73 Rear Spoke Trouble

Discussion in 'Norton Commando Classic Motorcycles' started by Connie73, Nov 13, 2017.

  1. Connie73

    Connie73

    Joined:
    Jan 27, 2015
    G'day all,

    Having a few issues with braking spokes on the rear tyre, 73 750 roadster. Firstly found 1 broken spoke, broken right at the bend into the hub on the right side of the bike. I had this repaired and the tensions adjusted by a reputable wheel builder. After only traveling maybe 200ks i found another 3 broken in the same spot but spread out almost evenly around the wheel. I had these replaced with new by a different wheel builder who said that the previous wheel builder had done a great job and couldnt fault his work and that he was unsure why they broke.
    Now after only a couple of hundred kilometres again i have another 3, but this time its 2 on the right and 1 on the left. From memory the broken ones have been outside spokes except for the random one on the left now.
    Before i regain some motivation to look at it, what should i be checking?

    Thanks all.

    Ross
     
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  2. gortnipper

    gortnipper VIP MEMBER

    Joined:
    Nov 11, 2013
  3. Joe Schlaberdowski

    Joe Schlaberdowski

    Joined:
    Jan 1, 2017
    There can be two or three main reasons. First, if there was uneven tension in the spokes "when it was built at the factory" due to a factory acceptable degree of warping of the rim, though it can be tensioned to be straight and true, some of the spokes will have a higher than normal tension while others will be tensioned less than normal. Over the years, guess what? The high tensioned spokes will begin to break. It will then require more force on the spokes just replaced to bring the wheel back in true. And then guess what. Perhaps the wheel experienced a severe stress -- giant pothole, bike in a wreck or dumped, and the wheel was put out of true with a bit of a wobble. When spokes were further tensioned to eliminate that wobble, we get the same process starting over again. And once spokes break because of age (usually at the bend) the wheel starts warping just due to that. And that whole process starts. The only cure is to check the rim by unspoking (evenly all the way around -- just like tightening head bolts) and then setting the rim on a perfectly flat table or floor to see how out of true it is. If its within acceptable limits you must start again with ALL new spokes and spoke nipples. One way to give a quick (but not very accurate) check is to check spoke tension by how it sounds like a guitar string. On three cross spokes the sound may so muted you can't tell. There are accurate tensiometers though I don't know how available.
     
  4. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 24, 2004
    What kind of spokes are you using? I have had stainless steel Buchannan spokes break, never had stock oem's break.
     
  5. Joe Schlaberdowski

    Joe Schlaberdowski

    Joined:
    Jan 1, 2017
    Just this bit more, with the amount of breakage you are experiencing you need to be careful about just replacing with even stronger spokes. It is possibly leading up to not only more spoke breakage, but rim failure. If that happens the rim will suddenly develope a potato chip like wave in it. If you want to save the rim it would be best to do that before catastrophic failure. A strong rim can be bent back true if it has not gone too far. This would be done with spokes removed. But if it gets to that point I'm guessing you would be best off with new rim and spokes.
     
  6. Mike B

    Mike B

    Joined:
    Oct 16, 2015
    They will also break if they are not tight enough.

    Mike B
     
  7. Frankie17

    Frankie17

    Joined:
    Feb 11, 2015
    some grades of old stainless spokes work harden then break normally right on the bend (once one spoke goes others normally follow ) and fitting replacements increases the strain on the existing spokes if this has happened more than once i would reccomend replacing them all with new spokes Central wheel in the UK and other UK spoke suppliers now use improved grades of stainless wire which is less prone to fracture even when used for motocross applications

    original british cad plated spokes are very flexible and will give good service for many years if kept rust free and correctly tensioned , beware of the cheap Taiwan manufactured plated kits some are very low carbon steel and plating makes them very brittle and prone to break
     
  8. worntorn

    worntorn

    Joined:
    Dec 22, 2006
    Wheels are often laced at very uneven spoke tension and also inadequate tension. This causes spoke breakage

    It's a good idea to use a spoke torque wrench.
    Even the professionals at Buchanan's use them on the final go round.

