2018 Chumba Cycles Ursa Major Base

Design
Flat Bar, Rigid, suspension corrected
Frame
Titanium
Features
Disc brake
Average stack and reachvs category
Average stack and reachvs category
Average stack and reachvs category
Somewhat upright stack and reachvs category

Geometry

SM
MD
LG
XL
Stack
607mm
614mm
626mm
638mm
Reach
406mm
424mm
438mm
452mm
Stack to Reach Ratio
1.5:1
1.45:1
1.43:1
1.41:1
Seat Tube Length, C-T
387.3mm
438.2mm
489mm
539.8mm
Top Tube Length, Effective/Horizontal Center
595mm
615mm
635mm
650mm
Top Tube Slope
24.5deg
19.4deg
15.3deg
11.3deg
Head Tube Angle
69deg
69deg
69deg
69.5deg
Seat Tube Angle
72.75deg
72.75deg
72.75deg
72.75deg
Head Tube Length
128mm
135mm
148mm
158mm
Bottom Bracket Drop
50mm
50mm
50mm
50mm
Bottom Bracket Height
356.5mm
356.5mm
356.5mm
356.5mm
Chainstay Length
439mm
439mm
439mm
439mm
Chainstay Length Max
459mm
459mm
459mm
459mm
Chainstay Length Horizontal
436.1mm
436.1mm
436.1mm
436.1mm
Chainstay Length Horizontal Max
456.3mm
456.3mm
456.3mm
456.3mm
Front-Center
671.7mm
692.7mm
711.6mm
723.6mm
Front-Center Horizontal
669.9mm
690.9mm
709.9mm
721.9mm
Wheelbase
1106mm
1127mm
1146mm
1158mm
Wheelbase Max
1126mm
1146mm
1166mm
1178mm
Fork Offset/Rake
46.7mm
47mm
47.4mm
46.9mm
Fork Length (Axle-To-Crown)
483mm
483mm
483mm
483mm
Trail
106mm
very high
105.7mm
very high
105.3mm
very high
102mm
very high
Mechanical Trail
99mm
98.7mm
98.3mm
95.5mm
Wheel Flop
35.5mm
35.4mm
35.2mm
33.5mm
Standover Height
660.4mm
692.2mm
717.6mm
749.3mm
Tire to Pedal Spindle
95.2mm
170 mm cranks
116.2mm
170 mm cranks
135.1mm
170 mm cranks
147.1mm
170 mm cranks
Pedal Spindle to Ground Clearance
186.5mm
170 mm cranks
186.5mm
170 mm cranks
186.5mm
170 mm cranks
186.5mm
170 mm cranks

Base Build

SM
MD
LG
XL
Wheel Size
26 in
559 mm BSD
26 in
559 mm BSD
26 in
559 mm BSD
26 in
559 mm BSD
Tire Width
5in
5in
5in
5in
Tire Outer Diameter
813mm
813mm
813mm
813mm
Bike Length with Tires
1919mm
1940mm
1959mm
1971mm

Stack and Reach vs. Category Trend

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
Rigid Fatbike
Source:https://www.chumbausa.com/ursa-major-titanium-fatbike/