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Steering Yoke conundrum....

Discussion in 'Norton Commando Motorcycles (Classic)' started by olympus, Aug 11, 2019.

  1. Time Warp

    Time Warp .......back to the 70's. VIP MEMBER

    Joined:
    Dec 3, 2012
    Thanks for the reply, I thought I had read it here but maybe it was a change to tapered rollers related post but the means to adjust clearance on the early bike having cup and ball makes sense though. (It would make going to a taper bearing easy over the later bikes)

    That being the reason I (mistakenly) regarded going from a tapered roller as a step backward (but is not the case as there was no taper as standard so clear on that now)

    Baz.
    A lot of newer bikes do have a cup and ball (Toyo) type steering head bearing but the balls have a plastic cage so are a little more upmarket. I do know Suzuki use those on many models but those that might see a higher load (DR650SE for one) have tapered rollers as stock.
    Before installing tapered rollers in the 850 I had looked at the Toyo caged cup and ball but the size availability did not suit the Norton needed dimensions (either way to big or way to small) but would have gone that route if something had been available as the first option.
    The outer makes them almost angular contacts.

    stem - Copy.jpg
     
    Last edited: Aug 11, 2019
  2. baz

    baz VIP MEMBER

    Joined:
    May 26, 2010
    Yes the only ones I seen have a cage
     
  3. o0norton0o

    o0norton0o VIP MEMBER

    Joined:
    Apr 27, 2015
    There's definitely more than one variation to the way the yokes and steering head were fabricated, so there's no simple either "A" or "B" situation.

    This thread was packed with info... Page 3 was a good one if you want to start there.

    https://www.accessnorton.com/NortonCommando/rake-and-trail-specs.10734/page-3
     
  4. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004

    Some '69-'70 owners have reported finding apparently original angular contact bearings and felt washers.
    https://www.accessnorton.com/NortonCommando/69-steering-dissasembly-stuck.13322/page-2#post-188336

    There appears to have been a change of headrace bearings for '69 as the parts supplement lists:

    "18263...Head races ... 2
    15691...Head race felt... 2
    "
    If 18263 is searched at AN it comes up equivalent to the later '71-on 06.7604 sealed ball bearing!
    No result for 15691.
    https://andover-norton.co.uk/en/shop-details/17179
     
    Last edited: Aug 12, 2019
  5. kommando

    kommando

    Joined:
    May 7, 2005
    Dimensions from 72 frame.

    Headstock overall length 161.6mm

    Top bearing register depth 14.7mm

    Bottom bearing register depth 20.6mm

    Calculated distance between registers 126.3mm which is less than the 129mm of the spacer ref Dynodave so makes sense.
     
  6. dynodave

    dynodave

    Joined:
    May 28, 2003
    Dimensions from S1 frame (68-70)
    headstock LOA 161mm (scaled)
    top bearing register 14.7mm
    bottom bearing register 14.7mm
     
  7. olympus

    olympus

    Joined:
    Aug 5, 2017
    Thanks Guys, i always knew the bike was a Heinz 57 but not to this extent
    I like the idea of converting to Taper roller set up if this will give me the desired clearance between yokes and a suitable bottom bearing seal can be identified?? .... your thoughts on this please
    The other option is to have a skim taken off the bottom yoke central shaft boss....So could i ask what is the exact distance between yoke faces (not measuring the recesses for "O" rings)

    Thank you
     
  8. olympus

    olympus

    Joined:
    Aug 5, 2017
    Hi Time warp,
    Can i ask where you obtained
    Hi Les looking at my options, if i convert back to cone bearings, will this give me the extra shaft protrusion through the bottom yoke i need... don't really want to go this way, but may have to
    Or is it that my set up is so way left field its anyone's guess??

    Thank you
     
  9. o0norton0o

    o0norton0o VIP MEMBER

    Joined:
    Apr 27, 2015
    Or just get the correct yokes, and whatever kit converts them to modern sealed bearings. That would increase your trail distance slightly, which you probably wouldn't notice. My '70 model yokes are the original 2 1/4" offset and are still on the original bearings with no issues. The steering stops on the headstock work with the original yokes too...
     
    Craig likes this.
  10. Time Warp

    Time Warp .......back to the 70's. VIP MEMBER

    Joined:
    Dec 3, 2012
    I got off the shelf tapered roller bearings, but they need some added work to get them to a set up I am happy with.

    https://www.accessnorton.com/Norton...head-bearings-removal-2016.20710/#post-423296

    Olympus, I will stick my neck out for the chopping block but...
    I had seen another thread and noted I had posted at the end of (regarding steering head bearings, might have been taper related) and not noticed it was some 6 pages long.... so ended up reading it from the beginning, some of the replies were a shock as far as mechanical aptitude.
    Just because you can do something and get away with it does not mean it is right and that thread proved it.

