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78' From mag to disk??

Discussion in 'The Garage' started by WPGxs650_brat, Mar 31, 2018.

  1. WPGxs650_brat

    WPGxs650_brat XS650 Enthusiast

    So much info on here, and I'm still confused a tad.

    I have a 78' with front and rear disk brakes, with mag's. 19" front and 16" rear. I'm wanting to switch to spokes.

    Easy enough fix for the rear. Find a spoke rear drum, and if able get the whole swing arm assembly. Question, what years will fit, 77" and up?!?

    If I can only find a 77" and up read spoke drum, will the sprocket align? Will I have to make/mill spacers?

    As for the front, from what I have read. The easiest would be to find a 77" and up spoke wheel with disk, and it should work, is this correct?

    And if i go lower than a 77" hub/wheel it will require what?
     
  2. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    front wheel any from 73 up will fit, rotor 77 up
    rear disk to drum
    you need the linkage from the splined pedal pivot shaft on back
    any 74 up drum swing arm will fit, the ones from standards have open rear slots with removable brackets that you will need to get also. You can just cut the torque bracket off the top of your arm and reweld it on the bottom.
    you will need the drum stye torque arm and bolts.
    you need the RH axle spacer from a drum wheel.
    You may need to mess with the brake light switch bracket.
    That about covers it.
     
    WPGxs650_brat likes this.
  3. WPGxs650_brat

    WPGxs650_brat XS650 Enthusiast

    Thanks for the reply,

    Easy enough, in theory for the front. Finding it is another issue lol.

    As for the rear, that's why I hinted at getting the entire swing arm brake linkage. Less ass pain!
     
  4. 5twins

    5twins XS650 Guru Top Contributor

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    I'm pretty sure any year rear wheel will work with the correct right side axle spacer as Gary mentioned. The aluminum rims didn't come along until '74. Earlier ones were chrome steel. If you get a front wheel older than '77, you will need to put your current disc on it. No problem, mounting bolt hole pattern is the same.

    The wheels from the old TX750 twin will also swap right on. It was only made for 2 years ('73-'74) but many had short lives due to motor issues. Many you find in bone yards are very low mileage. That means the running gear (wheels, swingarm) show very little use or wear. Speaking of the swingarm, it will also swap and is a very nice upgrade. It has nearly 1/4" larger tubes so is much stiffer. If I was buying a swingarm anyway, that's what I'd be looking for.
     
    Last edited: Mar 31, 2018
  5. Moturcyclenut

    Moturcyclenut Crusty old cormudgeon

    BROKEN 1.jpg BROKEN2.jpg BROKEN 1.jpg BROKEN2.jpg BROKEN 1.jpg BROKEN2.jpg BROKEN3.jpg Not sure if this is proper protocol or procedure but here goes.
    Mr.5Twins, O-Great Guru of all XS650 fiefdom. I, your humble padawan am in great need of your wisdom. Here is my sad tale of woe.

    Since I had all the oil drained from my 1981 XS I figured I’d go ahead and pop off the clutch side cover, clean it out and modify my starter spring for more tension. Low and behold as I started to remove the cover I heard a “thunk” as something dropped to my motorcycle lift. I looked down and spotted a washer. I pulled the cover a little bit more as to release it and I heard a “tink” hit the deck. I looked down and I saw this little thing, it looked like a button, one end of it looked as if it had sheared off of something. Part of the “button” fit into the hole of the washer perfectly, so maybe they are somehow interconnected with each other.

    Try as I may, that night, I could not get the clutch bolts to loosen. Surely, I thought these wayward parts came from behind there somewhere. Since that was not going to happen anytime soon, (I’m waiting on my JIS screwdrivers to arrive) I went in the house and tried to research parts books, I read a bunch of posts, I searched for used parts, anything to answer the nagging questions “What are these, where did they come from, do they matter, why are they floating in the bottom of my engine?” I had only ridden the bike once when I test rode it when I bought it. It ran great, shifted just fine, seemed to have no problems in that area at all. You will find pictures attached I am hoping in your great explorations inside the workings of the XS you might recognize these parts and be able to clue me in.

