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Seattle Leapfrog Frame Specifications

- Sizes (center to center) 15"L (38cm Step-Thru); 17" (43cm); 19" (48cm)  
- Head Tube Length: 10cm on 38 & 43; 15cm on 48cm
- BB Drop: 5cm
- Triple split housing tops on underside of downtube 10cm back from headtube
- Shimano BB bolt-on plastic cable guide
- Housing stop on both chainstays 18cm back from BB
- NO CANTILEVER BOSSES!
- Rack and Fender Bosses, Water Bottle style at chainstay and seatstay bridge
- Open Ended Brake Arm Boss forward facing on left chainstay 11cm forward of dropout (pac-man style), must be same length as drop-out
- 1 1/8" Steertube
- Long horizontal drop-outs
- Include standard derailleur hanger on right rear drop-out
- Extra beefy chainstay bridge positioned corectly for an Xtracycle attachment.


Frame Angles
	Headangle = 71.5°
	Seatangle = 69°

Major Lengths
	Wheelbase = 116 cm in center of drop out slots (will varry 1.75 cm for and aft with cog and chainring selection)
	Seat tube length (c-t) = 52 cm
	Seat tube length (c-c) = 50 cm
	Top tube length (effective) = 65 cm
	Top tube length (c-c)	= 61 cm
	Head tube length = 19 cm
	Bottom bracket height = 268 mm
	Bottom bracket drop = 50.0 mm
	Chainstay length = 50 cm
	Front Center = 66.5 cm

Wheel Specs
	Wheel diameter = 655 mm
	Tire width = 43 mm
	Gap between rear tire and seat tube ~ 100 mm
	Rear dropout spacing = 135mm

Fork and Headset Specs    (this is a rigid fork)
	Fork offset (rake) = 45.0 mm
	Fork length = 365.0 mm
	Lower stack height = 14 mm  (FSA Sky Pilot roller bearing)

Stability Info
	Trail = 62.96 mm
	Jones stability criterion = -2.53   (David E.H. Jones, Ph.D. see Physics Today article April 1970)
	Relative front projection = 0.0718972

Tube Diameters
	Seat tube diameter = 28.6 mm   (1 1/8")
	Top tube diameter = 28.6 mm   (1 1/8")
	Head tube diameter = 36.0 mm   (1 1/8")
	Down tube diameter = 28.6 mm   (1 1/8")

Seatstay Info  (seatstays are straight)
	Seatstay diameter	= 14 mm
	Distance from axle center to seatstay bridge center = 37.5 cm

Chainstay Info    (chainstay bridge is extra strong made out of chainstay stock)
	Distance from axle center to chainstay bridge center = 37.5 cm

Bottom Bracket Info
	Bottom bracket length = 68.0 mm
	Bottom bracket diameter = 40 mm

Welding Clearance Info
	Head tube extension above top edge of top tube = 55 mm
	Head tube extension below bottom edge of down tube = 10 mm
	Seat tube extension above top edge of top tube = 25 mm

Standard Braze-ons
	2 water bottles (seat and down tubes)
	cable guides (see below)
	Rack bosses
	Rear rack and fender eyelets
	Fender eyelets on fork
	Fender mounts on chainstay and seatstay bridges (water bottle style)
	ISO disc mount on fork
	Seat post clamp & bolt
	Xtracycle tounge bolt hole in chainstay bridge
	Cable guide on top of left side of BB for rear brake
	Plastic bolt-on Shimano BB cable guide (5mm threaded hole)
	Pump peg with stand-off to fit Zefal HPX #4 frame pump
	Kickstand plate   TO BE DETERMINED
	

Braze-on positions  (use standard 6mm split stops)
	Right gear cable housing stop from BB center = 235 mm
	Left  brake cable housing stop from BB center = 160 mm
	Front of brake arm "Pac-Man" mount from BB center = 360 mm   (mouth opens towards BB)
	Lower braze-on of seat tube water bottle from BB center = 160  mm
	Lower braze-on of down tube water bottle from BB center = 160 mm
	Down tube cable stops from BB center = 550 mm
	Rack barrel bosses from rear axle = 470 mm