Buyer’s Guide to Used Mountain Bikes

So you are looking for your next mountain bike. It is a big purchase, and a smart buy on the used market can save you a lot of money or give you a lot of headaches in the future. Many people abuse and improperly maintain their mountain bikes, and this may lead to problems easily noticeable as well as problems you will not be able to easily determine. This is where I hope to help. This guide combines the standard checklist for used bikes with a few extras to help you really get a good feel for how well taken care of the bike was.

Easy Tells
This is one step a lot of people don’t think about when buying anything used. Inspecting the bike for wear and damage will only tell you so much, but a few questions and indicators can tell you if the owner took good care of the bike or if it was abused and improperly maintained. The first thing to do is talk to the owner if you can. Don’t turn it into an inquisition, be casual. If you ask someone straight away how often did you maintain the bike most people will exaggerate the truth a bit. Start the conversation by mentioning that it looks like a great bike, or some other compliment, that’ll usually get them talking. Find out if they have other bikes or ride often, basically get a feel for their biking experience. Now is the time to find out how often they rode it and why they are selling it. Keep in mind that miles or ride time on a mountain bike mean absolutely nothing. I have seen bikes taken through washes and thousands of miles across country that were methodically maintained and remain immaculate. On the flipside I’ve seen bikes that were out ten miles and came back with broken chainrings and bent rear shocks. All you want to do is find out if this person knows bikes well, kept it maintained, had any accidents, just a little bit of the history.

After you had your little conversation, or even during, it is time to check some indicator spots to see if it was regularly maintained. A rusty chain, dry rotted tires, sun damaged reflectors, mud/dirt, and decaying seat mean this thing was stored outside and not cared for whatsoever. If it passes that test look for frayed cables, damaged cable housing, a bent derailleur hanger, and dirt and grease build up around and in the derailleurs. These mean that the owner probably put in some basic maintenance but not much beyond that. It doesn’t mean the bike is a bad choice, but there may be some hidden damage to watch out for. If it passes both of these tests with consideration (if it looks fine other than a frayed cable or something else very minor that’s not much to worry about) then you have the makings of a great bike, as the owner probably put in the time and effort to fully maintain it, and ensure the proper functioning of every part. You still are far away from a decision, but this will give you some background info to help make a final decision. Time for the rest of the tests.

Wheels
Check for loose, broken and missing spokes (spokes typically break at the nipple on the rim or the hub) by wiggling each one individually and carefully inspecting. Check the rim for any major damage and then wiggle the rim side to side to see if there is any play in the bearings. Spin the wheels checking wheel true (side to side movement in the rim) and listening for any strange noise from the bearings. Take time to inspect the wheels thoroughly.

Frame
First check the frame for cracks, dents or bends. If there is rust (only on steel frames) tap it to see if it flakes off or it is just on the surface. Aluminum, steel and titanium frames can take dents, gouges and dings without compromising the structural integrity, for the most part. Cracks, bends and huge dents mean the frame needs to be replaced. Face the bike like you are about to get on. Hold one of the handlebar grips in one hand and let the bike tilt away from you a little bit. Use your feet to rotate the cranks to their lowest point, and push on the side of the crank. As you do this make sure the frame flexes forward and back without any give or abnormal creaking noises. Most frames will creak when you do this, but you want to listen for any cracks being stressed, which will sound a bit different.

For carbon fiber frames you need to be a more cautious. Dings and scratches that do not fully penetrate through the resin clearcoat are nothing to worry about. Obviously cracks in any frame are a sure sign of failure, but smaller gouges through the resin coat may or may not prove to be a structural problem. Test the integrity of the frame by applying force. In other words you need to push against the frame, especially at joints to stress possible problem areas. If you hear carbon cracking (you’ll know it when you hear it) or see a crack in that spot opening, stop. This means the frame needs to be repaired or replaced. As a side note let the owner know what you are doing before you try this in case you open a crack: The owner may try to blame you for breaking their frame. On carbon fiber frames, sometimes the dropouts are carbon as well, so pull the wheels off and take a look just to be sure that there is no excess wear or damage.

