Honda CX 500 Forum banner

Melchiro's GL/CX 650 Project

28072 Views 52 Replies 13 Participants Last post by  melchiro
Well, I have finally rolled the 650 into the garage.. ... This is what it looked like 3 years ago when I brought it home...

Friday, Stripped it down to the frame to cut, weld, modify and clean up ... I have lots of plans and will share them as I go..

So far...

LOTS of rust to clean up...

See less See more
1 - 20 of 53 Posts
I was in the garage for most of the day.. Worked on the swingarm.. Why ? Because this GL/CX 650 will be ridden with performance in mind.. What kind?? The kind that will be flogged on a race track.. Anyways, in order to have the tires I need for this bike, size 150 or 160 -18, the swingarm had to be modified...

I test fitted an AVON AV56 Storm, 160/60-18 and marked the swingarm at the tires widest point...

Then, I "Scalloped" the swingarm..

Yes indeed, that is the driveshaft.....

Welded plate steel to close it up...

I bet by now, you are wondering, "Hey, I thought the GL650 was a Pro-Link suspension?" Yes, it used to be... I plan on going with dual shocks on my V-Twin.. So, I chopped off all of the support mounts.. I then welded up some bracing to the underside.. Like I said, I'm gonna need this in turn one at Pacific Raceways...

Just need to weld the left side shock mount, clean it up and apply paint ...

More question going through your head?? Like how the hell are you going to put a 160 size tire on these skinny ass rims??? That will be on my next posts.....

See less See more
Hey Kneeslider, nice job on your CX.. Looks cool. I bet it's fun to ride....

Here's a preview of where my Honda V-Twin is going..... Still lots of cutting, welding, modifying to do... Time to alter the rear part of the frame for the upper shock mounts, tank mount & seat support......

See less See more
I might have maybe 5 to 8 millimeters before the driveshaft touches... Won't know for sure till the motor is in... Rear wheel? I have a plan... I'll post when I get it going...

I did some more cutting and welding... Modified the rear subframe.. I still have to build the upper shock mount.. I also braced the frame for more strength..

Tacked welded around pivot area..

Here you can see how I chopped the rear.... New tank mount & seat support...

New steering stops for the forks...

What forks? Big strong 1982 GL1100 forks with CB900F triple clamps....

More bracing down the top tube..

All welded up, relocated rear seat support..

Front view with body on..

Side view.. I like it..

Still lots to do.. I'll have more time around Thanksgiving, 5 days off from work...

See less See more
I figured out my upper shock mounts ... Cut, welded plate steel & a bolt for the shock..

That is Not the wheel for this project.. Using to hold the bike up..
See less See more
I finally finish my GL1100 fork upgrades.. New fork seals, wiper boots, cleaning out the internals and fresh Bel-Ray 10 weight fork oil.. I also modified the damper rod and springs in order for a more taut & firmer suspension to handle my riding style...

First was to cut three inches off the progressively wound coils of the main spring ... I replaced this with a copper pipe, 2.5 inches long. Washers between springs add .25 inches. If I need more preload, I'll replace with a longer pipe.. This will result with a "stiffer" springs ..

Bottom fork leg is stock...

The damper rod modification, due to stiffer springs, I welded up one of the two rebound holes to increase the rebound dampening. This way, I can stay with light fork oil and not increase the compression..

Put it all together, fill the fork tubes with oil, amount of oil was with no springs inside, upper tube fully collapsed, oil was 127mm from the top of the tube.. Still need to paint the lowers a semi-gloss black..

This worked very well for me on my 1982 CB750F street bike.. Plus, no air pressure is needed...

I still need to weld on more "tabs" onto the frame. Fairing mounts, rear-set mounts, side cover mounts etc... I'll have time around the Christmas holidays.

See less See more
Hope everyone had a great Christmas...

Some progress to report... Cleaned the fork lowers, thought I would paint black but after scrubbing with a scuff pad, the satin aluminum finish looked great. So I clear coated it..

I cleaned and painted the front 18" Comstar...

Brakes.. I am not fond of the stock solid steel, smallish 276mm rotors.. So I scored off Ebay, a set of 1995 - 1997 CBR600-F3, 296mm floating rotors... these years came with the 58mm center holes, same as the Comstar. This is important to "Center" the rotor on the rim..

Now these have six holes.. Yeah, so I brazed them up in order to "re-drill" new 5-bolt hole pattern for the Comstar. Used aluminum welding rods made for propane torch. Good stuff... YouTube it..

Mounted up onto the Comstar..

Now here is where I had to research.. How will the calipers clear the larger rotor?? Simple, did you know that the 81 - 82 Honda Pro-Link CBX came with the ventilated 296mm rotors??? So I purchased a set of caliper mounts and presto.. Fits.. I also have these on my CB750-F, with EBC F3 rotors...

CBX on the caliper, stock on the right.. Kick the calipers out 10mm...

Comparison vs stock rotor.. These are on my CB750-F & the same GL1100 forks..

