What to look out for when buying second hand bike

Qualitymark wrote: »

Before anything else, make sure that you're not buying a stolen bicycle; this isn't always possible, but shifty guys in pubs or on advertising sites are to be avoided; I don't know if there's a database of frame numbers - anyone? Don't buy from any unlicensed-looking place in the region of Capel Street, Parnell Street, Cumberland Street, North Circular Road, etc without being very sure that you're buying a legitimate bicycle and no one's going to come back and claim it from you.

For frame size, measure your inner leg, from crotch to ground, in inches. Subtract nine inches from that. That's the rough guideline for your most comfortable frame size. Some people like to ride a stretchy bike, others a bike a little too small according to that guide. See what you like.

Ride a few different bikes to see if you like a short wheelbase (the distance from the hub of the front wheel to the hub of the back wheel), which makes it nippy, or a long wheelbase to make it glide along like a stately liner.

You want a bike that's light but strong. Work out what's a good weight for you, by the same borrowing-friends'-bikes method; also talk to friends about the type of bike they ride.

You're buying mainly for the frame - the most expensive part of the bicycle, and its CPU, as it were. Look also at the back wheel sprocket and derailleur (if buying a bike with derailleur gears (the kind that hang below the back wheel on an S-shaped gadget); you want the cogs to look un-worn. On the other hand, if you're buying a bicycle with hub gears or a hub brake, test it on a short ride to make sure the gear change is smooth or the brake doesn't slip.

Take a look at how well the bike has been maintained. Is it rusty in spots like that sprocket wheel, inside the brake cable housing (pull the brakes and peek). Ask about who owned it, what kind of cycling they did on it.

Check the frame for any welds in places other than the 'lugs' (the corners of the frame where the different tubes meet); you don't want a pre-crashed bike that's fragile from mending. Also, look at those lugs and see that they're nicely finished.

Look at the parts too - how are the brake handles, cables, shoes, etc? Are the wheels buckled? Are the tyres reasonably new with a good tread on them?

Once you've decided on your bicycle, you may want to make some changes. Obviously, buy two good locks, costing around 10-20% of what you've paid for the bike, one a small U-lock, so it can't be levered open easily, the other a good cable lock.

You may want a different shape saddle; consider whether you want a racing saddle, a Brooks leather one, whatever. You may want different handlebars - do you like flat bars, racing bars that let you hoop your back to be out of the wind, or turned-back High Nelly style old-fashioned handles? (Personally I'd go for the 1930s-style Marsh Bend if I could…)

What kind of pedals do you prefer, carriers, panniers, etc… but now we're getting into fiddly stuff. Basically, you want a good strong light frame the right size for you, and you want the rest of the bike to be up to scratch. And legit. And a fair price for what you're getting.