Titleist · Driver · 2021
TSi1
CaddyIndex™ breakdown — what the agentic research found across each of the six performance dimensions, with cited sources.
Senior or high-handicap (15-36) players with swing speeds 65-90 mph shopping the used market who need lightweight assistance to swing faster — a historical slow-swing-specialist precursor to TSR1 and GT1.
Your swing speed exceeds 90 mph (the lightweight build becomes a distance liability), you draw the ball naturally already, or you're shopping for current-gen tech (TSR1/GT1 refine this concept).
Pros
- ~40g lighter than standard drivers via an ultra-thin titanium crown — class-leading 2021 slow-swing-speed clubhead speed gain
- Largest sweet spot in the TSi family with the most forgiveness on outside-sweet-spot strikes
- Face-centred CG produces the most draw bias of any driver from the brand — a proven slice-correction tool
- Maximises distance better than almost any driver for 72-90 mph clubhead speeds
Cons
- 4 years old in 2025 — the heaviest recency penalty applied (-9.48); the TSR1, GT1 deliver refined versions of the same concept
- Distance ceiling capped for any swing speed above 90 mph — strictly a sub-90 mph specialist
- Single fixed rear weight plus a SureFit hosel only — minimal hardware adjustability
- Acoustic has a bit of hollowness from the lightweight crown — distinctive but less refined than later TSi / TSR sound
By dimension
Forgiveness
Reviewers note the head has the largest sweet spot and the most forgiveness with strikes outside the sweet spot in the family. The ultra-thin titanium crown allows for weight distribution to increase MOI and launch. However, the design prioritizes speed over forgiveness — the target player already hits a healthy percentage of fairways. Solid forgiveness for the slow-swing class but trades pure MOI for clubhead speed gain.
Distance
Reviewers note that for club head speed around 72-90 mph, the head maximizes distance better than almost any other driver. ~40g lighter than standard drivers enables 2-4 mph clubhead speed gain for the target audience. However, the head produces less distance than non-lightweight family siblings above 90 mph swing speed — strictly a slow-swing tool. Class-competitive for sub-90 mph audience but below-class above 90 mph.
Workability
Reviewers confirm the head has no movable weight system — single fixed rear weight. Face-centered CG produces the most draw bias of any of the brand's drivers. Most draw-biased model by design — opposite of workable for natural drawers.
Feel
Reviewers note feedback in hands matched up to the sound distribution. Players can normally find the general center of the face — every decent strike feels pure, while off-center contact still felt stable. Firm enough to feel stable. The lightweight head means less mass in hand than standard heads — players sensitive to weight may find it lacks the planted feel.
Sound
Reviewers describe the head as producing a metallic pop sound that predictably has a bit of hollowness to it but is also firm enough to feel stable. The driver produces a full, robust, head-turning, metallic thud with some bass to it. The lightweight ultra-thin titanium crown produces a thinner acoustic than standard heads — distinctive but slightly hollow.
Looks at address
Reviewers note the head has classic 460cc tour silhouette at address — premium aesthetic preserved despite the lightweight build. Visually it remains brand-appropriate — clean profile. The head was not recognized at the top tier of the 2021 industry Hot List (the standard-spec sibling was the Gold winner that year).
Sources
Some of the reviews, lab tests and head-to-head comparisons the agentic research read while grading this club.
- Titleist TSi1 Driver Review
- Titleist TSi1 Driver Review
- Titleist TSi4 Driver, TSi1 Driver and TSi1 Fairway Wood
- Golf Digest 2021 Hot List Titleist TSi3 Driver Giveaway Rules
- Titleist TSi1 Driver Review - Lightweight Performance
- Titleist TSi1 Driver
- Titleist Introduces Ultra-Lightweight TSi1 Metals Line
- Titleist TSi1 Driver Review