Honda CX 500 Forum banner
1 - 13 of 13 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
I'm having an issue with the rear shock on my 650 Turbo. It seems to have intermittent binding of motion and sometimes remains compressed. Today it remained so compressed that the side stand was unusable. Hours later it rebounded on its own. No oil leaks and it holds air pressure like always. Linkage is all good. The bike is pristine and only has 2700 miles on it. I am the original owner. I am wondering if this is not an uncommon problem and what can be done to fix it. Please help. I would like to keep it original and will probably attempt to disassemble to investigate but is there any aftermarket shock that anyone has had good results with? Does anyone have a very good serviceable OEM shock they would sell?
 

·
Registered
Joined
·
759 Posts
I would like to keep it original and will probably attempt to disassemble to investigate but is there any aftermarket shock that anyone has had good results with? Does anyone have a very good serviceable OEM shock they would sell?
My shock did the same and it seems to be a very common issue on the 650T. There's little information on rebuilding...I think you need a hydraulic press and correct seals may be unavailable. No amount of air pressure or weight could move mine (I put my shock between a floor jack and the frame of my SUV), so I'm not sure what froze up inside. In the beginning, mine would start off stiff and loosen up after a few miles. Eventually it seized completely leaving me with no rear suspension.

Most seem to go with an aftermarket shock. One or two companies offer them, but they're not cheap and not available in the US so shipping adds even more. They also don't look stock.

I simply installed a 500T shock. They're plentiful on eBay and dirt cheap. It bolts right in and looks the same as the 650T shock with the exception of the rebound lever.
There are currently 8 showing up on eBay, many under $50 bucks with shipping. Even if you want your bike 100% original, the 500T shock will get you back on the road until you can figure out what to do with your original shock.

The 500T shock doesn't seem to suffer the seizing problem of the 650T shock. For me, it's no different than getting rid of the junk 650T starter and installing a normal CX500 starter.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #3 ·
George, thank you for that info. I do remember seeing someone mention the same problem before and they indicated that it probably has to do with the rebound adjustment valving. I will be looking at a suitable 500 Turbo shock for permanent replacement. Would you know what company sells a good bolt in aftermarket choice? I will look at those too.
 

·
Registered
Joined
·
759 Posts
I can't remember the companies. I think they were in Europe and the "sticker shock" price tag (pun intended lol) turned me off.
I'm sure someone who went aftermarket will chime in soon. They do supposedly improve the ride if you're into hitting corners hard or taking the bike to a track.
 

·
Super Moderator
'84 CX650E that is evolving into a GL500
Joined
·
19,584 Posts
Is the problem the actual shock absorber or the Pro-Link system that it is attached to? It is pretty common for Pro-Links that haven't been disassembled for cleaning & re-lubing for a few years to exhibit similar symptoms to what you describe.
 

·
Registered
Joined
·
365 Posts
I wouldn't repair the old shock because it is already 40 years old. I know some who repaired it but it broke down again short after.
I bought a perfect substitude shock from Ebay. It is the YSS MZ456-290TRL-16 . This one fits like a glove and the performance is great, much better than original.
After all this is a very important live saving part.

This is the one you need.
 

·
Registered
1982 CX500EC
Joined
·
85 Posts
I second the view about buying a new aftermarket shock like the YSS or Hagon as they perform much better than the old Showa unit but understand a preference to keep the bike original.
I bought a Hagon for my 500EC and its performance far exceeds the old Showa.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #8 ·
Is the problem the actual shock absorber or the Pro-Link system that it is attached to? It is pretty common for Pro-Links that haven't been disassembled for cleaning & re-lubing for a few years to exhibit similar symptoms to what you describe.
Thank you, I have repacked these joints once...a long time ago but the bike only has 2700 miles on it and it has never seen rain or moisture of any kind. A binding bad enough to keep the shock from rebounding when bounced on and with 80 PSI of air pressure would have to have major issue! I will, of course check this again upon shock removal.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #9 ·
I wouldn't repair the old shock because it is already 40 years old. I know some who repaired it but it broke down again short after.
I bought a perfect substitude shock from Ebay. It is the YSS MZ456-290TRL-16 . This one fits like a glove and the performance is great, much better than original.
After all this is a very important live saving part.

This is the one you need.
Thanks very much. New would definitely have advantages and since the shock really isn't easily visable I may do this. Still thinking about it.
 

·
Registered
Joined
·
3,521 Posts
I have personally experienced this problem, and posted about it 8-10 years ago.
The reason 650t shocks fail where 500t do not is definitely the rebound damping system.
Can they be rebuilt?
Yes. It's possible and was done. By one expert. 12-15 years ago.
Can you do it?
No.
Can most machine shops do it?
No
Can the one guy who succeeded a decade ago do it?
Not likely anymore.

The parts required to do it no longer exist, and substitute parts, while available, won't work for long.

There is a long lost archive about rebuilding Showa shocks that was incredibly detailed. I sent a copy of it to Larry C (yes, the carburetor guru) a long time ago.
The problem is that one of the most critical components has been NLA for years. The main oil seal was a 3 ring compression type.
While you can find oil seals the same size, they, the last time I looked a decade ago, were 2 ring rotary oil seals.
They work, very, very briefly, then fail because the job they were meant to do is allow a lubricated machined cylinder to spin in circles, not support compression.

Then there are the plastic parts that cause the failure in the first place. A 3D printer can reproduce them, if you can program it.
And print the specific plastic that is long term oil resistant and doesn't disintegrate in an oil bath.

So, as mentioned, the choices are either to install a 500t shock or an aftermarket.
P.S.- 500t shocks fail too.
You might find one of my posts on this forum called CX500t or CX500 turbo hard tail.

At the end of the day, If you have the money to afford a turbo and actually ride it, buy a YSS, Hagon, or other rebuildable aftermarket shock.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #11 ·
You have excellent points here that I agree with 100%. It's making more sense to replace the shock with new.
I'm having a hard time finding a sutable Hagan replacement on line but I do find the YSS.
Wondering if anyone know if the Hagon is still available and can provide a link to find it. I'm also wondering if one might be better than the other. Any thoughts?
Thanks again.
 

·
Registered
Joined
·
2,401 Posts
I bought the YSS from Wehco and it came with free shipping. I ordered on Saturday and had it the following Friday. With the dollar being high this may be the cheapest you can buy stuff from Europe. If you want to rebuild, look at the 650E manual for instruction on that process, but know that parts may be an issue. I have three zero mile school bikes, if you want original, send me a pm and we can discuss.
 
1 - 13 of 13 Posts
Top