sbslider

I recently found my bike slowing down a bit on downhills. Three or so weeks ago I hit a speed I had not seen in several years, so I know the bike was in reasonably good shape then. The past few rides on downhills I noticed not getting as fast I would have expected. I mention this as evidence why I believe the degradation I saw evidence of today is recent. Perhaps this in not really germane, but those are my observations.

The evidence is that one of my front cones is pitted, and cone adjustment was tight enough to make it very obvious. I took the blemished cone to my LBS where I bought the bike 5 years ago. No cones anywhere close to mine in stock. The employee was very helpful, but did not have the parts. He helped me figure out the part number of my hub so I could buy the replacement parts online, or if I wanted would buy them and I could pick them up at his shop.

Found the parts, and since I ride my bike (I have only one) to work daily, I reassembled the wheel and installed it on the bike. I must have gotten very lucky, as the cone adjustment was a one step process, and I don't fell any play in the wheel. Even better, I don't feel or hear the grind of the one blemished cone.

The wheel seems good as new, what sort of risk do I take in riding for as is for a week, month, year?

Andrew R Stewart 

The risk of riding worn parts is that they wear more. The failure mode for cones/bearings is pretty slow and non catastrophic. Some ride well used up axle bearings until the play is so bad it interferes with safe bike handling. Your threshold of tolerance isn't known by us.


To add to your posting- Worn and/or overly tight hub bearings are a far less factor to speed then most think. The bearing friction is such a tiny component of total friction of a bike's ride that many times bearing friction is still a tiny part of the total. Perhaps the change of the bike's feel has you misdirecting reasons why. Andy

AnkleWork

0.228453 per week
18.459274 per month
956,724.174732 per year
(it's non-linear)

79pmooney

I've been riding a Campy Tipo front hub for years with pitted cones. Cleaned it and repacked with lots of marine hub bearing grease. Might have repeated this once. That hub has been my winter/rain/city hub and gets a couple thousand miles most years. The pitting just hasn't been an issue. Having said that, they will probably die tomorrow but I will take that chance.

Ben

HerrKaLeun

I hope you checked the inner races (the ones in the actual hub) as they are not replaceable and require hub-replacement.
If they are fine, you should be good. Re-pack the bearings every year or so depending on weather conditions. More water, more frequently. You basically clean it all out and use new grease and that removes all dirt and water that comes in. Some people also replace the balls every time they do that.

cny-bikeman

1. You should feel a little play in the wheel when it's off the bike but not when mounted IF it's a q/r hub, as the skewer will compress the bearing when mounted.

2. How would you hear the grind of the blemished cone if you've replaced it?

3. The hub will last many years as long as the cups are not damaged.

sbslider

Thanks for the serious responses, I appreciate the input. The cups / races are not damaged, I will likely replace both cones in the next month or so, just was curious how risky waiting this long would be. Sounds like not much of a risk.

And thanks for the insight on overall resistance Andy, I had forgotten how large a contributor wind resistance is vs mechanical resistance. If the cones were really slowing me down that much, it would have been much more noticable, that is going 40 mph would not even be possible.

cny, I have not yet replaced anything, I just disassembled the hub, found the blemished cone (1 only), tried to get a replacement, reassembled, and started looking for replacement parts. I could not really "hear" the cone, but I could feel the tightness as I slowly rotated the wheel, and also observed the wheel did not turn freely as it should.

sweeks

This is important. Cup-and-cone ball bearings generally show wear first on the cones. As these deteriorate, the metal bits can eventually cause wear on the balls and cups. If the bearings are serviced often enough, the wear on the cones may be prevented from damaging the cups which, as pointed out ^^, are generally not replaceable. Once the cups are damaged, the hub is shot, though it may provide service for a while.

A possible source of cones is this: https://www.bikeparts.com/categories...1&f%5B%5D=4161 (I recently found cones for my old mountain bike here)

A technical point of information: the cone is the "inner race" and the cup is the "outer race" in this type of bearing because of their relative diameters. You could consider the cup and cone "inboard" and "outboard" respectively.
Steve

pdlamb

O.P., did you replace the balls when you swapped the cone? Or at the very least, check carefully to make sure they weren't scored or pitted?

fietsbob

You can buy new replica cones, did you try asking at your LBS?

sbslider

I did not replace the balls, I plan to disassemble and replace both cones and balls over Christmas break.

sbslider

Yes, they did not carry any that worked on my bike. I will be getting a replacement set of cones and balls here in the near future.

fietsbob

Wheels Inc, Boulder is one source, I got a replacement <C> freewheel hub axle, from them, via LBS..

djb

re changing bearings, from my experience, I only change out the ball bearings if I see specific damage to them, or discolouration, and or if the cone has clear damage.

or from a broader view, if you regrease your hubs within reasonable time, or rather kms, and how much wet and dirty riding, if the hub is a good quality one, and the cones are properly adjusted, and all looks good, you can reuse the ball bearings with no issues.

that said, I still have three paper envelopes of diff bearing sizes, 100 each, that I bought 25 years ago + and still have lots left, so if you do like doing wheel work like this, or think you'll end up with more bikes, or a family, or whatever, finding a relatively inexpensive bunch of bearings is nice to have around.

although I'm not a working mechanic like these guys, I certainly have noticed how better quality hubs are much much better than cheap ones for keeping the grease clean because of better seals that keep water and grit out, so can go much longer between regreasing compared to a cheap hub with poor seal design.

Bike Gremlin

+1
Damaged cones will wear the balls more quickly and finally, if all is not replaced, damage the cups - which can't be replaced - it would require a new hub (sometimes even spokes, if the flange radius of a new hub isn't similar enough).

As for reusing balls, as others have said - if there's no visible damage, there's no need. However, if there's a worn cone, I usually replace the balls along with the cone - just to be on the safe side.

Though, they don't make parts as tough as they used to. I serviced a rear hub that had rusty balls and one broken in half, with no damage to the cups on a very old Czech hub!?! Newer (Shimano) stuff seems to have weaker metal.

capnjonny 

I work on mostly older 10 speeds and find that most cones on old bikes are not polished.The better ones , like the campi hubs I recently serviced, were highly polished. the every day Normandy or Arayacones look black when you remove them with a very narrow wear line where the ball touches the cone.

If there is just a small amount of pitting I will put the axle in my drill press with the cone from one side and it it's lock nut sticking out the bottom of the chuck and turn on the drill then take a piece of 400 grit wet dry sand paper and wrap it around something the same diameter as the cone and polish the cone face then reverse the procedure for the other cone. . I am not trying to eliminate the pitting. All I am trying to do is clean up the cone face and hopefully make it smoother .