identifying RM shocks

[LWC82PE]

I have got 2 remote reservoir KYB/Suzuki shocks and I want to be sure what they are off of.

KYB 021
62100-40330
Length – 395-397mm

Body welded at seal head end. Reservoir has a Schrader gas fill valve

KYB 8526
62100-41131
Length – 393-395mm

Body has is not welded at seal head end and appears to have a re-moveable cap. There is no Schrader gas valve in the reservoir

My research tells me that the KYB 021 is for 1980 RM 250/400 T and the KYB 8526 is for 78 RM 400 C and 78 1/2  RM 250 C2

Can owners of these bikes with the original shocks confirm this?

I am pretty sure I am correct so what I need is one original shock definitely off a 1980 RM 250/400 T. I’m not too fussed about the condition and the shaft doesn’t have to be useable. As long as it feels ok when its compressed and doesn’t feel gritty or rusty in side it will be ok for me to use.


Also does any one who has fiddled with these KYB units fitted on suzukis know if the bottom eyelets are re-moveable off the shafts? I attempted to remove the eyelet off a PE shock and had the shaft clamped in some special clamping blocks and applied some heat but I couldn’t undo it but at the same time didn’t want to force things and started to inspect further. I thought it must screw onto the shaft like every other shock I’ve seen but now I’m not sure if the eyes are somehow cast onto the shaft and are now one piece. I found that there was a collar I could move up the shaft as you can see in the photo and this is where I thought the thread was. This can be seen in my photo. So now there is just this eye tacked on to the end of the shaft so I can’t see that there can be anyway it is threaded onto the shaft at all. I’m now pretty sure that the eyelets are not removable. Am I right so far? This is the first time I’ve seen this so maybe it’s only common on old KYB units. If this is the case it makes life hard when you want to replace bump stops as you gotta pull the shocks apart and cant just unscrew the eyelet.

[brent j]

The eyelets are welded in place. From memory it's a resistance weld

I've cut these open and made them rebuildable in the past but they don't look quite standard.

If you've got any to get rid of I'd probably be interested.

Brent

[YSS]

If you treasure them Brent , I should keep some for you,  next  time.

[Maico31]

From memory the shock with the schrader valve came out on the T model and the one without the valve came out on the B and C models so sounds like you got it right.

[brent j]

Seriously Walter if you could hold on to one or even two pair of RM or PE, regardless of condition, that would be great.

The springs are handy and I have a good working combination for my XT projects. With three almost identical bikes it makes it easier.

Thanks

Brent

[YSS]

Good to know , because we normally bin them. I will try to put a pair aside

[Tim754]

I have a pair of remote resy shocks that have the Suzuki insignia on them (KYBs). Of course they will need some work but  if you want them Brent I will COD post them to you. Tim
 Before ya ask.... no charge free gratis zilch 

[Doc]

I personally like the remote res Kayaba's that came stock on the early RM pre '78. They've always served me very well. 3 way adjustable spring (more if you machine some extra snap ring grooves) and something a lot of people don't know is they have 2 way adjustable damping. 2 way ain't much but it makes me wonder how many unwittingly rode their bikes with the rear shocks on different settings as there is no way of telling which setting except by feel with the shock off the bike and the spring off the shock. 

[oldfart]

KYB 021  is correct  RM 250 T
 
They have been rebuilt by Rad  a few weeks ago   .... same as pic I sent you the otherday

[Tim754]

Brent I buffed the shocks and the best blind old me came up with was "KYB 631" I think.... appear to be the type that goes on upside down to most, so the remotes can be attached to frame.  Tim  perhaps someone can ID them ?

[LWC82PE]

Tim is there any other numbers on the ones you have?

i was going to send these shocks away to be dismantled and returned to me but figured I could save on labour 2 lots of postage and do it my self if I knew how to.

The 78 RM shock was pretty much of no use to me so I thought I would attempt to pull it apart since it had a press in cap to get an idea of what to expect with the others. I removed that cap and the bearing and seals down to the second c-clip but I think that’s as far as I can go. On this shock and the PE shocks there is a groove which appears to be an indentation (marked ‘A’ on photo) Is this put in to put a dimple or ridge inside the body to hold parts in place and therefore I cant remove any more parts because of this?

If that is right and that means I have to cut these shocks open, where should I exactly cut the body open? On the line or below the line? If below, how far? or is it better to stick it in a lathe and machine it open rather than carefully with a hack saw or what ever? or maybe thats not a good idea with the PE ones as they would still have oil in them.


On the T model RM shock there is no indentation so should I just open up at the weld (B)? where did you cut yours open Brent?

If all goes to plan I would like to use some/all of the RM-T internals in the PE shocks and get the damping/valving improved and then I will have 4 way adjustable damping on the PE shocks and still have an original appearance for an original resto. Still wondering how the PE ones are re-gassed and delt with at the floating piston end. Ive got some good sources for 12.5mm KYB seals and bushings and complete heads so once I figure out what parts I can use I can send it all off to get machined and rebuilt etc.

[Maico31]

Don't cut them open where the A mark is, that's about where the piston is when the shock is extended. I think you need to cut them where you have the B marking. I reckon you'll need to release the gas pressure first.

[Tim754]

Will look harder tomorrow Leith

[brent j]

The shocks I've used are the same as the bottom ones in the piccie. RM T also KLX 250.

I cut through the weld around/along it's centre. I've done them with a hacksaw or lathe, depends what's available on the day. I make a sleeve to fit over the end of the body with a groove to take a circlip. This is sweated in place.
I have considered using the bodies with the indentations but they will need a longer sleeve. I would cut them where the indentation is.

I found it's easier to make a new seal head rather than modify and refit the original. The shafts are 12.5mm and I use off the shelf 12mm oil seals and change them when I change the oil, once a year.

I may have a shock the same as you are after but it will be rough, I'll try and find it tomorrow.

If you have any to get rid of can you let me know, even blatant throw away stuff is good for springs and internal parts for what I do.

Brent

[oldfart]

35mm down from the flat section on middle pic , which should be a few mm below the groove  that is so you can remove the c/ clip
Then measure down 12 mm from the same place and make another cut .