2026 Ron's Bikes ALUMAX II Base

	XS	S	M	L	XL
Stack	560mm	575mm	590mm	606mm	622mm
Reach	388mm	395mm	400mm	410mm	422mm
Stack to Reach Ratio	1.44:1	1.46:1	1.48:1	1.48:1	1.47:1
Seat Tube Length, C-T	430mm	445mm	460mm	515mm	535mm
Top Tube Length, Effective/Horizontal Center	540mm	557mm	571mm	585mm	602mm
Top Tube Slope	16.2deg	15.9deg	15.7deg	11.4deg	10.7deg
Head Tube Angle	70.5deg	70.5deg	70.5deg	70.5deg	70.5deg
Seat Tube Angle	75deg	74.5deg	74deg	74deg	74deg
Head Tube Length	106mm	122mm	136mm	150mm	178mm
Bottom Bracket Drop	80mm	80mm	80mm	80mm	80mm
Bottom Bracket Height	284mm	284mm	284mm	284mm	284mm
Chainstay Length	435mm	435mm	435mm	435mm	435mm
Chainstay Length Horizontal	427.6mm	427.6mm	427.6mm	427.6mm	427.6mm
Front-Center	616mm	628mm	633mm	649mm	675mm
Front-Center Horizontal	611.4mm	623.4mm	627.4mm	644.4mm	661.4mm
Wheelbase	1039mm	1051mm	1055mm	1072mm	1089mm
Fork Offset/Rake	50mm	50mm	50mm	50mm	50mm
Fork Length (Axle-To-Crown)	413mm	413mm	413mm	413mm	413mm
Trail	75.9mm high	75.9mm high	75.9mm high	75.9mm high	75.9mm high
Mechanical Trail	71.5mm	71.5mm	71.5mm	71.5mm	71.5mm
Wheel Flop	23.9mm	23.9mm	23.9mm	23.9mm	23.9mm
Tire to Pedal Spindle	82mm 170 mm cranks	94mm 170 mm cranks	99mm 170 mm cranks	115mm 170 mm cranks	141mm 170 mm cranks
Pedal Spindle to Ground Clearance	114mm 170 mm cranks	114mm 170 mm cranks	114mm 170 mm cranks	114mm 170 mm cranks	114mm 170 mm cranks

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.

Category Trend

Source:https://ronsbikes.com/products/aluminus-maximus

Geometry