2020 Author Aura XR4 Base

	500	520	540	560	580
Stack	548mm	568mm	586mm	606mm	627mm
Reach	378mm	382mm	386mm	395mm	397mm
Stack to Reach Ratio	1.45:1	1.49:1	1.52:1	1.53:1	1.58:1
Seat Tube Length, C-T	500mm	520mm	540mm	560mm	580mm
Seat Tube Length, C-C	460mm	480mm	500mm	520mm	540mm
Top Tube Length, Effective/Horizontal HT Top	530mm	545mm	560mm	580mm	595mm
Top Tube Length, Actual C-C	518mm	532mm	546mm	563mm	576mm
Top Tube Slope	7.4deg	7.4deg	7.2deg	7.2deg	7.4deg
Head Tube Angle	70.5deg	71deg	71deg	71.5deg	72deg
Seat Tube Angle	74.5deg	74deg	73.5deg	73deg	72.5deg
Head Tube Length	120mm	140mm	160mm	180mm	200mm
Bottom Bracket Drop	70mm	70mm	69mm	68mm	68mm
Bottom Bracket Height	276mm	276mm	277mm	278mm	278mm
Chainstay Length	425mm	425mm	425mm	425mm	425mm
Chainstay Length Horizontal	419.2mm	419.2mm	419.4mm	419.5mm	419.5mm
Front-Center	598.9mm	604.9mm	615.5mm	626.2mm	630.2mm
Front-Center Horizontal	594.8mm	600.8mm	611.6mm	622.5mm	626.5mm
Wheelbase	1014mm	1020mm	1031mm	1042mm	1046mm
Fork Offset/Rake	68mm	68mm	68mm	68mm	68mm
Fork Length (Axle-To-Crown)	400mm	400mm	400mm	400mm	400mm
Trail	50.4mm mid/neutral	47.2mm mid/neutral	47.2mm mid/neutral	44.1mm low	40.9mm low
Mechanical Trail	47.5mm	44.7mm	44.7mm	41.8mm	38.9mm
Wheel Flop	15.9mm	14.5mm	14.5mm	13.3mm	12mm
Tire to Pedal Spindle	80.9mm 172 mm cranks	86.9mm 172 mm cranks	94.5mm 175 mm cranks	105.2mm 175 mm cranks	109.2mm 175 mm cranks
Pedal Spindle to Ground Clearance	104mm 172 mm cranks	104mm 172 mm cranks	102mm 175 mm cranks	103mm 175 mm cranks	103mm 175 mm cranks