How long should a chain and a cassette last?

[Harry Meatmotor]

@Vicegrip 147153 wrote:

ding! I suspect we have a winner. Cartridge bearings even within a single size, format, hardness and finish spec can be furnished open, simple dust shielded, sealed and environmentally sealed form to list but a few formats. The higher the environmental resistance the the bearing seal system the higher the internal resistance they often exhibit. Resistance is not a positive aspect for us low power producing meat motors. If you are on set # 3 or more of a brand and seal type of bearing you might want to look at increasing the environmental protection factor of the bearing. Bike makers don’t make bearings. Bearing makers make bearings and for the most part bike and bike component makers select the bearing they want to use from what is available. I suspect that bike based bearings rarely fail due to load and fail after being contaminated. I had a single front wheel bearing go bad. On disassembly and inspection I found that it had a little tiny ding/grit scrape in the wiper ring of the seal, the lubricant had been contaminated and had dried up. The other bearing, which saw the same service and exposure, was in great shape internally.

I’ll add one little thing: part of why folks pay the big bucks for Chris King is that they use nice seals in all their bearings. Similar to what enduro uses in their most expensive ceramics. And CK bearings are easily re-buildable.

[hozn]

@Harry Meatmotor 147163 wrote:

I’ll add one little thing: part of why folks pay the big bucks for Chris King is that they use nice seals in all their bearings. Similar to what enduro uses in their most expensive ceramics. And CK bearings are easily re-buildable.

Do CK use cartridge bearings for their hubs and headsets? (I think so, right?) I was surprised they didn’t for their bottom brackets. I was disappointed in those bearings/seals/system/whatever; with regular re-greasing (… I purchased their $55 grease injector …) I only got 9k miles from that bottom bracket. Just commuting. At $140 I figured it needed to last me at least 6 times as long as a regular BB to make economic sense. Probably more if I factor in that damned grease injector. Since it didn’t even last twice as long as a standard GXP, I decided I won’t ever buy another.

(Would anyone like to buy a CK bottom bracket grease injector fitting for $20?)

But obviously people love their hubs and headsets, so I imagine those are actually measurably better than the competition. But I have 20k miles on my Hope Pro II hubs and they don’t seem to be giving any indication of getting tired. So I’d need to be getting at least 40k miles from CK to justify the cost difference. And who has patience to ride the same wheelset for forty thousand miles !?

[EasyRider]

Fenders may be another reason I get years of service from my cheap square taper BBs, and for that matter, my chains and cassettes. All of my bikes, running tires from 28mm to 52mm, have fenders. Several years ago I zip-tied a strip of rubber stair tread mat to the front fender my commuter. After a messy commute, one glance at the DIY extension shows that it really does block a lot of salt, sand and grime from spraying the drivetrain.

[Harry Meatmotor]

@hozn 147172 wrote:

Do CK use cartridge bearings for their hubs and headsets? (I think so, right?) I was surprised they didn’t for their bottom brackets. I was disappointed in those bearings/seals/system/whatever; with regular re-greasing (… I purchased their $55 grease injector …) I only got 9k miles from that bottom bracket. Just commuting. At $140 I figured it needed to last me at least 6 times as long as a regular BB to make economic sense. Probably more if I factor in that damned grease injector. Since it didn’t even last twice as long as a standard GXP, I decided I won’t ever buy another.

(Would anyone like to buy a CK bottom bracket grease injector fitting for $20?)

But obviously people love their hubs and headsets, so I imagine those are actually measurably better than the competition. But I have 20k miles on my Hope Pro II hubs and they don’t seem to be giving any indication of getting tired. So I’d need to be getting at least 40k miles from CK to justify the cost difference. And who has patience to ride the same wheelset for forty thousand miles !?

I don’t like the king grease injector thingy – the split washer and seal are easy enough to remove (hint: use dental tools!) that overhauling the bearings is easier than fiddling with the grease injector. a trip through the parts washer/degreaser then alcohol or a lot of hot water is a given. also, use King’s Ring Lube to lube the bearings. don’t use ordinary Park or Phil’s grease.

[Harry Meatmotor]

@EasyRider 147178 wrote:

Fenders may be another reason I get years of service from my cheap square taper BBs, and for that matter, my chains and cassettes. All of my bikes, running tires from 28mm to 52mm, have fenders. Several years ago I zip-tied a strip of rubber stair tread mat to the front fender my commuter. After a messy commute, one glance at the DIY extension shows that it really does block a lot of salt, sand and grime from spraying the drivetrain.

if your feet get wet when you ride through a puddle, there’s gonna be gunk sprayed at your bottom bracket – long tail front fenders FTW!

[hozn]

@Harry Meatmotor 147180 wrote:

I don’t like the king grease injector thingy – the split washer and seal are easy enough to remove (hint: use dental tools!) that overhauling the bearings is easier than fiddling with the grease injector. a trip through the parts washer/degreaser then alcohol or a lot of hot water is a given. also, use King’s Ring Lube to lube the bearings. don’t use ordinary Park or Phil’s grease.

The folks at CK suggested Phil’s grease was a good choice, but I will bear this in mind if I find myself with another CK component. But all that cleaning sounds like way more work than a $20 replacement BB! Are you using a ultrasonic washer?

On that note, my BB is sounding pretty creaky today. I think the culprit was my “gravel” ride last weekend.

[Crickey7]

So, to rewind about halfway back, why don’t automotive wheel bearings fail more often? They’re submitted to the same environmental factors, higher weights and rpms. It is that they are simply sealed better and, if so, why aren’t bicycle bottom brackets sealed better?

