand-friendly to use.

Park DCW-1 and DCW-2.

Yes, I will use my angle grinder to do so. Thank you Andy. Always a pleasure.

​​​​​​​Yes. Thank you.

I prefer getting rid of bulges with a hammer and the flat on the bench vice. Same with alloy freehub notches.

I think the old Park wrenches were maybe thinner than they are now - and harder, too. Old Campagnolo wrenches are pretty thin, too.


You have to assume Shimano must make a thin wrench - but why was this necessary?

Over the years I have had many sets of cone wrenches. Every set has required adjustments with File and Hammer. Now days I use a Slim Jaw Cresent and a simple generic multi size cone wrench, any flavor will do...

FWIW, I measured all 5 of my Park Tools cone wrenches; they are all 2.3 mm thick at the business end.
These are the black ones, and they seem quite hard. I have used the 15 mm wrench as a pedal wrench (MKS AR-2 Ezy quick-release) with no distortion of the edges.

the flaring usually happens because of badly made cones on low end bikes... and then, there are the occasional 14mm (more likely 9/16") cones on BMX bikes. or antique hubs.

i once snapped one jaw right off a 13mm Park chrome cone wrench..
took it to a Performance bike shop (now long Closed), and they said they wouldn't give me a new one, but to email Park...
I Called Park warranty... they refused to believe i'd broken it without a helper bar, so i sent them a pic of the snapped wrench, the jaw half that broke off, and included my Forearm in the pic...... the new wrench showed up two days later..
i was trying to open up a Walmart Mongoose front hub for a re-grease... i think the factory got it a bit TOO tight... Both sides of the axle were that ridiculously tight.
they also forgot to put in the grease.... it was bone dry.

The Park chrome (nickle only?) plated ones are 1.9mm.
The Hozan chrome ones are 2.3mm.
I did get two sets of thin-but-thicker spanners, metric and imperial, 3.4mm - they've been properly useful a few times.

Does the axle have a 5mm hex inside the ends ?

If you can put the allen key in a bench vise horizontally, it can sometimes make it easier to not disturb one side while you are working on the other.

Kind of like an axle vise.

How skinny?

Did you measure it? Do yourself a favor and get a digital caliper also so you can measure how thick you need it to be, in the future.

My chrone Park CW-X cone wrenches are 2.3mm. The chrome DCW-x cone wrenches are 2mm and a set of black X Tools cone wrenches I bought are 1.9mm.

If you don't want to grind a wrench thinner, do this-
Use your 17 mm wrenches to break loose one of the cone/lock nut joints.
When reassembling, add a THIN washer to increase the gap slightly on that joint. Maybe cut one out of a pop can?

There seems to be a lot of variability between brands. I just measured Campagnolo at 2.0mm, ATD at 1.6mm, and VAR at 2.5mm.

My old Park wrenches are 1.83mm.