    The dimensions of the washer are as follows, Outside Diameter: 26mm (1.0235in), Hole diameter 8.20mm (.3230in), Thickness: 2.36mm (.0935in).

    The “button, or maybe it’s some kind of rivet?’ Big head size diameter is: 10.29mm (.04050in), Shaft size (that fits the washer hole is):8.13mm (.3195in) total length from the surface of the big end to where it looks sheared off is: 8.66mm (.3415in), Diameter of the shaft that is sheared is 4.84mm (.1905in).

    Thank you for your time and energy in reviewing my quandary.

    Sincerely yours,

    Moturcyclenut

    Could this be a follower for the neutral detent?

    Pictures as promised.
     

    Attached Files:

  6. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Since you asked 5t I won't tell you.

    :doh::yikes::laughing::laughing::laughing:
     
    Last edited: Mar 31, 2018
    TwoManyXS1Bs likes this.
  7. Moturcyclenut

    Moturcyclenut Crusty old cormudgeon

    Sorry, I did not mean to step on anybody's toes. I guess the friendliness and helpfulness of this forum was misunderstood by me. Please forgive my ignorance and accept my apology.
     
  8. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Since you were so nice about apologizing for the error of your ways
    take a look here;
    http://www.xs650.com/threads/broken-shift-mechanism.38278
     
  9. 5twins

    5twins XS650 Guru Top Contributor

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    It may be the "wheel" that's held against the shift star by the spring above it .....

    [​IMG]

    [​IMG]
     
  10. WPGxs650_brat

    WPGxs650_brat XS650 Enthusiast

    Ok, my best friend just let me know he has a 72 19" disk front I can have.

    How can I make this fit?
     
  11. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    The short but accurate answer is; you can't. Why we said 73 up.If you don't believe me, I have thread in here somewhere detailing all the differences.
     
  12. WPGxs650_brat

    WPGxs650_brat XS650 Enthusiast

    I'm reading through the thread as we speak, I'm just wondering, is why it cant be done.
     
  13. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    cause the 72 rotor does not bolt to the wheel!
     
  14. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    PS 73 and older are chromed steel rims.
     
  15. 5twins

    5twins XS650 Guru Top Contributor

    18,571
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    Yes, the '72 front wheel is the 650's "black sheep" disc front wheel. It was the first year Yamaha put a disc on and they went about mounting it in a rather odd, complex way. Every year from then on they just bolted the darn things on, lol. Do go look at your buddy's wheel though. The '72 version being so oddball and one-year-only, if something went wrong with it, a later wheel was often swapped on instead. That could have very well happened on your buddy's bike. Look at his wheel to see if it has disc mounting bolts.
     
    gggGary likes this.
  16. WPGxs650_brat

    WPGxs650_brat XS650 Enthusiast

    So the it's because the rotors can' be swapped out to keep rotors and calipers together. Are the axles different diameters as well?
     
  17. WPGxs650_brat

    WPGxs650_brat XS650 Enthusiast

    Can you tell from this oic
     

    Attached Files:

  18. Moturcyclenut

    Moturcyclenut Crusty old cormudgeon

    Thank you for restoring my faith in the brotherhood of all that is XS. Since we last communicated I was able to pull the clutch off and get a gander at the shift drum. I too had figured out where it came from and what it was for ( I kind of figured as much). Now I'm pondering my options as to how I will fix it. Welding is one, re-peening is another, sleeving and bolting is another. I don't want it to come off again that's for sure! I do believe the PO rode it like that for who knows how long. The PO was a ham-fisted knucklehead, all sorts of bad/poor nonexistence maintenance done to the poor bike. I'm glad I was able to rescue it from a certain death. I'm sure you know what I mean, some people just don't know how to give a bike a little love. Hope your day is going great. Happy Easter.
     
    gggGary likes this.
  19. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

  20. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    [​IMG]
    In your pic you can also see the rotor offset adjusting nut behind the axle nut used only on the 72.
    It's kinda weird that Yamaha didn't just grab a honda front disk brake and reverse engineer it.
     
    WPGxs650_brat likes this.

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