1999 Mongoose Supergoose Jr.

Archived: 1999 Mongoose Supergoose Jr. · BMX · Published sizes: Junior

• Confirm the frame markings and seller description match this archived model. Note every component that differs from the published build.
• Record the frame serial number. It should be legible, unaltered and consistent with the seller’s ownership history.
• Find the size marking on the bicycle and confirm the fit before judging the condition or price.

Archived: Frame: TIG-welded · Fork: Mongoose · Chromoly, unicrown crown

• Look for dents or shape changes and inspect the edges of welds around the head tube, bottom bracket, seat cluster and suspension mounts for hairline cracks.
• Stand behind and in front of the bicycle to look for obvious frame, fork or wheel misalignment. Ask directly about crashes, transport damage and repairs.
• Inspect the fork crown, blades, dropouts and visible steerer area. Check that it is straight, securely installed and free of cracks or impact damage.

Archived: Crankset: Mongoose 3-piece, 42 teeth · Rear cogs: 1-speed, 16 teeth · Chain: KMC, 1/2 x 3/32"

• Check chain tension and chainline, rotate the drivetrain through a full revolution and confirm the rear axle or tensioning hardware cannot slip.
• Measure chain wear with a compatible gauge and inspect chainring, cassette or freewheel teeth. A new chain does not rule out wear in the remaining drivetrain.
• Turn the cranks slowly, feel for rough bearings and check for side-to-side play. Inspect crank arms, chainring bolts and pedal threads for looseness or damage.

Archived: Brakes: Dia-Compe caliper rear brakes, Tektro rear levers

• Inspect pads, cables and housings, then examine both rim braking surfaces for concavity, cracking or heavy wear. Confirm each caliper returns and centers correctly.
• Before riding, test every installed brake separately at walking speed. Each should stop firmly and release cleanly without its control reaching the end of its usable travel.

Archived: Wheel size: 20" wheels · Rims: Mongoose aluminum, 36-hole · Hubs: Mongoose OS · Front tire: 20 x 1 3/8" Comp III style

• Spin both wheels and watch for side-to-side and vertical movement. Check spoke tension, rim condition and hub play.
• Inspect both tire casings for cuts, cracking, plugs, bulges or exposed threads and confirm the installed sizes are safe for the rims and available frame and fork clearance.
• Remove and reinstall or closely inspect both wheel-retention systems. Axles or quick releases should tighten correctly with undamaged threads, hardware and dropouts.

Archived: Headset: 1 1/8" threadless Aheadset · Handlebar: Mongoose Mini BMX · Stem: Mongoose alloy · Saddle: Mongoose Mini w/post · Pedals: Mongoose resin

• Apply the front brake and rock the bike to check for headset play or notchiness. Inspect the stem, handlebar and clamp zones, then confirm every fastener and control is secure.
• Check that the seatpost moves for adjustment and that the saddle, post and clamp hold securely without cracks, severe corrosion or damaged hardware.

• Before riding, confirm both wheels are secure, tires are safe, both brakes function, and the headset, handlebar, stem, cranks and pedals have no looseness.
• Begin at low speed. Test steering, braking and shifting progressively, then load the drivetrain and suspension only after the basic safety checks pass.
• Listen and feel for repeated knocks, grinding, skipping, brake pulsation or movement at joints. Stop the test if the bicycle cannot be controlled safely.