Steering head bearings.

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canyncarvr
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Post by canyncarvr »

re: 'what's the other portion...'

At the risk of being snotty...which other?

The part on top (of 92116) is the outer race, the part on the bottom is the bearing (inner race, tapered rollers and cage).

That question being asked makes a lot of this thread more clear to me.

The bottom bearing is indeed pressed onto the shaft. Said pressing makes removal tough if you don't use the 'press out the stem' method. Said pressing makes removal in one piece unlikely. Using the 'big screwdriver' or cutoff tool removal method obviously destroys the bearing...let alone the seal attached to it.

The outer races of both bearings are pressed into the steering tube (not into the same place, though. Well, into the same tube, but not into the same end of that tube. How about that? snotsnotsnot

The most likely part to fail (looking at it) is the outer race. You will see marks worn into the race facing before you will see anything wrong with the rollers.

I've taken out such a race and re-placed it 180º out, cleaned and repacked the bearing, and gotten another few months out of it.

Making the determination that a steering bearing set is OK because you can't feel it 'notch' when you turn the bars back and forth with the front-end on the bike leads to an incorrect conclusion. By the time you FEEL it through the bars it's been wasted a long time already!

Wibby: It worked! I'm annoyed already!

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Post by Mr. Wibbens »

>|<>QBB<
canyncarvr wrote: snotsnotsnot


Wibby: It worked! I'm annoyed already!

Cool! :wink:

I've had about a half dozen people pull over thinking I was a cop or something!

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Replace or reuse?

Post by crazybrit »

So I pulled the steering head bearings. Figured I should check before I ordered :grin:

The bearings looked surprisingly well greased, esp. given the sad state of the linkage bearings. No gunk. Moved smoothly.

I'm not an expert on when a bearing needs replacing so I took some pics. Hopefully someone can offer some advice.

Thanks

Tony

-------------------------

Top bearing: KOYO 32005JR.RS -- appears sealed to me
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Can see some yellowing on the bearing
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Top race. looks fine to me
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Bottom bearing, again can see some slight yellowing
Image
Image

Lower race, definately slightly worn, replace?
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Post by Indawoods »

Lowers for sure... it's scuffing on the bearing surfaces and races you are looking for.... I'd run the top if it runs smooth.

Any notchiness will also indicate a bearing will need replaced.
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Post by crazybrit »

Top bearing is only $19.00 so I'll just replace both. Thanks Inda. I figured the lower needed replacing.
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Post by canyncarvr »

re: 'Top bearing: KOYO 32005JR.RS -- appears sealed to me '

Of course, it is. There's never been a question about that. The question (my understanding) was whether an 'aftermarket' bearing would have the pictured (OEM) seal or some other dust cover 'supposed' to do the same thing.

The marks on the lower/outer race are exactly the sort of thing you won't feel with the front-end on the bike. You CAN feel it with the front wheel off..usually.

I wouldn't replace either bearing. Drift out the lower outer race, rotate it 180º, put it back in. Clean and repack the bearings, put it back together.

The steering stem will be on your regular maintenance schedule. Check 'em next time...or maybe check for 'notchy' next time you replace your front wheel bearings or put on a new front tire.

re: '..sad state of some linkage bearings..'

:wink: Like the lower shock?

Replace it with a double sealed, caged aftermarket bearing (pics, numbers in my gallery), machine the OEM grease seals to fit the added width of the new bearing. Mine is currently at 4X the life of an OEM unsealed bearing..and it's fine!

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Post by crazybrit »

canyncarvr wrote:re: 'Top bearing: KOYO 32005JR.RS -- appears sealed to me '

Of course, it is. There's never been a question about that.
Sorry, I thought somewhere someone had said that the OEM upper was not sealed. Anyways, it doesn't matter.
I wouldn't replace either bearing. Drift out the lower outer race, rotate it 180º, put it back in. Clean and repack the bearings, put it back together.
Well. Too late for that. I already cut off the lower one. Also, there was some odd wear marks on the upper bearing which are hard to see in the pics, basically wear marks along the rim of the cage between every roller.

Getting the top race out was easy peasy, 30mm socket was the right outside diameter. The lower is proving to be a PITA. I just gnarled the tip of a Craftsman screwdriver trying to drive it out and the race hasn't even moved. Is there a trick? I'd use heat to try and expand/shrink cycle the race except I don't want to damage the paint.

