WANTED, dimensions for Skunkworks rear linkage.

I believe those stock Elsinore shocks were 360mm long, so you could come pretty close by measuring a good photo carefully.

I have been thinking of making a set that way for a bike I'm building, but I found a test of the 7" version by Dirt Bike or MXA, who really wanted to like it, but said that with the recommended heavier springs, it was unusably stiff over small bumps, especially braking bumps. When I look at the ad, I wonder whether they inadvertently made it a falling-rate linkage in order to fit the available space. I could be wrong, but shouldn't the shock start perpendicular to the lower arm of the linkage, and swing to a more acute angle to make the rate rise?

If you try that on the bike in the photo below, I think the lower arm fouls the axle or adjuster area before it would bottom, plus you need a longer upper arm, unless you use a shorter shock. The 11" version didn't have the same falling-rate issue due to the swingarm shock mount being farther forward on something like a 1976 Elsinore. I hope there is a contemporary suspension maven out there who can clear this up, as I may have it backwards and be quite wrong, but if I made one for my bike, I intended to use different dimensions to address the issue I believe the original had.

Yeah, you're right, it is. I managed to find the MXA article again, and they seem peeved that it wasn't an easy bolt-on for their Elsinore, as the lower arm was fouling the axle and adjusters before the shock bottomed. They put a travel limiter on the shock and came out with about 130mm of wheel travel, barely more than stock, and a 50kg spring on the stock damper: no wonder it kicked, and not the linkage rate's fault.

I cannot link directly to the article, as it is a PDF download, but it's the Skunk Works item at article for a good look at the construction of the links.

I think they went far too stiff @ 50kg. Very puzzling, because back then 125s with the old shock mounting and typical (smaller) riders were using 25-35kg range springs. Even early forward-mount or laydown 125s seemed to use 40-45kg. springs for such riders. Worse still is that the stock shock is way underdamped for that 50kg spring, so the rear's bound to bounce around. Nor do we know how much preload was involved to get the 50kg spring onto the Honda shock body; it might have been a lot.

Probably only need a 20-30% higher than stock spring rate, and same increase in rebound damping if possible, like one click heavier on old Konis. I should think that when you mock it up, you can work out how to prevent the link from bottoming on the rear axle or adjusters, maybe by using shorter shocks but increasing their mechanical advantage a bit.

That setup was ahead of its time.

I have a NOS set in a box somewhere.If you are interested make me a decent offer and I will get serious and try to find it.

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Not mine. I'm looking for these for a KX125.

Yamaha DT400 YZ360 YZ250A DT250 DT360 Skunk Works Rear Shocks Absorbers
EBAY - Yamaha Skunkworks rear linkage