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General Category => General Discussion => Topic started by: Bazil on October 17, 2020, 04:04:47 PM

Title: Do I replace the headstem bearing?
Post by: Bazil on October 17, 2020, 04:04:47 PM

(https://i.ibb.co/9ydvC85/20201017-174716.jpg) (https://ibb.co/9ydvC85)

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Working my way through my V40 Targa at the moment and pulled the triple tree to search for grease. Luigi didnt have any in the 90s either - what little existed was dry and grungy, and the top bearing didnt run smoothly. Took it out and cleaned it, and it seems to run well now with no notchiness. Looking at the race, I can see wear marks but can't feel any depressions. Mileage shows less than 4000 km, but I suspect this may not be accurate.

Do you think its good enough to repack the bearing and reinstall it, or should it be replaced.
Cheers
Bazil
Title: Re: Do I replace the headstem bearing?
Post by: n3303j on October 17, 2020, 04:22:18 PM
Sure looks corroded to me. Parts are cheap and labor expensive. Replace the bearings while you are in there and stuff them with grease. Then ride 10 or more worry free years.
Title: Re: Do I replace the headstem bearing?
Post by: Chuck in Indiana on October 17, 2020, 05:37:39 PM
Yep. Knock out the races and replace them. Yeah, I know.. it's not a particularly fun job..
Title: Re: Do I replace the headstem bearing?
Post by: John A on October 17, 2020, 08:02:38 PM
Nonsense, a little crocus cloth on them races and they’re good for another half season. :evil:

Well, I thought it was funny.  Replace both the upper and lower cups and cones and it’ll be fine for a very long time.  The lower bearing can be troublesome to get off the stem.
Title: Re: Do I replace the headstem bearing?
Post by: Bazil on October 18, 2020, 03:23:25 PM
Thanks for the second opinions - I'll get some bearings on order.

That bottom race is a bear to get out too; last one I removed needed a Dremel in the end.

Bazil
Title: Re: Do I replace the headstem bearing?
Post by: Chuck in Indiana on October 18, 2020, 06:01:21 PM
Thanks for the second opinions - I'll get some bearings on order.

That bottom race is a bear to get out too; last one I removed needed a Dremel in the end.

Bazil

Yep.
Title: Re: Do I replace the headstem bearing?
Post by: guzzisteve on October 18, 2020, 07:07:28 PM
Thanks for the second opinions - I'll get some bearings on order.

That bottom race is a bear to get out too; last one I removed needed a Dremel in the end.

Bazil

I use a bearing splitter & steering wheel puller, still not fun.
Title: Re: Do I replace the headstem bearing?
Post by: Tom on October 18, 2020, 10:07:19 PM
Dremel cut and replace.
Title: Re: Do I replace the headstem bearing?
Post by: lucky phil on October 18, 2020, 11:41:17 PM
Thanks for the second opinions - I'll get some bearings on order.

That bottom race is a bear to get out too; last one I removed needed a Dremel in the end.

Bazil

OR you can run a bead of weld around the race and it will fall out. OR you can get you Barbeque gas bottle and turn it upside down outside and let liquid LP run onto the race and tap it out with a Brass drift.

Ciao
Title: Re: Do I replace the headstem bearing?
Post by: John A on October 19, 2020, 08:03:54 AM
Or you can just use a bloody great big hammer and punch and squarely drift it out.
Use a big hammer to move stuff and a small hammer to form stuff.
The cone that’s on the stem is sometimes troublesome when you are trying to save the rubber washer underneath it.
Title: Re: Do I replace the headstem bearing?
Post by: acguzzi on October 19, 2020, 08:17:05 AM
another option is to partially press the stem out of the triple clamp, just a little way so you can get a puller underneath the bearing, or press it further till it comes loose.
Title: Re: Do I replace the headstem bearing?
Post by: wirespokes on October 19, 2020, 09:22:14 AM
The bearings don't move much so they wind up leaving marks on the race. No biggie. If the rollers don't have flat spots and you can't feel any notches in the race, I'd re-use them. Grease and reassemble.

When in doubt, most guys will advise you to remove and install new. i know, I'm taking the unpopular approach, but with such low miles and no wear to speak of, they're still pretty much at beginning of life. I'll bet they have ten to twenty years of hard use left in them.

They say labor is the expensive part. Yeah - it took nothing getting to this point, it's going to be quite a bit more removing the lower tree and then removing the races. You'll be saving a bunch of labor by greasing and reinstalling what you've got.
Title: Re: Do I replace the headstem bearing?
Post by: Mayor_of_BBQ on October 19, 2020, 09:54:50 AM
Thanks for the second opinions - I'll get some bearings on order.

That bottom race is a bear to get out too; last one I removed needed a Dremel in the end.

