Welcome to the forum. Please add your location and your bike's model and model year to your profile so that you don't have to remember to tell us every time and we don't have to keep asking when you forget (see Forum Settings link in my signature).

And welcome to the world of antique vehicle ownership (they own us, not the other way around). Your bike is about 4 decades old and the Previous Owners may or may not have done the maintenance necessary to keep it safe & reliable so it is highly recommended to download the Factory Shop Manual for your model (available through the CX Wiki - link in my signature) and go through all of the service procedures, regardless of whether your bike has reached the specified mileage.
I also recommend looking on all rubber parts with suspicion because rubber does not age gracefully. Check the date codes on your tires and replace them if they are over 5 years old no matter how good they look & feel (old rubber simply cannot flow around the irregularities in the asphalt well enough to grip, especially if it is cool or wet). If your bike still has the original rubber brake line(s) (should be replaced every 2 or 3 fluid changes = 5 or 6 years) I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid). And don't forget things like the rad hoses and the boot between the engine and swingarm (they can crack on the bottom where you don't see it).

The best advice anyone can give you about customizing any vehicle is to get it safe & reliable in more or less original condition and use it for a while before you start making any changes so it can tell you what changes it needs to make it do what you want/need better. That approach almost always results in something you actually want to keep and use but making changes based on style or on what someone else (who may or may not really understand how the changes affect the way it works) has done often results in a piece of expensive yard art that you can't stand sitting on for more than a few minutes and might even be dangerous.

The GL1100 front end was designed for a bike that is quite a bit heavier than your GL500 so they are probably a bit stiff for the lighter bike. That could be dealt with but you will need to learn about spring rates &c to make it right.

Re seat/tank "lines", a lot of people get hung up on things like that but it is more important to make it work right (in the case of the tank, the end with the petcock needs to be lower so that the fuel will flow to it). If you make it work right it will look right but if you try to make it look a certain way without considering how it will work it probably won't work or look right.

BTW: The fork brace is there to improve handling, not "for running no front fender ". The fender is there to control splash when you have to get home in the rain and I believe it is a legal requirement in most (if not all) of Canada.

 

Welcome to the forum. Please add your location and your bike's model and model year to your profile so that you don't have to remember to tell us every time and we don't have to keep asking when you forget (see Forum Settings link in my signature).

And welcome to the world of antique vehicle ownership (they own us, not the other way around). Your bike is about 4 decades old and the Previous Owners may or may not have done the maintenance necessary to keep it safe & reliable so it is highly recommended to download the Factory Shop Manual for your model (available through the CX Wiki - link in my signature) and go through all of the service procedures, regardless of whether your bike has reached the specified mileage.
I also recommend looking on all rubber parts with suspicion because rubber does not age gracefully. Check the date codes on your tires and replace them if they are over 5 years old no matter how good they look & feel (old rubber simply cannot flow around the irregularities in the asphalt well enough to grip, especially if it is cool or wet). If your bike still has the original rubber brake line(s) (should be replaced every 2 or 3 fluid changes = 5 or 6 years) I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid). And don't forget things like the rad hoses and the boot between the engine and swingarm (they can crack on the bottom where you don't see it).

The best advice anyone can give you about customizing any vehicle is to get it safe & reliable in more or less original condition and use it for a while before you start making any changes so it can tell you what changes it needs to make it do what you want/need better. That approach almost always results in something you actually want to keep and use but making changes based on style or on what someone else (who may or may not really understand how the changes affect the way it works) has done often results in a piece of expensive yard art that you can't stand sitting on for more than a few minutes and might even be dangerous.

The GL1100 front end was designed for a bike that is quite a bit heavier than your GL500 so they are probably a bit stiff for the lighter bike. That could be dealt with but you will need to learn about spring rates &c to make it right.

Re seat/tank "lines", a lot of people get hung up on things like that but it is more important to make it work right (in the case of the tank, the end with the petcock needs to be lower so that the fuel will flow to it). If you make it work right it will look right but if you try to make it look a certain way without considering how it will work it probably won't work or look right.

BTW: The fork brace is there to improve handling, not "for running no front fender ". The fender is there to control splash when you have to get home in the rain and I believe it is a legal requirement in most (if not all) of Canada.

Welcome to the forum. Please add your location and your bike's model and model year to your profile so that you don't have to remember to tell us every time and we don't have to keep asking when you forget (see Forum Settings link in my signature).

