R6 Rear shock for RZ?

[JonW]

Good to hear youre getting sorted.

Strange Economy sent the wrong bushes, John is a good guy tho and will be quick to sort it out. He's doing some nice adjustable front preload tops as well now. worth a look perhaps.

[jools]

This MikesXS valve conversion isn't quite as straightforward as it looks.
Removing the inner piston tube: -it's in there tight, I had to make up an angled brass drift and use heat and a fair bit of force. (bigger 'ammer!)
Ok, then you have the fact that the valve doesn't fit into the piston top housing.
On another forum there's the suggestion to open up the piston housing with a lathe or by grinding. But the piston ring groove is narrower than the valve, and it's only about 3-4mm below the top. It seems to me that opening the housing up would weaken it at the ring groove area. Maybe if you only open it up to a depth of about 1mm it would be okay, but would that be enough for positive location of the valve?
Another option (seems to me) would be to insert a sleeve into the piston (approx 21.5 OD and 16.3 ID) this would mean the lower (smaller dia) part of the valve would insert, and the larger base would sit on the top of the piston.
Comments?
(I've shot pics but I'm having Photobucket issues so can't upload a pic, which would clarify all this).

[2TInstitute]

Just make something to hold the valve and sit on the damper rod no biggie.

[jools]

Yup, I think I'll stick the damper rods in the ol' lathe and machine a shelf about 1.2mm deep for the valves to sit in.
Now there's the matter of is it 6mm holes or 8mm holes to be drilled... opinions differ. (Sure you're right mate, "no biggie"... I can tend to get a bit anal about these things!)

Re: the rear end, Economy Cycle responded quickly and sent the correct bush that I need, so good on 'em for that. Now I can fit the R6 shock.

[jools]

Just thought I'd give my slant on this having now done it.

Removing the inner piston tube: -it's in there tight, I made up an angled brass drift and used a bit of heat at the 'mushroom end' and a fair bit of force. (bigger 'ammer!)

Ok, now you have the fact that Mike's valve doesn't fit into the piston tube top housing. You need to positively locate the valve otherwise the spring may displace it and it could scrape around inside the stanchion.
On another forum there's the suggestion to open up the piston housing by grinding. I don't reckon you could ever get an accurate enough ledge for the valve by grinding. The valve needs to sit up dead central within the fork stanchion. Job for a lathe I reckon. (or see sleeve insert option below)

Now, the piston ring groove in the damper rod is narrower than the valve, and it's only about 3-4mm below the top. This means that opening the housing up would weaken it at the ring groove area if you go down too deep. I machined mine down about 1mm -enough for positive location of the valve, but not so much that the rod is weakened.
(Another option would be to insert a sleeve into the piston (approx 21.5 OD and 16.3 ID) this would mean the lower (smaller dia) part of the valve would insert, and the larger base would sit on the top of the piston.

I drilled x 6 8mm compression holes at the damper tube base, I brazed up the rebound holes at the top (ignored the 2 little ones) and drilled x1 2mm hole. I'm using 10w fork oil.

A 550mm length of 1/2"OD x 3/8" ID alloy tube (Bunnings) - greatly aids assembly.

I haven't run the bike yet, but static it seems to have very nicely controlled damping. I've set the valve at 2.5 turns in as a starting point for brisk roadwork. Time will tell.
Jools

Photo - shows components before drilling and machining

[jools]

Ref: my post from when I did mine:
(SCROLL THIS QUOTE TO SEE THE PIC)
It might sound a bit complicated but it'll make sense when you do it. The main issue is, ideally, you need to machine a ledge in the top of the damper rod for the XS emulator to fit into. It's a 10 minute job if you know someone with a lathe.

Just thought I'd give my slant on this having now done it.

Removing the inner piston tube: -it's in there tight, I made up an angled brass drift and used a bit of heat at the 'mushroom end' and a fair bit of force. (bigger 'ammer!)

Ok, now you have the fact that Mike's valve doesn't fit into the piston tube top housing. You need to positively locate the valve otherwise the spring may displace it and it could scrape around inside the stanchion.
On another forum there's the suggestion to open up the piston housing by grinding. I don't reckon you could ever get an accurate enough ledge for the valve by grinding. The valve needs to sit up dead central within the fork stanchion. Job for a lathe I reckon. (or see sleeve insert option below)

Now, the piston ring groove in the damper rod is narrower than the valve, and it's only about 3-4mm below the top. This means that opening the housing up would weaken it at the ring groove area if you go down too deep. I machined mine down about 1mm -enough for positive location of the valve, but not so much that the rod is weakened.
(Another option would be to insert a sleeve into the piston (approx 21.5 OD and 16.3 ID) this would mean the lower (smaller dia) part of the valve would insert, and the larger base would sit on the top of the piston.

I drilled x 6 8mm compression holes at the damper tube base, I brazed up the rebound holes at the top (ignored the 2 little ones) and drilled x1 2mm hole. I'm using 10w fork oil.

A 550mm length of 1/2"OD x 3/8" ID alloy tube (Bunnings) - greatly aids assembly.

I haven't run the bike yet, (Yes I have!) but static it seems to have very nicely controlled damping. I've set the valve at 2.5 turns in as a starting point for brisk roadwork. Time will tell.
Jools

Photo - shows components before drilling and machining

-Jools

[JonW]

Thanks Jools

[jools58]

Good info Jools,

confusing now there are two of us on the forum i thought I had already regsitered !!!

i tried fitting some of Mikes XS emulators to my 250LC but they are a slight interference fit and cause sticking so i pulled them out.
one thing to consider is that they also provide some preload due to the way they sit between damper rod and spring.
i found that using them on the LC with a Hagon progreesive spring was too much spring.
Back to standard for now - but reading through all the interesting threads on this forum, I'll probably fit them into the restoration RZ. I also have an R6 shock that has now found a new home - which actually makes we wonder if I can fit some R6 RWU forks that I bought for my TZ but can't use because they are 43mm..................

Jools 2

[JonW]

Jools(2), if you want to sell on the emulators, do let me know, Id like to fit a set to my RZ.

Interesting you mention RWU R6 shocks... my thoughts are that you would need to mess with them quite a bit, they were always overly hard even on the R6 back in the day.

[jools58]

I bought them to fit on my 750 as I was told they were 41mm but turned out to be 43mm. They were cheap so I wasn't too bothered.

With static checks they don't seem too bad, but if they are a spring change is pretty simple.

Finally got all the paint off the wheels, now not sure what colour to do them