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CX650 motor project into a CX500 Turbo Frame - ongoing
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Discussion Starter · #1 ·
I planned on putting my CX650c motor into a CX500 turbo frame. At the moment I don't plan on cutting the frame, but I was curious how the CX crowd would feel about a turbo frame being cut. I'm edging away from the cafe style and looking more towards a sport build, but some of the concepts I have in mind could require cutting the back parts of the frame under the seat.

The CX500 turbo's don't seem as rare as a 650 turbo frame so I wouldn't think people would mind in general but I thought I'd ask.
 

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It sounds like you don't have a complete bike to start with so I don't think I would worry about what poeple might say.
 

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Who does the bike belong to? If the rightful owner is okay with modifying the frame then it is fine to modify. Remember, it is impossible to please everyone, so you will hear from critics that say otherwise. I am a proponent of private property and the owners right to do as he sees fit with his own property.
 

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CX500EC Eurosport 1982
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At the end of the day it’s your stuff so who gives a damn what the rest of us think. The important bit is to plan and prepare … lots … before going in with the angle grinder. I think a lot of fellas go straight in with the grinder without fully thinking what they’re going to do and end up with a mess or something ugly. Good luck.
 

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CX650 motor project into a CX500 Turbo Frame - ongoing
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Discussion Starter · #5 ·
It's my project and frame, I was just curious because the cx500 turbo frame with a 650 is not a common thing. The turbo 500 motor is there but it's just heads and case so that'll be put up for sale as I have no use for that. I am heavily contemplating the front forks; it will cost half as much or more to rebuild and make them better as a CBR front end would cost me; I might sell the stock turbo forks and brakes to pay for a CBR setup.

And yes, lots of planning and photoshop going on for now. The 650 engine will get torn down this December/January and while that's happening I'm finalizing some ideas so I'm not diving into it head first. Excuse the terrible photoshop but I'm playing with this idea:

Tire Wheel Fuel tank Vehicle Automotive fuel system
 

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CX650 motor project into a CX500 Turbo Frame - ongoing
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Discussion Starter · #6 ·
and in that I photoshopped out the radiator...I have plans :devilish:
 

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'84 CX650E that is evolving into a GL500
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It sounds like what you really want is a CX650E. Too bad you're in the US where they weren't imported.

I just looked at pics of a Turbo frame and engine mounts online and I don't think the Turbo mounts will work with the normally aspirated engine or the normally aspirated engine's mounts will fit the Turbo frame. You might be better off to graft the Turbo forks (or whichever ones you decide on) and swingarm onto a GL650 frame if you can get one.
 

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CX650 motor project into a CX500 Turbo Frame - ongoing
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Discussion Starter · #8 ·
It sounds like what you really want is a CX650E. Too bad you're in the US where they weren't imported.

I just looked at pics of a Turbo frame and engine mounts online and I don't think the Turbo mounts will work with the normally aspirated engine or the normally aspirated engine's mounts will fit the Turbo frame. You might be better off to graft the Turbo forks (or whichever ones you decide on) and swingarm onto a GL650 frame if you can get one.

I believe the frame is the same from a CX500 turbo to a 650e but I only have google searches of images so I'm not positive, and yes I am aware of the fabrication needs on the hangers. I've read and watched the videos on what needs to be done there. The reason I didn't go the GL650 route was I wanted a rear disc so when a turbo frame came up for sale I grabbed it. I was probably thinking some fab work on the engine hangar was easier than swapping the swing arm. From what I read there'd be some bushing/bearing work to swap the swing arm and I wanted the boomerang wheels as well, the front wheel is already dual disc too so that made another thing I wouldn't have to swap.

atm I'm contemplating rebuild the turbo forks or cbr swap and sell the turbo forks to make up for the cost of the CBR stuff but before all that I need the engine mounted and running.
 

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'84 CX650E that is evolving into a GL500
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The GL and E frames are very similar except for different lugs welded on in various places (e.g. the E has lugs for aluminum brackets that bolt to the frame to support the footpegs and mufflers). There are pics near the beginning of my Never Ending Build thread (link in my signature) that show some of what I did to convert an E in very sorry shape into something much closer to a GL and a pic of Eccles next to a GL frame from 2018.
From what I can see in online pics the Turbo's engine mounts attach to the frame completely differently.

I changed to a GL swingarm because the E needed a final drive, driveshaft and rear wheel and I couldn't find parts for it. As far as I recall the only differences between the E final drive and the GL500 one were a couple of lugs for brake stays and such and the part where the final drive attaches (the E had a 4 stud FD and the GL's is 3 stud). I don't think it would be hard to make a GL swingarm work with a disc brake.
I believe a few people have put Turbo swingarms into GL frames too, but I'm not sure what is involved in that.
 

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1983 cx650E
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At this stage of the motorcycles history, the market for a frame only his likely slim to none. But just in case there's someone out there who has a rotted out 500 Turbo frame and if you're considerate of a person who might need a frame only to start a build oh, you could throw it on eBay or on the Forum and see if someone would have a gl500 or gl650 frame to exchange for the turbo frame.. Likely not needed by anyone. Maybe the krolls?
 

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CX650 motor project into a CX500 Turbo Frame - ongoing
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Discussion Starter · #11 ·
The GL and E frames are very similar except for different lugs welded on in various places (e.g. the E has lugs for aluminum brackets that bolt to the frame to support the footpegs and mufflers). There are pics near the beginning of my Never Ending Build thread (link in my signature) that show some of what I did to convert an E in very sorry shape into something much closer to a GL and a pic of Eccles next to a GL frame from 2018.
From what I can see in online pics the Turbo's engine mounts attach to the frame completely differently.

