wheel bearing friction

[CaptainDura]

does anyone have any knowledge of when to replace wheelbearings.

 

I might be imagining things (or i am just way more unfit than i used to be) but it feels as if my front and back wheelbearings are more difficult to turn than what it was before causing more friction.

 

Should wheel bearings be free turning or should there be some friction on the bearing ?

 

When I turn my mtb front wheel at a certain speed the wheel makes about 10 revolutions. when i do the same with my road bike the wheel makes 3 times that.

 

Is it just the added weight of the wheel and the tires that makes the difference ?

 

Does wheel bearings becomme stiffer with more friction or looser with more play when they are past their due time.

 

There are no play when I move the wheel side to side, but definitely some friction...

[Andre Engelbrec]

I am not sure what it is but evey time i pick up a bit of weight it seems that my wheels are turning slower. It could be the extra weight on the bearings?

[Mudsimus]

Johaaaannn!!

[HammerHed]

I got the same problem with my MTB, the wheel feels like it slows down quit quickly when you spin it in your hands, and it is not touching the disc brake calipers or anything.

 

I did the Karoo 2 Coast in rain and mud and that fine silty mud got into everything on my bike, it wore out the rear disc brake pad. When I got back home I pulled all the bearings from the wheel hubs and cleaned everything with a degreaser and covered the wheel hub bearings in a teflon bicycle grease and rebuilt.

 

It ran much better but it feels a little uneven when you turn the axle in your fingers, was wondering if that is normal.

 

How do you know when the bearings / hubs are worn?

 

[CaptainDura]

Johaaaannnnnnn!!!!! help ons arme siele hier.....

[CaptainDura]

Those wheel bearings are sealed units so i dont think you can reapply grease after cleaning it out with degreaser..

 

What to do? what to do?

[CaptainDura]

Another question.

 

When buying new sealed bearings, do they run smooth and friction free or are there friction on them because of the grease inside ?

[Windbreaker]

 

I guess JB is pissed off with people putting words in his mouth. Don't blame him - every time he comments there are 4 or 5 23yr old rocket scientists (engineering students) that flame him.

 

ps and 1 not so young tar mechanic

 

Windbreaker2008-03-26 10:24:49

[dirtrider]

Ok well Since Johann does not wanna share with us let me try ! I had a problem where my front wheel only did about one turn by itself . This was a long ,long time ago . I loosened the axle a bit and it's been turning freely ever since . Don't expect it to do the same revolutions as your road bike , it just does not do it ! If there are no play on the bearings and they don't make funny snap,crackle and pop sounds then they most probably just to tight . If you really wanna clean the bearings and apply grease again then go ahead . It can be done .

[dirtrider]

Those wheel bearings are sealed units so i dont think you can reapply grease after cleaning it out with degreaser..

 

?

 

What to do? what to do?

 

 

 

Like I said before , nothing is sealed so tightly that you can not get inside . But before you get the hammer and chisel it is a good idea to have a spare set of bearings anyway ,

[HammerHed]

My wheel bearings Shimano hubs are not sealed, if you unscrew the nuts the whole axle comes out and the ball bearings are left inside, stuck in the grease.

 

I pulled all of them out and cleaned all the muck out and put teflon bicycle grease back inside the groove of the hub that the ball bearings sit in and then carefully put the ball bearings back in this groove, and assembled the axle again, and tightened just enough to not have too much friction and guess what? Bob was my Aunty.

 

It worked, perfectly. But it does not spin smooth like my road bike you can feel the bearings when you roll the axle with your fingers.

 

This is not rocket science, just basic bike maintenance.

 

[fiasm]

bump

[Johan Bornman]

Sorry Guys (as I slap my forehead), I just didn't see this topic. TV must have improved for a micro-second.

 

Wheel bearings.

 

The best way to test wheel bearings is to learn to hold a wheel by its QR and spin it. You'll quickly feel any roughness in the bearing, especially if you've trained yourself with a very smooth reference wheel first. Find a Suntour or new Campag wheel and spin that for a baseline reference. Suntour gets a 0 BSS* rating, Campag 1 and new Shimano 2. Zero is best.

 

Seal drag. Seal drag is good, it means your seals are new and still working. There should be some resistance as a wheel that spins for a very long time has worn seals and your next wet ride or wash could be the one where water gets in and ruins your bearings.

