Bike models › Gravel
Poseidon Redwood (Dropbar): specs, upgrades and what fits
A budget direct-to-consumer aluminum gravel bike on 650b wheels with fat 2.35in tires, an aluminum tapered fork, a microSHIFT Advent X 1x10 drivetrain and Tektro cable disc brakes. Best for: Rough gravel, dirt roads and bikepacking on a budget.
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My take, from the specs
Built for rough gravel, dirt roads and bikepacking, with 650b wheels on 2.35-inch tires, thru-axles, lots of mounts and a clutched microSHIFT 1x10 with an 11-48 cassette. It weighs about 13 kg. The Tektro cable disc brakes are the weak spot and need regular pad adjustment, especially on a loaded bike.
Sizes: XXS: 5′0″–5′3″ (152–160 cm) · XS: 5′4″–5′7″ (163–170 cm) · S: 5′7″–5′10″ (170–178 cm) · M: 5′9″–6′0″ (175–183 cm) · L: 6′0″–6′3″ (183–191 cm) · XL: 6′0″–6′6″ (183–198 cm)
Stock specs
| Type | Gravel |
|---|---|
| Year | 2025 |
| Price when new | $849 |
| Sold at | Poseidon (poseidonbike.com, direct to consumer; discontinued 2026, only last-call demo stock left) |
| Wheels | 650b × 60 mm tires |
| Gears | 1×10 · 38T · 11–48T |
| Brakes | Tektro MD-C550 mechanical, flat mount, short-pull |
| Fork | Poseidon Aluminum tapered fork, 3 bosses each side, 12mm thru-axle |
| Rear derailleur | microSHIFT Advent X with clutch, 10-speed |
| Shifter | microSHIFT Advent X short-pull dropbar levers, 10-speed |
| Crank | Prowheel Charm, 170mm |
| Bottom bracket | Generic Sealed cartridge |
| Axles | Thru-axle |
| Seatpost | 31.6 mm |
| Weight | 28.7 lb (13 kg) |
| Sizes | XXS, XS, S, M, L, XL |
| Stock colors | Matte Green, Shadow, Black Flake, Matte Black |
Upgrade limits
How far each part can go on this frame, and why. Measure your own bike to confirm the estimated ones.
| Part | Limit | Why |
|---|---|---|
| Widest tire (current wheel size) | 66 mm | No measurement yet. Estimate from owner reports and frame design. Your 26 mm internal rims suit roughly 38–68 mm tires. |
| Tubeless | Yes (tubeless-ready) | Tubeless needs a rim built to seal (bead hook + channel) and tubeless-ready tires. |
| Valve type | Presta | Decides which tubes and pump heads fit. Presta tubes fit Schrader rims with a grommet; not the other way. |
| Replacement wheels | Thru-axle · 100/142 mm · 6-bolt disc | Any wheel matching axle type, spacing and brake mount fits. Rear also needs the right freehub. |
| Biggest rear cog | 48T (now 48T) | Set by the rear derailleur (microSHIFT Advent X (clutch)): max low sprocket 48T, total capacity 37T. 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. |
| Front gears | 1x (38T) | One ring, no front derailleur. Adding a front derailleur needs a mount on the seat tube and a 2x crankset, so most riders change the ring size or cassette instead. |
| Chainring size | Unknown (now 38T) | 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 upgrades | 10-speed (HG body) | Shimano 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 bracket | Square taper · 68 mm shell · ? mm spindle | Any square-taper crankset fits with the right spindle length. Upgrading to Hollowtech II needs a new BB (same threaded shell). |
| Pedal thread | 9/16" × 20 | Every adult multi-piece crank uses 9/16". One-piece kids/cruiser cranks use 1/2". |
| Brake pads | Shape unknown | Disc pads only fit calipers with the matching shape. |
| Rotor size | 160/160 mm now · front 160 (flat mount: check fork) | 6-bolt rotors. Going bigger needs a caliper adapter: flat-mount adapter, and many flat-mount forks are rated 160 mm max. Most steel forks allow 180 mm; check the fork if a max rotor is printed on it. |
| Caliper upgrades | Road-pull mechanical | Road levers need road-pull calipers. |
| Stems & bars | tapered steerer · 31.8 mm bar clamp | Any stem for a tapered steerer with a 31.8 mm clamp fits. You can cut a bar narrower but not wider. |
| Seatposts | 31.6 mm | Buy posts in exactly this diameter. |
| Racks, fenders, bottles | Rack ✓ · Fender ✓ · 3 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) | Unknown | Wheels are usually the weak point under heavy loads. Stay under this with rider plus luggage. |
Best upgrades by area
Three options that fit the Poseidon Redwood (Dropbar) 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.