Front end completed & centered on the rotor..

I hope to have a rolling chassis soon..

See less See more
This is how I had to modify the CX500 rear-end... There are differences that had to be addressed, first being the axle size.. CX500 has 15mm axle , GL650 has 17mm . .. I bored out the receiving end of the differential just enough to fit the 17mm axle through.. The differential spacer/collar I had to make.. GL650 (left), will NOT fit.. CX500 (right) ... I cut a piece of 7/8" handlebar to the right length, (center), ground down one end and bored it out enough to slide over the axle...

I am doing all this work in order to mount an 18" Comstar wheel with disc brake .. .. How is this possible??

First, I obtained a GL1100 rear wheel... The size is 17" x 2.5"..

In order to fit this wheel, I had to "relieve-grind" down an inner step inside the CX500 hub....

Then I obtained a CB900F rear wheel and took both apart...

Using the GL1100 hub, the CB900F spokes and rim, bolted everything back together ... Presto, 18" x 2.5" Comstar..

See less See more
Well, 2.5" wide won't fit a 160 size tire, so I sent the wheel to KOSMAN SPECIALTIES, to have it widened, 4.25"...

Install new bearings, mount the tire, some touch up paint & I'll have a rolling chassis soon....

See less See more
Cost was $520.00. Total with shipping.. Sandy Kosman retired and sold the shop. New owner but same great staff as before.. Since this was my sixth wheel modified by them, they gave me a deal..

I only sent them the one wheel that I had modified.. No need to send two.. They will weld on the wider lip.. Two choices of styles, the square lip or the round lip, I chose round.. I have square on my CBX & CB750F... My track CB750SC-F has kinda squarish round...

A bit expensive? Maybe, but to me, I'll save up my money to do this...........

See less See more
My turn for the double post, never talk on the phone when posting

Cheers, 50gary

I've double posted in a few forums as well, so no worries. ... The rim weighs 18 pounds as pictured.. The front wheels is a 1982 GL1100 & is 2.5" wide x 18" diameter.

Only reason I went to this much trouble with 18" diameter is I wanted the largest diameter performance tire I can fit in the swingarm for top end speed..

A 160/60 or a 150/70 tire.. And no, I'm not going to Bonneville Salt Flats.. But Pacific Raceways for sure..
Got new "shoe" for the rims... Will spoon them on this weekend,,

See less See more
Here's what the 160 size Avon tire looks like... It is Sweet ! ! ! Still some room between the sidewall and the notched swingarm.. Maybe a 170 next time ..

The other tire is a stock size 130/90-16....

Progress is slow.... Front end work next , then disassemble for painting...
See less See more
Hey Scudman, yeah, still lots of work to be done... The wheel is centered inline with the frame.. Being offset kind of spooks me.. I have not seen race take offs in the 18" size.. Most performance radial tires in 18 inch sizes are "Sport-Touring".. I have Avon on my other three bikes..

David, yes these Avon Storms are unidirectional tires.. They are mounted correctly..
Is the 18" front wheel off of a GL1100?

Appreciate seeing your work!

Thx carolina... Yes the front is from a 1982 GL1100 Goldwing.. That was the only bike sold in the U.S. that had the "Reversed" Comstar in 18" x 2.5". I have this on my Track Bike CB750SC-F as well...

See less See more
Motivation.... Getting a bit hard to find these days.... I finally finished painting the frame and mounted the forks. New tapered steering head bearings & swingarm bearings... CB900F calipers, painted gold to match the rotors.. It now "rolls" around the garage.

Next up, Painting the engine, carburetor setup & install into the frame.... Now where did I put that other can motivation ?
See less See more
....... do you have any worries about the rim holding up? ........ what did you use to put it all back together?

Not worried at all... I replaced the five bolts with heavy duty allen head and the 10 rivets were replaced with standard grade steel allen head.. All with nylock nuts.

When cutting the original bolts, they felt a lot "softer" than what I replaced them with.. So, not worried at all... And you know, as with all of my bikes, this bike WILL be Track Tested, at Pacific Raceways, Auburn, WA.
Hey Gary, 20mm axle and bearings to fit inside the hub, THAT is a lot of work.... Very nice work..

Tron, I went down to my local ACE Hardware store & matched up the bolts... Nothing fancy.. The rivet ends, you'll know what size bolt is needed when you see how big the hole is..
9 months later, I finally did something to my project.... I spray painted my engine... Sheeezzz.. It's about time !

Maybe I'll install the motor next, then make my mounts for my rearsets, then the rear brake assembly... Who knows.. I need to open up a BIG can of "Motivation" take a couple swigs..
See less See more
Very nice work on this bike so far! I'm looking forward to seeing how it turns out.

Yeah, me too... Maybe this winter, I can start back up on this project.. I wonder if I have Fabrication Burnout? With other planned modifications to my CBX & CB750/1100, I'm struggling to find time to work on my CX Project.
1 - 20 of 53 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.