 

Seal drag robs you of 0,0000001% of your power, don't fret about it. Rather get your aero position a bit better.

 

Wheels with water in the bearings have a perculiar way of telling you that there's water in. They start to sound like little sweet wrappers being opened. By this I mean little crackling sounds that weren't there yesterday. They're difficult to pinpoint and people usually start looking for them in other places.

 

Grease: Any grease works on wheel bearings (in bicycles). I like a clear or translucent grease simply because it is easy to spot water and dirt ingression in those.

 

Bearings. Bearings (loose balls) come on Grades. Grade 100 means that the maximum aberation is 100 microns (in inches) big. Grade 20 is thus five times smoother. In South Africa no-one that I know of sells grade 20 balls and I always get a Duh look when I ask for them. Therefore I import my bearings from www.loosescrews.com  The stuff you buy in bike shops are all grade 100 and not worthy of fine Shimano and Campag hubs.

 

Cartridge bearings (what people here call sealed bearings) are not really sealed all that well, but that's another topic on its own. It's best to buy those made by reputable manufacturers outside of China and India. I am sure those two nations are capable of producing better bearings, but what I've seen here is rubbish.

 

Cup and cone bearings usually have two seals. One rubber wiper seal and one contactless labyrinth seal (most people think this is a dust cap). On the right hand side of most rear hubs the seal is compromised and dirt ingression usually start here first.

 

It is easy to overhaul both types of hubs. To judge the condition of your races, rub a fingernail or ballpoint pen over the bearing track. You'll soon feel the tiny pits. This is the beginning of the end of your uub. Balls are cheap, I usually replace them whenever I see the grease is dirty. However, when I get thrifty at the endof my supply, I take a magnifying glass and examine each (clean) ball. It is quite interesting to do this, you'll see scales, pits and rust that looks like Everest.

 

*BSS - Bearing Smoothness Scale (something I just invented here on the spot).

 

What have I missed? Perhaps later tonight.

 

[CaptainDura]

 

Seal drag robs you of 0' date='0000001% of your power, don't fret about it. Rather get your aero position a bit better.

  

[/quote']

 

Good advice there johan.

 

Now back to my initial question. If is spin my (mtb) wheel at a certain speed it makes x revolutions. How do I know if my bearings are done for?

 

They feel as if they are tighter and turn less than in the beginning.

 

Can I open up those sealed (mavic) bearings and clean them out like the unsealed ones, or do i just buy new bearings and get it over with.

 

On that topic - there is another thread on here that shows how to replace your BB bearings with new ones.

 

Does anyone know if I can replace mavic bearings with bearings from our local bearing suppliers ?

 

I know how to open and remove my bearings from my hubs. that is not the problem.  

 

Can I just take the bearing to any bearing shop and look for a similar replacement?

[Johan Bornman]

 

If is spin my (mtb) wheel at a certain speed it makes x revolutions. How do I know if my bearings are done for?

 

They feel as if they are tighter and turn less than in the beginning.

 

I doubt you can feel they're tighter than in the beginning' date=' unless of course they are way too tight and stop rotating after only 1/2 a turn or so.

 

Bearings are kaput (or dry) when they rumble and the turning smoothness is gone. You can also experience little hesitations at certain parts of the rotation as if something momentarily holds it back and then lets go again. As i said, the best way of getting used to the right feel is to start off by spinning a known good wheel.

 

Can I open up those sealed (mavic) bearings and clean them out like the unsealed ones, or do i just buy new bearings and get it over with.

 

If they are cartridge bearings (loose ball bearings can also be sealed), then I can assure you that Mavic doesn't have its own unique design and own factory run to make bearings. They've used a standard bearing. You simply remove the bearing by finding a way of knocking it out from the inside. Be gentle. You can order a bearing removal tool from www.loose-screws.com or get one from me for R110-00. It comprises an insert that fits into the bearing, split into two and mounted on a spring that opens it. Difficult to describe, perhaps I'll find the time to take a photo and show you.

 

Anyway, if Mavic got the bearing in there, you can get it out with very little fuss, just a little technique.

 

All bearings can be found from local suppliers. See if you can get a good quality one such as SKF or Nippon.