Hot answers tagged bearings
12
The short answer to your first question is "the power savings from using ceramic bearings compared to good steel bearings is almost zero." The short answer to your second question is "yes, it is possible to measure the difference but it's not easy." The longer answer, and the support for the shorter answers is below.
First, however, it depends a little on ...
6
There are several possible causes of noises you can get from your bottom bracket.
Bad bottom-bracket bearings
Bad pedal bearings
Loose crank arms
Loose bottom-bracket cartridge
Loose chainrings
Of these the loose crank arm (which may be silent or may be accompanied by a creak on each stroke) is probably the one needing the most immediate attention, since ...
6
Anti-sieze is a corrosion preventer.
It is not a lubricant. Generally, using it on threaded parts is acceptable, but using it on bearing races, bearings, pressfit installation points, seatposts, handlebar stems, etc... is not a good idea.
There is no hard and fast rule, but if you think about the purpose of the "lubricant" on the specific part, you should ...
6
It sounds like your headset is not adjusted. Your stem cap is used to adjust this. Specifically, the more you tighten the stem cap, the tighter the bearings will get, and the less play you will feel.
Here is a picture from Sheldon Brown's article on adjust headsets:
My process for checking headset adjustment:
Check the headset adjust:
Grab the front ...
5
It's not unusual for an asymmetric shaft (on some rear wheels or solid-crank bottom brackets, eg) to have different numbers of balls in one side vs the other. But it's a little unusual for a standard front hub. And if there's intentionally a difference then there would be a small but visible difference in the size of the races as well.
Likely the hub was ...
5
I don't have the source at hand, but from what I've read, converting your wheel bearings to ceramic will net you something like a 1 W savings at racing speeds, thanks to reduced mechanical losses. A ceramic bottom bracket would result in less improvement.
Considering the rider is putting out 200+ W at racing speed, the savings are clearly minor. Additional ...
4
I have ridden ceramic BB bearings. This is my one and only experience. They seemed to take a couple rides to break-in which definitely seemed odd. One of my training partners noticed the same thing, but in his case, it was after 90 minutes that the bearings seemed to spin freely.
I rode them for just shy of a year, which is approximately the same usage I ...
4
Yes, you can. You just need to get the right size of loose ceramic ball bearings as that's what shimano wheels use. They are available from various vendors, like here for instance.
You didn't ask this, but I'll answer it for you anyway: would I recommend replacing the bearings on a pair of WH-R550's with ceramic bearings? No, and neither would many others. ...
4
I've also never seen a bearing ball fail like that. In Jahaziel's answer to this question:
When do bearings need to be replaced?
he notes that in Honduras where he lives they sometimes could only get cheap Chinese bearings that "used to 'peel off' like an onion". Perhaps you got some of those? See also the response of "Mike" in this thread [1], who had ...
3
Pick the bike up so the problem wheel is off the ground. Grasp the tire and push it back and forth (left/right relative to the frame). If you can get any perceptible motion then the bearings are loose and need adjustment.
While the wheel is off the ground, spin it and watch the space between the rim and the brake block (assuming you don't have disk ...
3
The common Shimano Dynamo hubs don't actually use sealed cartridge bearings, see the DH-3N71 and DH-3D72 techdocs. Shimano dynohubs do use good seals, however, and should hopefully be maintenance-free for many thousands of miles.
Alistair Spence has a good exploded view of an Alfine DH-S500, which is very similar to the DH-3D71. He also links there to a ...
3
First of all, good on you for having a go at proper bike maintenance.
Unless you have an expensive American Classic or other 'pro' hub you will be needing 10 3/16 inch balls on either side of that front hub of yours.
Typically these are available from your Local Bike Shop in a pack that will have a few spares for the ones that run away whilst you put them ...
3
Some pedals are designed to be disposable, with sealed bearings as you mentioned. Usually these have a plastic dust cap (the cap you referred to) which is not easy to remove. If this is the case, you won't be able to do anything with the pedal, even if you get the cap off.
Typically, as you seem to know, if a pedal is designed to be serviceable, there will ...
