Buying a second-hand mountain bike: what to check and how much to pay (median €813)

If you're about to buy a second-hand mountain bike, it can be the best purchase of your life or a bottomless pit of workshop bills. The difference is half an hour of checks before you pay. An MTB takes more punishment than a road bike: mud, knocks, crashes and jumps. So what matters here isn't the brand, but how it has been treated.

This guide is about what to look at, part by part. If what you want to know is which brands are worth it, there's another guide for that. And if you've already spotted it in a listing, keep this list on your phone.

First, your size and your type of bike

Before you look at listings, be clear about your size. A mountain bike that's too big or too small can't be fixed with a seatpost or a stem: you'll feel it on every descent. Work it out with the bicis.net bike size guide and compare it with the model's geometry, not just the letter.

Hardtail or full suspension

A hardtail (fork at the front only) has fewer parts to check and fewer things that can go wrong. It's the safest buy if you're starting out or if you ride tracks and easy trails.

A full-suspension bike gives you control and comfort on technical terrain, but adds a rear shock and several linkage bearings. Each one is one more check and, if it's worn, one more bill. If you're going for a full-suspension bike, check it more carefully and ask for the service history.

Suspension: the most expensive thing to fix

The fork and shock are the first things you look at and they weigh most on the price.

Fork

• Stanchions: wipe them with a cloth and look at them against the light. Scratches, pits or areas missing the original coating mean they'll need replacing, and that isn't cheap.
• Seals: if there's a ring of oil or dirt stuck to the stanchions, the seals are leaking. Compress the fork a few times and look again.
• Play: hold the front brake and rock the bike back and forth. If you feel a knocking, there's play in the bushings or the headset.
• Action: it should go down smoothly, without jerks, and come back up without a hard clunk. Try the lockout if it has one.

Rear shock

Check the same things: a clean shaft with no scratches, no oil around the seal and no noises when you compress it. Sit on the bike and bounce a little: it shouldn't make noise or sink suddenly.

Ask about servicing

Ask when the fork and shock were last serviced and whether there's a workshop invoice. If it's never been done and the bike is a few years old, plan to do it as soon as you buy it and take it off the price.

Drivetrain and disc brakes

Drivetrain

• Chain: if you have a chain wear checker, use it. If not, pull the chain away from the chainring: if it lifts a long way off the teeth, it's stretched.
• Chainrings and cassette: shark-fin-shaped teeth mean wear. Replacing the chain, cassette and chainring is one of the most common bills.
• Shifting: run through all the sprockets. If it skips or is slow, it may just need adjusting, or the derailleur or hanger may be bent from a knock. Look at the hanger from behind: it should be straight.

Disc brakes

• Squeeze the levers: they should stay firm and not reach the grip. If they travel a long way or feel spongy, there's air in the system and it needs bleeding.
• Check the thickness of the pads and that the rotors aren't bent or blue from heat.
• Look for traces of fluid on the callipers and levers: a leak is a fault, not an adjustment.

Bearings, headset and wheels

An MTB's bearings soak up mud and pressure-washer water. Spin each wheel in the air: it should turn smoothly and quietly, without rubbing or a gritty sound. Move the wheel from side to side: there shouldn't be any play in the hub.

Turn the handlebar with the front wheel lifted. If you feel tight spots or "notches", the headset is worn. On a full-suspension bike, lift the rear wheel and move it sideways: if there's play, it's the linkage bearings.

Check the rims for dents and the tyres for cuts. If they're tubeless, ask when the sealant was last changed.

The frame: cracks, dents and serial number

Clean the bike or ask to see it clean. Take your time going over the areas that suffer most: the head tube junction, the bottom bracket, the chainstays and the suspension mounts.

• Aluminium: look for fine cracks near the welds and dents in the down tube.
• Carbon: tap gently around the frame with a coin. A dull sound in an area where it rang clear before may be delamination. Be wary of paint touched up in a single spot.
• Serial number: it's almost always under the bottom bracket. Ask for the receipt or check that the bike isn't registered as stolen before you pay.

If the bike has had a heavy crash, the seller should tell you. A crash doesn't rule a bike out; hiding it does.

How much to pay for a used mountain bike

This is the price asked by people selling their mountain bike on bicis.net. It's what the seller asks, not the final price, and it works as a starting point.

Data from 98 active mountain bike listings as of 29 October 2026, out of a total of 218 with a price. Source: bicis.net Cycling in figures.

Where does the one you're looking at fall? An entry-level hardtail is usually at the lower end. A full-suspension bike with a good fork and up-to-date servicing, at the higher end. Take off the price whatever you'll need to replace straight after buying it: unserviced suspension, a worn drivetrain or brakes that need bleeding.

To fine-tune for a specific model, see how to value a bike step by step in How much is my bike worth?. And if you're after an XC bike, there's the guide to the second-hand Orbea Oiz, with what's worth checking in that family.

The test ride: take it off-road

A spin round the street isn't enough. If you can, try it on a trail with rocks or roots. Listen: a healthy MTB sounds like its tyres and little else. Creaks when you pedal standing up, clunks on descents or rubbing brakes are clues that something needs the workshop.

Meet in daylight, somewhere with people around, and only pay when it's in front of you. Never pay in advance for a bike you haven't seen.

Got it? Have a look at the second-hand mountain bikes on bicis.net and go and find yours with this list.

Frequently asked questions

How much does a second-hand mountain bike cost?

On bicis.net, mountain bikes for sale have a median asking price of €813. The cheapest quarter ask less than €450 and the most expensive, more than €1,380 (98 listings, data as of 29 October 2026).

Is it better to buy a used hardtail or full-suspension bike?

A hardtail has fewer parts to check and is a safer buy if you're starting out. A full-suspension bike gives you more control on technical terrain, but adds a shock and linkage bearings that need checking and maintaining.

How do I know if the fork is OK?

The stanchions should be clean and unscratched, with no oil under the seals and no knocking when you brake and push the bike. Ask when it was last serviced and whether there's an invoice.

What if the frame is carbon?

With the bike clean, check the junctions and areas prone to knocks, and tap gently with a coin to listen for dull sounds. If in doubt, ask to see it at a workshop before you pay.

How do I know the bike isn't stolen?

Ask for the receipt or check the serial number, which is usually under the bottom bracket. If the seller can't explain where the bike comes from, it's best not to buy it.