Upgrades that fit as-is
Comfort
- 35° rise 60 mm stem, $. tapered" steerer matches · Get the 31.8 mm clamp version for your bar
- WTB Volt saddle, $$. Medium-width shape that suits most riders. Measure sit bones if comfort is the goal.
- Brooks C17 All Weather saddle, $$$. Vulcanized rubber top that flexes like a hammock, and this All Weather version is fully waterproof. No break-in like leather. Firm, not padded: made for long…
- Bikeroo oversized comfort saddle, $. Wide, soft and sprung for short upright rides on cruisers and hybrids. On rides over an hour wide padding can chafe; a firmer saddle that fits your sit bones…
- Cinelli Cork Ribbon bar tape, $. Made for drop bars ↔ your drop bar
- Selle Royal Respiro Moderate saddle, $$$. Made for a 60° "moderate" back angle (most flat-bar hybrids). Very upright cruisers suit the wider Respiro Relaxed. Standard round steel rails.
- Fizik Terra Argo X5 saddle (150 or 160 mm), $$$. Pick 150 mm for narrower sit bones, 160 mm for wider. Round 7 mm alloy rails fit every standard clamp.
- Ergon SR Allroad Core Comp saddle (men's or women's), $$$. Comes in S/M and M/L widths (measure your sit bones) and men's and women's shapes. Round CroMo rails; 120 kg rider limit.
- Lizard Skins DSP V2 bar tape 2.5 mm, $$. Made for drop bars ↔ your drop bar
- Lizard Skins DSP V2 bar tape 4.6 mm, $$. Made for drop bars ↔ your drop bar
- SR Suntour NCX suspension seatpost 31.6 x 350 mm, $$$. 31.6 mm post ↔ your 31.6 mm seat tube
- Redshift ShockStop Endurance suspension seatpost 31.6 mm, $$$$. 31.6 mm post ↔ your 31.6 mm seat tube
- Cirrus Kinekt 2.1 Aluminum suspension seatpost 31.6 mm (LR or XR spring), $$$$. 31.6 mm post ↔ your 31.6 mm seat tube
- Redshift ShockStop suspension stem 31.8 (±6° or +30°), $$$. tapered" steerer matches · Threadless stem ↔ your threadless steerer
- Redshift ShockStop PRO suspension stem 31.8 (±6°), $$$$. tapered" steerer matches · Threadless stem ↔ your threadless steerer
Control
- Race Face Chester composite flat pedals, $$. Big platform with pins. Feet stay put on bumps and in rain. Install with an 8 mm hex key (no wrench flats).
- ROCKBROS aluminum flat pedals, $$. Budget metal platform with pins. A big step up from stock plastic.
- Shimano PD-M520 SPD clipless pedals (cleats included), $$. Nearly indestructible two-sided SPD pedals. You also need SPD (2-bolt) shoes, about $60–100 more. Set the release tension low and practice unclipping before…
- Crankbrothers Stamp 2 aluminum flat pedals (small or large), $$$. Sized by shoe: small for US men's 5–10, large for 10 and up. Grease the threads and tighten to about 35 Nm.
- OneUp Components Aluminum flat pedals, $$$. Bearings and bushings can be serviced with a cheap kit instead of replacing the pedal. Grease the threads and tighten to about 35 Nm.
