The main places to buy an MTB
You can buy a mountain bike from a local bike shop, a big-box sporting goods store, an online retailer, or a used marketplace. Each route has real trade-offs: local shops charge more but fit the bike to your body and handle repairs; online retailers cost less but require you to assemble the bike or pay for assembly; used marketplaces offer lower prices but no warranty and require you to inspect the frame yourself.
The choice depends on your budget, how much mechanical work you want to do, and whether you need someone nearby to service the bike later. A beginner often saves money and frustration by starting at a local shop, even at a higher price, because the staff will make sure the bike actually fits and works before you leave.
Key Takeaways
- Local bike shops cost 10 to 20 percent more than online but include fitting, assembly, and a mechanic you can return to for repairs and adjustments.
- Online retailers and big-box stores sell the same brands for less money, but you assemble the bike yourself or pay an extra fee, and you have no local mechanic.
- Used marketplaces like Craigslist, Facebook Marketplace, and eBay offer lower prices but require you to inspect the frame for cracks, check the drivetrain, and test the brakes before buying.
- Entry-level bikes from any source cost between $300 and $800; mid-range bikes run $800 to $2,000; high-end bikes start above $2,000.
- Buying in person—whether new or used—lets you sit on the bike and check that the frame size matches your height and inseam.
Local bike shops: higher price, hands-on service
A local bike shop will fit the bike to your body, assemble it completely, and tune the brakes and gears before you ride it home. The mechanic will ask your height, inseam, and riding style, then recommend a frame size and geometry that matches. You sit on the bike, they adjust the seat height and handlebar reach, and they test the shifting and braking. This takes 30 minutes to an hour and costs nothing extra.
The downside is price. A bike that costs $600 online may cost $700 to $750 at a local shop. You pay for the fitting, the assembly labor, and the fact that the shop has rent and staff. But you also get a mechanic you can return to for flat tires, brake adjustments, and cable replacements—services that cost $15 to $60 each and keep the bike running safely.
Local shops also stock parts and accessories in the store, so you can buy grips, pedals, lights, or a water bottle the same day. If something breaks in the first month, many shops will fix it free or cheap as a goodwill gesture.
Online retailers and big-box stores: lower price, self-assembly
Online retailers like Amazon, Walmart, and REI sell mountain bikes for 10 to 20 percent less than local shops. A $700 bike at a shop might cost $580 online. The bike arrives in a box, partially assembled: the frame and fork are together, but the wheels, handlebars, and pedals are loose. You either assemble it yourself using an Allen wrench and a screwdriver, or you pay a local shop $50 to $100 to assemble and tune it.
If you assemble it yourself, watch a YouTube video for your specific model first. The most common mistakes are installing the front wheel backward (the quick-release lever should face backward), not tightening the stem bolts evenly (which makes the handlebars turn), and leaving the brake cables loose. These are fixable, but they take time and trial.
Big-box sporting goods stores like Dick's Sporting Goods and Walmart sell bikes in-store and online. The in-store bikes are usually assembled, but the staff are not bike mechanics—they may not catch a loose headset or misaligned brakes. Online orders from these stores arrive in a box like any other retailer.
The trade-off is that you have no local mechanic. If something breaks, you ship the bike back or take it to a local shop that may charge more because they did not sell it to you.
Used bikes: lower cost, higher inspection burden
Buying used cuts the price in half or more. A $1,000 bike from two years ago might sell for $500 to $700 used. You find used bikes on Craigslist, Facebook Marketplace, eBay, Pinkbike (a cycling-specific marketplace), and local classified ads. Some bike shops also sell used trade-ins.
Before you buy, inspect the frame for cracks or dents. Look at the welds where the tubes meet—cracks there are serious and expensive to fix. Spin the wheels to check they are straight and the bearings are smooth. Squeeze the brake levers and make sure the pads touch the rim or rotor evenly. Shift through all the gears and listen for grinding or skipping. Ride it a short distance to feel how it handles.
Ask the seller how old the bike is, how often they rode it, and whether it has been in a crash. A bike that sat in a garage for five years may have dry-rotted tires and rusty cables, but the frame is usually fine. A bike that crashed and was repaired may have hidden frame damage or bent components.