Bazil

(https://www.parktool.com/assets/img/product/_productEnlarged/RT-2_005.jpg)

(https://www.parktool.com/assets/img/product/_productEnlarged/RT-1_006.jpg)
Title: Re: Do I replace the headstem bearing?
Post by: n3303j on October 19, 2020, 10:28:16 AM
Recently read a great story where a boatyard removed a propeller under water with C-4 explosive.
That would be a fun experiment on the stem bearing.   :boozing:
Title: Re: Do I replace the headstem bearing?
Post by: jwinwi on October 19, 2020, 11:03:33 AM
(https://www.parktool.com/assets/img/product/_productEnlarged/RT-2_005.jpg)

(https://www.parktool.com/assets/img/product/_productEnlarged/RT-1_006.jpg)

I think the bottom race the OP is referring to is the inner race on the stem:  Much harder to remove than the 2 outer races. I've used a reinforced cutoff wheel on a Dremel to cut a good size notch and then hit it with a chisel which will crack it. YMMV
Title: Re: Do I replace the headstem bearing?
Post by: Mayor_of_BBQ on October 19, 2020, 12:18:56 PM
I think the bottom race the OP is referring to is the inner race on the stem:  Much harder to remove than the 2 outer races. I've used a reinforced cutoff wheel on a Dremel to cut a good size notch and then hit it with a chisel which will crack it. YMMV

Oh I see. In bicycles that would be the crown race, and I usually just knock them off with a screwdriver (i know, bad) or a chisel-shaped punch and a mallet.  Only works if there is a small relief in the fork crown to fit such a tool, or the race overhangs the edge by enough to get the tool seatedon it for the *WACK*
Title: Re: Do I replace the headstem bearing?
Post by: Antietam Classic Cycle on October 19, 2020, 12:32:57 PM
Large bearing separator clamped onto the stem under the inner race, separator supported in the (big) vise, nut threaded onto the stem to protect the threads, apply (big) dead blow hammer as needed.
Title: Re: Do I replace the headstem bearing?
Post by: moto-uno on October 19, 2020, 01:49:58 PM
  I'm with "wirespokes" on this one . If you can clean and grease the top (easily removed) neck bearing , I'd then take it
and push firmly up into the bottom race and rotate back and forth a slight amount . If you sense any roughness then replace .
And if not convinced , clean and grease the lower bearing (still on the lower tree ) and try again , no roughness , then why bother.
I only suggest this because for many people at home the lower bearing on the tree (stem) can be quite a struggle to remove .
Peter
Title: Re: Do I replace the headstem bearing?
Post by: wirespokes on October 19, 2020, 02:13:29 PM
I'm a firm believer of not fixing not-yet-broken stuff.

I like your method Charlie!  :thumb:

Thank you.

I wouldn't have thought of doing it that way, but my bearing separator doesn't get much use, so along with it and the press, it should be an easy job.
Title: Re: Do I replace the headstem bearing?
Post by: lucky phil on October 19, 2020, 03:34:21 PM
I'm a firm believer of not fixing not-yet-broken stuff.

I like your method Charlie!  :thumb:

Thank you.

I wouldn't have thought of doing it that way, but my bearing separator doesn't get much use, so along with it and the press, it should be an easy job.

Lucky you don't maintain aircraft :laugh:

Ciao
Title: Re: Do I replace the headstem bearing?
Post by: n3303j on October 19, 2020, 04:52:19 PM
Large bearing separator clamped onto the stem under the inner race, separator supported in the (big) vise, nut threaded onto the stem to protect the threads, apply (big) dead blow hammer as needed.
Aaaargggh! (Cringe)
There are so many ways to get that inner race off the steering tube that don't involve wailing away at the threaded end of the steering tube with any kind of hammer.
Pick any one of them first!
Title: Re: Do I replace the headstem bearing?
Post by: moto-uno on October 19, 2020, 05:00:24 PM
 ^^  You mean like Boeing ? :evil: , Peter
Title: Re: Do I replace the headstem bearing?
Post by: Moparnut72 on October 19, 2020, 05:46:49 PM
Lucky you don't maintain aircraft :laugh:

Ciao
There is some truth to that. Google the Warrington Effect.
kk
Title: Re: Do I replace the headstem bearing?
Post by: Moto Vita on October 19, 2020, 06:34:00 PM
Thanks for the second opinions - I'll get some bearings on order.

That bottom race is a bear to get out too; last one I removed needed a Dremel in the end.

Bazil

 After you have the race out use your dremel to cut a notch or two in the frame so you can use a punch to easily remove it next time.
Title: Re: Do I replace the headstem bearing?
Post by: moto-uno on October 19, 2020, 06:34:52 PM
 ^^ I just tried to google your "Warrington Effect " . Possibly you could supply a link . Everything that I found
 seems kinda irrelevant .  Peter
Title: Re: Do I replace the headstem bearing?
Post by: Antietam Classic Cycle on October 19, 2020, 06:56:38 PM
Aaaargggh! (Cringe)
There are so many ways to get that inner race off the steering tube that don't involve wailing away at the threaded end of the steering tube with any kind of hammer.
Pick any one of them first!

