Featherbed Headstock Bearing Choices

robs ss

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I can't remember the tube dimensions now but when I put sealed bearings in my slimline featherbed single I measured the column diameter, chose some stock steel tube to give clearance to both the column and inside the frame, making sure it was thick enough and engaged the inner race. Then cut & filed it to length as previously mention in this thread (measure upwards from the installed lower bearing... etc, etc.). Just made sure it was a bit (precision!!) too long, otherwise fitment of the tube is pointless.
From memory (fading) it was 30mm NB, 5mm wall tubing, but please check.
Also take care with squareness of ends if using hacksaw/file, as I did. If you have access to a lathe - no probs!
Hope this helps
Cheers
Rob
 
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To use the Commando set up in a Featherbed the bottom bearing needs to be fitted into the headstock as far in as it will go. Then measure from the top of this bearing to the top of the frame. From this length take off the width of the other (top) bearing. This is how long the spacer tube needs to be. It is not critical to a few thou' but better slightly too long rather than too short,as the top bearing doesn't need to bottom out in the frame...

Martyn.
I’m changing a Wideline to sealed bearings right now.

If the top bearing, as described above, isn’t fully seated in the headstock, does that mean that if big bumps in the road cause full fork extension, only the interference fit of the head bearings in the headstock is stopping the fork assembly from dropping the distance between the outer race of the top bearing and its seat in the headstock?

Maybe it doesn’t matter.
 

t ingermanson

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I’m changing a Wideline to sealed bearings right now.

If the top bearing, as described above, isn’t fully seated in the headstock, does that mean that if big bumps in the road cause full fork extension, only the interference fit of the head bearings in the headstock is stopping the fork assembly from dropping the distance between the outer race of the top bearing and its seat in the headstock?

Maybe it doesn’t matter.
Why wouldn't you go with the tapered roller bearings? No spacer, no worries.
 
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Why wouldn't you go with the tapered roller bearings? No spacer, no worries.
Because they don’t fit very well, height wise, I found adjustment to be fiddly and they get wet and corroded.

I could leave out the tube and adjust the ballraces’ end load, but I’d sooner go for the easy fit (and forget for a few years) screwed down rigid system, if it works.

If there are any problems with sealed balls and a spacer, that’s why I asked.
 
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Yes the Commando spacer need to be shorten to fit the Featherbed.
Ashley
Why wouldn't you go with the tapered roller bearings? No spacer, no worries.
I would only recommend a preloaded front bearing assembly which means a spacer tube inner column for either 6205 ball or tapered roller.
And for as many times as has been mentioned the featherbed (and Series 1 commando) the inner column/spacer is 134mm(approx) which makes it LONGER than a S2+ commando tube.

134mm featherbed/S1 commando
https://www.rgmnorton.co.uk/buy/spa...do-type-steering-head-bearing-067604_2226.htm

129mm S2+ commando
https://www.rgmnorton.co.uk/buy/steering-head-bearing-spacer-commando_2225.htm
 
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Pity you didn’t say that about the length yesterday Dave!

Wonder what I’ve got, to shim it with.

 
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Yesterday or 3 months ago? :)
https://www.accessnorton.com/NortonCommando/steering-yoke-conundrum.28477/#post-432951

yesterday:
Was busy surveying my property line with the neighbors fence recently put on my property...
The town has the legal authority to intervene but refuses..."it's a civil matter" putting a $10K-$20K + 2 year wait land court case as the penalty for moving to this (cocaine up your nose attitude) town. My "for sale" sign is now out on my front yard by the road.
 

t ingermanson

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I would only recommend a preloaded front bearing assembly which means a spacer tube inner column for either 6205 ball or tapered roller.
There is zero need for a spacer tube between tapered roller bearings if you have the ability to lock down the adjustment, once a slight preload is established, with something like a lock nut, as can be found on Norton headstock bearings. If one uses a specified length spacer tube, the adjustment then becomes how deeply the cups are pressed into the headstock tube, which is a terrible variable for bearing preload and adjustment.

The best bearings for combined axial and thrust loads is a pair of opposed tapered roller bearings, hands down.
 

t ingermanson

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Best in what way?

Not in the way of staying free of slackness or notchiness, long term, on my bike.

It’s not a wheel on a dump truck.
I've never experienced any of those issues, but have pulled out many completely blown out, notchy deep groove or angular contact sealed bearings, or loose ball cup and cone sets. The rollers just have much more surface area than a ball.

It's true they don't come sealed, but are easy enough to seal with non-migratory waterproof grease and some strips of rubber.

It's also true that not all bearings are created equal. I've seen some pretty bad sets that I wouldn't want holding my chin off the ground at any speed.
 
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IT"S NOT THE BEARINGS I'm worried about.
The super fine threads on featherbed or S1 commando triple tree stem is my concern. The take up collars (stem/inner column) IMO should be holding tighter (preload) than the shock load of wheelies or super bad bumpy road surface that would beat up the threads from shock if loose. I've already had to make a new commando stem and buy a 13/16-28 tap and die set to save a triple tree set. If the inner column is preloaded enough they will not become damaged from constant beating because the shock load does not exceed the column preload.
The 134mm tube with correct shims are used to set the bearing preload, which does not need to be a high as the inner column hardware.
I absolutely could not find a source for 13/16-26 for the featherbed except from English sources. USA & china=NO
 
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The sealed ballraces are in and it all turns nice and smoothly.

Now is when I have to decide whether to put the flat “Norton” bars back on or revert to clip-ons.
 
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My old gal still has ball races in and for numerous years now, and never been a issue. Steering may be a bit light for some but i'm a plodder now.
 
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Have now done about 70 miles with sealed ball races and a spacer tube in a Wideline and it feels good.

Hope it lasts!
 
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I don't think you did a bad thing with the ball bearing mod. I will be doing the same thing on two series 1 commando's and a tapered roller set up on one of my slimlines. Of course I will use a heavy preload against a shim adjusted inner column. I finally got the tap and die for the 13/16-26 pre commando set-up. (tracy tool)
Unpreloaded the the stem and adjusters get beat up.
 
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