Bike models › Mountain
Kent Flexor 29: specs, upgrades and what fits
A budget steel full-suspension 29er with a coil rear shock and suspension fork, 21-speed twist shifting with a Shimano rear derailleur and front and rear V-brakes. Best for: Paved paths and gentle dirt trails.
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My take, from the specs
A budget steel full-suspension bike for paved paths and gentle dirt, sized for taller riders. The coil rear shock and coil fork add weight, about 16.8 kg in all, more than real control, and the 3x7 twist shifters run on a thread-on freewheel with V-brakes. It ships in a box, so check the brakes, derailleurs and suspension bolts after assembly and keep it off rough trails.
Sizes: One size: 5′6″–6′3″ (168–191 cm)
Stock specs
| Type | Mountain |
|---|---|
| Year | 2025 |
| Price when new | $238 |
| Sold at | Walmart |
| Wheels | 700c × 61 mm tires |
| Gears | 3×7 · 42/34/24T · 14–28T |
| Brakes | Generic Linear pull |
| Fork | Generic Coil suspension fork (travel not listed) |
| Rear derailleur | Shimano 7-speed rear derailleur (model not listed) |
| Shifter | Generic 3x7 twist shifters |
| Crank | Generic Triple crank (type not listed) |
| Bottom bracket | External-cup BB (BSA) |
| Axles | Bolt-on |
| Weight | 37.0 lb (16.8 kg) |
| Sizes | One size |
| Stock colors | Red |
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) | 61 mm | Unknown until measured. Your 30 mm internal rims suit roughly 44–78 mm tires. |
| Other wheel sizes | 700c only | Rim brakes are set to the rim height, so the wheel size cannot change. |
| Tubeless | Not recommended | Tubeless needs a rim built to seal (bead hook + channel) and tubeless-ready tires. |
| Valve type | Schrader | Decides which tubes and pump heads fit. Presta tubes fit Schrader rims with a grommet; not the other way. |
| Replacement wheels | Bolt-on · 100/135 mm | Any wheel matching axle type, spacing and brake mount fits. Rear also needs the right freehub. |
| 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 gears | 3x (42/34/24T) · needs 32T capacity | A 3x drivetrain needs a front derailleur and left shifter. Your rear derailleur must take up (biggest − smallest ring) + (biggest − smallest cog) = 32T. Going 1x drops the front derailleur: simpler and quieter, with a slightly smaller range. |
| Chainring size | Unknown (now 42T) | 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 | Freewheel (≤8) | Threaded freewheel: up to 7/8-speed freewheels only. More speeds needs a new rear wheel with a freehub. |
| Cranks & bottom bracket | External-cup BB (BSA) | Match crank spindle to BB type. |
| Pedal thread | 9/16" × 20 | Every adult multi-piece crank uses 9/16". One-piece kids/cruiser cranks use 1/2". |
| Stems & bars | 1-1/8 steerer · ? mm bar clamp | Any stem for a 1-1/8 steerer with a 31.8 mm clamp fits. You can cut a bar narrower but not wider. |
| Drop-bar conversion | Possible with mods | Needs 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+. |
| Seatposts | ? mm | Buy posts in exactly this diameter. |
| Racks, fenders, bottles | No rack · No fender · 0 bottle | Threaded eyelets at the dropouts and seat stays take a rack and fenders. Fork leg mounts take cargo cages. |
| Max load (rider + cargo) | 276 lb | 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 Kent Flexor 29 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
Brakes
- Kool-Stop Salmon V-brake pads, threaded post (2 pairs), $$. threaded post pads ↔ your rim brakes
- Shimano Deore cartridge V-brake pads (2 pairs), $$. threaded post pads ↔ your rim brakes
- Jagwire Mountain Pro brake cable kit (Kevlar KEB-SL housing), $$. Made for flat bars ↔ your flat bar
- Shimano Deore BR-T610 V-brakes (front + rear), $$. threaded post pads ↔ your rim brakes · Long-pull caliper ↔ your flat-bar (long-pull) levers
- Shimano S65T V-brake pads, threaded post (2 pairs), $. threaded post pads ↔ your rim brakes
- Kool-Stop threaded V-brake cartridge holders with salmon inserts (2 pairs), $$. threaded post pads ↔ your rim brakes
- Shimano Alivio BR-T4000 V-brakes (front + rear), $$. threaded post pads ↔ your rim brakes · Long-pull caliper ↔ your flat-bar (long-pull) levers
Comfort
- 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…
- 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), $$$. Comes in S/M and M/L widths (measure your sit bones) and men's and women's shapes. Round CroMo rails; 120 kg rider limit.
Control
- Race Face Chester composite flat pedals, $$. 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.
Utility
- 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), $$. Keeps snacks, keys and a multi-tool within reach. Straps on, with a rain cover. Check your knees do not rub it when you stand up.
- Knog Oi Classic bell, $. Slim ring bell that wraps the bar. Large fits 23.8–31.8 mm bars; Small fits 22.2 mm kids and BMX bars. Required by law in some places.
- Wald 137 front basket, $$. Made for flat bars ↔ your flat bar
- 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, $$$. Daytime-running flash modes on both lights. ANT+ lets a Garmin or Wahoo show battery and switch them. Full power runs about 1.5 hours; medium lasts much longer.
