[Darth Lefty]

Soooo in the midst of the Ripley V4 launch thread I made a joke that their ostensible in-development MUSA bike would be a DW-Link Cousin It. Then after thinking about a little I posted over in the Tandem Mountain Bikes facebook group, why don't you see any short link tandems? The short answer is that only Ventana is making very many, and they're not. But there are a few others. They're all single pivot types. Someone posted that they had an MSC Zion tandem, and that's an interesting suspension. The bike has a big swing arm assembly. The floating link is not the chain stays, it's a little dogbone between the top of the swing arm and the shock. The floating link and the shock attach to a counter rotating pivot kind of like a Santa Cruz.

I can't find any other bikes like this except for one other bike from MSC, which did get an entry on the Linkage Design blog but not much discussion.

What does this accomplish? At first glance this should be a pretty stiff setup, what with the one big set of bearings and the big triangulated swing arm. What other advantages might it have? Disadvantages?

 

[TigWorld]

Nothing like DW/Maestro/VPP etc. twin link bike. MSC Zion MPS2 is just a single pivot with a linkage driven shock. The extra link is required to compensate for the circular path of the top of the swingarm, but by varying the pivot locations of the two links you can tweak the leverage ratio / shock curve. It's potentially better than a simple single pivot directly driving the shock (eg. Orange) but whether it is better or not is entirely dependent on the implementation.

 

[Jayem]

Generally, really short links are usually highly leveraged and put extreme wear and tear on the bearings, even moreso when they don't rotate very much, it ends up pitting and impacting the bearings. Foes has used some similar scissor-linkage setups with varying success over the years. As far as being stiff...the small connecting linkage is..well, pretty small, and it's an "extra" part in between the main linkage, this will only induce more flex, although the entire triangle needs to be considered, as well as the main attachment (out of the picture).

Hard to say anything really definitive though without more information.

 

[Darth Lefty]

I figured it would be stiff since it's a big triangulated swing arm like a short-link bike but instead attached directly to the frame. I can see how the narrow linkages at the upper end would provide less support there, though.

 

[Schulze]

It reminds me of the Focus FOLD system, but with the shock in a different position.

MSC Zion 27.5'' 2014 - Linkage Design

 

[One Pivot]

That's an incredibly high leverage ratio. It ramps up, but even at full ramp up its at 2.9:1.

All things considered, like having linkage design so readily available, I feel like we can put to rest the idea that mini link bikes do anything special in terms of pedaling ability. Its just more flexy parts to wear out, usually. While that one isnt really a "mini link" bike in the sense of an upper and lower virtual pivot bike, its still using one extra small link.