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2000 Boulder Bikes Sirius

Original specifications: Shimano XTR · 7-speed · mechanical rear derailleur · 20" wheels · 46 lb published weight.

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At a glance

Model year
2000
Category
Tandem
Original MSRP
$5,499.00
Sizes
Adjustable for rider height
Colors
Buyer's Choice
Weight
46 lb
Geometry
Legacy reference
In this record
27 specifications · original MSRP · geometry
Archive ID
49008
Original build7005 aluminum, butted w/replaceable derailleur hanger · Recumbent Mix · 20" wheels

Manufacturer catalog

Published sizes and colors

1 size · 1 color

Manufacturer-published sizes and colors; availability and exact size/color pairings may vary by market or production run.

Published sizes

Adjustable for rider height

Published colors

Buyer's Choice

Frameset

Frame ConstructionTIG-welded
Frame Material7005 aluminum, butted w/replaceable derailleur hanger
ForkBallistic 600 XL, 1.0" travel
Fork MaterialAluminum/chromoly, triple-clamp crown
Rear ShockWorks Performance/Boulder Bikes Spring/Oil, 3.0" travel

Drivetrain

Component GroupRecumbent Mix
ShiftersSRAM Quartz
Front DerailleurShimano Ultegra, bottom-pull/clamp-on 31.8mm
Rear DerailleurShimano XTR SGS
CranksetSugino XD600 Tandem, 38/50/60 teeth
Bottom BracketShimano BB-UN72, 122.5mm spindle
BB Shell Width68mm English
Rear Cogs7-speed, 11 - 30 teeth
ChainSRAM PC-61, 1/2 X 3/32"
PedalsNot included

Brakes

BrakesMagura HS 33 brakes, Magura levers

Cockpit & Contact Points

Headset1" threadless Chris King NoThreadSet
HandlebarRANS Tilt Bar-Stem Combo
StemRANS Tilt Bar-Stem Combo
SaddleRANS recumbent seat
SeatpostControl Tech Control Post

Wheels & Tires

HubsFront: SRAM Plasma, Rear: SRAM 3x7
RimsSun Rims CR18, 32-hole
SpokesDT stainless steel, 2.0mm straight gauge
Spoke NipplesBrass nipples
Front Tire20 x 1.50"
Wheel Size20" wheels

Geometry

Legacy reference · 3 measurements

Model-level measurements; the frame size was not recorded. Use these as a historical reference, not for size-specific fit.

All geometry measurementsLegacy reference · 3 measurements
MeasurementLegacy reference
Head-tube angle72°
Wheelbase740 mm
Fork offset / rake38.1 mm

The preserved source contains one model-level geometry set without an identified frame size.

Gearing

Chainring ÷ rear sprocket

Lower ratios provide more mechanical advantage for climbing. Higher ratios turn the rear wheel farther with each crank revolution.

Published build60/50/38T · 11–30T · 7-speed
Lowest1.27:1 Highest5.45:1 Total range431%
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Parts & serviceability

Find replacement parts

Original specifications
Chain · Original
SRAM PC-61, 1/2 x 3/32"
Bottom bracket · Original
Shimano BB-UN72, 122.5mm spindle
Rear derailleur · Original
Shimano XTR SGS Search: Shimano XTR 7-speed mechanical rear derailleur
More parts (1)
Headset · Original
1" threadless Chris King NoThreadSet

Based on the original build. Confirm the model, size and fit before ordering; installed parts may differ. As an Amazon Associate I earn from qualifying purchases. Velopedia may also earn from qualifying eBay purchases.

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Bike-specific inspection checklist 22 checks based on 6 archived component groups Open checklistClose checklist
0 of 22 checked Progress stays in this browser for this bike.

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.

Archived: 2000 Boulder Bikes Sirius · Tandem (recumbent) · Published sizes: Adjustable for rider height

Archived: Frame: TIG-welded · Fork: Ballistic 600 XL, 1.0" travel · Aluminum/chromoly, triple-clamp crown

Archived: Fork: Ballistic 600 XL, 1.0" travel · Rear shock: Works Performance/Boulder Bikes Spring/Oil, 3.0" travel

Archived: Group: Recumbent Mix · Shifters: SRAM Quartz · Front derailleur: Shimano Ultegra, bottom-pull/clamp-on 31.8mm · Rear derailleur: Shimano XTR SGS · Crankset: Sugino XD600 Tandem, 38/50/60 teeth · Bottom bracket: Shimano BB-UN72, 122.5mm spindle · Rear cogs: 7-speed, 11 - 30 teeth · Chain: SRAM PC-61, 1/2 x 3/32"

Archived: Brakes: Magura HS 33 brakes, Magura levers

Archived: Wheel size: 20" wheels · Rims: Sun Rims CR18, 32-hole · Hubs: Front: SRAM Plasma, Rear: SRAM 3x7 · Front tire: 20 x 1.50"

Controls and contact points

Archived: Headset: 1" threadless Chris King NoThreadSet · Handlebar: RANS Tilt Bar-Stem Combo · Stem: RANS Tilt Bar-Stem Combo · Seatpost: Control Tech Control Post · Saddle: RANS recumbent seat · Pedals: Not included

Before and during the test ride

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Specifications are presented as a reference. Components may vary by market, size, production run, or later manufacturer revisions.

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