Bicycle Mechanics - Resurfacing Cones

With the suggestion from fietsbob, and some info from Aaron Goss, I took a shot at resurfacing my Ofmega rear hub cones. I was having difficulty finding replacement cones (well I looked at one well stocked LBS), but since they were toast anyway, I took a shot at regrinding them.

Here's what I did:

I made a mandrel out of 1/2 inch aluminum round rod. Turned it down to 10mm diameter on the lathe, and threaded to 26 threads per inch. Instead of the mandrel, I could have used the axle, but I didn't want to take the chance of messing it up, and I didn't have a junk one to use.

Screwed the cone onto the mandrel and used the axle nut as a jam nut to keep the cone from slipping.

Put the mandrel into the drill press and while spinning the assembly used a Dremel with a cone shaped grinding stone to carefully and evenly grind out the pitting.

Used sanding paper of increasing grits to smooth grinding marks. Finished off by polishing with scotch brite hand pads.

This actually was very easy to do, and making the mandrel was the hardest part. From the time I got the cones into the drill press, it took maybe 1/2 hour.

We'll see how they last, not sure if I ground through all the case hardened metal and got to the softer stuff, but at least this gets me back on the bike while I source some new cones.

Attached pictures will give sense of what I did. Anyway, I hope this motivates some folks to give the process a try in a pinch. Cheers!

Maybe try some DIY case-hardening on the cone's race surface by heating it up to glowing red with a MAPP torch and then quenching it into some clean motor oil? (maybe have a fire extinguisher handy in case you ignite the oil...)

Just a thought. Never done it myself on a bearing surfaces although I've done it to some other metals (gunsmithin' in the Wile E. Coyote method.)

Yeah, I thought about packing it in charcoal and heating ala Guy Lautard, but I would actually like to see if it is necessary first. I'll ride the bike for a month or so and see if I can detect any noticible wear on the cones.

In the meantime, I'll find some new cones somewhere - maybe I should build them from scratch in the shop!

Are Campy cones interchangeable with Ofmega?

If so you can get Campy's on ebay for $5 each.

Cool job! I'd be interested to know how they hold up.

Are Campy cones interchangeable with Ofmega?

If so you can get Campy's on ebay for $5 each.


Well, I thought so, but the LBS has Campys and we tried 3 different styles and none fit right. I did get some new Campys for the front which worked perfectly, but it was NG on the rears. One guy told me that he thought you might have to switch out the axles for Campys, so maybe there is a 10x1 version that they made. I am going to check out a bunch of stores and see what I can find but now I have a way to get there!!

These should hold up pretty well, and last a good while. If ultimately you need replacements, and cannot find originals, buy a piece of air hardening steel and make a pair fresh, picking the basic dimensions off these.

Since air hardening grades often work harden, they may be hard to tap, so you can make the cone as a small ring with a 12mm or so ID, and minimum depth (length). Then press it onto a support nut made of milder steel, or your existing cones cut down to a step to accept the bearing race you've just made.

Or you can source a pair of right side cones for current, aluminum axle Campy hubs, and make the threaded carriers, to fit whatever axles you want.

Okay, I'm impressed. Nice work!


I'll ride the bike for a month or so and see if I can detect any noticible wear on the cones.

Prolly a good move anyway; if the metal's softer, this might break in a smoother track than you've created. If you keep rotating the axle...

Oh yeah, my mate reckons you should swap em onto the front if they're the same size, good call.

I like this kind of DIY reuse -- contemplating it with some pitted bottom bracket parts. :thumb:

Oh yeah, my mate reckons you should swap em onto the front if they're the same size, good call.

Unfortunately not the right size to swap - Front uses 7/32 balls and is compatible with campy cones, so I replaced them. But now I will make a mandrel and resurface the old fronts to have as spares.

I like this kind of DIY reuse -- contemplating it with some pitted bottom bracket parts. :thumb:

Yeah, I am a cheapskate, especially if I can find a way to fix something myself. the front cones cost me $12.50 apiece, which surprised me...

I would give it a shot. If pits are not too bad you might try using a bearing pressed into the end of a piece of tubing and some valve lapping compound available at your local NAPA to do the cups. I think the trick is to do as little metal removal as possible. To do the spindle, you might have to make some kind of fixture to hold the spindle coaxially in the chuck of your drill/lathe, or if you have a lathe could do it with a 4 jaw chuck.

Yeah, I am a cheapskate, especially if I can find a way to fix something myself. the front cones cost me $12.50 apiece, which surprised me...

I would give it a shot. If pits are not too bad you might try using a bearing pressed into the end of a piece of tubing and some valve lapping compound available at your local NAPA to do the cups. I think the trick is to do as little metal removal as possible. To do the spindle, you might have to make some kind of fixture to hold the spindle coaxially in the chuck of your drill/lathe, or if you have a lathe could do it with a 4 jaw chuck.

I'm a cheapskate myself. For $12.50 x 2 I could buy a set of spokes and a new-used hub and rebuild the wheel...

A proper cheapskate has a box of spare cones he's saved over the years ;)

...And a clever one has em ziptied in pairs. :thumb:

Gotta love Yankee ingenuity. I would also like to know how they hold up.
I have a wheel with a discolored cup - lightly scored. I'm thinking of polishing it with some toothpaste or Clover compound, then putting in new bearings. It would be an experiment, and it will give me a backup set of wheels in case the good ones need servicing.

Why couldn't you use an old axle for a mandrel?

When the cup was pitted, I have also used a different cone with a slightly different angle forcing the balls to run in a slightly different track.

They will wear in before they wear out.

Nice job

Why couldn't you use an old axle for a mandrel?



I would have if I had one, although this method also allowed me to be sure I had everything along the same axis, plus it gave me an opportunity to play with the lathe, which is always fun.

I can't wait for someone to come in the shop and say "hey, I saw that you can just resurface my cones on the internet!" Some guys seriously don't get the idea that a DIY project is when you Do It Yourself!

I can't wait for someone to come in the shop and say "hey, I saw that you can just resurface my cones on the internet!" Some guys seriously don't get the idea that a DIY project is when you Do It Yourself!

Well given the time it took, I suggest you tell them that you charge them $75 for labor to shut them up. If they still want to do resurfacing, contact me, and I will do it for $50 and you can keep the rest...

:thumb:


Also for anyone interested, I found new cones that work... They were NOS Campy Nuovo Record cones from the 70's. The Ofmega hub is from either 1983 or 4 (the bike is a 1984 Bianchi, and some of the parts are stamped 1983, even though I can't find a date on the rear hub). So the large number of folks that told me Campy cones are compatable are correct (sort of). You have to find the "right" Campy cones, so don't just buy em off the internet... go to your LBS and try them. Apparently the cup wall thickness is thicker on the older hubs so that the cones need to be narrower (at least this is what I now believe).

And, Kimmo - I now have the old cones ziptied together in the parts bin...:rolleyes:

that is just to cool.