1. Some members were not receiving emails sent from XJbikes.com. For example: "Forgot your password?" function to reset your password would not send email to some members. I believe this has been resolved now. Please use "Contact Us" form (see page footer link) if you still have email issues. SnoSheriff

    Hello Guest. You have limited privileges and you can't "SEARCH" the forums. Please "Log In" or "Sign Up" for additional functionality. Click HERE to proceed.

81 XJ650 Fork/Swing Arm Advice Needed.

Discussion in 'XJ Modifications' started by JoshuaG, Jan 8, 2024.

  1. JoshuaG

    JoshuaG New Member

    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Connecticut
    Hello all. I bought a cafe-racer modified 1981 XJ650. I was hoping to replace the rear arm of the bike with an XS (disk brake) arm and the front fork with a 2007 GSXR fork. I have worked as a trailer mechanic/mountain bike mechanic, but I am learning about motorcycles. Any references for what would and wouldn’t potentially fit would be appreciated. Dimensions to consider, suggestions on different modern(ish) parts, or new ideas welcome.
     
  2. Simmy

    Simmy Well-Known Member

    Messages:
    2,398
    Likes Received:
    1,193
    Trophy Points:
    113
    Location:
    Waterloo Ontario Canada
    The XJ is shaft drive
    The XS is chain drive
     
  3. JoshuaG

    JoshuaG New Member

    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Connecticut
    No my buddy has an 1980 XS850 sitting next to mine in the shop and it is shaft drive with a disk rear.
     
  4. Simmy

    Simmy Well-Known Member

    Messages:
    2,398
    Likes Received:
    1,193
    Trophy Points:
    113
    Location:
    Waterloo Ontario Canada
    My mistake, I assumed XS650
     
  5. Simmy

    Simmy Well-Known Member

    Messages:
    2,398
    Likes Received:
    1,193
    Trophy Points:
    113
    Location:
    Waterloo Ontario Canada
    Retro fitting a modern set of forks to an XJ is relatively easy. If you bring the GSXR front wheel with it there is a problem in my opinion.
    Finding a matching wide rim for the rear is difficult with a shaft drive bike.
    The OEM Maxim rear rim is 3.00 x 16 which will be skinnier than a a 3.50 x 17 GSXR front.
    With this set up you will be mixing a radial front tire and a bias ply rear, never recommended.
    A bike with a wider front rim than rear looks out of place IMO.
    I am unsure if an XS750/850 rear end will fit.
    Although it had a disc rear brake I don't consider it an upgrade over the XJ's drum.
    A disc might look cool and I can respect that, many custom bikes deliver cool aesthetics but hinder function, I get that.
    The 900 Seca had a disc rear brake which can be made to fit but it has a really skinny rim.
    If you view the @Mezzmo videos he fits a rear from the XJ900 Diversion (a bike never sold in NA) and that will give you a rim with a disc and wide enough to mount a corresponding 17" radial on the rear. I think a 150 can be made to fit.
    Post some pics, lets see what you're starting with.
     
    Franz likes this.
  6. 50gary

    50gary Active Member

    Messages:
    343
    Likes Received:
    128
    Trophy Points:
    43
    Location:
    Saginaw, Mi. USA
    PICT0008.jpeg
     
    Franz likes this.
  7. Simmy

    Simmy Well-Known Member

    Messages:
    2,398
    Likes Received:
    1,193
    Trophy Points:
    113
    Location:
    Waterloo Ontario Canada
    And that’s another way to do it!
    Beyond my shade tree ability @50gary your Maxim looks awesome BTW

    Another option is to find a set of spoke wheels from an 86 Virago. Once you have the hubs you can lace any size rim you want. Still drum brake though
     
  8. JoshuaG

    JoshuaG New Member

    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Connecticut
    @Simmy I appreciate all of the information. I definitely like the GSXR idea then and will be trying to convert like you said for the wider rear tire. As far as my motivation for disks, it’s what I am comfortable working on and riding. I am sure there are drum purists, but being in my 20’s, drum breaks are not in my wheelhouse. Hell, I’m learning carburetors with this bike as it is.

    Follow-up question to all of this, what sources to you look for to source parts? Facebook marketplace and eBay are where I am looking now to little success.

    Thank you.
     
  9. 50gary

    50gary Active Member

    Messages:
    343
    Likes Received:
    128
    Trophy Points:
    43
    Location:
    Saginaw, Mi. USA
    Thanks for the kind words, it looks terrible in this photo, it's now painted (professional) and I've got to get off my butt and post a new photo.
     
  10. JoshuaG

    JoshuaG New Member

    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Connecticut
    Just wanted to return on this thread. Have been having serious trouble finding a front end that will directly swap onto my bike. Therefore at a standstill. If anyone has a good reference where I could shop for a replacement front end I would be ecstatic.
     

Share This Page