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Specialized Sirrus (2012): specs, upgrades and what fits

Specialized's best-selling flat-bar fitness hybrid of its time with an A1 aluminum frame, steel fork, 24 speeds on a Shimano 8-speed 11-32 cassette, V-brakes and 700 x 32 tires; it sold new for $520. The 2011-2013 base Sirrus are close. Best for: Commuting and fitness rides.

Put this bike in your garageSee it in 3D

My take, from the specs

A used flat-bar fitness hybrid for commuting and fitness, with an aluminum frame, rack and fender eyelets, Shimano 3x8 on an 11-32 cassette and 700 x 32 tires. The V-brakes stop fine in the dry but wear the rims. On a used one, check the rim walls, the chain and cassette, and the steel fork for rust.

Sizes: XS: 4′11″–5′2″ (150–158 cm) · S: 5′1″–5′5″ (155–165 cm) · M: 5′5″–5′9″ (165–175 cm) · L: 5′9″–6′0″ (175–183 cm) · XL: 6′0″–6′4″ (183–193 cm)

Stock specs

TypeHybrid
Year2012
Price when new$520
Sold atSpecialized dealers (discontinued; common used)
Wheels700c × 32 mm tires
Gears3×8 · 48/38/28T · 11–32T
BrakesGeneric Alloy linear pull
ForkSpecialized Steel, straight blade, fender eyelets
Rear derailleurShimano Altus 8-speed
ShifterShimano EF-51 EZ Fire, 3x8 (integrated with brake levers)
CrankShimano FC-M131
Bottom bracketGeneric Sealed cartridge, square taper, 68 mm
AxlesQuick release
Seatpost27.2 mm
SizesXS, S, M, L, XL
Stock colorsGraphite, Gloss Green, Matte Sterling

Upgrade limits

How far each part can go on this frame, and why. Measure your own bike to confirm the estimated ones.

PartLimitWhy
Widest tire (current wheel size)32 mmUnknown until measured. Your 19 mm internal rims suit roughly 28–49 mm tires.
Other wheel sizes700c onlyRim brakes are set to the rim height, so the wheel size cannot change.
TubelessNot recommendedTubeless needs a rim built to seal (bead hook + channel) and tubeless-ready tires.
Valve typeSchraderDecides which tubes and pump heads fit. Presta tubes fit Schrader rims with a grommet; not the other way.
Replacement wheelsQuick release · 100/135 mmAny wheel matching axle type, spacing and brake mount fits. Rear also needs the right freehub.
Biggest rear cog32T (now 32T)Set by the rear derailleur (Shimano Altus 8-speed): max low sprocket 32T, total capacity ?T. A hanger extender can add a few teeth (hit-or-miss on non-Shadow derailleurs); a new derailleur is the reliable way to get more.
Brake pads (rim)Threaded-post pads (V-brake / U-brake)Rim brake pads are sorted by how they mount, which depends on the brake: threaded post with a nut (V-brakes, U-brakes), smooth post in an eye bolt (cantilevers), road cartridges (dual-pivot calipers) or short threaded pads (side-pull calipers). Any compound…
Front gears3x (48/38/28T) · needs 41T capacityA 3x drivetrain needs a front derailleur and left shifter. Your rear derailleur must take up (biggest − smallest ring) + (biggest − smallest cog) = 41T. Going 1x drops the front derailleur: simpler and quieter, with a slightly smaller range.
Chainring sizeUnknown (now 48T)Estimated from similar frames. Measure the chainring-to-chainstay gap to confirm. Check whether your ring is bolted or riveted. Spindle length (? mm) sets chainline; a big change in ring size may need a different BB spindle.
Gear count upgrades8 → 9 or 10 speedShimano HG 8/9/10-speed freehub: takes 8, 9 or 10-speed cassettes, Shimano 11-speed MTB and CUES/LinkGlide cassettes (7-speed needs a 4.5 mm spacer; most 11/12-speed road cassettes need an 11-speed road freehub, though the 11-34 HG700/HG800 fit). Shifter,…
Cranks & bottom bracketSquare taper · 68 mm shell · ? mm spindleAny square-taper crankset fits with the right spindle length. Upgrading to Hollowtech II needs a new BB (same threaded shell).
Pedal thread9/16" × 20Every adult multi-piece crank uses 9/16". One-piece kids/cruiser cranks use 1/2".
Stems & bars1-1/8 steerer · 25.4 mm bar clampAny stem for a 1-1/8 steerer with a 25.4 mm clamp fits. You can cut a bar narrower but not wider.
Drop-bar conversionPossible with modsNeeds road brake/shift levers (microSHIFT R8 makes 8-speed ones that pull Shimano 8-speed cable correctly), a drop bar, tape, and road-pull brake calipers because road levers pull less cable. Usually $250+.
Seatposts27.2 mm27.2 mm is the most common size: suspension posts and external-cable dropper posts are easy to find. Internal droppers need internal routing the frame does not have.
Racks, fenders, bottlesRack ✓ · Fender ✓ · 0 bottle · Fork cargo ✓Threaded eyelets at the dropouts and seat stays take a rack and fenders. Fork leg mounts take cargo cages.
Max load (rider + cargo)UnknownWheels are usually the weak point under heavy loads. Stay under this with rider plus luggage.

