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bearing condition - impact ride quality?

1K views 23 replies 9 participants last post by  freeriderB 
#1 ·
I just removed all 8 bearings from my VP Free (thanks to those who offered guidance in my previous post).
While all the bearings were filled with some dirt and crud, the lowers were REALLY gunked up. One in fact, barely spun when I tried to turn it with my fingers....

This got me to thinking...How much does a frozen bearing or (worn) bearing effect ride quality?
Will it impact the way suspension feels?
Or will it just result in play if it's worn?
 
#2 ·
what you should have done is remove all of the bolts and then pop the rubber washer out and clean and regrease your bearings. you can do all of this without taking the bearings out (i believe).

most bearings won't turn in your hand or its hard. that doesn't mean they are ruined.

what i did with my Intense SS is clean all the bearings out with a degreaser and then repack it with grease. then you move your suspension up and down without the rear shock mounted. if it feels smooth than the bearings just needed more grease. if its notchy then its probably time to buy new ones. also its usually the lower bearings that go out and the uppers you can still use.

since you have them out i would just replace them. i hear it sucks to get the things out so putting them back in just to check if they work would probably not be a good idea.
 
#4 · (Edited)
climbingbubba said:
oh and read through this thread, its from the intense forum about bearings. it will tell you all you need to know about bearings

http://forums.mtbr.com/showthread.php?t=139889
It's almost correct, the part where he says the "resting on 2 bearings is a myth" isn't really true. If it's a myth, then the bearings would never get "notchy" and the races would probably never split. These things happen mostly because bicycle pivots are a limited-amount-of-rotation situation and most of the time the suspension does in fact "rest" on 2 or 3 ball bearings (force is concentrated in a small area). It's only when it's cycling through the travel that the other parts of the race take the load. When he's talking about cars and stuff like that he fails to mention that the parts that have high amounts of rotation typically have ball bearings or some kind of tapered bearing, while the parts that have low amounts of rotation have needle bearings or even bushings. If they are subject to high radial loads then the needle or tapered bearings work well.

One thing you can maybe understand is that bicycle bearings are usually not perfect and a compramise. To design needle bearings or tapered bearings into a bike is usually pretty expensive, and the "enduro max" bearing isn't very far above those 'skateboard' bearings.

VPP designs are notorious for wearing out bearings due to their highly leveraged pivots. The intense guy also doesn't really do a good job of explaining this. On other bikes with longer links, or even single pivots, the bearings do not see nearly as much force exerted on them, but with small links there is usually a pretty high amount of force exerted, so they tend to wear out bearings faster than other bikes. This is true for most bikes with small linkages (sometimes referred to as "parallel linkages") such as the VPP and some DW type bikes.

It's not necessarily bad that you can't move the bearings with your fingers, you'd have to supply that extreme high amount of force (leverage) to replicate riding conditions. Can you compress your shock or shock-spring when it's off the bike? It's the same type of deal.
It's not uncommon to go through bearings pretty fast on VPP bikes.
 
#5 ·
replacement

climbingbubba said:
what you should have done is remove all of the bolts and then pop the rubber washer out and clean and regrease your bearings. you can do all of this without taking the bearings out (i believe).

most bearings won't turn in your hand or its hard. that doesn't mean they are ruined.

what i did with my Intense SS is clean all the bearings out with a degreaser and then repack it with grease. then you move your suspension up and down without the rear shock mounted. if it feels smooth than the bearings just needed more grease. if its notchy then its probably time to buy new ones. also its usually the lower bearings that go out and the uppers you can still use.

since you have them out i would just replace them. i hear it sucks to get the things out so putting them back in just to check if they work would probably not be a good idea.
I decided to remove all and replace them since I had some play coming from the lower pivot area, and it's been 2 riding seasons on the originals.
I also had to replace the lower link a few months ago, so i ordered a Pro pac set from SC and now since the snow is here...it's time to get to work.
 
#7 ·
Jayem said:
It's almost correct, the part where he says the "resting on 2 bearings is a myth" isn't really true. If it's a myth, then the bearings would never get "notchy" and the races would probably never split. These things happen mostly because bicycle pivots are a limited-amount-of-rotation situation and most of the time the suspension does in fact "rest" on 2 or 3 ball bearings (force is concentrated in a small area). It's only when it's cycling through the travel that the other parts of the race take the load. When he's talking about cars and stuff like that he fails to mention that the parts that have high amounts of rotation typically have ball bearings or some kind of tapered bearing, while the parts that have low amounts of rotation have needle bearings or even bushings. If they are subject to high radial loads then the needle or tapered bearings work well.

