Improving on Excellence
Although beaten to the honour of creating America’s first four-cylinder motorcycle by the Pierce Four introduced in 1909, when Scottish-born brothers William G. and Thomas W. Henderson founded the Henderson Motorcycle Co. in Detroit, Michigan in 1911 their aim was to manufacture a luxurious, reliable four-cylinder machine that was substantially better than anything else yet available in a US marketplace then dominated by often primitive singles, and the more potent but still evolving V-twins.
While Tom Henderson ran the company, brother Bill proved to be one of the finest engineers in the USA’s early days of motorcycle R&D, and the quality of his designs arguably outranked anything yet made by a European manufacturer – even Belgium’s FN company, which had invented the four-cylinder motorcycle in 1904. This resulted in the Henderson brothers’ products being christened two-wheeled Duesenbergs, considerably better engineered than the contemporary Pierce Four.
After building a single prototype in 1911 with belt final drive, in January 1912 Henderson Motorcycle Co. began manufacturing 25 examples for public sale of its first 7hp Model B Four powered by an F-head (inlet-over-exhaust) 934cc inline longitudinal engine with mechanically-operated valves and fully-enclosed chain final drive. While it had just a single-speed transmission, it did have a clutch -an uncommon feature on bikes of that era. Costing $325, the new Henderson Four retailed for $75 less than its Pierce rival, whose demise it surely hastened. On one of these its owner Carl Stearns Clancy became the first man to circumnavigate the globe on two wheels in 1912-13, covering 18,000 miles in 10 months of hard riding through four continents, on what was the longest and most perilous motorcycle journey yet attempted. An immediate commercial success with 2,000 examples built and sold from 1913 onwards, the Henderson Four was continually improved by the two brothers, and significant advances were made with the 1917 Model G. The oil was now held in the crankcase, as in a car, replacing the much inferior splash system, while a three-speed gearbox replacing the previous two-speeder was attached to the rear of the engine. Strong sales of the Henderson Four yielded capital for further product R&D, but without a range of smaller capacity singles and twins to increase sales volume, Bill Henderson was never to have sufficient funds to bankroll what he wanted to achieve. Hence in November 1917 he and his brother sold their under-capitalised company to Excelsior owner Ignaz Schwinn, who moved production to his huge Chicago factory. Schwinn had been developing his own four-cylinder Excelsior motorcycle, but decided that purchasing Henderson was a simpler and less costly way to fulfill that objective, allowing Excelsior to be the first of the Big Three (with Indian and Harley-Davidson) to offer a prestige four-cylinder model.
Winds of change
But Schwinn was evidently a very difficult man to work for, and insisted in adding weight and bulk to the Excelsior-Henderson Four in pursuit of a greater profit margin, which completely contravened the brothers’ accent on light weight and increased performance, coupled with reliability. So just a ►
year later in December 1918 the disillusioned Hendersons decided to exit their eponymous company. Tom left the motorcycle business altogether and moved back to Europe, but in October 1919 it was announced that Bill Henderson had secured financing from Haverford Cycle Co. owner Max Sladkin – like Schwinn, an Eastern European immigrant bicycle manufacturer who had long harboured a desire to found his own motorcycle company – to establish the Ace Motor Corporation in the recently defunct Savage Arms factory in Philadelphia, a post-WW1 peace dividend which was outside the jurisdiction of the state of Illinois. There, the partners’ plans were enacted to produce a completely different four-cylinder design, albeit still with lengthways cylinders, but to ensure
Schwinn couldn’t file a federal claim for copyright infringement, Bill Henderson was shrewd enough to ensure that no Henderson part would fit his new Ace Four engine, which debuted in February 1920.
An IOE 1,229cc design initially delivering 20 bhp at 3,000 rpm, this used bore and stroke of 68.58 x 82.55 mm, was sparked by a Simms magneto, and fuelled via a single 25mm Schebler carburettor via twin intake blocks perched atop the four separate cast iron cylinders. Its crankshaft was stronger than the previous Henderson design, with thicker journals and a heavier flywheel which also housed the multiplate oil-bath clutch with no less than 16 springs, while the conrods and aluminium pistons were drilled for lightness. The engine breathed through large 38mm inlet and exhaust valves set at a 75° included angle, with a volumetrically enhanced intake manifold and exhaust, and was very much a generational step forward compared to the older Excelsior-Henderson design. The Ace had a fresh, rakish look, strikingly finished in a Packard Blue paint scheme, highlighted with cream coloured wheels. The Ace Four’s tubular steel duplex frame with a 1499mm wheelbase was reinforced to eliminate flexing under load, but still allowed a low 737mm seating position, with a claimed “3½ inches total action of the special hygienic model saddle formed to fit pelvis bone”! That being the case, there was no rear suspension, but the clean-looking Flying Merkeltype dual girder fork featured enclosed springs and damping plunger, while the svelte 11.35 litre gas tank sandwiched between the upper frame tubes was novel in that the “absolutely waterproof” toolbox was inset into it on the right, and hinged at the rear to open upwards. The mudguards sourced from the same manufacturer as the Henderson’s were wider, with a different radius to allow larger tires to be mounted. Twin independently operated 6in/153mm external-band drum brakes were fitted at the rear, but there was no front brake.
