2026 Polygon Helios A9 Base

	151-161	154-164	162-170	168-176	174-181	180-187
Stack	503mm	511mm	523mm	533mm	551mm	571mm
Reach	375mm	385mm	390mm	400mm	405mm	420mm
Stack to Reach Ratio	1.34:1	1.33:1	1.34:1	1.33:1	1.36:1	1.36:1
Seat Tube Length, C-T	420mm	457mm	489mm	499mm	518mm	536mm
Seat Tube Length, Effective Unknown	74.7mm	74.3mm	74mm	73.7mm	73.3mm	73mm
Top Tube Length, Effective/Horizontal Center	513mm	529mm	540mm	556mm	570mm	598mm
Top Tube Slope	11.4deg	8deg	5.8deg	5.7deg	5.7deg	5.8deg
Head Tube Angle	71.3deg	71.5deg	72.3deg	72.5deg	72.8deg	73deg
Seat Tube Angle	74.7deg	74.3deg	74deg	73.7deg	73.3deg	73deg
Head Tube Length	100mm	110mm	120mm	130mm	150mm	170mm
Bottom Bracket Drop	78mm	75.5mm	73mm	73mm	71.5mm	71.5mm
Bottom Bracket Height	261mm	263.5mm	266mm	266mm	267.5mm	267.5mm
Chainstay Length	410mm	410mm	410mm	410mm	410mm	410mm
Chainstay Length Horizontal	402.5mm	403mm	403.5mm	403.5mm	403.7mm	403.7mm
Front-Center	578.8mm	589.9mm	586.1mm	597mm	605.5mm	624.4mm
Front-Center Horizontal	573.5mm	585mm	581.6mm	592.6mm	601.3mm	620.3mm
Wheelbase	976mm	988mm	985mm	996mm	1005mm	1024mm
Fork Offset/Rake	51.8mm	51.5mm	45.7mm	45.3mm	45.7mm	45.5mm
Trail	60.1mm mid/neutral	59.1mm mid/neutral	60.3mm mid/neutral	59.4mm mid/neutral	57.1mm mid/neutral	56.1mm mid/neutral
Mechanical Trail	56.9mm	56.1mm	57.4mm	56.6mm	54.5mm	53.6mm
Wheel Flop	18.3mm	17.8mm	17.5mm	17mm	16.1mm	15.7mm
Standover Height	685mm	720mm	752mm	761mm	780mm	799mm
Tire to Pedal Spindle	69.8mm 170 mm cranks	80.9mm 170 mm cranks	77.1mm 170 mm cranks	88mm 170 mm cranks	96.5mm 170 mm cranks	115.4mm 170 mm cranks
Pedal Spindle to Ground Clearance	91mm 170 mm cranks	93.5mm 170 mm cranks	96mm 170 mm cranks	96mm 170 mm cranks	97.5mm 170 mm cranks	97.5mm 170 mm cranks

	151-161	154-164	162-170	168-176	174-181	180-187
Wheel Size	700C/29 in 622 mm BSD	700C/29 in 622 mm BSD	700C/29 in 622 mm BSD	700C/29 in 622 mm BSD	700C/29 in 622 mm BSD	700C/29 in 622 mm BSD
Tire Width	28mm	28mm	28mm	28mm	28mm	28mm
Tire Width Max	34mm	34mm	34mm	34mm	34mm	34mm
Tire Outer Diameter	678mm	678mm	678mm	678mm	678mm	678mm
Bike Length with Tires	1654mm	1666mm	1663mm	1674mm	1683mm	1702mm

Published Sizing Recommendations

Height

151 cm

161 cm

154 cm

164 cm

162 cm

170 cm

168 cm

176 cm

174 cm

181 cm

180 cm

187 cm

Very Upright

Somewhat Upright

Average

Somewhat Aggressive

Very Aggressive

The Bike Insights Upright/Aggressive scale is based on analysis of a bike’s proportions relative to similar sized bikes in the same category.

Learn more about the Upright/Aggressive Scale

Category Trend

Performance Road

Source:https://www.polygonbikes.com/us/helios-a9-di2-powermeter/

Suggest Bike Edit

2026 Polygon Helios A9 Base

Geometry

Base Build

Published Sizing Recommendations

Stack and Reach vs. Category Trend