SIK Golf Flo C-Series Armlock Putter

High MOI Putter

Armlock putting was still a niche move in 2021, but SIK leaned into it harder than almost anyone, mostly because Bryson DeChambeau was winning majors with their putters jammed against his left forearm. The Flo C-Series Armlock is the flow-neck mallet from that lineup, built at armlock length and loft so you can anchor the grip to your lead arm without the face pointing at the sky.

The headline tech is the same as every SIK putter: Descending Loft Technology. The face is machined with four separate lofts that decrease from top to bottom, so the ball leaves with a consistent launch no matter where your hands are at impact. That matters more on an armlock than a standard putter, because armlock setups carry much higher static loft, usually five to seven degrees, and small changes in shaft lean swing the delivered loft around a lot. DLT smooths that out.

What makes the Flo a little unusual is the neck. Most armlock putters are face balanced on the theory that the method removes arc from the stroke. This one has mid toe hang. If you switched to armlock but never fully flattened your arc, that pairing makes more sense than it sounds.

Design

The head is a milled mid-mallet with weight pushed to the perimeter, which is where the high MOI rating comes from. Off-center strikes lose less speed and twist the face less than they would on a blade, and since armlock strokes tend to be long and slow, that stability shows up most on lag putts from 30 feet and beyond. There is no alignment aid on the crown. No sightline, no dots. You aim with the face and the topline, period. Some players find that freeing, others feel lost without a line, and with an armlock setup where the ball sits well forward in the stance, you should know which camp you are in before buying. The C-Series milled face keeps the feel on the firmer, more responsive side rather than muted.

Who It's For

• Players committed to the armlock method who still have a slight arc in their stroke, since the mid toe hang works with that motion instead of fighting it.
• Anyone who struggles with inconsistent launch and skid on putts, because the descending loft face is built specifically to fix that.
• Golfers who aim best with a clean topline and find sightlines distracting rather than helpful.
• Yippy or handsy putters looking for the wrist-locking stability of armlock plus the forgiveness of a high MOI mallet.

Technology

About SIK Golf

SIK Golf brings a distinctive approach to putter design, focusing on quality materials, precision manufacturing, and performance-driven engineering.

Specifications

Frequently Asked Questions

What length and loft is the SIK Flo C-Series Armlock?

Armlock putters run much longer and more lofted than standard models. SIK typically built these around 40 to 42 inches with roughly six to seven degrees of loft, since the forward press of the armlock setup delofts the face at impact. Confirm the exact spec on the specific listing, because SIK offered custom lengths.

Is the Flo Armlock the putter Bryson DeChambeau used?

Bryson used SIK armlock putters during his 2020 U.S. Open win and beyond, though his gamer was based on the Pro model with a JailBird-style setup rather than the Flo. The Flo C-Series Armlock shares the same Descending Loft Technology face and armlock build philosophy.

Why does an armlock putter have toe hang instead of being face balanced?

Most armlock putters are face balanced because the method reduces face rotation. The Flo's mid toe hang is for players whose stroke keeps some arc even with the grip anchored to the forearm. If you swing the putter slightly in-to-in, toe hang helps the face square up naturally.

What is Descending Loft Technology and does it actually work?

DLT machines four lofts into the face, decreasing from top to bottom. Because your angle of attack varies putt to putt, the ball contacts a different part of the face each time, and DLT keeps the launch consistent regardless. Independent robot testing has generally supported the consistent-launch claim, which is why SIK faces gained a following on tour.

Is it hard to aim without an alignment line?

It depends on your eyes. The Flo has no sightline, so you align using the topline and the face itself. Plenty of good putters prefer this, but armlock setups position the ball farther forward than usual, which changes your view at address. Try aiming it at a practice green before committing.

Alternatives to the SIK Golf Flo C-Series Armlock

Other high moi putter models from different brands, closest to its model year.

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