These scans are made from the  Sales Brochure for the 1924 Ace. This is the  year following  their stunning world speed record of 1923. See more about the world speed record breaker at this page. The 1924 models  were to be their greatest...

The brochure is a simple two page folder printed in yellow and black with the bike as b/w photo presented artistically agains these "yellow sceneries". 

The text is exactly the same, but the graphics are changed to suit this new media.

Any comments and questions are welcome


The "Perfected Four"

with the "Rochester" Motor




Detail specifcation

OWER PLANT -  The "Rochester" Motor, a four-cylinder unit power plant embodying the refinements and perfections worked out by Mr. W. Cr. Henderson and Arthur O. Lemon in designing and building four-cylinder motorcycles since 1911. Motor, Clutch and transmission form a complete unit, all being housed in a single crankcase and running in oil bath.

MOTOR   Long-stroke four-cylinder engine of 78 cubic inches piston displacement that, combines high efficiency with cool, quiet running, great flexibility and ease of control. Bore, 2.750"; stroke, 3.250". Smooth pulling, quick in acceleration, clean, silent.

CYLINDERS   F-head type, with inlet over exhaust, causing cold incoming gas to pass over surface of exhaust valve to assist in keeping the latter cool under sustained hard driving . One- piece casting of close-grained gray iron. Spark plug located in valve pocket where spark occurs in center of fresh, live gas, insuring quick and thorough combustion with no chance of fouling. High head fins give maximum radiating surface.

VALVE CAGES   Cast in pairs and provided with deep thin cooling fins that add large area to the effective radiating surface and produce cool running and high efficiency even under long sustained hard pulls or high speed. Gas enters opening in center of cage, from whence it passes to the inlet ports of the cylinders at both its ends.

VALVES   1 1/2" diameter, lift, giving free unobstructed flow of gases. Inlet valve, 30 seat,; exhaust, 45.  Both intake and exhaust tappets easily adjustable without removing from base. Tappets thoroughly lubricated by carefully designed oil returns which keep lubricant inside motor and prevent leakage.

VALVE MECHANISM Inlet rocker arm operate on hardened steel pivot pins centered for each pair. Tappet guides generous in size and provides with oil returns which ensure cleanliness of motor. Complete inlet; valve mechanism enclosed in dirt-proof pressed steel bonnets, with neat snap cover for ease of oiling, thus insuring absence of wear and silence of operation.

CRANK SHAFT   One-piece drop forging, case- hardened 1-1.6" deep. Three big bearings, ground to size. Front bearing, 1 1/8" diameter; 1 1/4" long.  Center, 1 1/8" diameter; 1 1/2"  Rear, 1 1/8" diameter; 1 1/2"

BE ARINGS  Bronze babbitt-lined, on crank shaft, connecting rods and counter shaft, adjustable to take up wear. Clutch bearing, 1 1/2" diameter;  15-16" long. Pilot bushing, 3/4" diameter; 1 1/2" long.

CRANK CASE   Finest qua1ity pure aluminum, light and strong. Upper half strongly reinforced by heavy webs. Lower half generously webbed inside and out to give great, strength and immunity against, road shocks. Three drain plugs, located in horizontal positions so as to be protected from damage.

ROAD CLEARANCE   Full 4 1/2" at lowest, point of motor base. Frame cradle clearance, 7 1/2". CONNECTING RODS   Drop-forged, I-beam section, with holes drilled through web to provide lightness combined with maximum strength. Heat-treated and quenched in oil, giving great toughness and endurance. Split at crank pin for take-up. Oil dipper on lower end.

PISTONS   Standard model fitted with closegrained gray iron pistons, very light and perfectly balanced, provided with oil returns to insure correct lubrication. Three rings to each piston, with light pressure on cylinder walls and narrow faces on rings, to reduce friction to minimum while preserving proper compression and high motor efficiency. Sporting Solo Model provided with long skirt aluminum alloy pistons.

WRIST PINS   Floating piston pins, with ends tipped by soft brass buttons to insure against scoring. Perfect bearing in piston and in connecting rod. Piston may be removed from connecting rod in moment's time, as wrist pin can he slipped out immediately when cylinder is removed. Long wearing, free running, trouble-proof.

