Rear tire: 27.5×2.35.
Velopedia Bicycle Archive
2021 Jamis Hudson Disc
Original specifications: Shimano Altus RDM-2000 drivetrain · 27.5 wheels · geometry for 3 published sizes.
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At a glance
Archive #900001721- Model year
- 2021
- Category
- Hybrid
- Original MSRP
- $839.95
- Sizes
- 17″, 19″, 21″
- Colors
- Ink, Rhino
- Geometry
- 3 manufacturer sizes
- In this record
- 21 specifications · 3 archived images · original MSRP · geometry
Original buildAluminum · Shimano Altus RDM-2000 · 27.5
Frameset
| Frame Construction | 6061 TIG-welded aluminum, Hudson laid-back design with low ride height, alloy kickstand |
|---|---|
| Frame Material | Aluminum |
| Fork | Hi-tensile unicrown with radiused blades |
Drivetrain
| Component Group | Shimano Altus RDM-2000 |
|---|---|
| Shifters | Shimano Altus SL-M2010-9R, 9-Speed |
| Rear Derailleur | Shimano Altus RDM-2000 |
| Crankset | Forged alloy crank, single 40T chainring, 170mm, with full length chainguard |
| Bottom Bracket | Sealed cartridge, 68 x 122.5mm |
| Cassette | Sun Race CSM90-9AW 11-36T |
| Chain | KMC Z9 |
| Pedals | Comfort platform with TPE non-slip insert |
Brakes
| Brakes | Tektro HD-M275 hydraulic disc brake |
|---|
Cockpit & Contact Points
| Headset | Internal cup, threaded, 1 1/8” |
|---|---|
| Handlebar | Comfort hi-rise, alloy 25.4 x 80mm rise x 15 ̊ sweep x 640mm |
| Stem | Jamis alloy, 180mm quill x 80mm extension |
| Saddle | Jamis Comfort with memory foam, synthetic suede top, burnished side panels and bumper springs |
| Seatpost | Alloy micro-adjust, 31.6 x 300mm, with alloy QR clamp |
Wheels & Tires
| Wheels | Alex DC25 alloy double-wall rims, 36H, Formula alloy QR hubs, 14g black stainless steel spokes |
|---|---|
| Front Tire | CST Metropolitan Palm Bay, 27.5 x 2.35 |
| Rear Tire | CST Metropolitan Palm Bay, 27.5 x 2.35 |
| Wheel Size | 27.5 |
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Geometry
Frame measurements by size.
Reference drawing
Select an available measurement to locate it on the frame.
All geometry measurements3 sizes · 9 measurements
| Measurement | 17″ | 19″ | 21″ |
|---|---|---|---|
| Effective top tube | 597 mm | 627 mm | 648 mm |
| Head tube | 160 mm | 180 mm | 200 mm |
| Head-tube angle | 68° | 68° | 68° |
| Seat-tube angle | 67° | 67° | 67° |
| Chainstay / rear center | 485 mm | 485 mm | 485 mm |
| Wheelbase | 1111 mm | 1141 mm | 1162 mm |
| Bottom-bracket height | 286 mm | 286 mm | 286 mm |
| Standover height | 761 mm | 797 mm | 824 mm |
| Fork offset / rake | 55 mm | 55 mm | 55 mm |
Dimensions as recorded.
Gearing
Lower gears help on climbs. Higher gears suit higher speeds.
RPM = pedal turns per minute.
How it works
Ratio = front teeth ÷ rear teeth. Hub gears also include the hub’s internal ratio. A 400% range means the highest ratio is four times the lowest.
Speeds are estimates from tire size and pedal cadence. Actual speeds vary.
Try your current gearingChanged tires or gears? Calculate your setup.
Your changes apply to this calculation. The archived build stays unchanged.
Gearing results
| Measure | Original | Your setup |
|---|---|---|
| Lowest ratio | — | — |
| Highest ratio | — | — |
| Total range | — | — |
| Lowest-gear speed | — | — |
| Highest-gear speed | — | — |
Speeds are estimates. These calculations do not establish component compatibility or available tire clearance.
Parts & serviceability
Find replacement parts
31.6 x 300mm, with alloy QR clamp

FSA Gossamer SB20 Seatpost Black, 31.6mm, 350mm
Replacement option
27.5 x 2.35
More parts (3)Fewer parts
9-Speed
Based on the original build. Check fit and installed parts before ordering. Affiliate links may earn Velopedia a commission. As an Amazon Associate I earn from qualifying purchases.
Service essentialsQuick reference before buying parts
Archived specifications for reference. Check the fitted parts before ordering.
- Front tire
- CST Metropolitan Palm Bay, 27.5 x 2.35Check: Verify the fitted tire’s size marking and rim type.
- Rear tire
- CST Metropolitan Palm Bay, 27.5 x 2.35Check: Verify the rear size; it may differ from the front.
- Drivetrain
- 9-speedCheck: Match the installed drivetrain family, not just its speed count.
- Seatpost diameter
- 31.6 mmCheck: Read the post’s diameter marking; seat-clamp size differs.
- Bottom bracket / shell
- Sealed cartridge, 68 x 122.5mmCheck: Verify shell type and width, crank interface, and spindle length or spacers.
Bike-specific inspection checklist 19 checks based on 5 archived component groups Open checklistClose checklist
This checklist uses the archived equipment for this bike. It cannot confirm the condition, service history or later component changes of the example in front of you.
Identity and fit
Follow the full used-bike inspection order →Archived: 2021 Jamis Hudson Disc · Hybrid · Published sizes: 17″, 19″, 21″
Frame and fork
Inspect the frame and fork →Archived: Frame: 6061 TIG-welded aluminum, Hudson laid-back design with low ride height, alloy kickstand · Fork: Hi-tensile unicrown with radiused blades
Drivetrain
Check drivetrain wear →Archived: Group: Shimano Altus RDM-2000 · Shifters: Shimano Altus SL-M2010-9R, 9-Speed · Rear derailleur: Shimano Altus RDM-2000 · Crankset: Forged alloy crank, single 40T chainring, 170mm, with full length chainguard · Bottom bracket: Sealed cartridge, 68 x 122.5mm · Cassette: Sun Race CSM90-9AW 11-36T · Chain: KMC Z9
Brakes
Inspect the brakes →Archived: Brakes: Tektro HD-M275 hydraulic disc brake
Wheels and tires
Check wheels and tires →Archived: Wheel size: 27.5 · Wheels: Alex DC25 alloy double-wall rims, 36H, Formula alloy QR hubs, 14g black stainless steel spokes · Front tire: CST Metropolitan Palm Bay, 27.5 x 2.35 · Rear tire: CST Metropolitan Palm Bay, 27.5 x 2.35
Controls and contact points
Archived: Headset: Internal cup, threaded, 1 1/8” · Handlebar: Comfort hi-rise, alloy 25.4 x 80mm rise x 15 ̊ sweep x 640mm · Stem: Jamis alloy, 180mm quill x 80mm extension · Seatpost: Alloy micro-adjust, 31.6 x 300mm, with alloy QR clamp · Saddle: Jamis Comfort with memory foam, synthetic suede top, burnished side panels and bumper springs · Pedals: Comfort platform with TPE non-slip insert
Before and during the test ride
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Gallery3 images
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Specifications are presented as a reference. Components may vary by market, size, production run, or later manufacturer revisions.





