digit datum
The Digit Datum frame, with 140mm rear travel suspension; (photos/Tim Lane)

Out With the Shock, In With the Strut: Digit Bikes Rethinks MTB Suspension

The Digit Datum is an all-mountain/trail bike with one critical innovation, a rear suspension strut, that opens the door to a lot of new capabilities.

Datum (n.): 1. A single piece of information. 2. A fixed starting point of an operation. Both of the dictionary definitions offer solid entry points to understand what Digit’s latest mountain bike brings to the table.

Following a successful crowdfunding campaign last summer, the very first Digit Datum mountain bikes — with their novel strut-based rear suspension — will hit the trails next month. And all the bike’s unique attributes cascade from that single component.

Digit says the Analog Suspension cuts weight, maintains pedaling feel from traditional four-bar suspensions, adds chassis stiffness, and increases reliability. It even says it accommodates the longest dropper posts on the market and leaves room for an extra water bottle.

And it provides 140 mm of rear travel with a 27.5″ rear wheel and 29″ front wheel “mullet” setup.

digit datum

Digit Strut Rear Bike Suspension Details

Led by Tim Lane and developed in California, the company developed the Analog Suspension to answer a weakness it identified in most existing four-bar systems.

During an extensive research and design process, it was found that the upper link of many traditional shock-based systems undergoes a lot of angular displacement in an impact. In other words, the bike gets slushy when the rider lands a drop. On the other hand, the Analog system functions like one long link that gives more control through the distance of travel.

And all the linkages in traditional rear suspension systems contain multiple sources of play and many components to get moving and reverse direction (“stacking up” of suspension.)

Digit bikes strut cutaway

The Digit Strut rear suspension design, called the “Integer,” purports to make the system both simpler and more effective. Analog reduces suspension components by removing linkages and pivots and improves stability under impacts at multiple angles.

This linkage reduction potentially improves reliability, as there are fewer parts and seals to fail, and allows a low 2:1 suspension leverage ratio, reducing loads on both frame and suspension components. And, finally, fewer parts can mean less weight.

The brand says the self-contained strut has more volume than a shock, allowing more oil for damping and air to act as the spring, a significant advantage in air/oil suspension systems. These larger volumes can deliver better damping, less heat-induced fade, and improved spring rate tuning.

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It’s also innovative because it delivers mechanical improvements without requiring specialist tools to maintain. Overall maintenance should also decrease because fewer parts are in play. And an array of external adjusters help riders tune it according to the ground under their tires — damping, rebound, lockout for climbing, etc.

Finally, the uninterrupted seat tube facilitates any length of dropper post plus an extra bottle cage.

Availability and Delivery; ‘Some Assembly Required’

All that being said, getting a Digit Datum ride-ready will not be a task for amateurs. Thanks to supply chain woes, Digit kicks off delivery with frames only. On its Indiegogo campaign page, the company lists compatible components for riders to gather and assemble themselves.

The aluminum frame weighs 7.25 pounds in size large (49-inch wheelbase).

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Four frame sizes are available in Digit’s anodized matte black stock paint. You can also get one custom-painted on a case-by-case basis. MSRP: $4,000, currently 18% off at $3,250 on Indiegogo.

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Sam Anderson
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Sam Anderson is a staff writer at GearJunkie, and several other All Gear websites.

He has been writing about climbing, cycling, running, wildlife, outdoor policy, the outdoor industry, vehicles, and more for 2 years. Prior to GearJunkie, he owned and operated his own business before freelancing at GearHungry. Based in Austin, Texas, Anderson loves to climb, boulder, road bike, trail run, and frequent local watering holes (of both varieties).