- Shimano PD-EH500 dual-sided SPD / flat pedals (cleats included), $$$. Comes with SM-SH56 multi-release cleats, which are easier to get out of in a panic. You still need 2-bolt SPD shoes to clip in.
- Shimano Deore XT PD-M8100 SPD pedals (cleats included), $$$. Cup-and-cone bearings are fully serviceable and last for years. Shoes with a 2-bolt SPD cleat sold separately.
- KS eTen-R external dropper 31.6 mm, 100 mm drop + KS Southpaw remote, $$$. 31.6 mm post ↔ your 31.6 mm seat tube
- TranzX YSP22 external dropper 31.6 x 450 mm, 125 mm drop, remote included, $$$. 31.6 mm post ↔ your 31.6 mm seat tube
- KS LEV external dropper 31.6 mm (100–150 mm drop) + KS Southpaw remote, $$$$. 31.6 mm post ↔ your 31.6 mm seat tube
Utility
- Topeak Explorer rear rack (disc mount), $$. Uses your frame's rack mounts
- USB rechargeable front + rear light set, $$. Daytime flashing lights cut collisions. Required by law at night.
- Pletscher adjustable kickstand, $$. Handy for errands. Check it clears the rotor and chainstay.
- Lisen clamp-style handlebar phone mount, $. Cheap and tool-free for maps on paved rides. On rough gravel or trails a locking mount (Quad Lock or Peak Design, about $45–70 plus a case) is much safer.
- Topeak TopLoader top tube bag (0.75 L), $$. Keeps snacks, keys and a multi-tool within reach. Straps on, with a rain cover. Check your knees do not rub it when you stand up.
- Knog Oi Classic bell, $. Slim ring bell that wraps the bar. Large fits 23.8–31.8 mm bars; Small fits 22.2 mm kids and BMX bars. Required by law in some places.
- Planet Bike Beamer 200 + Blinky Squared USB light set, $$. USB rechargeable, tool-free mounts. Use flash mode in daylight. Rear light is 30 lumens: good for town, modest on fast roads.
- Cygolite Metro Plus 800 + Hotshot Pro 150 USB light set, $$$. Nine headlight modes including a daytime flash. Aim the beam slightly down so you do not blind oncoming riders.
- Trek (Bontrager) Ion Pro RT + Flare RT light set, $$$. Daytime-running flash modes on both lights. ANT+ lets a Garmin or Wahoo show battery and switch them. Full power runs about 1.5 hours; medium lasts much longer.
- Topeak Super Tourist DX Tubular rear rack (disc), $$$. Uses your frame's rack mounts
- Tubus Disco steel rear rack for disc brakes (26" or 28"/700c), $$$. Uses your frame's rack mounts
Tires
- Maxxis Minion DHF 27.5x2.5 WT EXO 3C (pair), $$$. 64 mm tire ↔ your ~66 mm clearance
- WTB Trail Boss Comp 27.5x2.25 wire (pair), $$. 57 mm tire ↔ your ~66 mm clearance
- Maxxis Ardent 27.5x2.4 EXO TR (pair), $$$. 61 mm tire ↔ your ~66 mm clearance
- WTB Byway 650b x 47 TCS (pair), $$$. 47 mm tire ↔ your ~66 mm clearance
- WTB Horizon 650b x 47 TCS (pair), $$$. 47 mm tire ↔ your ~66 mm clearance
- Teravail Washburn 650b x 47 Light & Supple (pair), $$$. 47 mm tire ↔ your ~66 mm clearance
Tubes
- Continental MTB 27.5 x 1.75–2.5 Presta 42 mm tubes (pair), $. 650b wheel size matches · Presta valve ↔ your Presta rims
- Tubolito Tubo-MTB 27.5 x 1.8–2.5 Presta 42 mm (pair), $$. 650b wheel size matches · Presta valve ↔ your Presta rims
