Last Tuesday I strung a retail Head Speed MP at 52 lb with Luxilon ALU Power 16L — the numbers most often associated with Taylor Fritz — and hit with it for an hour before my usual session. The string bed felt board-stiff for the first basket; by the second, the ball was coming off flat and heavy in a way my normal 48 lb multifilament job never produces. One trial, one frame, one afternoon. But it pointed at the thing Fritz's setup is built to do, and at why most of us shouldn't copy it wholesale.
Here's what we're working from.
The setup, at a glance
- Frame: Head Speed Pro (paint) — almost certainly over a pro-stock mould, see below
- String main: Luxilon ALU Power (Rough or standard, gauge typically 16L / 1.25 mm)
- String cross: Same — full bed, not a hybrid
- Tension: ~52 lb / ~23.5 kg, surface variation not publicly confirmed
- Customisation summary: Lead added at 3 & 9 o'clock; spec'd to roughly 340 g strung with a head-light balance. Exact grams not publicly known.
- Last verified: May 2026
- Primary source: Do It Tennis pro-gear bundle listing
That's the panel. Everything below is us trying to explain what each line means, and what's confirmed versus what's the common guess.
The frame
Fritz plays a Head Speed Pro paint job. The retail Speed Pro is a 100 sq in, 18×20, 310 g unstrung frame with a 4-point head-light balance — a control-leaning all-court stick. That's the spec sheet a club player can walk into a shop and buy.
What Fritz actually swings is almost certainly not that exact mould. The strong working assumption across the stringers and racquet-tech community is that he's on a Head pro-stock — a PT57-family or Speed-coded layup under Speed Pro paint. We can't confirm the precise pro-stock code from the dataset, so we'll flag it as "likely pro-stock, exact mould not publicly known" rather than name a number we'd be guessing at. The visible tells — a slightly different bumper profile in bag photos, the consistency of his contact through the years across Head paint refreshes — line up with what we'd expect from a player on a stable pro-stock layup who lets the cosmetics change around it.
The customisations are the part that matters more than the mould name. Fritz's frame is reported to play around 340 g strung with lead added at 3 and 9 o'clock — weight in the hoop, not the handle. That's a meaningful jump over the 310 g retail unstrung number, and the 3/9 placement is a deliberate stability move: it widens the sweet spot laterally and adds plough-through on flat drives without raising the swingweight as violently as a 12 o'clock add would. Whether there's any handle counterweight or silicone in the pallet isn't publicly known. We'd guess yes, given how head-light most tour Speeds end up, but we won't quote a number.
So: retail-buyable cosmetic, almost certainly pro-stock underneath, customised toward stability rather than spin generation.
The string
A full bed of Luxilon ALU Power is one of the most copied string jobs on tour, and Fritz is squarely in that lineage. The dataset gives us the string and a 52 lb / 23.5 kg ballpark, with gauge most commonly cited as 16L (1.25 mm). What we don't have is a confirmed surface-by-surface tension split — no "drops 1 kg on clay" note we can stand behind — so we'll leave that as not publicly confirmed.
A few things follow from a full ALU Power bed at 52 lb in a 18×20 pro-stock.
The 18×20 pattern is already a control pattern: tighter string spacing, less ball bite, less natural spin, more predictable launch angle. Pair that with ALU Power — a stiff, low-powered co-poly that holds tension better than most — and you have a string bed engineered for the player who wants the ball to go exactly where they aimed, at the cost of a comfort margin most amateurs would miss within a set. 52 lb in that pattern is not especially tight by tour standards (plenty of pros are at 48–50 in 16×19s, which plays looser), but in an 18×20 it produces the stiff, flat response I felt on Tuesday.
Restring cadence isn't in the dataset. The tour-standard assumption — fresh frame every match, sometimes every set on a hot day — almost certainly applies, but we won't put a number on it without a stringer interview to point at.
Connect the string to the game: Fritz is a first-strike, flat-through-the-court, big-serve player who doesn't lean on heavy topspin to keep balls in. ALU Power full bed in an 18×20 is the string job that game asks for. A spin-first baseliner on the same frame would be fighting the stringbed to generate shape.
What this tells you
The setup is internally consistent in a way not every pro's is. Flat hitter, 18×20 pattern, stiff full-poly bed, weight added at 3/9 for stability rather than at 12 for swingweight: every choice points the same direction, which is "make the ball go where I aimed, fast and flat." Fritz isn't an outlier on tour for any single element — Head pro-stocks are common, ALU Power is the most-used string on the men's tour, mid-range tensions are normal — but the combination is unusually pure. There's no hybrid for arm comfort, no extra weight up top for free pace, no looser cross for a spin boost.
For a club player who admires Fritz, the honest read is: the retail Speed Pro is a real and buyable frame, but it's a demanding 18×20 control stick before any customisation. Stringing it with full ALU Power at 52 lb is the move of a player whose timing is good enough to find the centre of the string bed on most balls, and whose arm can handle a stiff poly week after week. Most club arms can't, and most club timing won't, and the result is a frame that feels dead and punishes mishits. A multifilament cross, or a softer poly like Solinco Hyper-G Soft, would be the sane translation.
The afternoon, revisited
Back to Tuesday. After that hour, I cut the ALU Power out, restrung the same Speed MP with my usual setup — a soft poly main, multi cross, 48 lb — and hit the same baskets the next day. My serves lost about 4 mph on the radar I borrow from the club (not a calibrated tool, take it lightly). Forehands felt easier to shape, harder to flatten. Two string jobs, one frame, one week. The Fritz spec did exactly what its internal logic says it should: it gave me more pace and less margin. I went back to my own setup on day three, because I am not Taylor Fritz, and the 4 mph wasn't worth the elbow.