I changed to a GL swingarm because the E needed a final drive, driveshaft and rear wheel and I couldn't find parts for it. As far as I recall the only differences between the E final drive and the GL500 one were a couple of lugs for brake stays and such and the part where the final drive attaches (the E had a 4 stud FD and the GL's is 3 stud). I don't think it would be hard to make a GL swingarm work with a disc brake.
I believe a few people have put Turbo swingarms into GL frames too, but I'm not sure what is involved in that.

@Sidecar Bob I thought none of the GL's had rear disc? I had gone the Turbo frame route mostly for that and the nicer looking final drive housing (the 3 bolt) and the wheels. I've seen (I think Murray's) rear end swaps for disc and some others and they all seemed like a good bit of work to get right.

@TonyG I did indeed need or want a 500 frame because the custom c650 frame I have has too much rake for what I wanted and not the rear disc. Since I'm new to the CX arena I figured I'd see what the opinion was like from people who know more than I, and yes your idea that someone would need a turbo frame is sorta why I asked; I've always preferred restoring over modifying and hate destroying original stuff if it's not necessary. Considering the CX500 turbo frame I have has been picked for parts down to the frame and wheels it wouldn't be affordable to make it a CX500 turbo again.
 
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'84 CX650E that is evolving into a GL500
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The GL500 and GL650 all came with drum rear brakes.
The CX650E has a disc rear brake but the frame is very similar to the GL models (it even has the tube at the bottom for the brake pedal shaft even though it isn't used) and it also has the Pro-Link rear suspension. It is basically the sport version of the GL650.
The E also has the "boomerang" Comstar wheels like the Turbos except in silver.

I just looked at pics of a CX500T final drive and it looks exactly like the one from a GL500 (same as on the CX500 but without the shock mount stud). The splines that engage with the wheel may be different though. I know the splines on the 4 stud final drives (as used on the CX650E, CX650T and some GL650) have different splines but I've never worked on a Turbo so I can't say which splines they have.
 

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I like the look of your photoshop project. Since I do not see any passenger footpegs, I would loose the passenger seat, unless you intend to ride double a lot, Just my opinion.

I am an oddball and may be looking for a frame someday as I have accumulated enough parts to build a bike (minus a frame) LOL. Although, I would not pay anyway near what breakers are asking for a frame on ebay, LOL. Not a lot of demand for frames out there right now. Might change at some point in the future, but probably not in my lifetime. If I did build something up from scratch, I would probably due something similar to what you are proposing as it would be a BITZA bike and not be much for resale. If it turned out good, maybe I could get some money back, but it would be fun to do something non traditional. We will see, I have way to many projects at the moment, LOL
 

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1983 cx650E
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@TonyG I did indeed need or want a 500 frame because the custom c650 frame I have has too much rake for what I wanted and not the rear disc. Since I'm new to the CX arena I figured I'd see what the opinion was like from people who know more than I, and yes your idea that someone would need a turbo frame is sorta why I asked; I've always preferred restoring over modifying and hate destroying original stuff if it's not necessary. Considering the CX500 turbo frame I have has been picked for parts down to the frame and wheels it wouldn't be affordable to make it a CX500 turbo again.
If you are near Canada, and have some conscientious Reserve about possibly cutting up a turbo frame, then the Eurosport frame would bur first option. The rear brake parts are interchangeable with the Turbo with the exception of the swing arm being aluminum on the turbo models. But I think the length of the swing arm is the same. Many of the body parts and panels on the turbo are interchangeable with the Euro or at least in dimensions and appearance. The Eurosport has a little access panel to the tool kit that sits above the rear wheel, but otherwise, though not identical many of the body panels and the seat could interchange on a Euro Sport and turbo. The boomerang wheels are a different size on the rear between the turbo and the Eurosport. At least the 500 Turbo wheels are 17in while the Euro Sport rear wheels are 18 in. You would also have no alterations needed for the front engine hangers as the Eurosport uses the very similar if not identical engine as the custom & G L models. I have interchanged a g l engine into a eurosport several times. If the frame has a title, and I assume that it does even for your project, there are a few people around the country who have possibly collected enough bits and parts and perhaps have stumbled across a parts bike turbo that has sat outside or was even wrecked and has a unusable frame. Those few persons would be the only potential market for a intact titled frame. But I don't know that anyone would blame you if you got to the rear part of your bike and decided to alter the seat support frame and so forth.

I hope that helps answer your question. Yes there is possibly a few people around the country who might need a titled 500 frame. But the effort to find and connect with those people and then to find a suitable substitute frame for the project as you want it, might not be equal to the degree of conscientiousness about preserving limited production motorcycles.?

Pete Kroll in Nebraska and Greg gross /Tim dienhard. In CA and Oregon are to such possible rebuilders.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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In North America, the Euro is even more rare than the 500 Turbo, especially in the US, where it wasn't offered.
If you had bought a complete bike to strip down and cut up, I'd say no. But this one would be prohibitively expensive to rebuild as a 500T.
Chop away!
 

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If you have doubts you may want to leave the cutting of the frame until late in the project. Get your engine sorted and running, suspension done then move on to the appearance mods.
 
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CX650 motor project into a CX500 Turbo Frame - ongoing
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Discussion Starter · #18 ·
If you have doubts you may want to leave the cutting of the frame until late in the project. Get your engine sorted and running, suspension done then move on to the appearance mods.
Oh for sure nothing's getting cut until it runs and rolls, and in all honesty if I can get away without cutting that back seat frame I'd be happy to leave it alone.
 
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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Oh for sure nothing's getting cut until it runs and rolls, and in all honesty if I can get away without cutting that back seat frame I'd be happy to leave it alone.
That's the approach I'm taking to a (very) long-term GL500 project. Other than paint, I'm avoiding any changes to the frame. If it turns out to be a terrible ride, I can revert it to something like stock.
 
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