84 XR500R Swingarm upgrade

[Flycast47]

This question may have been answered somewhere but I have not found it.  Will the aluminum swingarm from a 1985 - 1988 XR600R fit a 1984 XR500R?  If so, does it require the shock/spring linkage from the 600 or will the 500 linkage work?

[Horri]

I don't know for certain..I'll go with an 80% chance it will though,,I can't answer the linkage question..Get the swingarm if it's cheap enough and have a look..I take no responsibility if I'm incorrect,,Caveat emptor applies..

[JoeBlow Kokomo]

Yes, and you don't have to limit it to the 85-88 to fit.  I put a  2004 XR650L swinger on my 85 XR350 with no issues (that I could tell).  There are slight variations in bottom link length which can affect the linkage rate, but I've not found it significant. I am using the XRL linkage and rear shock, which is shorter and drops the seat height for me. (a good thing)

[davidbogart]

If its the 84 xr500r it has a steel swing arm and the 85 xr600r has aluminum swingarm they are close but i dont think it will be a direct put it on and ride situation please correct me if I'm wrong but the pro link hard wear should also be a very close fit but still is slightly different as I recall I tried to use the linkage from my 84 xr500r on the xr600r as I was replacing the xr600r mono shock with the taller mono shock from the 84 xr500r and i tried using the linkage from the xr500r and just wouldn't fit right I can't remember why it didn't but I know the mono shock was a direct bolt on but that was it

[valvesrule]

It is a bolt on. You need to use the original 500 link with the 600 pivot bolt and a custom spacer on the left side of side bolt. A couple SAE washers work nicely I know personally, the red bike in my avatar is an 83 500 with an 86 600 arm. The 600 shock fits too but interferes with the inside of the airbox boots since they were designed for the smaller diameter shock/spring of the 83. Likely could change them for 600 boots to fix that but I haven't bothered. Disc brake arms bolt in too but then you have to add all that other disc stuff which I still see as not being cost effective. If you're going that far just get a 90 or later 600/650 and ride instead of weld. I've got a ton of $$ in my 500 but I draw the line at disc, wheel, arm, calipers, pedal, mount fab, welding .......... Might even be a problem with the right footpeg since the 83/84 500 peg is unique and 85 up.

[Flycast47]

Following up on my original question.  

 

It is a bolt on. You need to use the original 500 link with the 600 pivot bolt and a custom spacer on the left side of side bolt. A couple SAE washers work nicely I know personally, the red bike in my avatar is an 83 500 with an 86 600 arm. The 600 shock fits too but interferes with the inside of the airbox boots since they were designed for the smaller diameter shock/spring of the 83. Likely could change them for 600 boots to fix that but I haven't bothered. Disc brake arms bolt in too but then you have to add all that other disc stuff which I still see as not being cost effective. If you're going that far just get a 90 or later 600/650 and ride instead of weld. I've got a ton of $$ in my 500 but I draw the line at disc, wheel, arm, calipers, pedal, mount fab, welding .......... Might even be a problem with the right footpeg since the 83/84 500 peg is unique and 85 up.

 What is the recommended size for the spacer washers - ID, OD and thickness?  Also, can a 1990 - 92 XR600R chain slider (p/n 52170-MN1-681)  be adapted to a 1988 swing arm?

[Onederer]

You would still retain the drum brake and only be getting an aluminum swinger with the swap you're asking about.  The XR500R steel swingarm may be Cro-Mo steel, not the cheaper stuff, and the weight difference between it and an aluminum one of the same vintage may not be significant enough to matter on a trail bike.

[Onederer]

http://i122.photobucket.com/albums/o260/wheelinthesky/HondaXR500R1a.jpg

[Horri]

Following up on my original question.  

 

 What is the recommended size for the spacer washers - ID, OD and thickness?  Also, can a 1990 - 92 XR600R chain slider (p/n 52170-MN1-681)  be adapted to a 1988 swing arm?

Wouldn't know with the washers,,Pull the bolt and measure the diameter..Washers are cheap..buy a few different sizes,,a file or grinder sorts out the thickness.

I have that many washers I'd make a fortune selling them as scrap..building sites are covered in the things,,sheer waste burying them under dirt.

The chain slider should be ok..They vary a bit in design,,you may need to drill a couple of new mount hole positions in

the swingarm to make it work,,it'll work though. I've seen people here saying they've pulled the entire swingarm from the bike putting one on. That

is totally unnecessary ..Cut the side of the slider rubber if needed to get it in there..some of them need that doing to them to get them on without

all the palava of removing a swingarm..They are a U shape but some have a sort of joining bit between the two sides..deal to it with a hacksaw or knife

then re-drill the holes to suit..

Edited April 18, 2014 by Horri

[valvesrule]

Following up on my original question.  

