Thomas1

Hi there,
I'm overhauling the front hub on my bike and I've noticed a small hole in one of the cones (see the picture linked to below). Should I replace it (I think yes)? If so, should I replace the other one too?

I can't post URLs or pictures, but you can paste the beginning of the address posted at the bottom of this message into your web browser to see the cone (please hover over the picture and click the right button on your mouse or, if you're using a mobile device, tap the picture and hold it till a menu pops up, select see the picture and zoom in as much as possible to see the hole). Hope this works.

ibb.co/LkMgDfk

JohnDThompson 

Replace both cones, use new balls, and check the dropout alignment as well.

CliffordK

@Thomas1's Album:
https://www.bikeforums.net/g/user/448463
https://www.bikeforums.net/g/album/16484979



You could take a close-up and then crop to make the image clearer.

CliffordK

What you have is a tiny pit.

I've effectively repaired similar pits by mounting a scrap axle into a drill press with the cone + lock nut reversed.

Then successively sanded from say 220 grit up to oil + 600 grit.

There is a question on whether some manufacturers are using a mild steel + case hardening, in which such an approach would reduce the overall longevity of the cone.

Nonetheless, doing nothing, the pit will grow, and could eventually destroy the hub.

Bill Kapaun

What hub is this?
It looks like some of the low end Shimano cones that don't have any treatment other than an "oxide" coating. No polishing or other finishing.
I've had pitting troubles on FH-RM-30 hubs, specifically the DS cone.
Fortunately, my LBS had "generic" rear cones for $1 ea that are so close, less the "coating".

Look at SJS Cycles in the UK for cones.
I had 4? delivered to my door in the US for $14 a few years ago. Far simpler & MUCH cheaper than sourcing one in the US.
I've switched to synthetic grease in hopes it will prolong their life.

davidad

https://wheelsmfg.com/products/hub-parts/all-cones.html

Bill Kapaun

Wheels probably doesn't carry the bottom end cones, considering the price of the cone being probably more than 1/2 as much as the entire hub it came in.
SJS can fill a lot of "gaps" and often cheaply.
https://www.sjscycles.co.uk/search/?term=cones&geoc=US

WizardOfBoz

What Clifford K suggests has apparently worked for him. On the other hand, bearing grinding and polishing machines are about 10 times more precise (less runout or "wobble") than most drill presses. Unless the cones are really special (e.g. this is a oem restoration of a 1934 Club bicycle with cones that have a Loewenherz thread spec) I'd replace the cones.

CliffordK

I had started doing it with new cones that weren't perfect. But, moved to minor pits.

I can make minor to moderate pits disappear, and get a mirror polish.

A minor change in the profile doesn't bother me. I can't say about the roundness of the finish product. I think it remains close.

Any minor scratches are circumferential, and largely irrelevant.

WizardOfBoz

As mentioned, you got it to work, and I know from reading your posts you have significant experience.

I'm probably overly persnickety. I grew up working in a machine shop (and a bike shop) and I'm an engineer.

CliffordK

I should make a video sometime.

But, if you have some moderate quality cones with a a couple of small pits... send them my way for a freshen-up.

WizardOfBoz

You have to realize that I've dealt with milling machines in which the preload is specified as an inertial whirl of the bearing, plus 10°. And if there is a compressed air hose that is within access range of the milling machine, the manufacturer voids the warranty (compressed air blows metal swarf away, but also blows dirt into bearings). Machines that (using polycrystalline diamond cutters) leave a mirror finish on aluminum.

I realize the need for expediency sometimes. I had to reassemble my Schwinn Superior wheels with a few pits (but clean, with new grease). But it was a little bit like fingernails on a blackboard to me!

BTW, I'd appreciate anyone correcting me if I'm wrong, but finding new cups to press into the old Normandy hubs from 1978 is going to be well nigh impossible, yes?

[On Edit] Someone has posted a thread about regrinding cones, here.
https://bicycleobsession.wordpress.c...ted-hub-cones/

Thomas1

Thank you all very much.
I'm gonna visit my LBC today and buy new cones and bearings (I think this is a good time to replace them).
@CliffordK, thanks for posting the picture. I'd tried to take a close-up but my phone camera wouldn't cooperate; it wouldn't focus on the cone this time round... I'll try to remember I can also post-edit the picutre in similar cases in the future.

Mad Honk 

Wiz,
How many do you need, and do you need both front and back? I have no problem with driving them in and out of hubs, and there is no shortage of those old hubs.
I doubt that the races have changed much in the last 40 years.
I wind up driving the races out of the hubs being recycled because the clean aluminium pays about twice what the dirty Al pays. Smiles, MH

jbucky1

To answer the OP. I would put it together as is, adjust it to the correct preload and see if I can feel it. If I cannot feel it then I wouldn't worry about replacing the cones. Otherwise, yes new cones and new balls.

www.buckyrides.com
ig: jbucky1

Darth Lefty 

I had a pitted cone on my bike a few months back. I found it cheaper and easier to buy a complete axle assembly on eBay. No one had the Wheels Mfg cone in stock and even if they had the price was identical

Thomas1

Thank you all. I've already bought new parts (the front wheel didn't feel too well when I rode the bike).

Thomas1

Thanks for this useful link. I got my hands on some other bikes with pitted/galled cones. I used the information on the website to refurbish them. I skipped the step with the grinding stone. Here are some pictures from before and after (most of) the grinding was done:






I don’t know yet how the bearings/cones are going to perform, because I just finished doing them. But I put back one hub which I overhauled, test-rode the bike for 1.5-2 hrs on flat surfaces, and the wheel seems to spin okay. On closer inspection I also didn’t notice the problems from before the hub was overhauled.


I wish there were an equivalent way to restore damaged (i.e. pitted/galled) hub bearing cups which cannot be replaced/taken off the hub. The method described at the referenced website is nice as it 1) uses tools commonly accessible in the home shop (from the more 'advanced' tools you basically need a drill); 2) is relatively simple, so the common DIYer can do the whole job without too much trouble and 3) is efficient – the cones come out nice. I realise in case of a pitted/galled cup it’s easier to buy a new wheel or in some cases the hub may be replaced, but there are situations in which neither of the above is possible; plus there are many wheels with damaged bearing cups which are otherwise fully functional (perhaps with the exception of other parts of bearings which on the other hand can be easily replaced/fixed).

Here's a thread on Resurfacing Galled Spindles and Cups. The method deals with bottom bracket bearings and uses a lathe which unfortunately is beyond my reach and, I suppose, it's rather imposible to secure a 26+' wheel to a lathe.

The only thing regarding repairing hub cups that I found on the internet is this:

I think this method could be further improved upon if the cup* is rotated, ideally by a drill (a common tool found nearly in any home shop). This would let one grind off cup races more evenly. Any ideas if it’s possible/how to do it? Also an alternative approach using similar tools wouod also be appreciated. :-)
*in most cases I have to do with, i.e. 90% of the time, I can't take cups out of the hub, which means that the whole wheel has to be rotated.

JohnDThompson 

A problem with re-grinding/polishing pitted cones is that many of these cones, particularly the lower-end models, are merely case-hardened, rather than through-hardened. Regrinding the bearing surface removes the hardened layer on a case-hardened piece, so the balls run on unhardened steel. This means that the newly-ground race will wear quickly. If new, replacement cones are available, those would be a better long-term fix.