2025 Dartmoor Bikes Thunderbird FR Pro

	Medium	Large
Stack	619mm	619mm
Reach	445mm	470mm
Stack to Reach Ratio	1.39:1	1.32:1
Seat Tube Length, C-T	430mm	450mm
Top Tube Length, Effective/Horizontal HT Top	540mm	565mm
Head Tube Angle	65deg	65deg
Effective Seat Tube Angle, ETT HT Top	81deg	81deg
Head Tube Length	110mm	110mm
Bottom Bracket Drop	12mm	12mm
Bottom Bracket Height	345mm	345mm
Chainstay Length	430mm	430mm
Chainstay Length Horizontal	429.8mm	429.8mm
Front-Center	776.3mm	801.3mm
Front-Center Horizontal	776.2mm	801.2mm
Wheelbase	1206mm	1231mm
Fork Offset/Rake	44mm	44mm
Fork Length (Axle-To-Crown)	566mm	566mm
Trail	117.9mm very high	117.9mm very high
Mechanical Trail	106.9mm	106.9mm
Wheel Flop	45.2mm	45.2mm
Standover Height	795mm	795mm
Tire to Pedal Spindle	249.3mm 170 mm cranks	274.3mm 170 mm cranks
Pedal Spindle to Ground Clearance	175mm 170 mm cranks	175mm 170 mm cranks

Published Sizing Recommendations

Height

167 cm

182 cm

183 cm

197 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.

Category Trend

Source:https://dartmoor-bikes.com/hardware/freeride/thunderbird-fr-pro-2025