Buying a bike

Please note that these guides do not constitute legal advice and any information provided in the guides should not be construed as legal advice or legal interpretation. We do not accept any liability for any loss caused by your reliance on this guide.

The DoneDeal Guide to buying a bike

Buying a used bike? Here’s what you need to know.

Whether you’re looking for a High Nelly or a carbon fibre triathlon bike, you can find your dream machine on DoneDeal.

With so much choice out there it can be confusing, especially for first-time buyers who don’t know their down-tubes from their derailleurs.  Follow our guide and before you know it you’ll be pedalling happily into the sunset.

Before you buy

  • Don’t rush your purchase
  • Know your needs. Will the bike take you through city streets or muddy forest trails? Are you hoping to load it up with panniers or just a basket up front?
  • How much money are you willing to spend? Do your research and find out what the going rates are for the type of bike you have in mind.
  • If you’re happy to buy a bike that needs a little patching up, chat with your local bike shop about the cost of general repairs. Remember to factor these costs in when you meet the seller.
  • Be wary of prices that are too good to be true
  • Only buy from a seller you trust. Ask him/her questions about the bike and their reasons for selling it.  A genuine seller will understand your caution.
  • Be wary of bikes that have all identifying marks removed/painted over.
  • If you think the bike is stolen don’t go through with the purchase. Notify the Gardaí or report the ad to the DoneDeal team.

Used bike checklist – the basics


  • Cycle the bike and make sure you can stop by pulling the brakes.
  • Brake pads should not be excessively worn.
  • Brake cables should not be frayed.
  • When the brake levers are released, the pads should fall back from the rim. If this doesn’t happen the cables may need replacing.
  • The wheel should spin freely; if it’s sticking the brake pads may need adjusting.
  • Check to make sure that the pads are gripping the rim and not the tyre.

Size and position

  • Stand over the crossbar with your feet flat on the ground. There should be an inch or two of clear space between your groin and the bar.
  • When sitting on the saddle your hands should comfortably grip the handlebars, allowing for a slight bend at the elbow.
  • When pedalling, your legs should not be completely extended; there should be a slight bend in your knee.
  • Make sure to carry out any slight adjustments e.g. lowering the saddle or changing the angle/height of handlebars, before you commit to the sale.
  • A bike that is a little small for you shouldn’t cause too much trouble. If the frame is too big it can be uncomfortable and dangerous to cycle.


  • Cycle the bike and run through all the gear combinations, ensuring they change smoothly.
  • Check the condition of the chain to make sure it’s not rusty.
  • If the chain is slipping from the cogs while cycling they may be worn out and need replacing.


  • Check for tears or holes in the fabric; if the saddle soaks up rainwater you’re in for an unpleasant experience!
  • The saddle should be firmly attached to the seatpost. Make sure it doesn’t wobble.
  • Check that you can raise and lower the saddle with ease.
  • Remember some saddles are designed specifically for men and women (slimmer for men, wider for women).  


  • If the wheels are flat, ensure that the tyres are sound and ask for a discount for the cost of a replacement tube.  
  • Tyres should not have cracks in the sidewalls.
  • The tyres should not be too bald or worn out.
  • A broken/missing spoke will need replacing as eventually it will cause your wheel to weaken or buckle.


  • The pedals should rotate freely.
  • Listen for a rumbling or grinding noise that may suggest an issue with the bottom bracket. This will only deteriorate and is a costly issue to repair.


  • Check for rusting and damage to the frame.
  • The tubes and forks of the bike should not be dented, cracked or bent out of shape. If so the bike may have been in a crash and the safety of the bike could be compromised.
  • If all identifying marks have been removed/painted over you might want to question the seller on where they bought the bike.

Bike Types

Bikes are built and sold to suit every purpose. For that reason features and parts can vary. Below are some of the main things to look out for when buying a specific bike type.


A lightweight ride that allows you to pick up speed on smooth surfaces.

  • Ensure you can comfortably reach the various hand positions on the ‘drop’ handlebars – hoods, hooks, drops and tops.    
  • Lift the bike; it could be an old steel frame and heavier than it looks.
  • The pedals may be outfitted with toe clips or straps; make sure you are comfortable using these or that you can remove them if necessary.
  • Remember with ultra-thin tyres you will feel every bump on the road.


The ideal bike if you want to load up and travel long distances.

  • Check for eyelets to mount front and rear racks.  
  • The tyres should be thick enough to give a comfortable ride and handle the extra weight.
  • The saddle should be suited to long hours and a more upright riding position.
  • The bike should be fitted with disc brakes or v-brakes. Calliper brakes do not have the same stopping power, considering the extra weight.
  • Touring bikes should have a wide range of gears (three front chain-rings).


Designed for off-road trails, these bikes are hardy but can be inefficient for everyday use.

