2018 Soma Fabrications Riff Base

Design
Flat Bar, Hardtail (Front suspension)
Frame
Steel
Suspension
120mm fork travel
Features
Disc brake
Somewhat aggressive stack and reachvs category
Suspension sag unknown
Geometry may mis-represent actual riding geometry
Somewhat aggressive stack and reachvs category
Suspension sag unknown
Geometry may mis-represent actual riding geometry
Somewhat aggressive stack and reachvs category
Suspension sag unknown
Geometry may mis-represent actual riding geometry
Somewhat aggressive stack and reachvs category
Suspension sag unknown
Geometry may mis-represent actual riding geometry

Geometry

XS
SM
MD
LG
Stack
579mm
589mm
593mm
598mm
Reach
386mm
403mm
426mm
454mm
Stack to Reach Ratio
1.5:1
1.46:1
1.39:1
1.32:1
Seat Tube Length, C-T
380mm
410mm
440mm
470mm
Top Tube Length, Effective/Horizontal Center
560mm
585mm
610mm
640mm
Top Tube Slope
23.5deg
20.6deg
17.3deg
14.1deg
Head Tube Angle
68deg
68deg
68deg
68deg
Seat Tube Angle
73.5deg
73deg
73deg
73deg
Head Tube Length
100mm
110mm
115mm
120mm
Bottom Bracket Drop
44mm
44mm
44mm
44mm
Bottom Bracket Height
301.3mm
301.3mm
301.3mm
301.3mm
Chainstay Length
427mm
427mm
427mm
427mm
Chainstay Length Horizontal
424.7mm
424.7mm
424.7mm
424.7mm
Front-Center
653mm
674mm
699mm
729mm
Front-Center Horizontal
651.3mm
672.3mm
697.3mm
727.3mm
Wheelbase
1076mm
1097mm
1122mm
1152mm
Fork Offset/Rake
45.5mm
45.5mm
45.9mm
45.8mm
Fork Length (Axle-To-Crown)
484mm
484mm
484mm
484mm
Trail
90.4mm
very high
90.5mm
very high
90.1mm
very high
90.1mm
very high
Mechanical Trail
83.8mm
83.9mm
83.5mm
83.5mm
Wheel Flop
31.4mm
31.4mm
31.3mm
31.3mm
Standover Height
749mm
768mm
784mm
801mm
Tire to Pedal Spindle
137.7mm
170 mm cranks
158.7mm
170 mm cranks
183.7mm
170 mm cranks
213.7mm
170 mm cranks
Pedal Spindle to Ground Clearance
131.3mm
170 mm cranks
131.3mm
170 mm cranks
131.3mm
170 mm cranks
131.3mm
170 mm cranks

Base Build

XS
SM
MD
LG
Wheel Size
650B/27.5 in
584 mm BSD
650B/27.5 in
584 mm BSD
650B/27.5 in
584 mm BSD
650B/27.5 in
584 mm BSD
Tire Width
2.1in
2.1in
2.1in
2.1in
Tire Width Max
2.8in
2.8in
2.8in
2.8in
Tire Outer Diameter
690.7mm
690.7mm
690.7mm
690.7mm
Bike Length with Tires
1766.7mm
1787.7mm
1812.7mm
1842.7mm

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
Hardtail Trail MTB
Source:https://www.somafab.com/archives/product/riff-27-5-hardtail-frame