One thing you can maybe understand is that bicycle bearings are usually not perfect and a compramise. To design needle bearings or tapered bearings into a bike is usually pretty expensive, and the "enduro max" bearing isn't very far above those 'skateboard' bearings.

VPP designs are notorious for wearing out bearings due to their highly leveraged pivots. The intense guy also doesn't really do a good job of explaining this. On other bikes with longer links, or even single pivots, the bearings do not see nearly as much force exerted on them, but with small links there is usually a pretty high amount of force exerted, so they tend to wear out bearings faster than other bikes. This is true for most bikes with small linkages (sometimes referred to as "parallel linkages") such as the VPP and some DW type bikes.

It's not necessarily bad that you can't move the bearings with your fingers, you'd have to supply that extreme high amount of force (leverage) to replicate riding conditions. Can you compress your shock or shock-spring when it's off the bike? It's the same type of deal.
It's not uncommon to go through bearings pretty fast on VPP bikes.
that's great.
are you staying at a Holiday Inn Express tonight too?
 
#12 ·
bpnic said:
Daisy-
I love the info, it's right up my alley. He's giving you his opinion mixed in with widespread bearing info.

It's trolling I hate.
And you assume the intense guy is correct at the bottom of his article where he says that bearings never pit or wear in specific places due to the bearing "sitting" in a certain position most of the time? I gotta say that goes against most common sense, as well as physics.

If you hate trolling so much, why did you do it in this thread?
 
#13 ·
Jayem said:
And you assume the intense guy is correct at the bottom of his article where he says that bearings never pit or wear in specific places due to the bearing "sitting" in a certain position most of the time?
No, I just think that clean and lubed bearings will last almost forever. It would be more hours of use than you or I could stand before those 5-6 (or 8, or 80)steel balls break down (or notch), let alone ceramic balls. The failure comes from contaminants and maintenance(cleaning/greasing) not being performed.

Jayem said:
If you hate trolling so much, why did you do it in this thread?
I wasn't trolling, just trying to help clear up any questions. I work with bearings (nearly every type and application, including journal) in the Hydroelectric industry. Sizes typically range from 1/2" i.d. to 48" i.d.

I don't have a history of trolling. Do you?
 
#14 ·
bpnic said:
I don't have a history of trolling. Do you?
Why does it matter? Trolling is trolling.

You can seriously tell me that a ball-bearing isn't going to wear into the race if it sits in the same spot (doesn't rotate) most of the time?
 
#15 · (Edited)
Jayem said:
Why does it matter? Trolling is trolling.
Fair enough.

Jayem said:
..... sits in the same spot (doesn't rotate) most of the time?
while riding, at any time, look down; if the shock is moving whatsoever, the bearings are moving. The more you compress that pig, the more ball bearings are spreading that load. I use every bit of travel as often as possible, judging by my nice blue Push industries sag indicator.
Using the same 2-3 balls in your theory, just isn't really a correct assumption.

Like I said a few posts up, everything wears. If cared for though, you can extend the life of just about anything.
 
#16 ·
bpnic said:
while riding, at any time, look down; if the shock is moving whatsoever, the bearings are moving. The more you compress that pig, the more ball bearings are spreading that load. I use every bit of travel as often as possible, judging by my nice blue Push industries sag indicator.
You really think that the bike doesn't spend something like 80-90 percent of the time in a certain travel range, say 1.5" of sag + or - half an inch?

Sure, you want to use your travel, but I think you're fooling youself it you claim that the bike spends an equal amount of time at full travel as it does it's dynamic no-bumps-encountered ride height, I'd wager that it spends most of the time in a pretty small range.
 
#17 ·
My take on this is somewhat a bit of what everyone is saying. Sure contaminants will kill almost every bearing. But I also agree that only a few balls are actually taking the load of the bike, hence the use of a full compliment enduro bearings to maximize the surfaces taking the load. The use of bushings will probably offer the most load bearing capacity but supposedly it affects the suspension.

