Time for another post.
I've contacted Fabio Cavalli, so now I'm hoping he does reply.
If not, I'm completely stuck and will have to build the bike to the best of my knowledge.
I've been able to get some more info by examining the parts.
The picture above is where I tried to fit an original 31.8 Sbike handlebar into the custom stems. They're obviously intended for a 25.4 handlebar.
All aluminium Sbikes built in 1992 or later had 31.8mm handlebars, and even the original 729 prototype (built in 1991) had a 31.8 handlebar.
That leads me to believe that this particular frame was built in 1990 or early 1991, which means it would predate all the production full suspension Sbikes.
We can now exclude the option of this being a later evolution or a downhill special. The 25.4 stem wouldn't be used on one of those.
Could this really be the first attempt at a full suspension Sbike? Unicorns don't get any better than this, at least not if you're into Sbikes.
If Mr. Cavalli replies and knows more about this frame, so much the better. If not, I'll go with 1991 as a guideline.
The high-end 1991 Sbikes sported a full '91 XT set and Ritchey WCS Pro rims. I know all the correct code numbers for the XT parts and should be able to find all that NOS if I spend enough time on eBay.
Regarding the welding that still needs to be done : I know FTW welded the first prototype that Francesco Quinn designed, so IMO he's the only man for the job.
While I'm waiting for Mr. Cavalli's response, I'll be taking the necessary pictures for FTW, so he knows what to do. I plan to ship it to Vermont somewhere in July or August.
So it looks like the actual build itself will only start during the winter months ... if I can get all the parts by then.
Anyway, by lack of new material, I'll show a bit more about the rear shock.
People have been wondering and asking me how these things work, so I was due to explain it anyway.
All the parts in the right order. I used the swingarm and broken top triangle of the (deceased) 828 to show where everything goes.
Putting the adjuster ring over the main shaft.
Sliding the bottom spring into the adjuster.
This washer fits nicely onto the main shaft.
Basically this washer supports the main spring. The bottom spring is merely used to hold the adjuster ring against the bottom of the main shaft at all times.
Main spring going onto the bottom assembly.
The spring cover sliding into place.
This part acts both as protection against dirt and as a bump stop. There's a rubber ring in there which will hit the adjuster ring if the shock compresses too far.
Pretty clever stuff really.
Putting the shock onto the frame. Top end first due to the length of thread sticking out.
Yet another spring.
This one seems to enable the top cap to tilt a bit when necessary, eliminating the need for a proper pivot. Basically the entire shock can tilt a few degrees around the top mounting plate, which is enough for proper operation.
Sliding the top cap over the top spring. This is a snug fit. In fact it touches the side plates of the mount.
This'll only get worse if I have the frame painted, so I might have to sand the cap down a bit or have a new one made.
Plenty of thickness, so there'll be no effect on integrity. Besides, this part is mainly cosmetic.
The top adjuster nut being screwed on. I read reports that mention this nut can apparently be tensioned up to the point where the suspension can be locked out.
Theoretically, that's possible indeed. However it means turning it so much that the bump stops engage.
This particular nut won't take that much thread because it's closed at the top, so at best it allows some control of the spring tension.
And there you have it, the frame with the shock installed.
The rear section will be polished to match the shock's finish, and then clearcoated (powder coat, of course).
The front will probably be red. It's a good thing I have a proper red Sbike already, so I can let the paintshop select the correct matching colour.
Those of you who paid attention, will probably notice that there's no damping whatsoever in this shock. Yes, it's a boing-boing affair indeed.
You probably noticed the lack of grease as well. That's because this is just a dry assembly for the pictures. I'll do it properly when the time comes to build the bike.
