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1989 Diamond Back Apex

a large 1989 Diamond Back mountain bike with smoke lilac colorway leans against a garden wall. The bike has BMX bars, knobby 26" tires, pads on the bars and top tube with colorful pink donut and pizza patter, and a brown handlebar bag 1989 Diamond Back Mountain Bike Catalog page featuring the Apex.

A $40 online classifieds find, in ok shape. Shifters are a bit gummy but still work, needed a chain and a shim for the 21.1mm quill stem (steerer is 22.2mm). I also replaced the seat which was missing its cover.

1989 Diamond Back Apex Build Specs

Weight: ?lbs, fairly light

Frame: 1989 20.5" Tange CrMo double-butted, Iridescent Lilac Smoke colorway. Serial XXXXXXXXX

Fork: 100% CrMo UniTrac with straight oversize taper blades and rack braze-ons

Cockpit

Handlebars: No-name BMX 22.2mm 2-piece (originally DB tapered AL black anodized flat bars)

Grips: Diamondback BMX

Stem: BMX quill 21.1mm stem (originally Tioga T-Bone 22.2")

Headset:

Saddle: ??? in bad shape (Originally Avenir Turbogel Lycra)

Seatpost: Delta DP 300mm

Seat Collar: DB QR

Shift Levers: Shimano Deore II 3x7 SL-MT62

Pedals: Wellgo Plastic HTI-P68 (originally Diamond Back alloy body/cage)

Brakes

Brake Levers: Shimano Deore II two-finger (F/R) BL-MT63

Brakes: Shimano Deore II cantilever (F/R) BR-MT62

Pads:

Drivetrain

Bottom Bracket: Shimano cartridge?

Chain: N/A (originally Shimano HG)

Crankset: Shimano Deore II, 175mm, 46/36/26t FC-MT60

Cassette: ?-28t (Originally Shimano Deore II 7-speed 13-30t check)

Front Derailleur: Shimano Deore II FD-MT62 3x

Rear Derailleur: Shimano Deore II RD-MT62 x7

Wheelset

Hubs: ??? F/R (originally Shimano Mountain LX F/R)

Rims: Araya AP-21 (F/R) (originally Araya RX-7 😔 )

Tires: Specialized Rockcombo 26x1.95" (F/R) (originally Tioga Farmer John Cousin 26x1.95" F/R)

1989 Diamond Back Mountain Bike Catalog page featuring the specs for the Apex.

Original catalog specs page

Component weights:

Wheelset: ? (F), ? (R)

Frame Geometry (20.5")

spec sheet + some of my measurements

Seat Tube (C-T): 20.5" (521mm)

Seat Tube (C-C): 19.5" (495mm)

Top Tube, Actual: 22.4" (570mm)

Top Tube, Effective (C-C): XX" (XXXmm)

Head Tube Angle: 70º

Seat Tube Angle: 73º

Chainstay Length: 16.9" (430mm)

Headtube Length: X" (XXXmm)

Bottom Bracket Drop: X" (Xmm)

Bottom Bracket Height: 11.8" (300mm)

Standover Height: " (mm)

Front Center: X" (XXXmm)

Wheelbase: 42" (1068mm)

Stack: XXXmm

Reach: XXXmm

Fork Rake: 1.77" (45mm)