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Sealed Bearings(17 posts)

Sealed BearingsJim Hubbard
Jun 6, 2001 1:18 PM
A question for the more knowlegable techie.... Where can I get a set of sealed bearings suitable for a set of good race wheels. By suitable I mean low drag. I brought a set of expensive race wheels that shall remain nameless a while ago, these wheels are great in almost every aspect except that the sealed bearings that they came with feel like they are running in mud. Having talked to some people I now know the reason for this, but I what to replace them anyway. Any suggestions? If the bearings are available over the net would you post the address.

Thanks
High Speed, Low Drag?L. Ron Cubbard
Jun 6, 2001 3:03 PM
Take the bearings out of the hub(bard). :) Lift the bearing cover with the edge of a razor blade or other suitable tool. Clean out the gunk. Clean everything, including your hands/fingers. Replace the stock grease/mess/muck with high speed lube of choice. White lightning ought to do it. I've even used light gun oil. Replace covers and re-install bearings. Ride.

All you will do by replacing these with those is get new gunk and same drag.

Give it a try. You'll thank me later.
Dubious Ideagrz mnky
Jun 6, 2001 4:06 PM
So you going to supply him with the replacement info once he cooks the bearings following your advice?

Root problem is that the seals suck. Popping them off, cleaning the gunk out, and replacing them with the latest snake oil will not change this fact. Running the bearing for an extended perior of time with inadequate lubrication will ruin them. The seals allow gunk to enter and this won't change. BTW - popping the seals and _replacing_ them only works if the seals aren't all metal. Of course if you don't care about the current bearings and have replacements.....

Get the bearing dimensions then look up the local bearing supplier in the Yellow Pages and order a better set. SKF is one of the, but not the only, big mfr.'s.
Dubious Idea?L. Ron Cubbard
Jun 6, 2001 4:20 PM
Cooked bearings? How do you figure? It is obvious that you have NO idea the temps and resistance to therms that firearm lubricants have. Humans don't pedal that fast. The seals suck? What seals don't suck? Metal or not, all seals can be easily popped. Last, bearings are so standardized and the tolerances so small, the last thing you need is lubricant induced drag.

Moly coating, another firearm based lube can be well adapted to bearings as well.
Point loadingsKerry Irons
Jun 6, 2001 6:27 PM
Bearings need grease - oil is too easily displaced, and the result is rapid bearing wear. Firearm lubricants are in different service. And White Lightning is THE LAST thing you should use on bearings - water based wax is not recommended for bearings under just about any circumstances.

Cute name. Mind Dynamics, anyone?
Relax.blue bayou
Jun 6, 2001 10:29 PM
I heard of your specious bearing loading technique way back when. Isn't it to be used only for a given ride on a given day? I think the other posters meant something...different.
Yeah, Dubiousgrz mnky
Jun 7, 2001 11:55 AM
So given that you're comparing apples to oranges, what is your point? The operating conditions for firearms are just a _tiny_ bit different from a bike. Start with the concept that you don't break-down a bike after every ride and clean every single surface. Add to that the fact that you don't run your weapon through dirt and rain and then let it sit around until your next use. Start thinking about viscosity and how it changes with temperature. Realize that the duration and magnitude of the forces are vastly different. Acknowledge that firearms primarirly consist of sliding linear type of friction, while bicycle bearings are typically point loaded rolling ball (or roller) bearings.

Most seals don't suck - they perform exactly as designed. Any seal can be removed - now try getting the all metal seals back on and not make things worse. If you don't care about the bearings, run without the seals, for a little while....

Yeah, lubricant induced drag is such a bad thing - why run any lubricant at all? I'm guessing, not knowing your age, that precision bearings have been well understood longer than you or I have been alive. Gun oil/grease well adapted to bearings? Quick, call the eggheads at the oil and chemical companies. I bet urine would work pretty well for a while also.

You're living in a dream world and have NO idea of the order of magnitude of things if you think that "bearing induced drag" of the grease from a set of proper precision bearings is even a factor in a race. Just think of how many races have been won or lost due to this greatly overlooked aspect.....

And, ahh, I do know a thing or two about firearms and lubricants having been in the military (fired & cleaned .45, M-16, M-60 & A-4 20mm cannon) and being a mechanical engineer.