Also, anyone know what pipe size works best for driving the lower bearing onto the stem? My original one was set back about 1mm from the bottom but it looks like I could drive it all the way down. Figure I'll set the new one about the same as the old was.

Tony
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Post by canyncarvr »

Dang...I gotta read this stuff bedder.

You are correct. I completely blew by the 'top' part. I swear my top bearing does NOT have that seal, the bottom does. Inda agreed, right? I've got one in my box-o-parts, I'll have to remember to look at it tonight........

Re: '..how to'

Something with more mass will work better. I use a honkin' locking pin used to..well..lock electric motors when changing bits/blades (tenoner). A ballpein hammer is fine, a 2# sledge is better. No, not to beat on it...just tap. Side to side to 'ease' the race out straight. Don't get it cocked in the steering tube!

I've changed mine a couple of times...changed 'em in other bikes too. Never a problem that required heat and/or other 'extreme' measures.

Re: '...anyone know..'

Yep. But I'm not gonna tell you!!

Dang agin, but I never memmer what size it was..1 1/4" I think? I took my stem to the hardware store, picked up a 24" nipple (IC? :shock: ) that fit. No 'sweating' or 'rubbing' required, but DO get a cap for one threaded end of the nipple (IC? :shock:). Much better to hit that cap with your sledge when you seat that bottom bearing than to smack a raw edge of pipe.

Drive it 'til it seats. Support the stem from the bottom, NOT the clamp.

**edit**
Yep. Both of my spares...AND the one on my KDX tree are sealed up top.

Gee...who'd a thunk!? Not me!!

Any snottyness about it being otherwise on MY part is taken back, recused, exorcised, forsaken, AND apologized for! :oops: :prayer:

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Post by crazybrit »

Something with more mass will work better.
Yeah. I have a rubber mallet but they never work well. Too much damping. I either need to get a _real_ mallet or since I'm in a tool making mood (for the fork holder) I may just make a replica of the Park Tools Steering stem remover.
Drive it 'til it seats. Support the stem from the bottom, NOT the clamp.
It dawned on me that I should just use the old race. I made a radial cut in it (so I can jam it open with a screwdriver to get it off the stem). The old inner race upside down gives me good contact with the new inner race plus a wide area to use pretty much any diameter pipe I feel like.
Any snottyness about it being otherwise on MY part is taken back, recused, exorcised, forsaken, AND apologized for! :oops: :prayer:
No worries CC, snottyness and cluelessness is a bad combo. Fortunately you're pretty clueful so you can get away with it. Plus, it was sarcasm, no :-)

t
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Post by canyncarvr »

I didn't worry about getting the maximum amount of bite on the inner race. The next size up pipe from the size that the stem didn't fit in was 'it'.

No worries is good!

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Post by crazybrit »

In case anyone finds this thread remotely useful (hey, it is possible :-) I'm attaching a pic of the remover I made to remove the lower steering stem race. It's just a 1" od (.75" id) piece of aluminum pipe with 4 cuts in it. Cost about $4.

It popped out the race (with the same regular hammer that previously had just bent up the tip of a hardened screwdriver) in about 10 seconds.

In case it's not obvious, you pull it up through the lower race and the widened section compresses and then pops back into place behind the race.

Tony

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Post by Indawoods »

Your just like my eccentric Dad.... always making tools outta junk! :lol:
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Post by crazybrit »

>|<>QBB<
Indawoods wrote:Your just like my eccentric Dad.... always making tools outta junk! :lol:
Who's your (eccentric) daddy :-)
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Post by canyncarvr »

Good deal!

But..... :wink: I have no idea how a piece of aluminum did the job when a hardened piece of steel did not. Yeah..I get all the 'even pressure' parts of any argument. With so many pressure points, applied pressure would be spread out a WHOLE lot more'n the tip of a screwdriver in a spot.

But it worked!! ...let alone WHO'S your DADDY!? :wink:

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Post by crazybrit »

>|<>QBB<
canyncarvr wrote:Good deal!

But..... :wink: I have no idea how a piece of aluminum did the job when a hardened piece of steel did not.
Like you said, amount of surface area in contact with the race. I pounded on the Craftsman screwdriver and didn't move the race one bit. All I succeeded in doing was marring both ends of the screwdriver.

Also, with a tool like this which locks itself in place against the race you can really whack the !$@% out of the head without worrying that it'll pop out of position like a narrow screwdriver tip can.

t
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Post by canyncarvr »

Here's to whacking the !$@% out of stuff!! :partyman:

Good job, MacGyver!

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