Basso Astra

An all-round road bike from 2026, made in 7 sizes from 45 to 61. Fits tyres up to 35 mm.

Size

Stack 576 mmReach 380 mm

Geometry

Basso Astra geometry by frame size
Size
Fit
Stack (mm)How high the front sits	539	539	563	576	602	625	650
Reach (mm)How far forward the bars start	371	371	375	380	382	384	386
Stack ÷ reach Higher = more upright	1.45	1.45	1.50	1.51	1.58	1.63	1.69
Top tube (effective) (mm)Horizontal top-tube length	505	515	525	545	560	575	590
Seat tube angle Saddle position over the pedals	76°	75°	75°	74°	73.5°	73°	72.5°
Seat tube length (mm)Frame size reference	450	480	510	530	560	580	610
Head tube length (mm)Front-end height	125	125	150	162	180	204	228
Handling
Head tube angle Steeper = quicker steering	71.8°	71.8°	72°	72.3°	73.5°	73.5°	74°
Chainstay (mm)Shorter = snappier	404	404	404	404	406	410	410

Underlined values are calculated by BikeLens. A dash means the brand doesn't publish it.

Between race and comfort. A good fit for sportives, club rides and fast days out.

Size 53 is more upright than 83% of the 218 road frames we track.

The closest road frames from other ranges, against size 53 here.

Bikes with a similar fit, compared with size 53 of this bike
Bike	Size	Stack	Reach
Giant Contend AR 12026Stack −2 mm, reach same	M	−2 mm	same
Basso Venta R2026Stack −5 mm, reach +1 mm	53	−5 mm	+1 mm
Giant Defy Advanced 02026Stack +1 mm, reach +4 mm	ML	+1 mm	+4 mm
Kross VENTO DSC 5.02026Stack −2 mm, reach +4 mm	M	−2 mm	+4 mm
Bmc Roadmachine TWO2026Stack −6 mm, reach +3 mm	54	−6 mm	+3 mm
Grind Grit2026Stack −5 mm, reach −2 mm	M	−5 mm	−2 mm