Page 1 of 2

Long post on Bearings. Good throne reading.

Posted: Wed Sep 01, 2010 1:40 pm
by Red
Good morning everyone. -Not so much a question as sort of an obvious heads up

So after getting down to the bottom of my charging issue (thanks a ton!) I Noticed a little sloppy handling in the corners and control issues at low speeds that I attributed to the notched steering bearings. Wanting to procrastinate on pulling the front end apart as long as possible, I made my way down to DMV to get tags and try to legalize my new bike.

On the way there I was leaning through a decent right hand corner in town when the rear wheel skipped to the left a few inches almost causing me to go down. I pulled over onto the sidewalk, hosed out my boots and grabbed the rear wheel with the bike on the centre stand and clack a clacka clack... shot rear wheel bearing. One of the cages had exploded. OK, to be expected with a bike that sat for years plus I was gonna do ém soon anyways, so off I go to the local (retail) bearing house, McGuire. After the counter person informed me they have no Timken, SKF or FAG bearings, he produced (4) Axis brand bearings which are the private label for McGuire. I thought what the hell, ISO standards are in place for a reason and no matter where they are made, they should be fine. Later I found the origin tag in each bearing box (China) the bearings were only marked with size on the inner race.

I measured out the assemblies, took a couple thou off the wedding ring spacer for the rear, packed them with the good grease and rode the bike home. Felt great. Still notchy in the head, but no more shorts-greasing moments in public. 2 days later I pulled the wheels off to put new S11 Spitfires on her and wiped the grease oozing past the front seal off with my finger and noticed tiny metal flakes in the grease, so out come the wheel bearings again, and the outer races show insane scoring evenly around the wear surface with no heat blueing whatsoever. It's like the metal had no hardness at all. Kind of scary. I took them back to McGuire and after an hour of the counter guy pissing in my ear about installation errors on my part the manager refunded my money. I then went through a wholesaler and sourced 70's production TImkens made in France in the wax-board boxes, installed them and put 500 Trouble free miles on them. SO: Don't buy Chinese bearings. But you already knew that ;)

During the 500 trouble free miles up the Isle of Vashon TT and back, I had a horrifying tank slap from the worn steering bearings, heavy wind & ruts and had to stop at a friends house along the way to replace them in his driveway. Luckily he had the race extractor tool, and 2 guys I was riding with went to the stealership and fetched new bearings. By the time they returned from Fife, WA the bike was apart and ready for the new parts. Now she handles like a dream and is as safe as she can be in I-5 traffic. What a week! If anything I am more familiar with this bike now.

Happy riding!

Re: Long post on Bearings. Good throne reading.

Posted: Wed Sep 01, 2010 2:02 pm
by Zombie Master
Good read Red. I've heard a lot about wheel bearing failures lately.

Re: Long post on Bearings. Good throne reading.

Posted: Wed Sep 01, 2010 3:15 pm
by Max Headroom
Like everything else, there are Chinese bearing manufacturers producing good quality products and others producing crap. The difficulty with the majority of Chinese bearings is that they only conform to ISO for boundary dimensions, leaving such details as load capacity, surface hardening and ball/roller configuration to their own discretion. And frustratingly, you can't tell by looking at the cardboard packaging . . .

When I was selling bearings, we made a point of recommending them for materials handling equipment, conveyors and other non-critical applications. We actively discouraged their use in electric motors or gearboxes or other applications where loads or clearances were more important. My boss didn't want the hassle of claims arising from premature failures, and our customers appreciated the advice. That was six years ago, and I suspect that little has changed. Safer to stay with reputable known brands such as SKF, FAG, NSK, Timken, NTN, Nachi, etc.

Re: Long post on Bearings. Good throne reading.

