The DW Link - the Heart of a Pivot

Pivot Mach 5.7

So we’ve been talking about how much we love how Pivot bikes handle for awhile now. You’ll hear us say they are plush, efficient, stiff, supple, bottomless, sweet and much much more. What makes them so sweet? Careful frame design and construction and attention to detail for sure. But the heart of the design is the DW-Link, so I thought I would spend a bit of time explaining this suspension system and why it, in our opinion, is the best suspension design on the market.

What are the factors to consider when engineering a suspension system? Comfort, acceleration efficiency, traction on climbs and in corners, bump absorption, pedal feedback, braking influence, frame strength and stiffness, frame geometry and frame manufacturability are all factors that must be considered during the development of a suspension system. That is certainly not a short list!

Let’s think about some the things we don’t like about suspension systems:

• Bob - that dreaded feeling that when we accelerate, the bike sinks and it feels like all our effort just makes the bike squat. This suspension correction is simply physics - do you remember High School Physics? That would be Newton’s Third Law of Motion, remember? Every action has an equal and opposite reaction? The feeling of bob is the “reaction” the bike makes to the rider’s mass moving forward.
• Pedal Feedback happens when the aligned distance between the center of the bottom bracket and the rear axle changes during the compression of the suspension. The less this distance changes, the less pedal feedback you get.
• Extra damping can compensate for these two problems, but it also creates it own problem - poor small bump compliance and less traction in corners and while climbing because the rear wheel is bouncing off the obstacles rather than rolling over them.
• Squat during braking - with many single pivot suspension designs when you brake the bike will squat as the braking interferes with the suspension.

So how does the DW-Link overcome these issues?

• 3 stage anti-squat curve: The DW-Link patented position sensitive anti-squat balances the rear transfer of mass (that’s BOB, folks) to increase efficiency, traction and bump sensitivity while eliminating pedal feedback.
• Reduces pedal feedback by using a smooth and positive chainstay lengthening effect to offset negative gearing effects. This results in a smooth ride with imperceptible pedal feedback over entire gear range.
• Progessive to Linear Rate: each DW-Link frame is designed to work with a specific spring and damper. DW-Link suspensions do not rely on pedal dampers so that the suspension keeps excellent small bump compliance. And that also means that it is really important to get your shop to set up your DW-Link suspension bike for your riding style and weight. Expect that a shop will ask you how much you weigh and make adjustments before they send you out on a test ride or a demo.
• Balanced braking: the DW-link actually works under hard braking so that the bike doesn’t squat under braking unlike single pivot designs.

Check out this site for more detailed explanations.

The motion of the DW-Link suspension has the rear wheel move backwards at the beginning of the travel then vertically through the middle of the travel. This gives the bike small bump absorption and helps with traction while climbing. And when you move farther through the travel of the suspension, you get that bottomless feeling because of an increase compression damping. The travel direction together with the short stiff linkages and triangular rear swing arm increases the weight to stiffness ratio - that means the bike is more efficient and will go the way you point it rather than flexing through rock gardens and veering off course.

And Pivot backs up all that with some great frame design to compliment the DW-Link. Pivot uses 92 mm press fit bottom brackets, through axles, oversized pivot bearings all contribute to a frame design that is stiff. Don’t worry if you don’t understand the physics of why the DW-Link works, we have the best way to explain it - come into the shop and ride a Pivot!