Why? This works (for me). The threads are protected by the nut and a dead blow hammer isn't going to deform them anyway! Unless the inner race is rusted stuck, it doesn't take a lot of force to remove. Never damaged any of the dozens of steering stems I've done this way.
Title: Re: Do I replace the headstem bearing?
Post by: n3303j on October 19, 2020, 07:10:40 PM
Why? This works (for me). The threads are protected by the nut and a dead blow hammer isn't going to deform them anyway! Unless the inner race is rusted stuck, it doesn't take a lot of force to remove. Never damaged any of the dozens of steering stems I've done this way.
You are a professional. So am I. In our experience background we learned just how much "hammer" was acceptable. Just like we get to break a few bolts while learning how hard is "too hard" when extracting a frozen fastener.

Most people don't have enough hammer experience to know the crossover point between persuasion and disaster. Best they begin with a less expensive project for their training session.
Title: Re: Do I replace the headstem bearing?
Post by: Kiwi_Roy on October 20, 2020, 04:17:12 AM
The top bearing looks ok but what's the bottom one like?
If you need to do one you might as well do them both.
Use a lot more grease of course.
Title: Re: Do I replace the headstem bearing?
Post by: s1120 on October 20, 2020, 06:10:12 AM
I saw a vidio ad on facebook the other day. It was meant for removing the inner race that sometimes stays on a car wheel hub when you press the bearing off. It was a cone that spun. You mount it in a vice, put the hub on, spun it while heating the race with a torch. In the vid it just slid off..and we know how that is..  but it still looked like a cool fixture to get heat all around. I wondered if it would work for stem bearings.
Title: Re: Do I replace the headstem bearing?
Post by: John A on October 20, 2020, 07:58:36 AM
another option is to partially press the stem out of the triple clamp, just a little way so you can get a puller underneath the bearing, or press it further till it comes loose.



This works for pre 98 forks but on later ones it is more likely to destroy the stem, they are tighter than Dicks hat band.
I tried to get the stem out of a couple trees with no success. Ruined the stem on both, they bent before moving. They were from crashed bikes so it was a trial but if I need a stem I will turn one on the lathe.
Title: Re: Do I replace the headstem bearing?
Post by: blackcat on October 20, 2020, 10:39:21 AM
I was lucky on the recent LeMans project, just gave the stem with nut a reasonably hard hit with a BFH and it popped right out.
Title: Re: Do I replace the headstem bearing?
Post by: Bazil on October 20, 2020, 02:35:10 PM
Wow - so many ways to crack a walnut !

I've used Charlie's method before too - worked fine but the amount of brute force needed was a bit of a worry, for me at least. I'm attracted to the BBQ gas chilling method - something about the slim possibility of going up in a ball of flames appeals to my daredevil side :evil:

In response to Roy - the bottom race is in better nick than the top race; what little grease existed was a bit more mobile and there didn't appear to be any surface corrosion or chafing on the race. The bike had been sitting outside under cover and the top race must have been a bit more weather exposed. The chrome trim ring on top of the bearing has some surface corrosion too.

I'm tempted to just replace the ( much easier) top race, as I haven't got around to ordering parts yet.

thanks everyone
Title: Re: Do I replace the headstem bearing?
Post by: wirespokes on October 20, 2020, 02:44:06 PM
I'm also curious about the Warrington Effect. I'm guessing it's the liklihood of the replacements or the act of replacing causing trouble when there was none before. There have been discussions about shifter springs (at least on airheads) being more likely to break if replaced - the new ones aren't as good. And then there's the thing about condensers - that's a long standing recommendation - if it's working best not change it even though it's part of a tuneup.

In this case, what's the worst that can happen if the bearings fail? Until the bearings were inspected, there was no issue with the steering.
Title: Re: Do I replace the headstem bearing?
Post by: John A on October 20, 2020, 08:16:37 PM


In this case, what's the worst that can happen if the bearings fail? Until the bearings were inspected, there was no issue with the steering.
[/quote]



OK, picture this.  1500 miles from home,After a eight hundred mile day, it starts to rain. You are only forty miles out of East Jesus, North Dakota. Coming out of the Bad Lands, third gear sure feels good as you blast past some lumbering motor homes. You glance at the tach, 72K rpms. Better not run that fast as you ease around some low foot hills. Hmm do I have a flat tire, I ask myself. Got kind of a head shake too . Then I remember, I only did a half assed job on the steering head.  Truthfully if the lower one looks good, I would not have a problem with a cleaning and packing the lower bearing. Get them at a bearing supply , the number is in Guzziology. If nobody else posts it, when I get to the shop, I’ll look it up. 8 inches of snow here today.
Title: Re: Do I replace the headstem bearing?
Post by: Moparnut72 on October 20, 2020, 09:47:55 PM
^^ I just tried to google your "Warrington Effect " . Possibly you could supply a link . Everything that I found
 seems kinda irrelevant .  Peter

Sorry, I should have proofread my post. It was supposed to be the Waddington Effect.
kk
Title: Re: Do I replace the headstem bearing?
Post by: moto-uno on October 20, 2020, 11:53:20 PM
^  Perfect  :wink: , something to do with the belief that only new is good enough .
42 years in the trade and I've never seen a neck bearing suddenly fail , get old , yeah so
did I , but holy crap , everything we ride is used , no ?  Peter