  • The weight of the bike is generally a good indication of its quality. A really heavy bike is probably from a department store while a light mountain bike should be well made.
  • Decide how much suspension you need. Beginners can start with hardtail bikes (just front suspension) whereas more advanced riders may require full suspension (front and back) which is a more expensive option.
  • Cycle the bike and bounce up and down on it. The suspension should feel smooth and not make any creaking noises.
  • If you plan on using the bike on roads check to see that you can lock out (turn off) the suspension to increase efficiency.


These bikes provide a comfortable, more up-right position for short distances and everyday use.

  • Wearing a backpack when cycling can be a real pain, especially in warm weather. You might want to check that there is a way for you to carry items – either in a basket or panniers – or that the bike allows these features to be fitted.
  • Ring the bell!
  • Mudguards are a must for commuter bikes to protect your clothes from spray. Make sure the mudguards aren’t rubbing against the tyre as this will create resistance and cause an unpleasant ride.
  • Tyres should be robust to prevent punctures from sharp objects.


Similar to a racer, these bikes allow the rider to take up an aerodynamic position.

  • Ideally the bike should be as light and aerodynamic as possible.
  • These bikes are generally expensive so be sure you trust the seller completely. It is within reason to ask for proof of purchase.
  • Make absolutely sure there are no cracks in the frame. Considering the high speeds these bikes can reach you could have a nasty accident if the strength of frame has been weakened.
  • If any original parts seem to have been replaced (e.g. new wheels) ask why; it could be due to a crash.
  • Know your ideal bike measurements and be sure to bring them along and compare to the bike being sold. Only buy a bike that truly fits.


Used to describe a wide range of bikes that were built before modern conventions. They are generally sought after due to aesthetics and quality.

  • Some vintage bikes can be resold at prices way beyond their worth. Make sure you do your research and determine the actual value of the model being sold.
  • If the advert says the bike has been ‘restored’, ask what work was carried out.
  • If the bike requires new parts consider the difficulty of sourcing them.
  • A little patching up is fine but if the bike needs a lot of work, check prices beforehand in your local bike shop.
  • Vintage bikes are often steel-framed and heavy, be sure to test.
  • Some models may have features you are unfamiliar with such as down-tube or bar end shifters, make sure you are comfortable using them.  


A bike that does exactly what the name suggests – folds up! Ideal for commuters and those with storage problems.

  • Make sure to fold and unfold the bike yourself.
  • Examine the locking mechanism to make sure it is strong.
  • Check the size of the bike when it is folded, is it suitable for your needs?
  • Some fold-ups come with a carry case. Be sure to ask the seller for any necessary accessories.
  • Fold-up bikes offer a different riding experience. Take it for a test and make sure you are comfortable with all the design features.


Two wheels specifically designed for juniors.

  • Sizing is crucial. Use this guide to help you determine the best measurements for your child.
  • If the bike is too big the child may find it awkward or impossible to cycle.
  • If the bike is too small, steering and control will be difficult.
  • Make sure the child can comfortably put both feet flat on the ground when sitting on the saddle.
  • The brakes should not be too difficult to pull.
  • Check that the bike has been assembled properly and that all fittings are secure.
  • If the bike has stabilisers make sure you can remove them if necessary.

Biking gear and accessories

  • Helmets should fit properly – not too snug or too loose.
  • Check that helmet has a CE mark and meets recommended safety standards.
  • Never buy a helmet that shows cracks or signs of damage.
  • A child’s bike seat should be in good condition. Check straps can be adjusted and securely buckled.
  • Cycle clothing should be as described in advert. Check for tears or holes especially along seams. Check zippers, Velcro etc.
  • If buying panniers make sure they can be adjusted to properly fit your luggage rack without heel strike.

Protection and storage

  • Consider the value of your bike when choosing a lock.
  • Cable locks are easily cut through and should only be used in low-risk areas.
  • If buying a rigid D-lock/U-lock test to make sure it fits around the tubes of your bike.
  • Most locks are sold with a spare key, be sure to ask the seller for both sets.
  • If buying a second-hand lock, ensure that the mechanism is not rusted and that the key turns smoothly.
  • Use better locks – no cable locks
  • Double lock
  • Watch what you lock toIf considering outdoor storage such as a bike shed or tent, make sure to buy a heavy duty lock to prevent theft. The top three places bikes are stolen are:
    • Car parks
    • Home
    • Streets
  • Know your frame and model number
  • Register your bike for free on so if it’s found or offered for sale it can be traced
  • Always report bike theft

Transporting your new bike

  • Consider what transport option is best suited to your vehicle e.g. does your car have a hitch to mount a hitch rack?
  • Weigh up the pros and cons of roof versus rear mount racks in relation to your needs.
  • When you find a rack you want to buy, make sure to fit it to your car before purchasing to ensure compatibility.
  • Check that all straps and levers are fully functioning and secure.

If you follow all these guidelines you are well on your way to finding (and holding onto) your dream bike. Happy cycling!

Did we miss anything? Let us know!

Find out more about looking after your bike from the Dublin Cycling Campaign who contributed safety advice to this advice guide.