Compare: 2023 BMC Switzerland Kaius 01 One 47 vs 2026 TanTan Cycling (Seraph) Gr209 Base 46

Insights

Somewhat aggressive stack and reach vs trend of progressive gravel bikes

Design deviates from other sizes of BMC Switzerland Kaius

Somewhat aggressive stack and reach vs trend of all-road/gravel bikes

Stack	510mm	549.5mm +39.5mm
Reach	390mm	382mm -8mm
Stack to Reach Ratio	1.31:1	1.44:1
Seat Tube Length, C-T	428mm	460mm +32mm
Top Tube Length, Effective/Horizontal Center	546mm	540.4mm -5.6mm
Top Tube Slope	11.1deg	11.9deg +0.8deg
Head Tube Angle	71deg	71deg +0deg
Seat Tube Angle	73deg	73.9deg +0.9deg
Head Tube Length	85mm	80mm -5mm
Bottom Bracket Drop	80mm	80mm +0mm
Bottom Bracket Height	271mm	276mm +5mm
Chainstay Length	—	426mm
Chainstay Length Horizontal	420mm	418.4mm -1.6mm
Front-Center	596mm	604mm +8mm
Front-Center Horizontal	583mm	598.6mm +15.6mm
Wheelbase	1003mm	1017mm +14mm
Fork Offset/Rake	50mm	55mm +5mm
Fork Length (Axle-To-Crown)	387mm	—
Fork Length, Unknown	—	397mm
Trail	68mm high	64.4mm -3.6mm mid/neutral
Mechanical Trail	64.3mm	60.9mm -3.4mm
Wheel Flop	20.9mm	19.8mm -1.1mm
Standover Height	684mm	—
Tire to Pedal Spindle	75mm 170 mm cranks	88mm +13mm 160 mm cranks
Pedal Spindle to Ground Clearance	101mm 170 mm cranks	116mm +15mm 160 mm cranks

Wheel Size	700C/29 in 622 mm BSD	700C/29 in 622 mm BSD
Tire Width	40mm	45mm +5mm
Tire Width Max	44mm	—
Tire Outer Diameter	702mm	712mm +10mm
Bike Length with Tires	1705mm	1729mm +24mm
Crank Length	170mm	160mm -10mm
Handlebar Width	—	360mm
Stem Length	80mm	80mm +0mm
Stem Angle	-12.5deg	—
Suspension Type	Rigid, non-suspension corrected	Rigid, suspension corrected
Bar Type	Drop Bar	Drop Bar
Frame Material	Carbon/Composite	Carbon/Composite
Fork Material	Carbon/Composite	Carbon/Composite
Brake Type	Disc	Disc