En lang og teknisk pressemelding fra Dave Weagle dukket nettopp opp i redaksjonen. Vi lar meldingen publiseres i første omgang, men kort fortalt fungerer det nye systemet som følger:
1. Det er singlepivot-konstruksjon2. Den har et konsentrisk svingpunkt rundt akslingen3. Systemet er designet for å opprettholde den gode akselerasjonen et høyt svingpunkt på en singlepivot kan gi når det er riktig designet, men den konsenstriske plasseringen av svingpunktet bak gjør at den kan ha meget aktive bremseegenskaper. 4. DW hveder at dette kan være vel så bra, og bedre enn mange FSR-modeller i dag - men mener at f.eks DW-link er et bedre system.5. Systemet skal være enkelt å bygge for produsenter
Her er pressemeldingen:
Dave Weagle launches new suspension system, SPLIT PIVOTThis week, Dave Weagle, the creator of the World Champion and internationally acclaimed dw-link suspension introduces a new system to the cycling world. The new system is called SPLIT PIVOT and features worldwide patent pending concentric dropout pivot technology never seen before. A web site dedicated to the system, www.split-pivot.com, was launched earlier in May 2007.
Dave had the following to say about the launch of the new system: “I’m thrilled to finally be able to show Split Pivot off. This has been something that I’ve worked on for quite a while, years actually, licensed to partners and talked to others behind closed doors, built prototypes, but nobody in the public has seen it yet. It’s so hard to keep something so exciting a secret for so long so I am glad that part is over. I think that riders are really going to enjoy this system. It allows for atypical pivot placement that works great for acceleration and bump absorption and the concentric dropout pivot lets me tune braking forces at the same time. Basically the Split Pivot bikes are a lot of fun to ride.”
What is it?
Split Pivot is a worldwide patent pending suspension system for high performance bicycles, where traction, efficiency, maneuverability, and frame stiffness are important factors on the track and trail. Split Pivot’s [concentric dropout pivot] is the heart of this new design and provides performance that no single pivot can duplicate. Shaped by Dave Weagle's competition proven engineering, Split Pivot is designed to offer a ride that will make you smile.
How does it work?
Split Pivot separates acceleration forces from braking forces in the suspension. The system reduces excess suspension compression due to acceleration forces, and at the same time reduces excess compression due to braking forces. Braking neutrality can be tuned independently of acceleration characteristics, and leverage rate curves can be tuned to meet the needs of the application. Shock layout can be vertical, horizontal, floating or even driven by a modifier link.
The system lends itself to ease of manufacture, and can be engineered to build lightweight frame structures without resorting to exotic materials or tube shapes. Featuring 12mm thru axle, QR 12mm axle, or 10mm vertical QR possibilities, plenty of stock wheels fit the design.
Bottom Line: Split Pivot can be engineered to offer a ride that will make you want to be on your bike more often.
Split Pivot will be available Worldwide in late 2007 and early 2008, details on brands and models to come soon. Prototypes are out there, keep your eyes peeled!
Split Pivot, Split-Pivot.com, and Ride for fun! are pending trademarks of Split Pivot Inc. Split.Pivot@gmail.com www.split-pivot.com Ride for fun!
source: Dave Weagle, e13components.com
Rett fra kilden
Dave Weagle postet dette på mtbr:
Yes, these are all-mountain bikes in the pictures, in the 160mm travel range. Basically your every day rip-around the local woods or mountain trail bikes.
So far there havve not been any 29ers, but there has been some talk about it. Definitely it is possible.
Ginsu, single shear for each seperate side, yes, but double shear if you look at it as an assembly (which it is). There is no way for the skewer to preload the bearings in any way. I think that the cutaway shows this pretty clearly. The reason that the stays ore offset is to make sure that the bearings are loaded against the flanges on the seatstays under compression. This also allows more reliable mounting of the derailleur hanger and elimninates the possiblity of loosening pivots if a rear axle gets stuck due to lack of maintenance. A lot of thinking went into the assembly, and there are a lot of little details that maybe aren't apparent to the untrained eye.
Here is some info that I posted in other forums in response to other questions.
The Split Pivot bridges the gap between a single pivot and a dw-link. It can do everything that an FSR suspension can do, but it can never have the complex anti squat curve and and performance associated with it that dw-link has.
So bottom line with this system, it is a single pivot for acceleration purposes, a multi pivot for braking purposes. In reallity, performance wise it can exactly duplicate what most FSR bikes have done. With a little knowledge (i.e. pivot placement) I think that it can outshine many of the FSR bikes that have been built.
The raw idea is that it uses a single pivot location that offers some real benefits for acceleration purposes, but without a floating brake this pivot location that works so well for acceleration would have some real drawbacks under braking. This is where the Split Pivot (the concentric dropout pivot) comes in. The seatstay link and assembly acts as a floating brake arm, exactly like FSR does. Nothing new there at all. The pivot location around the axle is the novelty and why I had to apply for patents etc...
Lower cost through an emphasis on wider manufacturing tolerances is one of the biggest advantages of this system. A dw-link needs to be held to tight tolerances to perform as designed. This usually menas CNC machining the entire weldment after heat treat, or pretty careful fixturing and alignment. 1mm is a huge number in dw-link world. A Split Pivot could be welded by a monkey and still probably work out allright. 1mm is practically inconsequential with Split-Pivot.
I don't think that Split Pivot could be lighter than dw-link in an ideal world, but it can make a pretty light bike without too much cost. dw-link is structurally pretty hard to beat.
Is this bike going to be better than a dw-link bike? Sadly, no. Is it going to ride better than a single pivot or other linkage bikes? I believe completely that it has the ability to. No matter what, Split Pivot can be used to build a pretty light bike with good performace characteristics. There is nothing wrong with that in my book.