    If you swap a later bike out to tapered roller steering head bearings only an idiot or someone who knows no better will leave the inner spacer tube out.
    There is no form of vernier adjustment so the inner tube is used to set the bearings.
    The end result is flawless rotation and a breeze to set up once done, simply torque the bottom nut which you can not do with the inner spacer removed, the lower triple pinch bolts would become part of that equation if that Micky Mouse method was used. :D
     
    Last edited: Aug 12, 2019
    dynodave likes this.
  11. olympus

    olympus

    Joined:
    Aug 5, 2017
    Speaking with a machine shop today, and looking at the above calculations from both yourself and dyno Dave i checked my headstock and indeed the lower bearing aperture is 14.7mm deep
    So if i have machined off the lower yoke centre shaft boss 6mm i should be back to the correct spacing between yokes.



     
  12. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    7 1/4".
     
  13. baz

    baz VIP MEMBER

    Joined:
    May 26, 2010
    What was your reason for changing to taper rollers?
     
  14. Time Warp

    Time Warp .......back to the 70's. VIP MEMBER

    Joined:
    Dec 3, 2012
    The short answer is because I can.
    A taper roller bearing has no problem with axial or radial load and both of those forces are applied in the steering head one way or another.
    I bought new 6205 bearings and then thought about using angular contacts but setting the preload would be time consuming, I then thought about a taper bearing in the lower for load with a 6205 in the upper for alignment but then just used the two taper bearings.
    Of course the later bike has no means to adjust tapers so to me it is not a simple swap (unless you take the time to set the inner spacer tube length)

    Does it matter, probably not, no doubt someone would post they had had the same 6205's in their Commando for 60 years and ran the bike on chip fat for the same time with no problem.

    Its not that there is anything wrong with the stock bearing set up (The 6205 bearings are large enough to compensate for being in axial load) but to me based on what was used before and even that seems to be vague (cup and ball or angular contacts) suggests the 6205 was a budget measure based on a simplified triple clamp at a time when the company was under financial pressure.
    My Moto Guzzi and three Ducati's of the same time period came stock with tapered roller steering head bearings but of course all have twin bearing adjusting rings which the Commando does not have hence the retained inner spacer tube in my case, done and dusted now and no doubt will never need touching again by me.
    It can go in the same line of thought as the Continental radial tyres, not a necessity but can do no harm and might be an improvement.
     
    dynodave likes this.
  15. dynodave

    dynodave

    Joined:
    May 28, 2003
    TW
    I'm pretty much along the same lines as you. I had thought of trying to do a tapered bearing set up and was going to do it by definitely using a spacer tube. The next step was to finish the job by measuring the slop using a long spacer (with shims) then removing some of the stack of shims to give me the "preload" I wanted. The inner column could then be tightened to far exceed the expected load, even if doing wheelies or stoppies. It is still a project to be finished among the other 999 to go...but my path and vision is clear.
     
    Time Warp likes this.
  16. Time Warp

    Time Warp .......back to the 70's. VIP MEMBER

    Joined:
    Dec 3, 2012
    The devil's in the detail DD.
    There is nothing in this picture that did not need some form of attention before use and all name parts.
    I need to knock a little shine off those lowers mind you.

    Image-125.jpg
     
  17. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009
    What did the Pedge do to you? :confused::):D
     
  18. slimslowslider

    slimslowslider

    Joined:
    Jun 29, 2010
    Since the weight on the bottom yoke comes from above, it would make sense that the outer ring of the bottom bearing is driven home fully in the bottom recess of the headstock. The top bearing is only for radial fixation. You tap it in just so far that the inner ring just touches the spacer tube. Not sure about this particular model, but that is how it is for the Mk3, see Section G6 of the manual.
     
  19. kommando

    kommando

    Joined:
    May 7, 2005
    The bearing depth is 15mm, so on the ball bearing headstock the top bearing recess being 14.7mms the top bearing gets driven in to full depth and stops 0.3mms proud, the bottom bearing hits the spacer tube before it can meet its housing register.
     
  20. olympus

    olympus

    Joined:
    Aug 5, 2017
    The 68 frame i have is the pits and until i can replace it, this will have to suffice... so I'm having 5mm machined off the centre shaft boss to give me at the very least a full nut
     

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