Classic & Vintage - How many balls are ideal?

Sorry about the title. I'm really not trying to be funny.

I'm rebuilding a 1982 Trek 613. It has a Sugino bottom bracket with caged bearings. Each bearing has 9 balls.

I've heard, and it seems reasonable, that by replacing the caged bearings with 11 loose balls, it will be smoother and will last longer. There is no problem with the existing bearings, and there appears to be very little wear. This is just a routine servicing, but if I can gain any benefit at all by replacing the bearings, I'm all for it.

Also, is the Park Polylube a preferred lubrication for bottom brackets?

Thanks, everyone.

11 sounds right when replacing a cage bearing with loose balls in a BB. Park is what I use on flips Phil is what I use on personal builds.

I always replace the bearing balls with new grade 25 balls. They are cheap and typically of better quality than what they replace.

Just about any quality waterproof grease is as good as another in a situation such as a bicycle bottom bracket. I use Park Polylube myself, but haves use marine grease from auto parts stores as well.

Well, Lance has been getting by with only one for years....

this is not intended to dissuade you from replacing your BB caged bearings with loose bearings, but reminiscing at a bit, i recall losing them in the chainstays :(, down the seattube :eek: and up the downtube :mad:. i came the admire the cage after that...

they don't readily come out of the tubes with grease on them either. :notamused:

to answer your question, i think i remember it being recommended to put in as many as you can and then remove one. in practice, i put in (when i was still doing this) only as many as patience allowed. :lol:

I always use as many as will fit. I've checked many headsets for example where there was a bit of running clearance even after fitting the full complement of balls.
Taking one out could lead to unstable bearing support and localized overloading in cases where the number of balls is small, such as in a hub or bb.

[QUOTE=ColonelJLloyd;15169512]I always replace the bearing balls with new grade 25 balls. They are cheap and typically of better quality than what they replace. /QUOTE]

I got a bag of a hundred of these off Ebay to use on my keeper bikes. It wasn't expensive.

I use phil grease, or marine grease from an tub. Put as many balls as will fit, if they are jammed tight take one out, if they are slack (about one ball space total) then you are good. I have had more than one cage break and make a mess, loose balls can be a PITA but I think they are better in the long run.

Aaron :)

Well, Lance has been getting by with only one for years....

Sounds right to me. Any more and you are just showing off.

11 per side, 1/4 inch bearings of course, + pick up a tub of marine grease at the local auto parts store.

Phil grease sucks, the oils seperate out and it dries out much quicker than almost any grease I've ever used.

I use red Mobile 1 synthetic in a tub for flip bikes and Dura Ace grease for my keepers. Dura Ace grease is the absolute best grease ever made for bicycle use.

Oh no, the grease discussion again......

Two.

One is not enough.

Three is too much.

Oh no, the grease discussion again......Not really. I'm far more interested in the question about the bearing. The grease question was kinda' parenthetical. I was at the bike shop yesterday, and he was out of Phil's, so the question is really moot anyway. I'm sure a company like Park wouldn't put their name on a product if it wasn't at least very good.

Miamijim: I hadn't thought about the Mobil 1. I use it in my car, and I'm a true believer. That's a real possibility.

Oh......I'll be offline for a couple days. We're going to Las Vegas to celebrate our wedding anniversary, so let me thank all of you for your valuable opinions. They are all useful, even Captain Blight's.

Well, Lance has been getting by with only one for years....

But is that ideal? That was the question, correct? :P

I've always packed 'em until tight, and then removed just one, but in the light of recent news I'm thinking it might be an advantage to have two and lose one, especially if you're looking for sympathy and an excuse to be a rotten cheat!

Shame the bloody cheats! All of 'em!

- Wil (don't forget the Phil's Waterproof Green Gundge)

i take it something like this would be ok for replacements!?

http://www.ebay.com/itm/100-1-4-inch-Diameter-Chrome-Steel-G25-Deep-Groove-Radial-Ball-Bearings-/130572871141?pt=LH_DefaultDomain_0&hash=item1e66bfe5e5

what does G25 mean, is that the hardness of the balls?

As I understand it, it has to do with the precision (roundness) of the ball. 25 is the best that is commonly available. In this case, 300 is not better, even though it sounds like it should be.

And the number of the counting shall be eleven, thou shall not count to ten and thou shall not count of twelve.

...

The grading number relates to how accurate bearings are in millionths of an inch so grade 25 is 25/1,000,000 which means they are very consistent... beyond this you get into ceramic which has no practical benefit on a bicycle but can be made to an even higher level of precision.

..........what does G25 mean, is that the hardness of the balls?

Grade 25
Surface finish, sphericity (sp) etc.