No one is saying you can't do what you suggest, but you should probably secure a set of replacements before you do it and make it clear that what you suggest isn't supported by anyone else or by research.
I didn't measure, but am proudL. Ron Cubbard
Jun 9, 2001 12:21 AM
of the number of letters and spaces YOU, GM absolutly WASTED of this fricken idiot.

Get the troll hook out of your mouth, unless--nah, you the taste.

You really are a GM. BTW, rhymes with bone head.

GFYourself.
Now there's the voice of reason,....grz mnky
Jun 11, 2001 12:43 PM
not.
Dubious Idea: Grzy mnkysteeve0
Jun 7, 2001 11:31 AM
There goes the grzy monky: First thing he always writes is that someone has said something or done something wrong. Check his previous posts, his first line is always critical. What an a$$.
That's Funnygrz mnky
Jun 12, 2001 1:08 PM
I always say nice things about you.
re: Sealed BearingsJim Hubbard
Jun 6, 2001 9:03 PM
I didn't make myself clear the first time. The reason that there is drag is because the bearings are double sealed contact bearings. This is all good and well if the aim is to keep the crap and road grime out but for getting a minimal amount of drag the idea sux. What I wanted to know is, are there any particular bearings that rate above the rest. I have already cleaned them out to see if this eliminated the drag and it did not.
Check out the ABEC rating, if availiable.blue bayou
Jun 6, 2001 10:25 PM
Otherwise, can you decrease your sensitivity? I fought the durometer of my bar tape for a while.....then I got over it.

If you can detect drag in bearings in a blind test, you are The Man.

The rest of us mortals cannot.

BTW, I think MR whatever was ripping off a use once treatment for a given race.
have they broken in?jw25
Jun 7, 2001 11:17 AM
As I understand it, new sealed bearings feel very stiff because of seal drag. As the bearings are run, and the seals wear a bit and seat, the drag drops quite a bit, though still not to loose balls and labyrinth sealed levels.
So, you might want to pop them open (assuming they have a rubberized metal seal, not a metal shield), clean them out well, and relube with grease (definitely not oil. I've seen numbers somewhere on the net that show the benefit of oil, and it's very small compared to the risk of wearing the bearings prematurely. Sure, you can replace them, but it's a pain, and expensive). I really like Prolink's EPX grease, it starts out very tacky (nice for loose balls), then thins out after a few hours of use, and is very smooth. Can't vouch for longevity, though, as I've just started using it in March.
However, if you haven't got many miles on the wheels (and they're race wheels, so it's possible), go use them. Go for easy rides on smooth roads, the bearings only care about mileage. Based on experience, I'd say 100 - 150 miles ought to get them pretty smooth, with incremental gains over time. If the seals are really tight, it may take longer, but most of the rubber shielded bearings have loosened up in that span.
If you must replace the bearings , though, the best source I know of is www.bocabearings.com. They should have some exotic cartridges that'll do the trick. You really only need a seal on the outside of the cartridge, too, so if they're removeable, try that. Good luck. Jon.
have they broken in?grz mnky
Jun 7, 2001 11:27 AM
I hear what you're saying and the idea of breaking in the bearings has a bit of merit, but realize that these things are rated on the order of 60,000 hours at continuous maximum rated service. We don't even come close to any of this on our bikes.
Benefits of sealed bearingssalmonwheel
Jun 12, 2001 11:55 AM
Most of what I read, here and elsewhere, regarding roadbike components is to maximize performance. I understand there is a balance between performance, durability and ease of maintenance, but performance seems to be weighted pretty heavy. Why then use sealed bearings in a hub if they increase friction (and therefore rolling resistence), is it just to reduce maintenance. I am barely competent as a wrench, and overhauling a cup and cone hub takes but a few minutes and maybe 60 cents worth of parts (grease and balls). Am I missing something.
Answergrz mnky
Jun 12, 2001 12:53 PM
They don't.

People tend to spin wheels in their hands in a bike shop or at home. They then use this unloaded condition for comparison and do not expect that things will change. A cone/loose ball bearing system friction changes with an increase load since the balls move around a bit. It is also an order of magnitude thing - any difference in friction at the hub bearings is lost in comparison to the other forms of loss. It's basically noise.

Compare the adjustment process for a high-end sealed bearing system. Most require little if any adjustment and it's very easy to make with the wheel in the bike (Mavic). Now think about the process for adjusting a typical cone system and how often it needs to be done. Cleaning and regreasing most precision sealed bearings is not even an issue.