LUBRICATION   Entirely automatic and trouble-proof. Constant level, circulating splash system of type used on fine automobiles. Oil carried in reservoir in motor base supplied in constant streams to splash troughs under the connecting rods by positive gear pump.

OIL GAUGE   Oil gauge, with notched rod dipping into sump, shows amount of lubricant in oil sump. Capacity of oil reservoir, 1 gallon.

REMOVABLE PAN   Oil pan in bottom of crank case. Lower half of cast aluminum crank case may be removed without, taking engine Out of motorcycle frame, thus facilitating inspection or overhauling. 

BREATHER   Breather incorporating oil filler, with baffling device to avoid loss of oil, bolted on left of crank case. Long air pipe extends well down side of motor base. T-head filler cap for easy removal hy hand.

MUFFLER   Muffler and exhaust manifold in one unit, with 1 1/4" gas passages arranged in sweeping lines, having no sharp bends or corners to  obstruct. free movement or cause back pressure. Generous expansion chamber, 2 1/2"diameter, permits gases to coo1 and lose velocity before passing into large tail pipe leading to rear of machine. Silent, cool and efficient. Cutout; of improved pattern operated by foot,; produces pleasant bass hum when open.

INLET MANIFOLD   One-piece casting with two outlets. Gas passage forked to supply same vo1ume of mixture to each cylinder. Main gas channel straight, from carburetor, with no sharp bends or curves to retard flow of vapor.

HEATING DEVICES   Air heated by passing through tube enveloped by exhaust flames in muffler before reaching lower air intake of carburetor. Hot spot, provided by stamping connecting rear of valve cage to manifold, insures thorough vaporization, thus assisting both in producing maximum power and reducing carbon deposits.

CARBURETOR   Ace-Schebler, special model designed to meet, the particular requirements of this motor. Adjustments for high and low speeds. Special warm air intake. Located in convenient position for easy adjustment, while riding. Easy starting, smooth running, free from delicate or complicated parts.

IGNITION   Simms high tension magneto, armored and water-proof. Ignition wires enclosed in black fiber tube for protection. Spark plugs, metric.

LIGHTING GENERATOR  Electrically equipped Ace motorcycles use the regular high tension magneto for motor ignition and are equipped with an entirely separate unit to provide current for lights, so that no derangement of the lighting circuit has any effect on the operation of the power plant. Lighting current produced by standard Splitdorf generator. Mounted underneath tank on left side, protected from weather or accident. Driven by black fiber sheave wheel, split and clamped on magneto shaft.

ELECTRICAL EQUIPMENT   Power accumulated in Wico storage battery mounted in box suspended from frame under t,he sacidle, readily accessible and 1ocated so as to give best balance. Lid can be removed and battery refilled without removing terminals. Powerful headlight mounted on strongly braced bracket, with parabolic reflector and dimmer controlled by switch. Taillight,. Motor-driven electric horn securely clamped to frame in inconspicuous position below tank. Horn button ahead of left grip.

LIGHT SWITCH   Lights may be operated singly or together by means of switch conveniently located on side of battery box.


MOTOR CONTROLS   Spark advanced or retarded by turning the left grip on handle bar. Throttle operated by turning right grip. Simple and positive mechanism that does not rattle or develop lost motion. Controls remain where set when hands are removed from bars; do not jar open or shut. Smooth in action, dependable and secure.

STARTER   Step starter with engaging mechanism completely enclosed. Ratchet dogs with flat face tooth to prevent chipping. Large and powerful drop-forged foot lever. Solid knurled pedal. Motion down and back. Lever returns to top position by spring at end of down stroke. Folds back out of way when not in use. TRANSMISSION   Three - speed progressive type, housed in rear of motor base and running in oil bath. Lubricant automatically supplied by splash and requires no attention from rider. Gears of hardened nickel steel, 8-10 pitch, stub tooth, face 5/8" wide. Gear shift locking mechanism inside crank case eliminates need of locks on operating lever quadrants. Drive through spiral bevel gears gives silence of operation and absence of wear. Gear shift, controlled by lever on left side of tank.

CLUTCH   Multiple steel disc seven-plate clutch built, into fly wheel and running in oil bath. Abundant friction surface gives tremendous pulling power for heavy loads or high speed. Discs held in engagement by fourteen large, carefully tempered coil springs, each 1 5/8" diameter and 2  1/2" long. Full range of action compresses spring only small fraction of its length, so that its strength is not affected by long service and tension remains constant. Pressure distributed over all springs, so that none is subject to material strain. Requires no adjustment or other attention from rider. Three sets of large chromium steel ball bearings to carry thrust. Controlled by hand lever on left side of tank or foot lever by left foot board.

