Basso Gravel Size Guide: Find Your Fit by Height and Reach

Basso sizes its gravel bikes with letters, XS to XXL, on a sloping frame. There is no seat tube number to anchor you, and Basso publishes no rider height chart on any of its model pages. What it does publish is a complete geometry table per model, which is the more useful document anyway. Read stack and reach first, then check the seat tube length for saddle height and standover.

The current gravel range on bassobikes.com is the Palta III, the Palta, and two e-gravel bikes, the carbon Volta and the aluminium Vega Gravel. The Tera is no longer a bike you can buy: it survives only as a reference on the Vega Gravel page, which says the Vega inherits Tera's gravel geometry. Browse all Basso bikes at Bikeroom.

Please note. The height and inseam bands in this guide are indicative and produced by Bikeroom, not by Basso. They are a starting point built from official geometry and average body proportions, not a guarantee of fit. Torso length, arm length, flexibility and riding style all move the answer. Confirm with a bike fit or with our team before you buy.

Quick size finder

Find your height row, cross check the inseam column, then read across. The Palta III and the Palta use similar stack and reach at the same letter, so the labels track closely. The Volta starts at S and the range tops out at XL.

Trust the inseam over the height when the two disagree. Inseam sets saddle height and standover, which are the two things a frame size cannot be adjusted around.

How to measure yourself

Height. Stand barefoot against a wall, heels together, looking straight ahead. Rest a flat book on your head, level against the wall, mark the edge and measure from the floor.

Leg length (inseam). Barefoot, feet about 15 cm apart, press a book spine up between your legs as if it were a saddle. Hold it level against the wall, mark the top edge, measure from the floor. This number matters more than height for sizing.

The quick formula. The inseam times 0.66 shortcut only works for brands that label frames in centimetres of seat tube. Basso labels its gravel bikes XS to XXL, so the formula does not apply here. Use the geometry tables instead.

Palta III (gravel flagship)

The Palta III is the current carbon flagship, a 970 g frame in size M that Basso positions for both racing and long weekend rides. It comes in six sizes, XS to XXL, with 430 mm chainstays at every size and clearance quoted as 52 mm front and 50 mm rear. Reach grows by 51 mm from XS to XXL while stack grows by 90 mm, so the frame gets proportionally taller as it gets longer.

Official Basso geometry, model year not published. Rider heights are the Bikeroom estimate, since Basso publishes none. A moderate gravel fit: taller in stack than a road frame of the same reach, but not upright.

Two details change the fit inside a given size. Basso offers two seatpost setbacks and three cockpit configurations, the Strato stem with the Carbon Gravel Handlebar, the Fuga and the Levita. Head angle also varies sharply across the range, from 68 degrees at XS to 71 degrees from L upwards. The small frames steer slower to keep the front wheel clear of the rider's foot.

Palta (previous generation, widely found pre-owned)

Basso still lists the Palta alongside the Palta III, and its own design section refers to it as the Palta II. It is the bike most riders will meet on the second hand market. Five sizes, XS to XL, 425 mm chainstays and clearance quoted up to 45 mm on 700c wheels, with the caveat that the figure is guaranteed with gravel groupsets. Basso states compatibility with 1x and 2x, mechanical and electronic, up to a 52-36 chainset.

Official Basso geometry, model year not published. Rider heights are the Bikeroom estimate. Slightly lower in stack than the Palta III at the same letter, with shorter chainstays and less tyre room.

The important comparison is S to S. The Palta S carries 370 mm of reach against 362 mm on the Palta III, with 8 mm less stack. Riders moving from a Palta S to a Palta III S will find the newer bike shorter and taller, which usually means a longer stem to keep the same position.

Volta (carbon e-gravel)

The Volta is the Palta platform with a Polini E-P3+ GP motor and a 500 Wh Polini Evo 2 battery, quoted by Basso at 15.2 kg. Four sizes, S to XL. Chainstays stretch to 440 mm, clearance is quoted up to 45 mm, and stack rises sharply. The Volta S sits at 549 mm of stack against 542 mm on a Palta S, with 22 mm less reach.