Posted: Wed Sep 01, 2010 3:39 pm
by StephenB
The following caught my attantion:
Red wrote:I measured out the assemblies, took a couple thou off the wedding ring spacer for the rear, packed them with the good grease and rode the bike home.
Red,

Just in case I understood this wrong and you have a bike with tapered wheel bearings: all tapered bearing (true for both wheels and headstock!) have to be installed with a bearing preload of anywhere between 6 and 9 Nm or thereabouts. Not zero play! Under no circumstances! You simply can not measure the inner and outer stack and assume you have them installed correctly. I urge you to read Duane's write-up on installing tapered bearings. There is only ONE (1) right way to install tapoered bearings (and it is NOT zero play) and you can laugh all day long about Duane's shake the wheel test but it gets you the required result.

If you are still running on zero play, I'll give you another 700mls until you have destroyed the next set of bearings.

Again, just in case I got you wrong!

On a side note: I run cheap Chinese NGK bearings on my GS since 12,000mls and they see plenty of gravel! They last about half the lifetime of a Timken ... about another 150yrs?

Re: Long post on Bearings. Good throne reading.

Posted: Wed Sep 01, 2010 7:06 pm
by Max Headroom
StephenB wrote: On a side note: I run cheap Chinese NGK bearings on my GS since 12,000mls and they see plenty of gravel! They last about half the lifetime of a Timken ... about another 150yrs?
Yeah, I don't doubt that Stephen. Some good stuff coming from China, particularly from the joint-venture companies, but it can be frustrating to weed out the rubbish. The known brands are a safer bet generally.

Re: Long post on Bearings. Good throne reading.

Posted: Wed Sep 01, 2010 8:48 pm
by Red
Stephen, -I have used Duane's method of bearing set up for the last 10 years on all of my pre-70 bikes and I have seen what happens when things are set up too tight as well. I just use the bench measurement as a baseline and install the wheel to make my final check. You are right, -it works like a charm every time.

A side note to your side note: The Off-Brand Chinese garbage cost $15.55US ea and the TImkens came in at $12.05 ea through the wholesaler at 4 on a Friday afternoon. I lucked out, but quality can be had afford ably in some cases.

Cheers!

Re: Long post on Bearings. Good throne reading.

Posted: Wed Sep 01, 2010 9:54 pm
by StephenB
You sure, Timken doesn't outsource bog standard runners/bearings to chinese subcontractors? At less than the price of a chinese bearing, they simply can't be produced in the US for that money, can they?

Re: Long post on Bearings. Good throne reading.

Posted: Wed Sep 01, 2010 9:56 pm
by StephenB
Red wrote:Stephen, -I have used Duane's method of bearing set up for the last 10 years on all of my pre-70 bikes and I have seen what happens when things are set up too tight as well.
That is good to hear, so you must have experienced premature catastrophic material failure.

Re: Long post on Bearings. Good throne reading.

Posted: Thu Sep 02, 2010 12:14 pm
by Red
Good point on Timkens, -The Shop that handles all of my cylinder head work is also a well known Harley Drag racing engine builder. Harley Motors use tapered rollers on either end of the crank and the shop has used Timkens forever for this app, but lately they have been receiving bearings from the supplier that have huge amounts of axial runout from in precise grinding. Turns out that there are a great deal of counterfeit name-brand bearings in circulation coming from our friends and National creditors in Asia that are absolute garbage. So beware. As I mentioned in my initial post, the Timkens I sourced were NOS goodies in the old waxy boxes with "France" etched on the inner race. -The good old stuff that I recall seeing on my grandpa's workbench in the barn while he repaired his tractors. I am confident the Bearings I am now running are up to snuff, but you raise a very good point, Stephen! I was able to get the bearings at shop price, hence the low price.

Re: Long post on Bearings. Good throne reading.

Posted: Fri Sep 10, 2010 12:10 am
by Chuey
[quote="StephenB"]
If you are still running on zero play, I'll give you another 700mls until you have destroyed the next set of bearings.

When this was recently discussed here, the consensus was that a slightly loose bearing would last longer than a slightly tight one.

Chuey