Suspension
First visually inspect the suspension for any major dents or breaks. If it looks good compress it and let it rebound a few times. Focus on how it feels when you compress the suspension. It should be smooth and even in the travel. Watch for any oil leaking while you compress it. If the bike has air suspension and it is currently empty make sure you pressure test it to ensure the seals are good. Check to make sure all of the adjustments like rebound, compression and travel adjust function, if the bike has them.

Brakes
Inspect the levers and make sure they function with no issues. Check the cables and housing/hydraulic lines for any damage. For rim brakes make sure the calipers rebound promptly after you release the brake lever and they are not bent. For disc brakes spin the wheel watching the brake rotor for any bending or warping. Minor warping is common and that can be fixed if you know how, or want to pay for it. You can also run disc with slight warping, they will change due to the frictional heat. 

Drive train
Visually inspect the drive train keeping an eye out for major dents, a bent front derailleur cage, or a bent or broken derailleur hanger. Check over the shifters and either ride the bike or lift the rear tire off of the ground to shift through the gears. Pull the rear derailleur cage forward then release it to make sure the springs and bearings in the tension mechanism function properly. Grab one of the cranks arms and wiggle it towards and away from the bike to check for any play in the bottom bracket. Carefully inspect the teeth of the chainrings up front and the cassette in back for wear and damage. Any bent or broken teeth mean a replacement should probably be purchased. Also keep in mind that the more wear these have the sooner you will need to replace them.

Other Parts
Check the tire tread so you know if they will need to be replaced soon. Look at the seat for tears, and check that the seat rails are straight. Stress the stem and handlebars to make sure they have no give and carbon bars and stems do not crack. Turn the handlebars while the front wheel is off the ground to make sure the headset is smooth. With the front wheel back on the ground hold the front brake and push the bike forward and back to feel any play in the headset. Be careful not to confuse headset play with movement in the front suspension fork. Go through the quick releases to make sure they all function. Check the pedals for any play in the bearings or damage that might affect their performance.

Ride It
The final test is to ride it. A street ride is ok, but try to find some dirt to get a good test. Load and unload the suspension; make sure the brakes stop and rebound properly; shift through the entire gear range; sprint hard to make sure the drive train doesn’t slip and all of the other components hold up. Pay attention to any odd noises or resistance besides the occasional frame creak.

Put it All Together
After you have finished your test it is time to look at the big picture. In reality you are probably not going to find a mint condition bike with no signs of damage and a perfect maintenance record. You can expect dents and dings from normal trail use as well as some signs of improper maintenance. The important thing is to take everything you have learned from the tests into consideration. The main point of a check over like this is to check for major problems and determine if the bike is worth the money. Keep in mind that minor and even major problems shouldn’t always turn you away. If you discover a problem don’t hesitate to point it out to the owner. More often than not you can use this to negotiate a lower price. For instance the bike may have a broken frame, but you can turn it into a great parts buy, and find a frame elsewhere. Just keep in mind labor costs from the local shop if you can’t do the work yourself.

One good idea is to bring along a friend who has some bicycle knowledge. It doesn’t take an expert to spot a problem if they know where to look, but it never hurts to bring someone that really knows what they’re doing. To help you out I’ve also put together a checklist that goes though pretty much everything in this guide. I know it may sound kind of silly to bring a checklist with you, but it is important that you don’t miss any details. You will feel really stupid if you get the bike and end up having to replace the bottom bracket or the rear derailleur because you forgot to check it. Don’t rush yourself either: Check, recheck and check everything again if you have to.

Where to Buy Used Bikes

• Ebay can be a good source of used bikes but you can’t see the bike for yourself and ride it to make sure everything functions properly. Be careful.
• Craigslist is an excellent way to find bikes in your local area and you can find some great deals.
• Bike Shops sometimes sell used bikes but they are often overpriced.
• Newspaper Classifieds will sometimes have used bike listings.
• Thrift Stores are the perfect place to find cheaper and vintage bikes.
• Forums can have areas where users sell their bikes, just be sure you know what your buying first.
• Friends around you may have a mountain bike sitting in their garage that they never ride anymore.

Thanks for reading and if you have any questions, correcting, feedback or anything else, please don’t hesitate to leave a comment, I’d love to hear from you.

• October 14, 2008 -- Used Mountain Bike Buyer’s Checklist

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• October 14, 2008 -- Used Mountain Bike Buyer’s Checklist