15-Point Pre-Purchase Checklist for Buying a Used Bicycle

Introduction: The Appeal and the Traps of Used Bikes

A brand-new high-end road bike easily costs NT$100,000 or more, but a used bike of the same tier on the secondhand market might go for half or even a third of that price. This makes used bikes the first choice for many riders.

But a used bike isn’t like a new one — you can’t see its history. It might have been lovingly maintained for five years, or it might have sat rained on in a garage for three years and been hastily cleaned up before being listed. This 15-point checklist will help you tell a good bike from a landmine before you commit.

Basic Homework Before Viewing

Do this homework before you go see the bike:

1. Check market prices: compare new and used prices for the same model and year
2. Confirm frame size: make sure it fits your height and reach
3. Prepare inspection tools: bring at least a 5mm hex key and your phone (for photos)
4. Meet outdoors, in daylight: good light is essential for a careful inspection

The 15-Point Checklist

Item 1: Frame Number and Provenance

Importance: ★★★★★

• Confirm the frame serial number exists and is legible
• Cross-check it against the seller’s proof of purchase
• A ground-off number = very likely a stolen bike — walk away immediately
• Note the frame number down; you can search online to check for theft reports

Item 2: Frame Integrity

Importance: ★★★★★

Metal frames:

• Check welds for cracks
• Check tubes for dents
• Check for serious rust
• Check that the rear dropouts are straight

Carbon frames:

• Check the surface for cracks or whitening (stress marks)
• Tap around with a knuckle and listen for consistent sound
• Focus especially on: head tube, BB shell, and around the rear dropouts
• Check for signs of a serious impact

Item 3: Headset

Importance: ★★★★

How to check:

1. Grab the front brake and rock the bike back and forth
2. There should be no clicking or play
3. Lift the front wheel and turn the bars — steering should be smooth with no binding
4. If there’s an issue: servicing costs NT$300-800, replacement costs NT$1,000-2,000

Item 4: Bottom Bracket (BB)

Importance: ★★★★

How to check:

1. Wiggle the crank by hand — there should be no side-to-side play
2. Spin the crank — it should turn smoothly with no odd noise
3. Gritty sound or play may mean it needs replacing
4. Replacement cost: NT$500-2,500 (depending on type)

Item 5: Wheelset

Importance: ★★★★

Check Item	Pass Standard	Fail Signs
Trueness	Side-to-side deviation under 1mm	Visible wobble
Spoke tension	Roughly even when squeezed	Some loose, some tight
Rim wear	Braking surface flat	Grooved (rim brakes)
Hub	Spins smoothly	Noise or play
Carbon rim	No cracks	Any suspicious marks

Item 6: Drivetrain

Importance: ★★★★

Check Item	Method	Estimated Cost
Chain stretch	Chain wear checker (or ask seller for mileage)	NT$300-1,200
Cassette wear	Are the teeth shark-finned?	NT$800-5,000
Chainring wear	Are the teeth sharp and asymmetric?	NT$1,000-5,000
Shifting smoothness	Actual shifting test	NT$200-500 (adjustment)

Item 7: Brake System

Importance: ★★★★★

Rim brakes:

• Pad thickness (are the grooves still there?)
• Is braking power sufficient?
• Do the brake cables move smoothly?

Disc brakes:

• Pad thickness
• Is the rotor warped (check while spinning)?
• Any sign of oil leakage?
• Does the lever feel normal?

Item 8: Tires

Importance: ★★★

• Tread depth
• Sidewall cracks
• Tire age (production date is printed on the sidewall)
• Tires over 3 years old should probably be replaced
• Replacement cost: NT$500-2,000 per tire

Item 9: Seatpost and Saddle

Importance: ★★★

• Does the seatpost slide up and down smoothly?
• Is the seat clamp working normally?
• Any pinch marks or cracks on a carbon seatpost?
• Saddle condition (can be swapped later, but it’s still a cost)

Item 10: Handlebar and Stem

Importance: ★★★

• Any cracks in the handlebar (especially carbon)?
• Are the stem bolts in normal condition?
• Bar tape condition (a low-cost item to replace)
• Integrated cockpits need extra-careful inspection

Item 11: Fork

Importance: ★★★★★

• Any cracks in a carbon fork?
• Is the steerer tube deformed?
• Any scratches on the fork legs?
• Strongly avoid a fork that’s been crashed

Item 12: Rear Derailleur and Hanger

Importance: ★★★★

• Does the rear derailleur show signs of an impact?
• Is the derailleur hanger straight?
• Does shifting run smoothly (especially into the largest and smallest cogs)?
• Are the pulley wheels worn?

Item 13: Quick Release / Thru-Axle

Importance: ★★★★★

• Does the quick-release lever close firmly?
• Is the thru-axle thread in normal condition?
• Is the wheel secure once clamped down?

Item 14: Test Ride

Importance: ★★★★★

You must test ride it! Ride for at least 10 minutes:

Test Item	What to Watch For
Straight-line stability	Does the bike pull to one side?
Shifting	Do front and rear shifts run smoothly?
Braking	Is power sufficient, any odd noise?
Noises	Any abnormal sounds
Comfort	Does the size actually fit you?
Out-of-saddle test	Any frame noise while sprinting

Item 15: Accessories and Extras

Importance: ★★

• Are accessories like a computer or pedals included?
• Spare parts (spare hanger, spare tube, etc.)
• Original manual and warranty card
• Proof of purchase or receipt

Price Negotiation Reference

Depreciation Estimates

Bike Age	Reasonable Discount (vs. new price)	Condition
Under 1 year	70-80%	Good condition
1-3 years	50-70%	Normal use
3-5 years	35-50%	Well maintained
5+ years	20-35%	Depends on condition

Additional Deductions

Issue	Deduct
Chain and cassette need replacing	-NT$2,000-5,000
Tires need replacing	-NT$1,000-4,000
BB needs replacing	-NT$500-2,000
Bar tape needs replacing	-NT$300-1,000
Brake pads need replacing	-NT$200-800
Headset needs servicing	-NT$300-800

Notes on Used-Bike Deals in Taiwan

Common Trading Platforms

• Various cyclist Facebook groups
• Shopee / Ruten auction sites
• Consignment through local bike shops
• Word-of-mouth among riders

Safe Trading Tips

1. Prefer meeting in person: avoid purely online deals
2. Meet in a public place: outside a bike shop is a good choice
3. Trade during daylight: good light is essential for a careful inspection
4. Bring a friend: an extra pair of eyes is extra protection
5. Ask to see ID: confirm the seller’s identity
6. Keep a record of the deal: chat screenshots, transfer records

Conclusion

A used bike can be a great choice for getting started or upgrading, but “cheap” shouldn’t be your only consideration. Go through this 15-point checklist carefully and you’ll avoid most landmines and find a bike that’s genuinely worth the price.

Remember: a deal that looks too good usually has a catch. If a bike that normally sells for NT$80,000 is listed at only NT$20,000, it’s not your lucky day — there’s something you’re not seeing.

Good luck finding the bike that’s meant for you!

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