XR500 Super Motard gets a cartridge Showa fork

Forks have seen significant improvements over the last two decades and one of the first item I want to swap for the Super Motard transformation is the XR500’s fork which design and technology descends from the 70s .  Fortunately Honda used the same 26mm triple clamp stem diameter and length on several of its bikes until the early 90s.  So I picked up a ‘90 CR500 cartridge Showa fork on eBay.  This fork is a bolt on swap for the ‘82 XR500, no modifications needed.  I also purchased the CR500 front disk brake system to replace the XR500 anemic drum which in emergency situations produces the ultimate sphincter tightening experience!  No thanks.

The cartridge Showa fork offers measurably better handling with reduced fork flex and twist.  Its tubes are 45mm, significantly beefier than the original XR500 37mm.  The Showa’s triple clamps are also stiffer with an improved design.

The original XR500 fork as it came off of the XR500 frame.

The ‘90 Honda CR500 cartridge Showa fork which will be installed on the XR500 Super Motard.

Triple clamp from the CR500 on the left, XR500 on the right. Same stem dimensions making it an easy swap.

CR500 at the top XR500 below.

Before sending the frame to media blasting and powder coating I verified that the Showa triple clamp stem would indeed be a bolt on swap.  It is, and the steering stops are a perfect match as well.

To have the Showa fork and the rear shock perform at their best, I had both rebuilt with grade 5 oil and new seals by Marvin Rosencrans at RMK – Marv is a magician when it comes to rebuilding and fine tuning suspensions.

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12 Responses to XR500 Super Motard gets a cartridge Showa fork

  1. mike disney says:

    There is not a better guy than Marv at Rocky Mtn Kawasaki. Once you have the 500 together he will set sag and get you tuned in. Your project is very fun Mike.Thanks for the updates

  2. Roland Linder says:

    Salut Big Bike Chief, this is a major improvement and wil give bigger rigidity on the front.
    I was surprised to see that the stems were the same on both. Cool and cheaper for you.
    The bike is taking shape a great speed, thanks to the cold weather you have.. Bring here in the South where we can already drive each day..haha!
    Remember to to check the swing arm bushings! You don’t want to have sway in the rear while your front end is solid.
    Keep up the good work, can’t wait get my ass on her…
    Hello to all

  3. jeremy says:

    ok so the bottom bearings on my cr500 trees will only go into place with out the race in place still not under standing how u were able to make this work i see u still used the race pressed into place in the pic but im still puzzled tought i had it figured out lol

  4. Petot says:

    I am from France.
    I am looking to build a supermoto on an xl500.
    Could you give me the measures of the axle of your triple clamp so that I could check with my to see if I would be able to put a fork of Cr500? (Diameters of the two bearings seat and the diameter in the centre of the axle)
    Your bike is really cool. The spokes of your wheels, are they standard?
    Thanks in advanced.


    • Mike says:

      The dimensions of the triple clamps, XR500 and CR500, were exactly the same (diameters and length) thus absolutely no modification was necessary to mount the CR500 fork on the XR500 frame. Apparently, several other forks could be candidates outside of the CR500’s.

  5. Tim Tiemeyer says:

    I am going through with this swap over the winter and I’m curious about the lower bearing. Both bearings on my 84 XR5R are the same, and match the upper bearing on the 91 CR5 tree I’m using. The lower bearing however, has a larger inside diameter and is a larger bearing. It will not seat into the XR lower frame race. Did you have this problem as well? And if so, what did you do to fix it?

    • Mike says:

      In my case everything was a perfect match — inner and outer diameters were exactly the same. Even the turn stops of the lower T matches the stops on the XR frame. It was really a simple swap.

  6. Jared says:

    I’m rebuilding an 82 xl500r and was wondering if a 1990 cr500 front end will fit my bike? I read your article and after I rode the bike I see the need for some more modem tech!

    • Mike says:

      Sorry, I don’t have the answer. However, you could measure the fork stem of the ’90 CR500 and compare to the one on your bike. There is some likelihood that they will be a match.

  7. sina khorsand says:

    I’m trying to do a front end conversion for my 1980 Honda XL500s. I checked out the allballs site, and it says I have a 26mm ID top bearing size, but my bottom bearing size has an ID of 27mm, which makes it difficult to find a compatible stem. Also, the bottom bearing width is 18mm, unlike 15mm.
    Now- does this mean if I wanted to put in a 26 top and 26 bottom stem on my bike (which accepts a 26 top and 27 bottom), all I have to do is get the conversion bearing kit from allballs?
    Should I be worried about the width of the bottom bearing?

    If you have any suggestions for a front end that may fit my XL500, I’d be very happy to hear.

    Thank You

    • Mike says:

      Hello Sina – All BALLS Racing offers some very interesting conversion kits (http://www.allballsracing.com/index.php/forkconversion). I would strongly recommend you contact them and discuss your case. They will be able to make the appropriate recommendation based on the front end you’re trying to adapt to your ’80 XR500. Lots are available so there is a good chance that things will work out with one of their kits.

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