And welcome to the world of antique vehicle ownership (they own us, not the other way around). Your bike is about 4 decades old and the Previous Owners may or may not have done the maintenance necessary to keep it safe & reliable so it is highly recommended to download the Factory Shop Manual for your model (available through the CX Wiki - link in my signature) and go through all of the service procedures, regardless of whether your bike has reached the specified mileage.
I also recommend looking on all rubber parts with suspicion because rubber does not age gracefully. Check the date codes on your tires and replace them if they are over 5 years old no matter how good they look & feel (old rubber simply cannot flow around the irregularities in the asphalt well enough to grip, especially if it is cool or wet). If your bike still has the original rubber brake line(s) (should be replaced every 2 or 3 fluid changes = 5 or 6 years) I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid). And don't forget things like the rad hoses and the boot between the engine and swingarm (they can crack on the bottom where you don't see it).

The best advice anyone can give you about customizing any vehicle is to get it safe & reliable in more or less original condition and use it for a while before you start making any changes so it can tell you what changes it needs to make it do what you want/need better. That approach almost always results in something you actually want to keep and use but making changes based on style or on what someone else (who may or may not really understand how the changes affect the way it works) has done often results in a piece of expensive yard art that you can't stand sitting on for more than a few minutes and might even be dangerous.

The GL1100 front end was designed for a bike that is quite a bit heavier than your GL500 so they are probably a bit stiff for the lighter bike. That could be dealt with but you will need to learn about spring rates &c to make it right.

Re seat/tank "lines", a lot of people get hung up on things like that but it is more important to make it work right (in the case of the tank, the end with the petcock needs to be lower so that the fuel will flow to it). If you make it work right it will look right but if you try to make it look a certain way without considering how it will work it probably won't work or look right.

BTW: The fork brace is there to improve handling, not "for running no front fender ". The fender is there to control splash when you have to get home in the rain and I believe it is a legal requirement in most (if not all) of Canada.

thanks for taking the time to write that. I definitely have a lot to learn that’s for sure. I do have a hard copy of the repair manual but I will need to look into spring rates to make that fork set optimal. Any recommendations on a good place to start gaining the right info? The bike was in running condition before it was stripped, but I will assume everything needs looking at. Things like break lines and rubber bushings will definitely be replaced. And the tires are definitely pst their prime. Unfortunately as I received the bike in pieces I don’t have anything to base stock performance on. I did plan on refinishing just about every part, but would you recommend putting the bike back together first to see where I’m at, and then tear it down again for refinishing? I dorealize that many parts will be installed and removed during the build.

 

Do you know if the engine runs properly? The best time to find out that it doesn't is at the start of the project before a lot of time and money are expended.

 

The bike was a driver before my friend stripped it. And apparently ran just fine? Maybe I should throw it back in the frame and give it a test run before spending the time on the rest.

 

The 18" front wheel won't be a problem, but it might be wider than your 2.50x16" rear. That could have adverse effects on handling.

 

Ok noted I will check the width of both front and rear wheels. I guess you can always run a taller tire to make the outside diameter the same as stock.

 

 

 

 

I hate it when people just lop the back end off of a bike's frame like that. It usually means they intend to weld in a simple loop level with the part of the frame they left and sit a seat on top of that but they don't understand that the braces that connect the sides of the frame back there are arched because the top of the wheel is higher than the top of the frame when the suspension is fully collapsed (like when you hit a bump)....
BTW: I have a GL500 frame that isn't cut that you are welcome to if you decide you don't want to do that but you would have to pick it up.

If you have the time and enough of the parts to put it back together that would be the best thing to do. Use it as daily transportation for at least a few weeks if you can (better if you could use it all summer to get a real feel for what you need to change and then work on it over the winter).

BTW: The front rim on my '83 GL1100 is a 2.50-18 and the stock tire size is 120/90-18 (for both '82 and '83) so the theoretical outer diameter 26.5".
The stock front tire for your GL500 is a 3.50-19 which has a theoretical diameter of 26".
The GoldWing's wheel and stock tire would actually be slightly taller but also much wider so I doubt there would be enough clearance between the GL500's forks for the GL1100 wheel.

BUT you were planning to use the whole GL1100 front end so none of that really matters. I would be more concerned about

• The length of the forks, whether the GL1100 forks would raise or lower the front end and by how much.
• How much more the 1100 forks & wheel weigh (if any). Lower unsprung weight = better handling.
• How "stiff" the new forks will be compared to the originals.
• Narrower tires handle better because wider tires are harder to lean into turns. You should be able to get away with a 110 width tire on that rim without distorting the tire's profile (cross sectional shape) too badly but if you went much narrower than that it could result in a more square profile (flatter across the tread) instead of the rounded profile that makes leaning into turns easier.

FWIW, I run a 4.00-18 tire (about equivalent of a 100/100-18) on my 1100's 2.5" rim and a 3.50-18 tire on my CX's 2.5" rim to intentionally produce squarer than normal profiles for sidecar use.

 

I hate it when people just lop the back end off of a bike's frame like that. It usually means they intend to weld in a simple loop level with the part of the frame they left and sit a seat on top of that but they don't understand that the braces that connect the sides of the frame back there are arched because the top of the wheel is higher than the top of the frame when the suspension is fully collapsed (like when you hit a bump)....
BTW: I have a GL500 frame that isn't cut that you are welcome to if you decide you don't want to do that but you would have to pick it up.

