2006 Diamondback RM 20

Archived: 2006 Diamondback RM 20 · Juvenile · Published sizes: 20" Jr. Sidewalk

• 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: Diamondback · High-tensile steel, unicrown crown

• Check paint damage, vent holes and accessible internal surfaces for corrosion. Look for dents, bent tubes and cracking around welded or brazed joints.
• 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: One-piece, 36 teeth · Bottom bracket: Loose ball · Rear cogs: 1-speed, 18 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: Linear-pull front/coaster brake rear brakes, Alloy 2-finger 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: Rims: R-1000 Alloy, 36-hole · Hubs: Front: steel, Rear: steel coaster · Front tire: 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" threaded 1" threaded · Handlebar: Hi-tensile steel · Stem: 1" steel/aluminum · Seatpost: Steel pillar · Saddle: DB BMX padded · Pedals: Platform

• 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.