McCallum Twin
Jeff McCallum's upright performance twin: drawn for a tight turning radius rather than for long drawn arcs.McCallum designed this pair for his own shapes, and the template is upright — the tip sits over the base instead of trailing well behind it.
The Fin
Jeff McCallum's upright performance twin: drawn for a tight turning radius rather than for long drawn arcs.
McCallum designed this pair for his own shapes, and the template is upright — the tip sits over the base instead of trailing well behind it. Solid fiberglass with a flat inside foil, sold as a pair on Futures bases, in charcoal or ivory charcoal.
How that reads
Rake is what makes a fin draw a long turn; take the rake out and the fin turns on a shorter radius and changes direction with less warning. McCallum keeps enough base under it for drive, so what comes out is a twin that pivots off the tail rather than arcing off the rail, and the flat inside foil keeps the pair driving forward while it does it.
Who it suits
Shortboard-scale twins ridden in the pocket, and anyone whose complaint about a keel or a raked twin is that the board will not come round tightly enough. If drive down a long wall matters more than turning radius, a keel template is the better answer.
If this is not the one
Want drive and a long arc instead of a tight radius? The McCallum Keel - Futures Compatible (Solid Fiberglass). Want four fins on the same board? The McCallum Quad - Futures Compatible (Solid Fiberglass).
Specifications
The upright outline is the whole point: it pulls the pivot point under your back foot rather than stringing the turn out toward the tail, so the board redirects off the back foot instead of arcing around, keeping a wider-tailed board from washing out in the turn.
Put this on a fish or twin shortboard with a pulled-in to medium tail when you want to surf vertically and redirect fast — it tightens the turning radius and gives you a real top turn instead of a long carve, good in beachbreak and points where you are actively working the wave. If your board has a wide keel tail and you want speed and hold over pivot, the McCallum Keel is the one instead.
The McCallum Twin is an upright performance twin-fin set designed by San Diego shaper Jeff McCallum and made by True Ames in Futures-compatible solid fiberglass, sold as a pair. The template runs upright with modest rake and enough base to hold a line. It is intended for swallowtails, fish, round pins, and twin-fin shortboards with pulled-in to medium tails.
Mentioned in the review — McCallum Keel · Gephart 70/30 Keels — not something we carry.