If you have the time and enough of the parts to put it back together that would be the best thing to do. Use it as daily transportation for at least a few weeks if you can (better if you could use it all summer to get a real feel for what you need to change and then work on it over the winter).

BTW: The front rim on my '83 GL1100 is a 2.50-18 and the stock tire size is 120/90-18 (for both '82 and '83) so the theoretical outer diameter 26.5".
The stock front tire for your GL500 is a 3.50-19 which has a theoretical diameter of 26".
The GoldWing's wheel and stock tire would actually be slightly taller but also much wider so I doubt there would be enough clearance between the GL500's forks for the GL1100 wheel.

BUT you were planning to use the whole GL1100 front end so none of that really matters. I would be more concerned about

• The length of the forks, whether the GL1100 forks would raise or lower the front end and by how much.
• How much more the 1100 forks & wheel weigh (if any). Lower unsprung weight = better handling.
• How "stiff" the new forks will be compared to the originals.
• Narrower tires handle better because wider tires are harder to lean into turns. You should be able to get away with a 110 width tire on that rim without distorting the tire's profile (cross sectional shape) too badly but if you went much narrower than that it could result in a more square profile (flatter across the tread) instead of the rounded profile that makes leaning into turns easier.

FWIW, I run a 4.00-18 tire (about equivalent of a 100/100-18) on my 1100's 2.5" rim and a 3.50-18 tire on my CX's 2.5" rim to intentionally produce squarer than normal profiles for sidecar use.

Well
I took a couple quick measurements of both bikes while in the shop today.
My gl500 has a 2.5wide front wheel and 3” wide back wheel the fork length from axle center to top of tube (not cap) is 32 1/4 inches

the gl1100 has a 3”wide front wheel and 3.5”wide rear. The fork length (measured the same way) is 31”

so the gl1100 fork is 1 1/4 shorter then the stock gl500.

also there are a couple of gl500 near me for sale. I’m considering the possibility of picking one up and riding it stock for the summer. Also It may make the project a little easier if I pull it all apart myself and and know where the bike is at prior. And also gain more riding experience as I’m a novice rider. I can always build a second one for my wife, Who has much more experience then I on a bike. Or just have the parts between two to make one.

I’ll post a pic of the gl1100 I have as a front end donor.

 

 

 

If you can find a stock one you might be better if in the long run using the cut one for parts.

Silly question: Why would you take apart a GoldWing that is that complete for parts?

BTW: There is no way that your bikes have the rim widths you mentioned. Those might be the outside widths of the rims but rim width is measured inside the rim where the beads of the tires seat. The sizes are stamped into the rims as shown on the pics on this page

Comstar wheel differences - Honda CX500, GL500, CX650, GL650

“Wondering what the wheel differences are between all of the Honda CX and GL twisted twins? Find out here!”…

motofaction.org

 

Sorry buddy those measurements were just with a tape across the rim. Thanks for clearing that up and showing me the way.
gl500
front 2.15 x19
Rear 2.50 x 16
Fork length 32.25”

gl1100
Front 2.50 x 18
Rear 3.00 x16
Fork length 31”

so if I were to put the whole front end Of the 1100 on the 500 both front and rear wheels would be 2.50 wide. Is it ok to run both front and rear same width? Would that cause any issue that couldn’t be correct with tire sizing? Or would I have to try to put the 3.00 from the 1100 on the back as well?

Would the 1.25” shorter fork be an issue? I know lots of people talk about lowering the front but I’m sure that effects drive angles. I’m used to building off road jeeps and I’m very familiar with the battle between customization while trying to maintain proper drive angles. I Just lack knowledge on bikes in particular.

as far as parting out what looks to be a mostly complete gl1100: it has been passed around a few times since being the start of someone else’s project. It hasn’t seen the road since the early 2000’s and had been improperly stored out doors for the past few years. It’s very weathered and seems to be at best a parts bike. I paid$150 for the whole bike with the idea to only use the complete front end and possibly the wheels if needed as they matched the gl500 originals . I’m sure there are some other bits and bobs I can steel off it before seeing if any 1100 guys need parts. I also consider not getting rid of it once I’m done and keeping it for parts for a future gl1100 project. But I’ll just stick to the 500 for now.

 

Those sizes sound more like it.

The 1100 rear won't mate with the 500 final drive. I don't think it would fit between the swingarm with the correct tire size very well either, and then there's the work that would be involved in converting to a disc brake (you can't convert the 1100 wheel to drum).

Re correcting with tire sizing, see my comments in post #11 about rim width and tire profile. And using the same width on each end isn't a great idea either (if it was they would make them that way).