You may find them cheaper at your local "power transmission shop" that sells hydraulic pumps, hoses, BEARINGS etc. when you factor in S&H. Else buy several 100 to amortize shipping.

My local "PTS" is a bit spendy on 1/4" size ($14?/100) and VERY inexpensive on the smaller sizes. You have to buy a "box" full. A box full of the smaller sizes contain a LOT of balls. IIRC, 3/16" size ($7/175?).

As I understand it, it has to do with the precision (roundness) of the ball. 25 is the best that is commonly available. In this case, 300 is not better, even though it sounds like it should be.

You have to be a princess to notice the difference between grade 100 and grade 25... it is much like folks who say grade 4 ceramic is smoother than grade 25 steel.

Bah.

11 per side, 1/4 inch bearings of course, + pick up a tub of marine grease at the local auto parts store.
I use the LubriMatic marine grease, it's green and doesn't have that nasty smell the regular bearing grease has.

I use red Mobile 1 synthetic in a tub for flip bikes...

Can I buy your flippers? That's way beyond the quality level evident in most flips I've seen!

As I understand it, it has to do with the precision (roundness) of the ball. 25 is the best that is commonly available. In this case, 300 is not better, even though it sounds like it should be.

I picked up grade 24's from one of the online hardware suppliers that was linked from one of the threads here, I think the next best bearing ( lower # ) was ceramic.

Glenn

Two.

One is not enough.

Three is too much.

These guys got it right.


http://www.youtube.com/watch?v=xOrgLj9lOwk

So... what about using ceramic bearings for cup-and-cone applications? Is that kosher or is it just asking to score the races?

So... what about using ceramic bearings for cup-and-cone applications? Is that kosher or is it just asking to score the races?

My understanding is the latter, that the typical cup and cone bearing assemblies standard in bikes
for many years are designed with a certain useful lifespan that includes a few bearing replacement
cycles..........i.e. the races are more durable than the bearings, which are cheaper and more easily
replaced. But I have to admit I've never tried it.

And the number of the counting shall be eleven, thou shall not count to ten and thou shall not count of twelve.





I always like a good Monty Python reference.

I always like a good Monty Python reference.

Oh? Try this (http://www.youtube.com/watch?v=GrZuijlJKc0).

There is less friction with the nine balls and the cage. When a rolling ball touches the cage, it is a rolling ball against something not moving.
When a rotating ball touches a neighboring ball it is two surfaces going in opposite directions. That's worse. Bearing makers know how to make bearings, most of the time. Not always.

There is less friction with the nine balls and the cage. When a rolling ball touches the cage, it is a rolling ball against something not moving.
Interesting. I wonder how much the grease reduces that. It would seem the coefficient of friction for the unpolished cage could be as high as the highly polished counter-rotating surfaces of the balls. I'm sure the difference is minuscule, especially with appropriate lubrication. I was more interested in the potential for reducing wear due to greater load distribution over a higher number of bearings. I'm over 200#, so I have to think about these things. Going from 9 balls to 11 represents an over-20% increase in bearing surface.

it depends on if you add a grease with a P.E.D to it. :roflmao2:

Interesting. I wonder how much the grease reduces that. It would seem the coefficient of friction for the unpolished cage could be as high as the highly polished counter-rotating surfaces of the balls. I'm sure the difference is minuscule, especially with appropriate lubrication. I was more interested in the potential for reducing wear due to greater load distribution over a higher number of bearings. I'm over 200#, so I have to think about these things. Going from 9 balls to 11 represents an over-20% increase in bearing surface.

I'm sure it is minuscule. All this stuff is on the interwebz, I bet you could find analysis of the differences. I got this info from a bearing company, where I used to buy bearings.

:)
I'm sure it is minuscule. All this stuff is on the interwebz, I bet you could find analysis of the differences. I got this info from a bearing company, where I used to buy bearings.
You would expect them to know, I reckon.

You guys & gals are overthinking this a little bit. Assuming the intended lubrication is present, the majority of friction will be due to sliding between the ball bearings that are taking the instantaneous load, and the races of the cone and the hub. Sliding is unavoidable because a monolithic ball bearing rotates at a given rate, while the range of line contact between the balls and the races require a variable rotation rate of the ball bearing. Of course, any non-circular irregularity in the bearings or the races will add to the friction, but that is mostly independent of the number for balls.
In the first approximation, sharing this sliding friction among more or fewer ball bearings will not appreciably change the net friction. It seems to me, that the main advantage of more ball bearings is increasing their longevity and that of the races, due to reduced cumulative fatigue damage (since the load is shared over more net contact area).

It seems to me, that the main advantage of more ball bearings is increasing their longevity and that of the races, due to reduced cumulative fatigue damage (since the load is shared over more net contact area).

^^That.

I think I remember Oprah asking this question in her interview last night.