I'm not fully convinced that if you clean and re-grease your the bearings on an Intense often that it will never need replacing. It'll last longer because you've reduced one of the factors contributing to its wear. You still have all the forces going on all directions being aplied to the balls and races and I'm sure that's doing something to wear the bearing. Then there's also the fact that Enduro isn't actually a "real" bearing company. All they manufacture are for the use of bikes and skateboards.... not industrial use. I would say that the steel, the grease and even the manufacturing tolerances they are using are substandard to the ones NSK uses. In addition, having fairly small bearings (smaller contact surfaces to spread the load) mounted on the VPP doesn't help it last longer too. It's a bit of everything.
 
#18 · (Edited)
Jayem said:
You really think that the bike doesn't spend something like 80-90 percent of the time in a certain travel range, say 1.5" of sag + or - half an inch?

Sure, you want to use your travel, but I think you're fooling youself it you claim that the bike spends an equal amount of time at full travel as it does it's dynamic no-bumps-encountered ride height, I'd wager that it spends most of the time in a pretty small range.
My argument:
Not 80-90%, but closer to 60-70%. And if maintained properly, would last, not forever, but long enough to not justify arguing over. Most people forget their bearings are even there, and the deterioration process is accelerated. This is true for all bearings, not just Vpp bikes (Most people just are too busy to flush and lube Vpp bearings more than regularly, which they need because of location).
Assuming the bearings are spec'ed and installed right, they should handle the leverage and weight loads without problem for long enough to satisfy the owner.
 
#19 ·
peachy-B said:
My take on this is somewhat a bit of what everyone is saying. Sure contaminants will kill almost every bearing. But I also agree that only a few balls are actually taking the load of the bike, hence the use of a full compliment enduro bearings to maximize the surfaces taking the load. The use of bushings will probably offer the most load bearing capacity but supposedly it affects the suspension.

I'm not fully convinced that if you clean and re-grease your the bearings on an Intense often that it will never need replacing. It'll last longer because you've reduced one of the factors contributing to its wear. You still have all the forces going on all directions being aplied to the balls and races and I'm sure that's doing something to wear the bearing. Then there's also the fact that Enduro isn't actually a "real" bearing company. All they manufacture are for the use of bikes and skateboards.... not industrial use. I would say that the steel, the grease and even the manufacturing tolerances they are using are substandard to the ones NSK uses. In addition, having fairly small bearings (smaller contact surfaces to spread the load) mounted on the VPP doesn't help it last longer too. It's a bit of everything.
Yup, that was what I was essentially saying. The intense article is mostly correct, so that includes most of that info, the only thing that wasn't quite right was where he claimed the bearings don't spend most of the time in a fairly fixed position. It is possibly not the hugest point, but they will wear out and this is one of the things that helps bearings wear out faster. There are usually better bearing systems that can be used, but the cost and effort can be prohibitive. The only beef I had with the intense article is that they seemed to be pushing some less-than honest information at the end by claiming the bearings would last almost forever and would not be affected by remaining in the same place most of the time. How many VPP bearings have lasted that long? Did intense and everyone else make the bearings so you could service them?
 
#20 ·
bpnic said:
My argument:
Not 80-90%, but closer to 60-70%. And if maintained properly, would last, not forever, but long enough to not justify arguing over. Most people forget their bearing are there, and the deterioration process is accelerated. This is true for all bearings, not just Vpp bikes (Most people just are too busy to flush and lube Vpp bearings more than regularly, which they need because of location).
Assuming the bearings are spec'ed and installed right, they should handle the leverage and weight loads without problem for long enough to satisfy the owner.

Let's agree to disagree.
Propaganda is propaganda, and your rationalization points to the fact that the intense guy has no problem putting out propaganda vs. real information. Last almost forever? Why did intense design such a lousy bearing with lousy seals? It would be kind of lame for me to attack this, but realistically lots of VPP bearings have failed, and they tend to fail well before other bike's bearing systems. Your assumptions are conjecture and easily disproved by the experiences of users on this site. Not to mention that it is also a fairly established fact that bearings that sit in one place most of the time tend to wear down in those areas. Plenty of evidence all around for that. Your attempts to defend intense break down because they have been KNOWN to have weak (in terms of durability/reliability) bearing systems. They have ever-improved them, as has SC, but it's always been a weak area with their bikes. Now, are intense owners just stupid and that's why intense bikes have more problems on average? No, of course not. It's a combination of a highly leveraged ball bearing that sits in the same place most of the time in a remote location with no grease port or easy access. Far from the optimal bearing setup or design, but again cost and other design issues present a huge challenge.