Brakes
- Tektro MD-C550 dual-piston mechanical disc calipers, road pull, flat mount (pair), $$$. Disc-brake part ↔ your disc brakes · Short-pull caliper ↔ your road (short-pull) levers
- TRP Spyre Flat Mount mechanical disc calipers, road pull (pair), $$$. Disc-brake part ↔ your disc brakes · Short-pull caliper ↔ your road (short-pull) levers
- Juin Tech F1 cable-actuated hydraulic disc calipers, road pull, flat mount (pair), $$$. Disc-brake part ↔ your disc brakes · Short-pull caliper ↔ your road (short-pull) levers
- Shimano SM-RT56 160 mm 6-bolt rotor (1 rotor), $. Disc-brake part ↔ your disc brakes · 160 mm rotor ↔ your 160 mm front rotor
- Galfer Wave 160 mm 6-bolt rotor, 1.8 mm (1 rotor), $$. Disc-brake part ↔ your disc brakes · 160 mm rotor ↔ your 160 mm front rotor
- Shimano SM-RT86 Ice-Tech 160 mm 6-bolt rotor (1 rotor), $$. Disc-brake part ↔ your disc brakes · 160 mm rotor ↔ your 160 mm front rotor
Drivetrain
- KMC X10 10-speed chain with Missing Link, $$. 10-speed chain ↔ your 10-speed drivetrain
- Shimano CN-HG95 10-speed chain (XT level, 116 links), $$. 10-speed chain ↔ your 10-speed drivetrain
- KMC X10 EPT 10-speed anti-rust chain with Missing Link, $$. 10-speed chain ↔ your 10-speed drivetrain
Gearing
- Shimano Deore CS-M4100-10 10-speed cassette 11–46, $$. Cassette ↔ your Shimano HG freehub · 10-speed ↔ your 10-speed drivetrain
- microSHIFT Advent X CS-G104 10-speed cassette 11–48, $$$. Cassette ↔ your Shimano HG freehub · 10-speed ↔ your 10-speed drivetrain
- SunRace CSMS3 10-speed cassette 11–46 (steel), $$. Cassette ↔ your Shimano HG freehub · 10-speed ↔ your 10-speed drivetrain
- Shimano Tiagra CS-HG500-10 10-speed cassette 11–34, $$. Cassette ↔ your Shimano HG freehub · 10-speed ↔ your 10-speed drivetrain
Fits with small changes (25)
- Suspension seatpost 27.2 mm (budget), $$. Your seat tube takes 31.6 mm: needs a 27.2→31.6 shim.
- Redshift ShockStop suspension seatpost 27.2, $$$$. Your seat tube takes 31.6 mm: needs a 27.2→31.6 shim.
- External dropper post 27.2 mm, 100 mm drop + remote, $$$. Your seat tube takes 31.6 mm: needs a 27.2→31.6 shim.
- Ritchey Comp 2-Bolt alloy seatpost 27.2 mm, $$. Your seat tube takes 31.6 mm: needs a 27.2→31.6 shim.
- Thomson Elite seatpost 27.2 x 330 mm, $$$. Your seat tube takes 31.6 mm: needs a 27.2→31.6 shim.
- Ergon CF Allroad Pro Carbon flex seatpost 27.2 mm, $$$$. Your seat tube takes 31.6 mm: needs a 27.2→31.6 shim.
- SR Suntour NCX suspension seatpost 30.9 x 350 mm, $$$. Your seat tube takes 31.6 mm: needs a 30.9→31.6 shim.
- Redshift ShockStop Endurance suspension seatpost 30.9 mm, $$$$. Your seat tube takes 31.6 mm: needs a 30.9→31.6 shim.
- Cirrus Kinekt 2.1 Aluminum suspension seatpost 27.2 mm (LR or XR spring), $$$$. Your seat tube takes 31.6 mm: needs a 27.2→31.6 shim.
- Cirrus Kinekt 2.1 Aluminum suspension seatpost 30.9 mm (LR or XR spring), $$$$. Your seat tube takes 31.6 mm: needs a 30.9→31.6 shim.
- KS eTen-R external dropper 27.2 mm, 100 mm drop + KS Southpaw remote, $$$. Your seat tube takes 31.6 mm: needs a 27.2→31.6 shim.