Official Basso geometry, model year not published. Wheelbase and bottom bracket drop are not published for the Volta. A noticeably taller and shorter fit than the pedal bikes, which suits the extra weight over rough ground.

The aluminium Vega Gravel sits below the Volta in four sizes, S to XL, with 450 mm chainstays and 45 mm clearance. Its published stack is shared between S and M, and again between L and XL, so it is effectively a two geometry frame with four seat tube lengths.

What riders say about Basso sizing

Independent feedback on Basso gravel fit is thin. We found no owner thread that puts a rider height next to a frame size, and nothing usable at all on the Volta or the Vega Gravel. What follows is only what the press has published.

The Palta III is taller and shorter than the bike it replaced. Reviewing the launch for Cyclist on 10 February 2026, Ewan Wilson reported the stack raised by 5 mm and the seat tube shortened by 20 mm on the larger frames. The charts above agree: the L seat tube drops from 540 mm to 520 mm.

A size L reads as a 56 in road terms. Writing for BikeRadar on the same day, Jack Luke described his test bike as a 56 cm equivalent and its 590 mm stack as generous but not tall. That is the L row in the table above.

Tall testers land on XL, not L. Warren Rossiter, 188 cm, tested the previous Palta in XL for BikeRadar on 14 June 2023 and recorded 600 mm of stack with 402 mm of reach. He read the frame as 5 mm lower and 10 mm longer than a typical endurance road bike.

The stem you pick at checkout does real work. In the off-road.cc first ride on 10 February 2026, Liam Mercer traced a nervous front end on descents partly to the low bar and long stem of his test bike. He also pointed out that the stem is a purchase decision, not a workshop fix.

Between two sizes?

The usual rule holds. The smaller frame gives a lower front end, a shorter wheelbase and quicker steering, which suits racing and riders with a short torso. The larger frame gives more stability on loose descents and less strain over long days, which suits riders with a long torso and arms.

Two Basso specifics narrow the decision. First, the seatpost setback choice moves your saddle fore and aft independently of frame size, so a borderline reach can be solved without changing frames. Second, the cockpit is a chosen option rather than a fixed integrated bar, which means stem length is still a lever after purchase. If you need help reading the numbers, our guide to stem length covers how much a stem can realistically correct.

Keep the size change honest. A frame two sizes too small cannot be rescued with a 130 mm stem and 40 mm of spacers.

Shop Basso at Bikeroom

• Basso road, gravel and electric bikes for the full range in stock
• Basso bikes for the shorter brand selection
• Gravel bikes to compare the Palta against other gravel frames
• Pre-owned gravel bikes where earlier Palta generations usually appear

For Basso's road geometry, which uses different size labels, see our Basso road bike size guide. For a comparison with another Italian gravel range, the Wilier gravel size guide covers the same ground. If you are new to the category, start with our introductory guide to gravel bikes.

If you are weighing a Palta S against a Palta III S and cannot tell whether the 8 mm of reach will help or hurt, talk to our concierge.

Disclaimer: the size suggestions here are indicative and offered as general guidance, not as a fitting guarantee. Stack, reach, seat tube and chainstay figures are official Basso manufacturer data taken from the model pages on bassobikes.com, which do not state a model year for their charts. Rider height and inseam bands are estimated by Bikeroom, because Basso publishes none. Geometry can change between model years, so confirm against the exact bike you are buying.

Sources: Basso Palta III geometry; Basso Palta geometry; Basso Volta geometry; Basso Vega Gravel geometry, all read 21 September 2026; Cyclist, Basso Palta III first ride, 10 February 2026; BikeRadar, Basso Palta III, 10 February 2026; BikeRadar, Basso Palta Disc Ekar review, 14 June 2023; off-road.cc, Basso Palta III first ride, 10 February 2026.