Wilier Time Trial Bike Size Guide: Turbine SLR, Turbine SL and Supersonica SLR

Wilier gives its entire time trial and triathlon range the same three size labels: XS/S, M and L/XL. Three sizes looks thin next to the eleven on a modern road flagship. It works because a time trial bike is fitted from the armrests down, not from the saddle up. The frame sets the window and the cockpit sets the position inside it. Browse all Wilier bikes at Bikeroom.

Please note. The suggestions here are indicative only, a starting point rather than a guarantee of fit. Wilier does not publish rider height bands for its time trial models. The height rows below are our reading of the geometry, not a Wilier chart. Confirm your size with a professional bike fit or with our team before you buy.

Quick size finder

Find your height, cross check your leg length, then read across. All three bikes use the same labels, so the row you land on is the same whichever model you choose.

Trust the Accu-Fit pad numbers below over this table. On a time trial bike the armrest position decides the size.

How to measure yourself

Height. Stand barefoot against a wall, heels together, and measure to the top of your head.

Leg length (inseam). Barefoot, feet about 15 cm apart, press a book up between your legs as if it were a saddle. Hold it level against the wall, mark the top edge and measure from the floor.

Why the inseam formula does not help here. Multiplying your inseam by 0.66 works on brands that size in centimetres. Wilier's time trial frames are lettered. The numbers that matter are your armrest height and armrest reach from a fit session.

Why a time trial size is not a road size

Four things change when you move from the road range to this one.

• Pad stack and pad reach replace stack and reach. What counts is the distance from the bottom bracket to the armrest, not to the top of the head tube.
• The seat angle gets steeper. Road frames sit near 73 degrees. Time trial and triathlon frames run roughly 76 to 80 degrees, which rotates the rider forward and opens the hip angle.
• Most riders end up one size below their road size. The frame only has to carry the armrests, so a shorter head tube and shorter reach leave room to build the position back up with spacers.
• The rules differ. UCI time trial racing limits how far forward the saddle may sit and how far the extensions may reach. Triathlon has no equivalent limit.

Turbine SLR (time trial and triathlon flagship)

The Turbine SLR is the disc brake flagship. Wilier states that it keeps the geometry of the original Turbine unchanged. Wilier also states that the frame meets UCI standards, including for athletes above 190 cm, under the rider height register introduced on 1 January 2023. Claimed frame weight is 990 g and fork weight 390 g, both with a 5 per cent tolerance.

Fit character: 34 mm of stack and 21 mm of reach between sizes. That is a wide step, and the Accu-Fit chart is how you close it.

Turbine SL (triathlon and fast training)

The Turbine SL is the more accessible frame, and the one with the steep seat tube. Wilier quotes 78.5 degrees at XS/S rising to 80.2 degrees at L/XL. The dedicated seatpost lets the saddle sit about 2 cm ahead of the bottom bracket centre. Claimed frame weight is 1,270 g and fork weight 475 g, both with a 5 per cent tolerance.

Fit character: within 3 mm of the Turbine SLR on stack, but 12 to 14 mm shorter in reach at every size.

Supersonica SLR (pure time trial)

The Supersonica SLR is the low one. Its seat tube angle is 82 degrees at every size, the steepest in the range. Its stack sits 17 to 35 mm below the Turbine SLR at the same label. Claimed frame weight is 1,450 g and fork weight 550 g, both with a 5 per cent tolerance.

Fit character: the same reach as the Turbine SLR with a much lower front end. Choose it only if you can already hold a low position.

The Accu-Fit chart: Wilier's pad numbers

Wilier publishes an Accu-Fit chart for the Turbine SLR. It is the one document that answers the question a time trial buyer actually has. You arrive with three numbers from your fit: pad X, pad Y and extension tilt. The chart returns the frame size, the pad position and the spacer height that produce them.

The full chart covers tilt angles of 0, 2.5, 5, 7.5, 10, 12.5 and 15 degrees. It runs twelve pad positions and spacer heights from 0 to 70 mm in 5 mm steps. The table below is the outer envelope at zero tilt.

The three windows overlap heavily, so most riders have two workable sizes. The tie breaker is how much spacer sits under the pads.

Wilier adds its own advice in that document, and it cuts against the usual rule of thumb. On time trial and triathlon bikes it prefers the larger size, for greater stability at the aerobars. It also warns that the larger frame can leave no room to go lower later. A rider who expects to get more aggressive should take the smaller one and run spacers.

What riders say about Wilier time trial sizing

Published owner feedback on the current Turbine range is thin, and it is more useful to say so than to dress it up.

The Slowtwitch launch thread ran on at length about the folding base bar, the price and the cable routing. It barely touched fit. One poster there singled out the bar's adjustment range and tilt function as unusually generous for a bar designed in house by a frame brand. The Accu-Fit numbers support that reading: 70 mm of spacer and twelve pad positions is a wide window.

The pattern that does hold across the range is the seat angle spread. Moving from a Turbine SLR at 76.5 degrees to a Supersonica SLR at 82 degrees changes where you sit on the saddle. Saddle choice and saddle height both need revisiting, not just the frame label.

Between two sizes?

Take the smaller frame if your fit numbers sit near the bottom of the pad Y column, or if you expect to go lower over the next couple of seasons. Take the larger frame if you are already near the top of the smaller size's spacer stack. A tall tower of spacers usually means the frame is a size too small.

Torso and arm length matter more here than on a road bike, because the armrests carry your upper body weight. If your fit sheet lists a pad X and a pad Y, use the Accu-Fit chart and ignore your height. If it does not, book a fit first.

Our Wilier road bike size guide covers the road range, where the sizing logic is different. If you are choosing between a UCI legal frame and a triathlon one, time trial bicycles versus triathlon bicycles sets out what the rules allow. For a second hand frame, the practical guide to buying used triathlon bikes lists what to check.

Shop Wilier at Bikeroom

• All Wilier bikes for the full range, road and time trial.
• Wilier Supersonica for the pure time trial frame.
• Time trial and triathlon bikes for the whole category across brands.
• Pre-owned triathlon bikes for frames that have already been ridden.

If a pad X near 460 mm leaves you choosing between an M with spacers and a flat L/XL, talk to our concierge. We will read the Accu-Fit chart against the bikes we have.

Disclaimer: the size suggestions here are indicative only and do not guarantee a correct fit. Geometry and Accu-Fit figures are official Wilier Triestina data for the model year 2026 Turbine SLR, Turbine SL and Supersonica SLR. Wilier publishes no rider height bands for these models, so the height rows are editorial guidance. Frame and fork weights are Wilier claims with the stated tolerance. Always confirm against the exact bike and model year you are buying.

Sources: Wilier Triestina, Turbine SLR; Wilier Triestina, Turbine SL; Wilier Triestina, Supersonica SLR; Wilier Accu-Fit chart, Turbine SLR model year 2026; Slowtwitch forum, Wilier Turbine launch thread. All accessed 24 September 2026.