I have no problems with intense bikes and as I said, SC and Intense have made efforts to design better bearing systems, but the intense guy puts out some propaganda at the end, and you keep trying to tell us that a bearing that sits in one place most of the time will not cause excessive wear in that specific place (pitting/notchy/etc). I don't believe that for a second. You don't find many enduro-type ball-bearings in industry unless they are high-rotation situations. I'm in aviation and turbine engines vs. the rest of the aircraft are good examples. There are bushings in places, there are bearings in places. There are usualy no bearings in limited-rotation situations, or if they are they have far more contact area through the use of a needle or tapered bearing.
 
#21 · (Edited)
Jayem said:
Propaganda is propaganda, and your rationalization points to the fact that the intense guy has no problem putting out propaganda vs. real information. Last almost forever? Why did intense design such a lousy bearing with lousy seals? It would be kind of lame for me to attack this, but realistically lots of VPP bearings have failed, and they tend to fail well before other bike's bearing systems. Your assumptions are conjecture and easily disproved by the experiences of users on this site. Not to mention that it is also a fairly established fact that bearings that sit in one place most of the time tend to wear down in those areas. Plenty of evidence all around for that. Your attempts to defend intense break down because they have been KNOWN to have weak (in terms of durability/reliability) bearing systems. They have ever-improved them, as has SC, but it's always been a weak area with their bikes. Now, are intense owners just stupid and that's why intense bikes have more problems on average? No, of course not. It's a combination of a highly leveraged ball bearing that sits in the same place most of the time in a remote location with no grease port or easy access. Far from the optimal bearing setup or design, but again cost and other design issues present a huge challenge.

I have no problems with intense bikes and as I said, SC and Intense have made efforts to design better bearing systems, but the intense guy puts out some propaganda at the end, and you keep trying to tell us that a bearing that sits in one place most of the time will not cause excessive wear in that specific place (pitting/notchy/etc). I don't believe that for a second. You don't find many enduro-type ball-bearings in industry unless they are high-rotation situations. I'm in aviation and turbine engines vs. the rest of the aircraft are good examples. There are bushings in places, there are bearings in places. There are usualy no bearings in limited-rotation situations, or if they are they have far more contact area through the use of a needle or tapered bearing.
This, for me, from the beginning was always about bike bearings. Not Intense, or what they write. I couldn't care less what they tell people, and I only skimmed his article for the sake of skimming. I wasn't defending them, just what I believe to be true regarding ball bearings.
(Go back and reread my posts, rarely do I bring Vpp into the argument.)

We'll just agree to disagree.

edit:
lets compare apples to apples.
I never said the bearings won't wear, or last forever. I've said the opposite.
But I'd be willing to wager that nearly 90-100% of SC's and Intense Vpp bearings have failed because of contamination. Not because of the balls/races breaking down on their own, due to ball placement or too high a leverage ratio.
Most of the owners that have had problems, probably could honestly tell you they run their bikes hard and put them away wet. It would take too long and too many miles to wear clean and lubed bearings into a state of failure. If so, then they (bearings) were spec'd(not designed as you stated) wrong by SC and Intense.
The bearings should be able to take the leverage and weight loads if spec'd properly by SC and Intense.
Better seals and grease ports were added to help fight contamination. Leverages were revised for suspension feel.
 
#23 ·
Back to the OP's question, bad bearings really do make a difference in suspension feel and the performance of the bike. Depending on what is wrong with the bearing, you could get vibration and noise, stiction resulting in bad small bump compliance, or flex/play in the rear end that makes the bike track poorly.
 
#24 ·
orig post

skatetokil said:
Back to the OP's question, bad bearings really do make a difference in suspension feel and the performance of the bike. Depending on what is wrong with the bearing, you could get vibration and noise, stiction resulting in bad small bump compliance, or flex/play in the rear end that makes the bike track poorly.
This is what I was asking...
Especially the small bump compliance.
Towards the end of this season, I found myself screwing with air pressure and preload because I thought the shock was feeling "weird."
I'm guessing it was the crud in my lower bearings (considering I had my shock PUSHED at the beginning of the DH season).
 
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