- KS eTen-R external dropper 30.9 mm, 100 mm drop + KS Southpaw remote, $$$. Your seat tube takes 31.6 mm: needs a 30.9→31.6 shim.
- PNW Components Pine external dropper 27.2 mm (90 or 110 mm) + PNW Loam lever, $$$$. Your seat tube takes 31.6 mm: needs a 27.2→31.6 shim.
- TranzX YSP22 external dropper 30.9 x 410 mm, 125 mm drop, remote included, $$$. Your seat tube takes 31.6 mm: needs a 30.9→31.6 shim.
- KS LEV external dropper 30.9 mm (100–150 mm drop) + KS Southpaw remote, $$$$. Your seat tube takes 31.6 mm: needs a 30.9→31.6 shim.
- Stan's NoTubes tire sealant 16 oz, $. In tubes: needs tubes with removable valve cores (Presta or Schrader to match your rims).
- Orange Seal Endurance tubeless sealant 16 oz, $. In tubes: needs tubes with removable valve cores (Presta or Schrader to match your rims).
- SILCA Ultimate Tubeless Sealant 16 oz, $. In tubes: needs tubes with removable valve cores (Presta or Schrader to match your rims).
- Shimano SM-RT56 180 mm 6-bolt rotor (1 rotor), $. Your front rotor is 160 mm: a 180 mm rotor fits with a post +20 mm caliper adapter (check your fork's max rotor size).
- Galfer Wave 180 mm 6-bolt rotor, 1.8 mm (1 rotor), $$. Your front rotor is 160 mm: a 180 mm rotor fits with a post +20 mm caliper adapter (check your fork's max rotor size).
- Shimano SM-RT86 Ice-Tech 180 mm 6-bolt rotor (1 rotor), $$. Your front rotor is 160 mm: a 180 mm rotor fits with a post +20 mm caliper adapter (check your fork's max rotor size).
- microSHIFT Advent X drop-bar 1x10 kit (brake/shift levers, clutch RD, 11–48 cassette, 10-speed chain), $$$$. Installs as a set: shifter, derailleur, cassette and chain together.
- Kalloy Uno SP-602 alloy seatpost 25.4 x 350 mm, $. Your seat tube takes 31.6 mm: needs a 25.4→31.6 shim.
- Thomson Elite seatpost 25.4 x 330 mm, $$$. Your seat tube takes 31.6 mm: needs a 25.4→31.6 shim.
- Sunlite adjustable suspension seatpost 25.4 mm, $$. Your seat tube takes 31.6 mm: needs a 25.4→31.6 shim.
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Buying one used? Fair prices
Worked out from the price new ($849), age and condition, not live market data. If it needs tires, a chain or brakes, take off what fixing them would cost.
| Condition | Today (2025 model) |
|---|---|
| Like new | $480–$630 |
| Good | $420–$555 |
| Fair | $345–$455 |
| Needs work | $265–$345 |
See what these really sold for on eBay · Other used bike prices
Geometry (size M)
| Stack | 570.7° |
|---|---|
| Reach | 384.4 mm |
| Head angle | 71° |
| Seat angle | 73.5° |
| Chainstay | 440° |
| BB drop | 63.4 mm |
| Wheelbase | 1042 mm |
| Head tube | 138 mm |
| Seat tube | 520 mm |
| Standover | 789.9° |
Compare with
- Ozark Trail G.1 Explorer Drop Bar · compare frames side by side
- Specialized Diverge 3 Alloy (Diverge E5, Shimano CUES) · compare frames side by side
- Giant Revolt 2 · compare frames side by side
- Cannondale Topstone 4 · compare frames side by side
Sources: BikeInsights: Redwood Drop Bar M geometry (Poseidon data) · 99 Spokes: 2025 Poseidon Dropbar Redwood specs · 99 Spokes: 2023 Poseidon Dropbar Redwood (IS 42/52 headset) · Slickdeals: Redwood last-call deal (fork, brakes, 160mm rotors, $850 list)