Used bikes come with no warranty. If the drivetrain fails a week after you buy it, the cost of repair is yours. Budget $100 to $300 for a tune-up at a local shop after you buy used, to replace worn cables, adjust the brakes, and clean the drivetrain.
Frame size and fit: the most important step
Buying the wrong frame size is the most common mistake. A frame that is too large makes the bike hard to control; a frame that is too small puts your knees too high and your back too bent. You determine your size by height and inseam (the distance from your crotch to the floor when you stand with your feet 6 inches apart).
Most brands publish a sizing chart on their website. Trek, Specialized, Giant, and Cannondale all have charts that match your height and inseam to a frame size in centimeters. A person who is 5'8" to 5'10" usually rides a medium (17 to 18 cm) frame; someone 5'10" to 6'0" usually rides a large (18 to 19 cm). But these are starting points, not rules.
The only way to know for sure is to sit on the bike. When you straddle the frame with your feet flat on the ground, there should be 1 to 2 inches of clearance between your crotch and the top tube. When you sit on the saddle with the pedal at its lowest point, your leg should be almost straight—not locked, but not bent at a sharp angle.
If you buy online and the bike does not fit, returning it costs shipping both ways and takes weeks. If you buy used, you cannot return it. Buying in person—at a shop or from a private seller—lets you test the fit before you hand over money.
Price ranges and what you get at each level
Entry-level mountain bikes cost $300 to $800 and come with a steel or aluminum frame, a front suspension fork (no rear suspension), and basic components. The brakes work, the gears shift, and the bike is safe to ride on beginner trails. Brands in this range include Huffy, Mongoose, and the house brands from Walmart and Target.
Mid-range bikes cost $800 to $2,000 and have better components: lighter aluminum or carbon frames, smoother shifting, more reliable brakes, and often a rear suspension. Brands include Trek, Specialized, Giant, and Cannondale. These bikes are lighter and faster, and they last longer before parts wear out.
High-end bikes start above $2,000 and use carbon frames, premium components, and advanced suspension tuning. They are lighter, stiffer, and more responsive, but the difference is noticeable mainly to experienced riders. Most people who ride for fun or fitness do not need to spend this much.
What to bring when you shop in person
Wear the shoes and clothes you plan to ride in. Bring your inseam measurement (or let the shop measure you). If you have a specific budget, tell the shop—they can recommend bikes in that range instead of showing you everything.
Bring a list of where you plan to ride. A bike for smooth park trails is different from a bike for rocky, steep terrain. The shop can recommend suspension travel (how far the fork compresses) and tire width based on your local trails.
If you are buying used from a private seller, bring a bike pump and a pressure gauge so you can check that the tires hold air. Bring a flashlight to inspect the frame in detail. Meet in a public place during daylight.
Frequently Asked Questions
Is it worth buying a used bike to save money?
Yes, if you inspect it carefully and budget for a tune-up. A used bike that cost $1,000 new might sell for $500 to $700, and a $100 to $300 tune-up brings it back to working condition. You save $200 to $400 compared to buying new. The risk is hidden frame damage, which you can spot by looking for cracks and dents but not always by riding it once.
Can I assemble a bike myself if I have never done it before?
Yes, if you watch a video for your specific model and take your time. The main steps are installing the front wheel, attaching the handlebars, and adjusting the brakes and gears. Most people take 1 to 2 hours. If you get stuck, a local bike shop can finish it for $50 to $100, which is still cheaper than buying from them.
What size frame do I need?
Measure your inseam and check the brand's sizing chart on their website. Most charts match your height and inseam to a frame size. The only way to be sure is to sit on the bike—there should be 1 to 2 inches of clearance between your crotch and the top tube when you straddle it.
Should I buy from a big-box store or a local shop?
A local shop costs more but includes fitting and a mechanic you can return to. A big-box store costs less but offers no fitting or local service. If you are new to biking, a local shop is worth the extra cost. If you are experienced and comfortable with basic repairs, a big-box store or online retailer saves money.
What is the difference between hardtail and full suspension?
A hardtail has a suspension fork in front but no suspension in the rear—the rear wheel is attached directly to the frame. A full-suspension bike has suspension in both front and rear. Hardtails are lighter, cheaper, and faster on smooth terrain. Full-suspension bikes absorb bumps better and are more comfortable on rocky, rough trails. Most entry-level bikes are hardtails.