Sizing a Basso road bike
Basso builds its carbon road range around three current models: the Diamante, the lightweight climbing focused race bike; the Astra, the taller and more comfortable endurance all rounder; and the Venta R, the approachable performance all rounder. The single most useful thing to know is that these three share almost the same reach at a given size, but the Diamante sits lower at the front while the Astra and Venta R stack up taller, so the model you choose changes how upright you sit more than which size you pick.
Browse the range: all Basso bikes at Bikeroom.
Please note. These sizes are indicative, a starting point rather than a guarantee. Height and leg length give a strong first read, but riding style, flexibility and reach preference all matter. When you are close to a boundary, talk to us before you buy.
Quick size finder
Find your height, check your leg length, then read across to the suggested frame size for each model. Basso publishes seven sizes across the range, labelled by seat tube length in centimetres.
| Rider height | Leg length (inseam) | Diamante (race) | Astra (endurance) | Venta R (all rounder) |
|---|---|---|---|---|
| 150 to 162 cm | 68 to 74 cm | 45 | 45 | 42 |
| 162 to 169 cm | 73 to 78 cm | 48 | 48 | 48 |
| 168 to 175 cm | 77 to 82 cm | 51 | 51 | 51 |
| 174 to 181 cm | 81 to 86 cm | 53 | 53 | 53 |
| 180 to 186 cm | 85 to 89 cm | 56 | 56 | 56 |
| 185 to 191 cm | 88 to 92 cm | 58 | 58 | 58 |
| 190 to 198 cm | 91 to 96 cm | 61 | 61 | 61 |
How to measure yourself
Height. Stand barefoot with your heels, back and head against a wall, looking straight ahead. Mark the wall level with the top of your head and measure from the floor to the mark.
Leg length (inseam). Barefoot, feet about 15 cm apart, press a book up into your crotch as if it were a saddle and hold it level against the wall. Measure from the floor to the top edge of the book. This number drives saddle height and is a reliable cross check when your height sits between two sizes.
Basso Diamante (race and climbing)
The Diamante is Basso's flagship race bike, a light and lively climber with rounded tube shapes and the lowest front end of the three. Reviewers describe it as stiff, reactive and a genuinely quick climber that stays stable and predictable when the road points down. Available in seven sizes from 45 to 61. Stack and reach below are official Basso figures, rounded to the nearest millimetre.
| Frame size | 45 | 48 | 51 | 53 | 56 | 58 | 61 |
|---|---|---|---|---|---|---|---|
| Stack (mm) | 522 | 522 | 546 | 559 | 584 | 608 | 632 |
| Reach (mm) | 375 | 375 | 379 | 385 | 387 | 389 | 391 |
| Rider height | 156 to 163 cm | 162 to 169 cm | 168 to 175 cm | 174 to 181 cm | 180 to 186 cm | 185 to 191 cm | 190 to 198 cm |
Fit character: racy but refined, a low and stable climbing position that rewards riders who want speed first.
Basso Astra (endurance all road)
The Astra keeps Basso's racing DNA but softens the edges, with a noticeably taller stack, slightly shorter reach and clearance for tyres up to 35 mm. That taller front makes for a more upright, comfortable position that suits long days and lighter unpaved roads. Available in seven sizes from 45 to 61. Figures are official Basso data, rounded to the nearest millimetre.
| Frame size | 45 | 48 | 51 | 53 | 56 | 58 | 61 |
|---|---|---|---|---|---|---|---|
| Stack (mm) | 539 | 539 | 563 | 576 | 602 | 625 | 650 |
| Reach (mm) | 371 | 371 | 375 | 380 | 382 | 384 | 386 |
| Rider height | 156 to 163 cm | 162 to 169 cm | 168 to 175 cm | 174 to 181 cm | 180 to 186 cm | 185 to 191 cm | 190 to 198 cm |
Fit character: upright and comfort focused, an endurance position built for long rides and mixed surfaces.
Basso Venta R (performance all rounder)
The Venta R is Basso's accessible performance road bike, with aero shaped tubes, tyre clearance up to 35 mm and an all rounder geometry pitched between the racy Diamante and the endurance Astra. It runs seven sizes from 42 to 61, so it reaches a little smaller than the other two and suits shorter riders well. Figures are official Basso data, rounded to the nearest millimetre.
| Frame size | 42 | 48 | 51 | 53 | 56 | 58 | 61 |
|---|---|---|---|---|---|---|---|
| Stack (mm) | 534 | 534 | 559 | 571 | 580 | 621 | 645 |
| Reach (mm) | 372 | 372 | 375 | 381 | 383 | 385 | 387 |
| Rider height | 150 to 162 cm | 162 to 169 cm | 168 to 175 cm | 174 to 181 cm | 180 to 186 cm | 185 to 191 cm | 190 to 198 cm |
Fit character: an approachable, balanced all rounder position with a modern, easy going front end.
What Basso riders find
Owners and reviewers consistently praise Basso's road bikes for a planted, confident feel that never gets nervous, along with build quality and finish that stand out in the category. On the Diamante, riders highlight how efficiently it climbs and how composed it stays at speed, with a firm but not punishing ride. Astra and Venta R owners point to the taller front and wider tyre clearance as the reason those bikes stay comfortable over long distances and rougher tarmac. Across the range, most riders find Basso true to size, so the frame you would normally ride from other brands is a sound starting point here.
Between two sizes?
If your height lands on a boundary, let your leg length and riding style break the tie. A longer inseam and a preference for a stretched, lower position point to the smaller size with a longer stem, while a shorter inseam or a wish for a more upright, relaxed cockpit favour the larger size. Remember the model matters too: if you want the Diamante's speed but a slightly taller front, the Astra or Venta R deliver that without changing your size. When in doubt, size down on the Diamante for a sharper race position and consider the Astra or Venta R if comfort is the priority.
Shop Basso road
- All Basso bikes at Bikeroom, including the Diamante, Astra and Venta R
Still not sure which Basso or which size is right for you? We fit riders to bikes every day and we are happy to help. Talk to our concierge.
These sizes are guidance, not a fitting guarantee. Stack and reach are official Basso figures rounded to the nearest millimetre. Recommended height and leg length ranges are indicative Bikeroom bands, because Basso does not publish rider height ranges per size. Note also that the Venta R shows a large step in stack between its 56 and 58 sizes in Basso's published table. Always confirm the numbers against the exact bike and model year before you buy.
