Jamis Helix A2

Name: Jamis Helix A2
Brand: Jamis

2019 MountainCross-country Manufacturer page

Last known price: $499

Prices shown first for United States
Fork travel: 100 mm
Wheels: 27.5″
Drivetrain: 3 × 7 24–42t / 14–34t
Gear range: 425%
Weight: 14.51 kg 32.0 lb · Reference configuration not specified
Frame: Aluminum
Brakes: Mechanical disc

Sizes

Size guide

The manufacturer did not publish rider heights for these sizes.

Components

13 of 19 identified

Parts found in a manufacturer catalog show their brand, model and key numbers, and the steps show how precisely they are identified: brand, series, model, or the exact product. The info button has every detail and the text the manufacturer published.

Frame and fork

1 part

Frame

6061 aluminum main tubes, over-sized seat tube, zero-stack head tube, over-sized stays, replaceable derailleur hanger Not identified

Suspension

1 part

Fork
- SR Suntour XCE28

Drivetrain

7 parts

Bottom bracket

Sealed cartridge Not identified
Cassette
- Shimano Tourney TZ MF-TZ500 14–34t
MF-TZ500
Chain
- KMC
Crankset

Forged alloy, 42/34/24T Not identified
Front derailleur
- Shimano Tourney FD-TY500
FD-TY500
Rear derailleur
- Shimano Tourney RD-TY300 7 speeds
RD-TY300
Shifters
- Shimano ST-EF41
ST-EF41

Brakes

1 part

Brakes
- Tektro MD-M280
MD-M280

Wheels and tires

2 parts

Cockpit and contact points

7 parts

Grips

Kraton Not identified
Handlebar
- Jamis
Headset

Zero-stack internal cup threadless, 15mm cone spacer Not identified
Pedals

MTB platform, hi-impact resin Not identified
Saddle
- Jamis
Seatpost
- Jamis
Stem
- Jamis

Sizes and geometry

3 sizes Open in the geometry plotter

Complete rider-height ranges are not published for these sizes. You can still explore the geometry below.

Size 16"

Table

Geometry diagram unavailable

The drawing needs reach and stack, which the manufacturer did not publish. Available facts remain in the table.

Size

Complete manufacturer geometry table 3 published sizes

Complete manufacturer geometry by size
Measurement
Top tube lengthmm	540	560	580
Seat tube lengthmm	356	406	457
Head tube lengthmm	105	110	120
Head tube angle	70°	70°	70°
Seat tube angle	72.5°	72.5°	72.5°
Chainstay lengthmm	435	435	435
Wheelbasemm	1029	1050	1070
Front centermm	598	619	639
Bottom bracket dropmm	46	46	46
Bottom bracket heightmm	309	309	309
Standover heightmm	668	704	731

Not published by the manufacturer: Reach, Stack, Fork rake, Trail, Stack/reach ratio, Front travel, Rear travel, Crank length, Handlebar width, Stem length, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Aluminum
Fork material: Aluminum
Bicycle weight: 14.51 kg

32.0 lb

Suspension

Suspension configuration: Hardtail
Front travel: 100 mm

Drivetrain

Derived by Bikelake

Front chainrings: 3
Smallest chainring: 24
Largest chainring: 42
Rear sprockets: 7
Smallest sprocket: 14
Largest sprocket: 34
Lowest gear: 19.4 in
Highest gear: 82.5 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Mechanical disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Fork spring: Coil
Tire width: 2.25″
Wheel material: Aluminum
Wheel size: 27.5″

Technical analysis

3 measures

How these figures sit among bicycles of the same class and model year. Context, not a ranking.

Front travel

100 mm

This value is within the central range for this class.

Cohort: Mountain / Cross-country Model year: 2019
Sample: 850 bicycles with this information
Coverage: 96.0% of the class

Lowest gear

19.4 gear inches

This value is within the central range for this class.

Cohort: Mountain / Cross-country Model year: 2019
Sample: 799 bicycles with this information
Coverage: 90.2% of the class

Highest gear

82.5 gear inches

This value is below the central range for this class.

Cohort: Mountain / Cross-country Model year: 2019
Sample: 799 bicycles with this information
Coverage: 90.2% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 7.4 km/h
Highest gear: 31.6 km/h

Total gear range 425%

Technical details and class reference

These speeds describe the gearing at the selected cadence, not how fast you can ride.
Calculated from published gear-inch values and their wheel-size assumptions.
These gearing values describe the bicycle, not a selected frame size.
A 100% range means one ratio; 500% means the highest ratio is five times the lowest.
For e-bikes, motor assistance cutoff is not represented.

Gear-inch range

Lower gear-inch values travel less distance per pedal revolution; higher values travel farther.

This bicycle: 19.4–82.5 gear inches
Class reference (p10–p90): 16.8–105.0 gear inches; The band runs from p10 for the lowest gear to p90 for the highest gear.

Cohort: Mountain / Cross-country Model year: 2019
Lowest gear: 799 bicycles with this information, 90.2% of the class
Highest gear: 799 bicycles with this information, 90.2% of the class

Lineup changes

The published facts that differ across this family's builds and from the same model a year earlier. Missing information never counts as zero.

Differences across 2019 builds

Differences across 2019 builds
Specification	This bicycle Jamis Helix A2	Jamis Helix A1
Frame
Bicycle weight	14.51 kg	14.17 kg
Drivetrain
Rear sprockets	7	8
Smallest sprocket	14	12
Largest sprocket	34	32
Lowest gear	19.4 in	20.6 in
Highest gear	82.5 in	96.3 in
Brakes
Brake type	Mechanical disc	Hydraulic disc