    Glen
     
  9. Madnorton

    Madnorton

    Joined:
    Jun 9, 2008
    The forming of the bend and countersunk portion of the spoke is critical, it is actually a ball joint. Standard spokes are very process heavy to make and it must be in the right order, one step not completed or not done properly - ping! It is often seen that the spokes are bent around others to get them in. There is also the drilling to consider - when ordering a rim, it must be drilled to the Norton pattern, not any old 40 spoke pattern. Most wheel rim suppliers in the UK know this, including CWC.
     
  10. Connie73

    Connie73

    Joined:
    Jan 27, 2015
    Jimbo,

    They are Bucchanan's SS. Did you go back to the OEM's.
     
  11. Connie73

    Connie73

    Joined:
    Jan 27, 2015
    Hi all,

    Thanks for the replies. Previous i had what may have been the original spokes and i decided to tidy them up with new Buchanan's SS spokes and gear. Nothing else has changed in the wheel area. My wheel builder is a professional and i have had his worked checked by another wheel builder with no faults.

    Thanks in advance
     
  12. Joe Schlaberdowski

    Joe Schlaberdowski

    Joined:
    Jan 1, 2017
    The one wheel builder has not faulted the other wheel builder, but the continuosly breaking spokes have faulted them both! Well built and well repaired wheels don't break spokes. There is a glaring problem that would be hard to nail down without wheel in hand and doing the examination I suggested. That they decided to just replace a few spokes in the face of what happened is a red warning light of false economy -- unless, of course, they wanted to do a good rebuild and something stopped them. Spokes break for a reason (see my post and others). A "good" wheel builder upon examining the wheel with the broken spoke(s) could, and should, tell you why. I'm sure a good and true rim built with Buchannon spokes would be very satisfactory. And you did not say that it was the replaced spokes that broke(or did you -- I can't remember). If they were the ones that broke were the correct bend angles chosen? But still, so many broken spokes should stop anybody. At any rate, trying to get back on the road with a couple more good spokes might be acceptable if you just needed to putt home, but I would not be riding around on it thinking I was all safe and good to go. Read my previous post about a full rebuild.
     
  13. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 24, 2004
    Nope, My wife and I were interstate traveling on the Interstate back then, 75mph+ , and I could not see having spokes break often as they were. Bucchanan's at that time seemed to not be too concerned. I installed cast tubeless wheels and I never looked back. Got the aluminum flanged wheels with the broken spokes hanging in the rafters, the rear wheel spokes were the only ones breaking. FYI there are many threads here discussing spokes and spoke breakage. I believe for show bikes and pop around towners , SS spokes should be OK. Correctly restored to original Nortons should never have them, but only that's my opinion , and I am in the minority .


    nort mine DSC05082.jpg
     
  14. Mr. Rick

    Mr. Rick VIP MEMBER

    Joined:
    Feb 6, 2009
    Beautiful machine, Jimbo!
    Is that a Hyde fork brace under the gaiters? Looks good.
    Send me a PM if you wanna sell those wheels in the rafters. Assuming they are 19 inch, that is...
     
  15. rvich

    rvich VIP MEMBER

    Joined:
    Jul 25, 2009
    Pretty funny Jimbo. You don't think it is proper for a Norton to have SS spokes but you run cast wheels? Wish we were sitting around drinking beer, I think this discussion would have some legs! And yes, I know you said "correctly restored", but I couldn't resist commenting.

    Russ
     
  16. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 24, 2004
    IMHO Properly restored bikes should not have SS spokes. But we have to define "restored". "Restored" means many different things to many different people . My definition is : a restored bike means trying to build it to as close as original as possible. I think to a lot of people "restored" means get the bike on the road and look great to their taste. My MK3 is not a show bike, I built it to run highway fast, hence there is nothing really original or correct on it anymore! See my other bike for a real good "correct" . Me and Mr. Sam Adams are getting along well here too!

    norton 126381.jpg
     
  17. o0norton0o

    o0norton0o

    Joined:
    Apr 27, 2015
    Cast wheels on a commando Jimbo?!?! Blasphemy!

    [​IMG]
     

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