[bentbike33]

@hozn 147183 wrote:

On that note, my BB is sounding pretty creaky today. I think the culprit was my “gravel” ride last weekend.

On an ancient mountain bike that I recently donated to “Bikes for the World”, there was a plastic derailleur cable guide attached to the bottom bracket shell by a screw the hole for which went entirely through the BB shell. Since the BB was of the threaded-cup variety, I used this hole as a grease port and kept the shell filled with grease. Then, periodically injected more grease until it came out clean around the seals. Those bearings lasted forever without any noise.

[EasyRider]

I don’t know much about cars, but I think we’d have to define “fail” in both contexts.

Subjectively, for me, a BB bearing fails when the crank doesn’t spin or the knocking is so much as to interfere with pedaling. Minor pitting of the races, or a bit of grittiness or noisiness would annoy me, but I wouldn’t consider it failure, even if it does mean it’s time for servicing or replacement. Perhaps car wheel bearings suffer from these same ailments but it doesn’t justify replacing them, since a driver wouldn’t notice them the way a cyclist would.

[KLizotte]

@EasyRider 147186 wrote:

I don’t know much about cars, but I think we’d have to define “fail” in both contexts.

Subjectively, for me, a BB bearing fails when the crank doesn’t spin or the knocking is so much as to interfere with pedaling. Minor pitting of the races, or a bit of grittiness or noisiness would annoy me, but I wouldn’t consider it failure, even if it does mean it’s time for servicing or replacement. Perhaps car wheel bearings suffer from these same ailments but it doesn’t justify replacing them, since a driver wouldn’t notice them the way a cyclist would.

When my front hub started making a horrible noise all of a sudden because it needed to be re-lubricated I read that it was dangerous to ride in such a situation because the hub could freeze up without warning. 😮 True, not true?

[Crickey7]

I’ve had bearings in wheels disintegrate. The hubs don’t actually freeze, but they get really sluggish really fast. And you destroy the entire component because the wreaked bearings score the walls.

[mstone]

@Crickey7 147184 wrote:

So, to rewind about halfway back, why don’t automotive wheel bearings fail more often? They’re submitted to the same environmental factors, higher weights and rpms. It is that they are simply sealed better and, if so, why aren’t bicycle bottom brackets sealed better?

Because the bearing assembly on a car weighs as much as a whole fancy bike. Also the spinny parts on a car aren’t in the spray line from the wheels. (They’re all inside some big piece of metal which also weighs as much as a bike.) A better analogy to bikes are boats, whose moving parts have lifetimes measured in hours…

[Harry Meatmotor]

@bentbike33 147185 wrote:

Those bearings lasted forever without any noise.

Well, they ought to in a 3lb grease bath!!!! Jeeez…

[Vicegrip]

@Crickey7 147184 wrote:

So, to rewind about halfway back, why don’t automotive wheel bearings fail more often? They’re submitted to the same environmental factors, higher weights and rpms. It is that they are simply sealed better and, if so, why aren’t bicycle bottom brackets sealed better?

(Caution the following answer contains opinions and 45 years of mechanical mayhem life learned advice. No text books were harmed during the formulation of this post but plenty of machines were put under the knife)
Simple answer on the bottom bracket question. Torque. A fully sealed bearing has a lip seal that is fixed to the outer race and gently contacts against the inner race forming the seal. The contact between the two parts one spinning one not causes a slight amount of friction. In a car this amount of friction is so small it is not measurable. On a bike we measure everything to the last erg. So bike part makers boast that that their bearing saves XX over 40 miles or the like when by far the torque or internal friction is largely the seal and lube used. No contact and light lube makes for an easy spinning and short lived bearing when exposed to commuter type environmental conditions. Bearings are made to set standards and finishes even within the same format. Two bearings of the same size might be rated one for 2000 and the other 20,000 RPM with a wide range of temp and environmental exposure conditions between them. Ceramic bearings are harder than steel but still suffer from contamination and lube loss damage like steel. (and are often not 100% ceramic)

Answer to the automotive bearing question. Fully sealed bearings.

We can dither all day long about washing with a hose of not. If your bearings are not fully sealed dust and water can get in when you ride in said conditions. Keeping direct spray out of the bearings helps. total submersion of a non fully sealed and fully lubed bearing is the beginning of the end unless you fully service the bearing. Operation while submerged is even worse as you are now very efficiently blending water and grit into the lube. This messes up the surface adhesion of the lube. Surface adhesion and the thin film it promotes is the whole key to the lube. If the grease looks like mousse it is no good.

Pushing new grease into a dirty bearing only delays the inevitable failure as it leaves contamination behind in the nooks and crannies.
In order to save a contaminated but not damaged bearing you need to 100% remove the lube. You cannot do this by flowing grease through it. Remove the bearing, remove the shields*, remove all the lube, remove all the solvent**, repack with correct lube and reinstall the shields. I suppose you could push new in run the bearing for a while and repeat with the contamination being further diluted with each cycle.

*Some shields are removable if you take care and don’t touch the inner lip area.
** For Dog’s sake don’t spin a dry bearing with compressed air. Compressed air is great for removing solvent from a bearing but don’t let the bearing spin while you are cleaning it. It is great fun and cool to watch but it just kills the bearing. It is not hard to air spin a dry unsealed bearing to 100,000 RPM.

[dkel]

^^^ tl:dr Just replace the bearing. :rolleyes:

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