2025 Gravity Zilla AL PRO

Design
Drop Bar, Rigid, non-suspension corrected
Frame
Aluminum
Fork
Carbon/Composite
Features
Disc brake
Average stack and reachvs category
Average stack and reachvs category
Average stack and reachvs category
Average stack and reachvs category
Somewhat upright stack and reachvs category
Very upright stack and reachvs category
Very upright stack and reachvs category

Geometry

46cm
49cm
52cm
54cm
56cm
58cm
61cm
Stack
550mm
561.4mm
577.5mm
593.6mm
614.6mm
633.6mm
654.7mm
Reach
371.4mm
374.3mm
378.8mm
382.5mm
381.9mm
376.8mm
383.7mm
Stack to Reach Ratio
1.48:1
1.5:1
1.52:1
1.55:1
1.61:1
1.68:1
1.71:1
Seat Tube Length, C-T
460mm
490mm
520mm
540mm
560mm
580mm
610mm
Top Tube Length, Effective/Horizontal Center
526mm
530mm
545mm
555mm
570mm
575mm
590mm
Head Tube Angle
70deg
70.5deg
71deg
71.5deg
72deg
72deg
72.5deg
Seat Tube Angle
74.5deg
74.5deg
74deg
73.5deg
73deg
73deg
72.5deg
Head Tube Length
110mm
120mm
135mm
150mm
170mm
190mm
210mm
Bottom Bracket Drop
65mm
65mm
65mm
65mm
65mm
65mm
65mm
Bottom Bracket Height
296mm
296mm
296mm
296mm
296mm
296mm
296mm
Chainstay Length
440mm
440mm
440mm
440mm
440mm
440mm
440mm
Chainstay Length Horizontal
435.2mm
435.2mm
435.2mm
435.2mm
435.2mm
435.2mm
435.2mm
Front-Center
599.4mm
601.4mm
606.3mm
610.3mm
611.3mm
612.3mm
620.2mm
Front-Center Horizontal
595.8mm
597.8mm
602.8mm
606.8mm
607.8mm
608.8mm
616.8mm
Wheelbase
1031mm
1033mm
1038mm
1042mm
1043mm
1044mm
1052mm
Fork Offset/Rake
45mm
45mm
45mm
45mm
45mm
45mm
45mm
Fork Length, Unknown
405mm
405mm
405mm
405mm
405mm
405mm
405mm
Trail
83.5mm
very high
80.1mm
very high
76.7mm
high
73.3mm
high
70mm
high
70mm
high
66.6mm
high
Mechanical Trail
78.5mm
75.5mm
72.5mm
69.6mm
66.6mm
66.6mm
63.6mm
Wheel Flop
26.8mm
25.2mm
23.6mm
22.1mm
20.6mm
20.6mm
19.1mm
Standover Height
727.7mm
760.7mm
782.1mm
801.9mm
821.9mm
842mm
868.7mm
Tire to Pedal Spindle
68.4mm
170 mm cranks
70.4mm
170 mm cranks
72.8mm
172.5 mm cranks
76.8mm
172.5 mm cranks
75.3mm
175 mm cranks
76.3mm
175 mm cranks
84.2mm
175 mm cranks
Pedal Spindle to Ground Clearance
126mm
170 mm cranks
126mm
170 mm cranks
123.5mm
172.5 mm cranks
123.5mm
172.5 mm cranks
121mm
175 mm cranks
121mm
175 mm cranks
121mm
175 mm cranks

AL PRO Build

46cm
49cm
52cm
54cm
56cm
58cm
61cm
Wheel Size
700C/29 in
622 mm BSD
700C/29 in
622 mm BSD
700C/29 in
622 mm BSD
700C/29 in
622 mm BSD
700C/29 in
622 mm BSD
700C/29 in
622 mm BSD
700C/29 in
622 mm BSD
Tire Width
50mm
50mm
50mm
50mm
50mm
50mm
50mm
Tire Outer Diameter
722mm
722mm
722mm
722mm
722mm
722mm
722mm
Bike Length with Tires
1753mm
1755mm
1760mm
1764mm
1765mm
1766mm
1774mm
Crank Length
170mm
170mm
172.5mm
172.5mm
175mm
175mm
175mm
Handlebar Width
400mm
400mm
420mm
420mm
440mm
440mm
440mm
Stem Length
70mm
70mm
80mm
80mm
90mm
90mm
90mm
Stem Angle
-6deg
-6deg
-6deg
-6deg
-6deg
-6deg
-6deg

Published Sizing Recommendations

Height
5 ft 0 in
to
5 ft 3 in
5 ft 3 in
to
5 ft 5 in
5 ft 6 in
to
5 ft 8 in
5 ft 8 in
to
5 ft 10 in
5 ft 10 in
to
6 ft 0 in
6 ft 0 in
to
6 ft 2 in
6 ft 2 in
to
6 ft 4 in

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
All-road/Gravel
Source:https://www.bikesdirect.com/products/gravity/bike-packing-bikes/zilla-al-pro-bikepacking-gravel-bikes-adventure-road.htm