FINAL DRIVE   One heavy Duckworth roller chain, 5/8"' pitch, 3/8" wide, from transmission to rear wheel. Ace design eliminates the usual engine - to - countershaft short chain, and thus provides improved efficiency of service and silent running without jerk or rattle.

FOOT CONTROLS  Clutch actuated by foot lever at left foot board. Service brake operated by lever at righ t foot board. Emergency brake operated by lever located so as to be pressed down by heel of left foot when additional holding power is desired. Clutch may be operated by hand lever when desired.

BRAKES  Two entirely independent brakes; two powerful double - acting external bands acting on large drums on each side of hub. All parts of each brake interchangeable. Special grade of long - wearing asbestos composition brake lining.

HUBS  Rear hub, one - piece steel shell with Timken adjustable taper roller bearings, cups and cones of chromium steel. Knockout axle, diameter; 4 1/4" between spoke flanges, extra large and strong for side car use. Front hub, one - piece steel shaft with Timken roller bearings. Knockout axle, 1/2" diameter.

WHEELS  27" diameter, using heavy CC steel rims; strongest and most rugged type of wheel used oo motorcycles; forty spokes front and rear.

TIRES   27 x 3 1/2 " Firestone non-skid. Large air capacity of this size tire is unusually effective in cushioning rider and machine from road shocks or vibrations, while the increased diameter provides augmented steadiness and security in riding sand and mud or crossing car tracks.

GUARDS   Very wide, full crown mud guards that protect rider and machine from mud or road dirt,. Generous clearance to allow use of tire chains. Extension aprons on sides of front guard.

FRAME   Suspension cradle type, giving great, strength and low distribution of weight. Made of 1 1/4", 13-gauge seamless steel tubing. Front bar, 1 3/8"  11-gauge, with powerful internal reinforcements. Head frame and fittings are solid drop forgings. Reinforcing brace bars from rear fork crown to cradle bar relieve all strain on rear fork connections and give great strength and durability. Side members of frame protect motor, transmission, control mechanism and all vital parts from injury by fall.

WHEELBASE   59 inches, combining smooth riding qualities and road comfort with ease of control, ready responsiveness and ability to turn quickly.

SADDLE   Ace special integral design, built in as part of the motorcycle. Bucket seat top scientifically, shaped for comfort.

TANK   Pressed steel two - piece construction, beveled front and rear, with all corners rounded. Capacity 3 3/4" gallons. Provided with efficient gasoline strainer and sediment trap. Large filler opening to accommodate hose nozzles on gasoline pumps at filling stations.

TOOL BOX   Built flush inside gasoline tank, out of sight. Lid at top. Tool compartment deep and narrow, with bottom heavily padded to avoid rattle. water-proof, neat and convenient.

HANDLE BARS   Standard model, low and wide, giving comfortable position for arms and wrists. Braced by cross bar 15-16" steel tubing. Sporting Solo, 1 1/8" tubing, 13-gauge, no cross bar, heavily copper-plated and nickeled. Extension cushion rubber grips, deeply corrugated.

SPRING FORK   Double fork with straight sides. Springs and plunger completely enclosed. Angle and leverage of rocker arms designed so as to absorb both small vibrations and severe road shocks; motion of axle back and up. Hardened steel bushing in rockers. Studs of large diameter, hardened, give exceptional strength at point where shocks are met.

FINISH   ACE BLUE high gloss baked enamel, with fine gold stripe on tank, fork and mud guard; gold Ace emblem on tank.

GUARANTEE   Every Ace Motorcycle is fully covered by the guarantee of the Ace Motor Corporation, the standard form of warranty endorsed by the Motorcycle and Allied Trades Association.

The Ace Motor Corporation reserves the right, to make improvements or changes in design or construction of its product without notice at any time it considers advisable. All quotations are subject to change without notice in case of strikes, fluctuation of material prices, or other unforeseen causes, and in the event, of such changes or improvements no liability shall attach to this company

Equipped with Timken Adjustable Roller Bearing Hubs