Tires
- WTB Riddler 700x45 TCS Light (pair), $$$. 45 mm tire ↔ your ~61 mm clearance
- Maxxis Ardent 29x2.25 EXO TR (pair), $$$. 57 mm tire ↔ your ~61 mm clearance
- Pirelli Cinturato Gravel M 700x45 (pair), $$$. 45 mm tire ↔ your ~61 mm clearance
- WTB Trail Boss Comp 29x2.25 wire (pair), $$. 57 mm tire ↔ your ~61 mm clearance
- Continental Race King ProTection 29x2.2 (pair), $$$. 55 mm tire ↔ your ~61 mm clearance
- Maxxis Minion DHR II 29x2.4 WT EXO 3C MaxxTerra (pair), $$$. 61 mm tire ↔ your ~61 mm clearance
Drivetrain
- KMC X8 8-speed chain with Missing Link, $. 6/7/8-speed chain ↔ your 7-speed drivetrain
- KMC Z7 6/7-speed chain (116 links), $. 6/7-speed chain ↔ your 7-speed drivetrain
- KMC Z8.3 6/7/8-speed chain (116 links), $. 6/7/8-speed chain ↔ your 7-speed drivetrain
- KMC X8 EPT 6/7/8-speed anti-rust chain with Missing Link, $$. 6/7/8-speed chain ↔ your 7-speed drivetrain
Tubes
- Schwalbe AV19 29 x 1.5–2.4 Schrader 40 mm tubes (pair), $. 700c wheel size matches · Schrader valve ↔ your Schrader rims
Gearing
- Shimano Acera RD-M3020-8 SGS 7/8-speed rear derailleur (40T max), $$. 7-speed ↔ your 7-speed drivetrain · Shimano cable pull ↔ your shifter
Fits with small changes (18)
- WTB Byway 700x40 (pair), $$$. Outside the ideal range for your 30 mm rims (44–78 mm): it will mount, but the shape is less stable.
- Panaracer GravelKing SK 700x40 (pair), $$$. Outside the ideal range for your 30 mm rims (44–78 mm): it will mount, but the shape is less stable.
- Schwalbe Marathon 700x38 (pair), $$$. Outside the ideal range for your 30 mm rims (44–78 mm): it will mount, but the shape is less stable.
- Ergon GP1 ergonomic grips, $$. You have twist shifters: buy the short (Gripshift) version.
- Budget ergonomic lock-on grips, $. You have twist shifters: buy the short (Gripshift) version.
- Continental MTB 29 x 1.75–2.5 Presta 42 mm tubes (pair), $. Presta valve: a Schrader rim needs a grommet so the valve sits snug.
- Ergon GA3 lock-on grips, $$. You have twist shifters: buy the short (Gripshift) version.
- Ergon GP5 ergonomic grips with built-in bar ends (S or L), $$$. You have twist shifters: buy the short (Gripshift) version.
- Panaracer Pasela 700x38 wire (pair), $$. Outside the ideal range for your 30 mm rims (44–78 mm): it will mount, but the shape is less stable.
- Schwalbe Marathon Almotion 700x38 (40-622) V-Guard Addix (pair), $$$. Outside the ideal range for your 30 mm rims (44–78 mm): it will mount, but the shape is less stable.
- Continental Contact Urban 700x40 (40-622) wire (pair), $$$. Outside the ideal range for your 30 mm rims (44–78 mm): it will mount, but the shape is less stable.
- Panaracer GravelKing Slick 700x40 (2025, pair), $$$. Outside the ideal range for your 30 mm rims (44–78 mm): it will mount, but the shape is less stable.
- WTB Riddler 700x37 TCS Light (pair), $$$. Outside the ideal range for your 30 mm rims (44–78 mm): it will mount, but the shape is less stable.
- Tubolito Tubo-MTB 29 x 1.8–2.5 Presta 42 mm (pair), $$. Presta valve: a Schrader rim needs a grommet so the valve sits snug.
- Stan's NoTubes tire sealant 16 oz, $. In tubes: needs tubes with removable valve cores (Presta or Schrader to match your rims).
- Orange Seal Endurance tubeless sealant 16 oz, $. In tubes: needs tubes with removable valve cores (Presta or Schrader to match your rims).
- SILCA Ultimate Tubeless Sealant 16 oz, $. In tubes: needs tubes with removable valve cores (Presta or Schrader to match your rims).
- Magura HS11 hydraulic rim brakes with levers (front + rear), $$$. Replaces your brake levers. Your shifter stays.
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Buying one used? Fair prices
Worked out from the price new ($238), age and condition, not live market data. If it needs tires, a chain or brakes, take off what fixing them would cost.
| Condition | 1 year old | 3 years old | 5 years old |
|---|---|---|---|
| Like new | $110–$145 | $80–$105 | $60–$75 |
| Good | $100–$130 | $70–$95 | $50–$70 |
| Fair | $80–$105 | $60–$75 | $40–$55 |
| Needs work | $60–$80 | $45–$60 | $30–$40 |
See what these really sold for on eBay · Other used bike prices
Compare with
- Hyper Bicycles Havoc 29 · compare frames side by side
- Giant Stance (2026, replaces Stance 2 in the US) · compare frames side by side
- Trek Fuel EX 5 Gen 7 · compare frames side by side
- Marin Rift Zone 1 (29) · compare frames side by side
Sources: Kent: 29in Flexor (fit 5'6"-6'3", weight, 275 lb limit) · Walmart: Kent Flexor (1,800+ reviews, Shimano RD, twist shifters)