The Ace Four was a huge success, with thousands of examples sold all over the USA, as well as abroad. Its success was such that within its first year of operation the Ace Motor Corp. ran into trouble financially – it was simply undercapitalised to meet the huge demand for its products. But early in 1921 Sladkin came up with a cash injection of half a million dollars (the equivalent of $ 7.0 million today) which allowed production to restart, with all suppliers paid. To promote further sales, Ace then embarked on a series of record-breaking exploits, with the legendary Cannonball Baker using an Ace Four to set his final coast-to-coast record in September 1922 of less than seven days – the first time this feat was achieved in under a week. But shortly afterwards, on December 11 tragedy struck, when Bill Henderson, 39, was killed when hit by a car just outside the factory while testing the new 1923 Ace Sporting Solo model. His passing inevitably left a huge void in the company which was only partially resolved when Sladkin and his associates hired Henderson’s former assistant engineer at Excelsior, Arthur O. Lemon, to succeed him.
Art Lemon's initial brief was to design a competition machine which would remove any doubts in the public's mind that, without Bill Henderson, the Ace was no longer the trump card on two wheels. In three months, using a then-rare and expensive but invaluable dynomometer, Lemon produced the 74ci XP4 prototype, which factory rider T.N. Terpening took to a convincing victory in its debut appearance in a hill-climb in July 1923, at Rochester, NY. On the same bike, in November that year, Charles ‘Red’ Wolverton, another former Excelsior employee who’d moved to Ace, set a new electronically-timed 129.61mph World Land Speed Record for motorcycles on the streets of Philadelphia, on Roosevelt Boulevard – an early example of U.S. concrete-paved freeway. After repeating the run a fraction slower, a special lightweight racing sidecar was then attached to the bike, and with Lemon’s assistant engineer Everett DeLong as passenger, Wolverton registered a speed of 106.82 mph – another World record. The USA was not then part of the FIM, which explains why Wolverton was never universally acclaimed as being the first motorcyclist to travel at more than two miles per minute – albeit timed in one direction only, entirely in accordance with American rules. It took until 1930 for Joe Wright to beat that speed under the FIM’s aegis with the Zenith-JAP.
This feat greatly boosted demand for the Ace Four road bike, but owing to financial mismanagement and apparent incompetence on Max Sladkin’s part, it took over a year for Ace management to realise that the low retail price of $335 meant that each bike they manufactured was in fact being sold at a considerable loss! The more bikes they sold, mainly as a result of Cannonball Baker's and Red Wolverton's successes, the worse the problem became. Bankruptcy inevitably followed in November 1924, and production of this outstanding motorcycle ceased. Although an effort was made in 1926 to restart the business in Detroit, it lasted only a short time with just a few hundred bikes built before the Ace marque was absorbed by Indian, and production moved to Springfield, Mass., with Art Lemon following suit. After initially being marketed as the Indian Ace on its January 1927 debut at New York’s Madison Square Garden Show, garnering hundreds of orders, in 1928 the Ace Four was rebranded as the Indian Four Model 401, having been redesigned to incorporate the cycle parts of the Model 101 Scout, as part of an inevitable cost-cutting process of rationalisation. It remained in production until the bombing of Pearl Harbour in December 1941 brought all production of civilian motorcycles to an end – permanently, in the case of the Indian Four.
Moving right along
Relatively few examples of the coveted Ace Four have survived today, and especially the 1920-22 models built while Bill Henderson was still alive. But a 1922 model bearing frame no. 21199 with engine no. B4011 lives in the southeast of England, and belongs to Nick Roud, whose brother Simon has a collection of Early American bikes which the two of them share. “We used to go to quite a few ►
“Art Lemon's initial brief was to design a competition machine which would remove any doubts in the public's mind that, without Bill Henderson, the Ace was no longer the trump card on two wheels.”
European rallies before they made it so hard for us to do so after Brexit,” says Nick, “and about nine years ago an Ace Four turned up at a rally in Denmark we were at. I’d never seen one before, and I can only describe it as falling in love. I think it’s such a beautiful bike that epitomises the excellence of Early American engineering. I desperately wanted to own one, but it took me two years to track one down for sale in Belgium, and I sold everything I had to be able to afford it – but then I still had to get a bank loan to top it up. It’s completely exceeded my expectations – but only after spending even more money to get it into the state it’s in today!”
Indeed so, for Nick Roud’s Ace saga is a clear case of caveat emptor, with a happy ending only after he’d parted with another wodge of cash to purchase the necessary parts for his mate Chris Newbold, a skilled motor engineer, to repair the engine after the crank snapped on one of the first occasions he rode it – fortunately while the engine was idling at a stop light. Chris takes up the story.