3
Are you sure you're putting in the right number of balls? Generally, when a bearing is new there is about a half-ball space left when you have a full complement of balls. As the bearing wears this gets to be closer to a full ball's space. It's easy to see the space and think you should put in another ball, but you don't need one.
(To hold the balls in ...
3
I'd ask Trek.[1] Most likely you have a 20-tooth splined bottom bracket that the Park Tool BBT-22 would remove[2], but check first. You'll also need to know what width the bottom bracket is (varies) and its threading (probably ISO).
You may be able to just replace the bearings and not the whole bracket. If you want to go that route, you're best off ...
2
The general rule is a full race minus one ball. But if the race holds, say, 20.5 balls (ie, has space for more than 1/2 additional ball but not a full additional ball) then you can use as many as will fit (without forcing).
There probably is a (very small) rolling resistance advantage in using fewer balls (down to perhaps 3/4 full) but it would be at the ...
2
http://wtb.com/pdf/manuals/ServiceLDLiteV6.pdf
This service .pdf indicates that you need 15x26x7 bearings. I did a quick search on Enduros website and they don't appear to make this size in ceramic.
A quick web search came up with one option that I could (quickly) find.
http://www.vxb.com/page/bearings/PROD/Kit7872
Typically, in my experience, the ...
2
The Shimano hub dynamo bearings on one side probably not so difficult and you can look at their drawing but on the other side it can be difficult. I haven't tried to open the other side but you can check this out: http://www.bikeforums.net/archive/index.php/t-700163.html
2
It depends on the kind of bearing, but I can offer a little hint.
The easy ones are the open bearing, the kind that comprises a race, a cone, bearing balls (or rollers) and (optional in many cases) a ball/roller cage or retainer. These are common in non sealed hubs, non sealed headsets and non sealed bottom bracket.
For these types of bearing, proper ...
2
I refurbish a lot of older bikes for re-sale. The first thing I do is to pop off the wheels and manually turn the axles to see if the bearings are suspect. If the axle turns roughly, has side-to-side play, or is hard to turn...They probably do.
There should be "no more friction than supplied by the grease" when turned by hand. You cannot do this with ...
2
If your bearing cones are loose, you should be able to feel it if you have the wheel off the bike, and wiggle the axle (not the quick release 'skewer' that slides through, but the hollow tube that the quick release skewer slides through). With the wheel on the bike, you would also be able to feel it by wiggling the rim side to side (perpendicular to the bike ...
2
10 each side!
Invariably a bicycle has 10 3/16" balls on each side on the front and 9 1/4" balls on each side in the rear wheel.
You may want to read the Park Tool guide that confirms this and has plenty of tips for doing the job properly:
http://www.parktool.com/blog/repair-help/hub-overhaul-and-adjustment
You will need cone spanners, some clean grease ...
2
If your bottom bracket is going, then there will probably be some play in it - you can easily check for this by holding one pedal in each hand and pushing/pulling to pivot the cranks around the bottom bracket. First try pulling both pedals away from the frame then push them both towards the frame - if you feel any movement then your bottom bracket probably ...
2
I would try to buy new bearing balls and fit 10 brand new balls properly greased in each side.
I can't think of any reason for a front wheel to have more balls in one side.
I assume that your wheel uses rim brake, which being properly adjusted should put a fairly symmetrical load to the wheel assembly. Most modern hubs designed for Disc Brakes also use the ...
2
Unfortunately I have seen this all too many times working as a workshop manager in a performance bike shop, Cheaper wheels and in certain cases some expensive japanese made ones use a cup and cone system which when correctly adjusted and maintained will give the same minimal rolling resistance and smoothness as ceramic catridge bearing wheel sets.
...
1
First, to remove a cassette freehub does require a specific tool. The Park Tool version is called the FR-5.
There is no need for more than one kind of grease. Use any light bearing grease like the Park Poly Lube 1000.
There is a good set of instructions here on how to do the rebuild.
From Park Tool's repair help site:
Hub Overhaul and Adjustment
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