Best upgrades by area

Three options that fit the Specialized Sirrus (2012) as-is in each area, from budget to best. ★ marks the one most worth the money. How we pick. Typical US prices, checked October 2026. They change often: check the price at the store.

AreaGoodBetterBest
TiresPanaracer Pasela 700x32 wire (pair)
$$$ ★ Our pick
Panaracer GravelKing Slick 700x32 (pair)
$$$
Continental Grand Prix 5000 700x32 clincher (pair)
$$$
Brake padsShimano S65T V-brake pads, threaded post (2 pairs)
$ ★ Our pick
Kool-Stop Salmon V-brake pads, threaded post (2 pairs)
$$
Kool-Stop threaded V-brake cartridge holders with salmon inserts (2 pairs)
$$
Grips & tapeBudget ergonomic lock-on grips
$
Ergon GP1 ergonomic grips
$$ ★ Our pick
Ergon GP5 ergonomic grips with built-in bar ends (S or L)
$$$
SaddleWTB Volt saddle
$$
Fizik Terra Argo X5 saddle (150 or 160 mm)
$$$
Ergon SR Allroad Core Comp saddle (men's or women's)
$$$ ★ Our pick
PedalsRace Face Chester composite flat pedals
$$ ★ Our pick
Crankbrothers Stamp 2 aluminum flat pedals (small or large)
$$$
OneUp Components Aluminum flat pedals
$$$
ChainKMC Z8.3 6/7/8-speed chain (116 links)
$
KMC X8 8-speed chain with Missing Link
$
KMC X8 EPT 6/7/8-speed anti-rust chain with Missing Link
$$ ★ Our pick
BrakesShimano Alivio BR-T4000 V-brakes (front + rear)
$$ ★ Our pick
Shimano Deore BR-T610 V-brakes (front + rear)
$$
—
SeatpostSuspension seatpost 27.2 mm (budget)
$$ ★ Our pick
Redshift ShockStop suspension seatpost 27.2
$$$$
Cirrus Kinekt 2.1 Aluminum suspension seatpost 27.2 mm (LR or XR spring)
$$$$
Bar & stemWald 8095 swept touring handlebar 25.4 mm
$$
Sunlite Northroad Touring alloy handlebar 25.4 mm, 3.5" rise
$$
Nitto B352AA Albatross handlebar 25.4 mm, 55 cm
$$$ ★ Our pick
LightsPlanet Bike Beamer 200 + Blinky Squared USB light set
$$ ★ Our pick
Cygolite Metro Plus 800 + Hotshot Pro 150 USB light set
$$$
Trek (Bontrager) Ion Pro RT + Flare RT light set
$$$
Racks, bags & fendersTopeak Explorer rear rack (disc mount)
$$ ★ Our pick
Topeak Super Tourist DX Tubular rear rack (disc)
$$$
Tubus Disco steel rear rack for disc brakes (26" or 28"/700c)
$$$

Upgrades that fit as-is

Tubes

Brakes

Comfort

Control

Utility

Tires

Drivetrain

Wheels

Gearing

Fits with small changes (18)

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Buying one used? Fair prices

Worked out from the price new ($520), age and condition, not live market data. If it needs tires, a chain or brakes, take off what fixing them would cost.

ConditionToday (2012 model)
Like new$135–$175
Good$115–$155
Fair$95–$125
Needs work$75–$95

See what these really sold for on eBay · Other used bike prices

Geometry (size M)

Head angle71.5°
Seat angle73.5°
Chainstay445°
BB drop70 mm
Wheelbase1073 mm
Head tube165 mm
Seat tube485 mm
Standover786°

Compare with

Sources: Specialized (Canada site): 2012 Sirrus product page (full spec + geometry) · BikePedia (via web.archive.org): 2012 Specialized Sirrus, MSRP $520, colours · Bicycle Blue Book: 2012 Specialized Sirrus (lists MSRP $500)