 

 What is the recommended size for the spacer washers - ID, OD and thickness?  Also, can a 1990 - 92 XR600R chain slider (p/n 52170-MN1-681)  be adapted to a 1988 swing arm?

Mount it up and measure the gap between the left side bolt boss and the link. Go to the hardware store and measure an assortment of washers to get as close to a zero fit. I think they're 12mm I.D. but don't recall for sure. O.D. only matters as to not interfere with the shock, link or swingarm. The allen head of the link thru bolt should remain in the boss as much as possible. The weight difference between the aluminum/steel arms is significant but only you can decide if the swap is worth it. Can't say on the slider, I've never compared them directly. Edited April 18, 2014 by valvesrule

[Onederer]

^^

 

Do you have actual weights? I couldn't find anything online except the usual conjecture.

Edited April 18, 2014 by Onederer

[valvesrule]

^^

 

Do you have actual weights? I couldn't find anything online except the usual conjecture.

No, after comparing the alum vs steel arms one in each hand I just threw all the steel spares in the scrap bin. You could feel the difference, I let that decide. If it makes a 300 lb bike 298 I'm good with it. They're easy to find and relatively cheap too. I've seen them on ebay as low as $20 + shipping. The aluminum arms are harder to bend or twist as well.

[Backwoods-Bomber]

Im not sure on the 500's but when comparing the steel swingers on xl600's to the aluminum xr600, the aluminum one is about an inch and a half longer. If the 500 steelie is shorter, this could be a reason besides weight savings to go aluminum.

[Flycast47]

I completed the upgrade on my '84 XR500R using a swing arm from a 1988 XR600R (will post pictures and detail later).  I am having trouble adjusting the rear brake.  The brake is binding as if the shoes are beginning to engage when the adjustment is set for correct pedal travel.  If I back it off to eliminate the binding the pedal travel is much too long.  Has anyone had this experience with a similar upgrade or with a stock 500?

[davidbogart]

The brake drum may be out of round just a thought

[Flycast47]

The brake drum may be out of round just a thought

I don't think that is the problem.  The wheel rotates freely and the brake action is smooth and consistent when the brake control rod is disconnected  and I operate the brake arm by hand.  I think that problem may be due to the greater length of the XR600 swing arm.  Once the bike is on the ground and the suspension is compressed the brake drag is relieved.

[Flycast47]

^^

 

Do you have actual weights? I couldn't find anything online except the usual conjecture.

I did weigh both swing arms.  The original XR500R steel part weighed 12.2 lbs (5.53 kg) and the XR600R Aluminum part weighed 10 lbs (4.53 kg).  Not much, I agree, but any little bit helps.

[Horri]

Use the adjuster on the back of the brake pedal/frame to take up some slack..That fails I guess buy an XR brake rod or extend the one you have or rotate the arm on the drum back/forwards till you're happy. Plainly with that you can't go backwards as you already have no room for adjustment with the shorter rod and you don't want to be moving it forward on the splines as that stuffs up the purchase system..I say extend the rod or get one off a 600..no telling whether they fit correctly on the actual pedal though.

Edited August 4, 2014 by Horri

[Onederer]

I did weigh both swing arms.  The original XR500R steel part weighed 12.2 lbs (5.53 kg) and the XR600R Aluminum part weighed 10 lbs (4.53 kg).  Not much, I agree, but any little bit helps.

 

Two pounds is a good weight savings considering a used aluminum swingarm doesn't cost that much. That's the difference of having two 1lb bags of Skittles strapped to each side of the swingarm.  Ride the rainbow.

[Flycast47]

Use the adjuster on the back of the brake pedal/frame to take up some slack..That fails I guess buy an XR brake rod or extend the one you have or rotate the arm on the drum back/forwards till you're happy. Plainly with that you can't go backwards as you already have no room for adjustment with the shorter rod and you don't want to be moving it forward on the splines as that stuffs up the purchase system..I say extend the rod or get one off a 600..no telling whether they fit correctly on the actual pedal though.

Horri,

 

Thanks for the tips.  I have made adjustments that you mention.  I moved the brake arm slightly forward so the brake rod engages correctly.  Also made adjustment to the pedal stop.  The problem is most noticeable when the rear suspension is fully extended.  When there is normal load on the bike the drag is relieved.  This makes my think the problem has to do the angle between the brake rod pivot and the swing arm pivot.  I am going to reduce the rear suspension spring load slightly to increase the sag (it is a bit too stiff now) and I will also make an adapter to extend the upper arm on the brake pedal to get the break rod closer to parallel with the swing arm.  From what I can tell from comparing pictures of an '84 500 and the '88 600 the brake pedal to brake rod hinge point does seem slightly higher on the 600.