“It was in mint condition when Nick bought it back in 2014, and supposedly the engine had been thoroughly rebuilt by a German engineer. Anyway, the week after he got it we went off for a breakfast ride together, with Nick on the Ace and me on my BMW, and we’d stopped at a junction, when it suddenly made a little clunk, and just stalled. So I went and got the van, and back in the workshop we found it had snapped the crank right by the flywheel. Fortunately, because it was only on tickover, the crankcases survived – but we just looked at it and thought, this is horrendous – how do we fix this?
The pistons were pretty bad, too – they weren’t Ace pistons, and weren’t designed to take the heat, so they’d collapsed, and lost all their shape. But we asked around and found an amazing place called Phoenix Crankshafts in Slough, and the gentleman there was incredible. We took the broken crank there and I said, “Can you make that?” And he said, “Yes. See that crank there – that’s for a Maserati Straight 8, so if I can make one of them, we’ll walk this.” I said, “Could you make new conrods, too?” and he said,
“Of course.” I said, “This is just fantastic, how long?” “Six weeks, but do you want the crankshaft counterbalanced?” Which it never was originally, by the way. So six weeks later we went back there, and true to form he’d made this beautiful crankshaft in EN40B chrome-moly nitriding steel, he’d balanced the crank, there were the four rods all made, and he’d fitted it all up perfectly from scratch. We then took it over to Gosnay’s Engineering in Essex who did all the white metalwork for us.”
“So that was the snapped crankshaft fixed – but now we didn’t have an Ace piston to copy, and they’re so, so rare. But I phoned a gentleman in
Essex I know who’s got a good collection of pistons, and asked if he had any for an Ace Four?” He said, “Yes, I have a full set!” After a lot of chat I persuaded him to lend us one, took it to Gosnays who sent it to CP Pistons in California, and they made us four more within four weeks. Rings, gudgeon pins, pistons, everything came back beautiful, and then we rebuilt the motor. There were lots of other little tricks we picked up along the way, so it came out pretty well, and Nick’s put a lot of miles on it since.” Thanks to Nick Roud’s generosity I put a few more on it myself on a lovely late summer day in the English countryside. This is indeed a gorgeous looking piece of American hardware about to celebrate its centenary in 2022, whose rakish yet classy appearance set new standards for others to aspire to. Bill Henderson may first and foremost have been a superlative engineer, but he also knew a thing or two about styling. He’d also further rationalised the layout of his motorcycle, so that the Ace’s riding position is both comfortable and commanding, with the long pulled-back handlebar arms dropped slightly downwards as they nestle into your hands. You don’t have to reach forward to grasp them – just sit upright on the surprisingly comfortable Troxel leather seat pivoting on the rear of the fuel tank with extensive springing low down either side. Thank heavens the throttle is in the right hand twistgrip with its ridged rubber grip, with the ignition control in its opposite number – not the other way around, as on many other Early Americans. It’s a very welcoming motorcycle which seems plush and substantial when you’re seated on it, with your legs stretched forward for your feet to rest on the ample footboards. There’s a foot clutch on the left, but also a supplementary one via the outer of the two levers on the left of the tank, which is useful for hill starts as it’s easier to slip than the more on/off foot-operated version. One of Chris Newbold’s ‘other little tricks’ in rebuilding the Ace engine was to halve the number of springs in the four-plate clutch from sixteen to eight, and replace the steel plates with Kevlar ones, on the grounds that this DuPont mega-material is not only almost impossible to wear out, but is also more astringent than steel, so grips better, with a much lighter clutch action.
The inner lever on the left of the Ace is the gearchange for the three-speed transmission, with first far forward and a neutral between each gear
as you pull the lever back towards you, which are sometimes all too easy to find. Fortunately, the engine had such massive torque that even second gear proved almost superfluous except on steep hills – I shifted to top early on, and let the torquey engine do the work. The noise from the thin 4-1 exhaust running down the right side before looping under the rear wheel hub sounds like a small 1930s motor car. It’s a motorcycle that’s comfortable to ride, with the long wheelbase delivering stability over bumps, and the ride quality aided by the surprisingly compliant Merkel leading-link girder fork. The Ace also felt secure in a straight line, without shaking its head if I hit a bump despite its rigid rear end, but revving the engine at rest or while down-shifting resulted in the inevitable torque reaction from a lengthways crank. I could appreciate how difficult these fours must have been to ride at full blast on a bumpy track or on a hill-climb, backing on and off the throttle to maintain momentum.
Stopping a bike weighing 168 kg dry from anywhere near its estimated 130 km/h top speed would always have been a challenge with no front brake, but at my reduced speeds of around 50 mph the twin small six-inch/152mm external contracting band rear brakes worked surprisingly well by the standards of the time. The four-cylinder engine was extremely smooth, making it an ideal device to cover long distances aboard back in the days of setting coast-to-coast or 24-hour records. No wonder Ace riders usurped their Hendersonmounted rivals in ruling the roads of America in motorcycling’s early days.
And no wonder too that Nick Roud covets his twowheeled American lady so greatly. I’m very grateful to him for having allowed me to ride such a sophisticated and positively avantgarde device, which would set the standards for others to emulate for years to come – even after the company’s demise owing to the incompetence of its owners. ■