If you use shorter forks the rake angle will become steeper, the trail will decrease and the handling will change.
A couple of years ago I had the opportunity to compare the frame of my CX650E based machine and a GL500 frame and I couldn't see any difference in the steering head angle between them but the CX-E's forks are about 2" shorter than the GL's. Why? Because the GL500 is designed for touring so stability at speed was more important than manoeuvrability and longer trail produces that but the CX650E is the lay on the tank sport model so manoeuvrability was more important than stability on the highway and reduced trail produces that.
The only concerns I would have about 1.25" shorter forks on the GL500 are 1) does the tank still slope to the rear?, 2) Will something hit when the suspension bottoms? and 3) Are the springs from a heavier bike suitable for a lighter bike?

BTW: My GoldWing sat for 10 years before I got it, 6 of those outside. The guy I got it from told me he had to cut down a tree that had grown up between the engine and crashbar before he could move it. The engine was seized, the exhaust was rotted away, the windshield had started to flake apart and the brake fluid had crystallized in the lines and the master cylinders. I wasn't concerned about the engine because I had the one from my first GoldWing that had been written off in a collision so what I was most concerned about was whether the tank had been drained before storage so it wouldn't be full of goo (it had been).

I think it came out OK (pic from 6 years after I put it together)

And got even better (pic from last year)

 

There will probably be little or no need for the air pressure assist if using the original GL1100 springs.

 

There is a lot more to it than that. The fork spring preload spacer calculation linked below will allow you to adjust the springs to suit your weight and the weight of your bike for optimum suspension sag, which will improve handling significantly.

How your suspension works

motorcycleinfo.calsci.com

All telescopic forks have air pressure inside them when under load because the fixed volume of air becomes compressed as the length of the fork decreases and the "springiness" of that air adds to the spring rate of the actual springs. Forks with air fittings allow you to add more air pressure to increase the overall spring rate of the system to compensate for changes in load on the suspension.
I used to think that it was a neat to be able to compensate for the weight of a passenger that way until I realized that you aren't so likely to be able to make adjustments except at home so if you pick someone up or drop them off you are pretty much stuck with the way you set it before you left. I guess it would be OK if you used the bike for both carrying a lot of gear when touring and carrying not much more than your lunch when commuting but unless you expect to make a lot of significant changes to the load on your bike it is probably just one more maintenance item to remember and one more thing to go wrong (speaking of which, whichever forks you end up with I highly recommend getting rid of the balance hose between the fork legs so that a blown seal won't cause both legs to lose pressure). I used the page linked above to calculate preload spacers for both of my bikes' forks that compensate for the load of the sidecar without needing added air pressure.

But all of the discussion about changing the forks aside, I still recommend getting an unmollested bike to learn to ride on and using the one with the cut frame as a parts bike (or at least putting it aside until you learn what you really want/need a bike to do).

 

Thanks so much for the very useful information. There is a fellow near me selling a 83 GL650, how compatible Is it with the gl500? Are there many differences other then motor displacement. I tried to do some research but most was people asking about the carb compatibility and rear fearing compatibility mostly between CX/GL and things like that. I Couldn’t find much general info on the differences between them.
The bike looks to be in decent clean original shape, Unmolested and still has the all the original interstate body components installed and intact. Bike has 63,000k he was riding it until a few weeks ago (bought a bigger bike) and was safety’d last summer He’s asking $2500 obo. I was planning on bringing a friend and going to see it early next week.

 

In order to have increase the displacement they made the cylinders longer, which made the engine slightly taller and required different engine hanger brackets at the front. The drivetrain is somewhat different (mostly because the 650 has a larger axle) and 650 has cast wheels. There are also some minor differences in the fairing and things like that.
The most significant differences from a maintenance point of view are
1) GL650 head gaskets have not been available from Honda for several years and most aftermarket head gaskets aren't considered reliable. Joe Hovel in Australia has had had gaskets made (also available through Murray) that can be reliable if installed according to his instructions (different from what the FSM says because they don't contain asbestos so multiple re-torques are required).
2) All CX/GL500s made for North America came with the manual camchain tensioner adjuster but the 650s have the automatic adjuster. Some of us feel that this was a step backwards because the auto adjuster doesn't have as much range of adjustment, which means that the chain will last a lot longer with the manual one before needing to be replaced. It also means that if you don't notice that the chain has worn past the adjuster's ability to compensate the chain will start to slap around and damage things, often including the adjuster itself (new replacements are not available).
(On the other hand, setting the manual adjuster takes about 10 seconds if done while checking the valve clearances.)

I would recommend looking up how to use a dental mirror to inspect the adjuster and determine the condition of the camchain before buying any CX/GL650 and if it is more than half worn out remember that you will need to remove the engine and open the rear cover to replace it when the time comes.