Coker bearings - Coker MUni

In what way are the bearings failing?
Is the outer race getting sloppy (you can wiggle the outer and inner
races back and forth)?
Is it getting packed with dirt and crud?
Is the grease getting washed out?

Open up one of the failed bearings and see what it looks like inside.
You can pop off a seal from the bearing using small pointy tools. Then
you can see if the bearing is full of dirt or maybe something is broken
inside (like one of the ball bearings or the cage that the ball
bearings fit in).

Are you using metal shield or plastic/rubber shield bearings?

For muni use I have found that expensive bearings aren't worth it.
Dirt and crud destroy the bearing too quickly. The only time that
expensive bearings might be useful would be for an expert level indoor
freestyle unicycle or a road Coker going for a world record. Otherwise
the generic bearing (with plastic/rubber shield) will do the job just
fine.

--
john_childs

john_childs (att) hotmail (dott) com
Team Never Wash Your Muni
Gallery: http://gallery.unicyclist.com/john_childs
'Unicycling Bookmark List' (http://backcountry.unicyclist.com/) ::
'World Clock' (http://tinyurl.com/2blym3)
------------------------------------------------------------------------
john_childs's Profile: http://www.unicyclist.com/profile/449
View this thread: http://www.unicyclist.com/thread/61679

Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
http://www.usenet.com

I use the SKF bearings with plastic/rubber shield. When I cycle I can
feel the wheel is being hold back when the bearing is damaged. Like the
brake is a little on, then after some while it is rolling fine again.
Then after a while again the bearing not roll god and the wheel starts
to brake. I only Unicycle in god weather. Of course it is some dust,
but I don't think that is the problem. When I take of the wheel the
outer race is a little sloppy.

A friend (not Unicyclist) told me these bearings was not god on sideway
pressure and give me a tips to use Spherical roller bearings. But after
some reading I cant find that the Spherical bearings are made to fit
the 17-mm ID, 40-mm OD Coker bearings.

--
unijuul

www.unijuul.com
------------------------------------------------------------------------
unijuul's Profile: http://www.unicyclist.com/profile/13774
View this thread: http://www.unicyclist.com/thread/61679

Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
http://www.usenet.com

I get many thousands of km on a set of Coker bearings. The exception was
on my original Coker in 1999 - they shipped with unsealed (open on one
side) bearings and I only got 1500km on them but I remember people
riding in wetter climates only got 200-300km on them.

I do a mix of road and offroad riding, but lots of climbing either way.
In fact my original Dave Stockton wheel from 2003 has now been on NUT,
AUT, LUT and leaving today for MUT. Plus at least 3000-4000km of other
riding. All on the original bearings. I am not positive which type they
are though. It's all packed so I can't look. I think SKF.

---Nathan

--
nathan
------------------------------------------------------------------------
nathan's Profile: http://www.unicyclist.com/profile/251
View this thread: http://www.unicyclist.com/thread/61679

Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
http://www.usenet.com

unijuul said:

I use the SKF bearings with plastic/rubber shield. When I cycle I can
feel the wheel is being hold back when the bearing is damaged. Like the
brake is a little on, then after some while it is rolling fine again.
Then after a while again the bearing not roll god and the wheel starts
to brake. I only Unicycle in god weather. Of course it is some dust,
but I don't think that is the problem. When I take of the wheel the
outer race is a little sloppy.

Hey man, feel free to pry off the covers and squeeze some grease into
the bearings, pushing out the dirt etc. Then pop the covers back on.

unijuul said:

A friend (not Unicyclist) told me these bearings was not god on sideway
pressure and give me a tips to use Spherical roller bearings. But after
some reading I cant find that the Spherical bearings are made to fit
the 17-mm ID, 40-mm OD Coker bearings.

I've spent many, many, many hours scouring the bearing info for a better
bearing solution for different uni situations and, at this point, there
isn't one. In fact, your bearings are spherical single row deep groove
bearings, which are a kindof mid-compromise bearings that handle both
axial and radial loads in an ok way. Bear also in mind that more
exotic solutions get _very_ expensive _very_ fast (read: cost more than
your complete unicycle).

However, there should be minimal sideways pressure on your bearings. I
adjusted your frame carefully to match the bearing width to eliminate
that kind of pressure. However, perhaps there have been some
not-gentle crashes!

nathan said:

I do a mix of road and offroad riding, but lots of climbing either way.
In fact my original Dave Stockton wheel from 2003 has now been on NUT,
AUT, LUT and leaving today for MUT. Plus at least 3000-4000km of other
riding. All on the original bearings. I am not positive which type they
are though. It's all packed so I can't look. I think SKF.

Should be. Good luck Nathan and crew! And AJ too, from Austin!

--
U-Turn

Weep in the dojo... laugh on the battlefield.
-- Dave Stockton
------------------------------------------------------------------------
U-Turn's Profile: http://www.unicyclist.com/profile/691
View this thread: http://www.unicyclist.com/thread/61679

Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
http://www.usenet.com

I have no Crashes on my new Unicycle. A couple of UPD, but have managed
to take the Unicycle in the handle before it got the ground. I think
maybe I could fasten the frame a bit looser, but on my first ride it
was to lose and I had to tighten it a bit more.

What kind of SKF bearings do you recommend to use? I find 10 types of
17*40 bearings on SKF's web site.

98203
6203*
6203 ETN9
6203-2RSH*
6203-2RSL*
6203-2Z*
6203-RSH*
6203-RSL*
6203-Z*
62203-2RS1

--
unijuul

www.unijuul.com
------------------------------------------------------------------------
unijuul's Profile: http://www.unicyclist.com/profile/13774
View this thread: http://www.unicyclist.com/thread/61679

Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
http://www.usenet.com

These same type, quality of bearings (just different size) I have used
in motorcycles. Failures are rare, even at 50, 000 + miles. Actually, I
have never had a failure, just a notchy feeling, so I replace the
bearing while I change the motorcycle tire, only if it feels like it
has a stick spot while moving it with my finger.🙂
Follow John's advice on installing the bearing. I am almost certain
that you are damaging it while putting it on.😎

--
feel the light
------------------------------------------------------------------------
feel the light's Profile: http://www.unicyclist.com/profile/14551
View this thread: http://www.unicyclist.com/thread/61679

Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
http://www.usenet.com