"Apow0-1••••••?rwa-Nrike-votv."Ap"lpowNpowdo•v-PApivve*Nroulvl PROMINENT SPEEDMEN : I. P. Riddoch.


I N early post war days, the writer, being then in the first flush of youthful motor enthusiasm, actually

pedalled a push-bicycle full thirty miles to see his first hill-climb. The push bicycle was merely a despised and hated means to an end since several years elapsed before an engine responded to the touch of his throttle finger ; it can be imagined then what envy was aroused by the sight of several thundering Zenith-Graduas as they raced up the rutted slopes of Kop Hill. We will draw a veil over the tragic termination of this event, by police intervention, but the first few classes allowed us our first glimpse of the subject of these notes— I. P. Riddoch, and also of the mount on which he was destined to achieve fame—the 8 h.p. Zenith, then owned by L. P. Openshaw.

I. P. Riddoch was educated at Rugby, a school which seems to produce an inordinate number of motoring enthusiasts, and when due to go to Oxford, met with that effective changer of man's career, the war. His inclination for motors led him to become a despatch rider and later a member of the tank corps, in which capacities he saw service throughout the period of hostilities.

On demobilisation Riddoch carried out his original intention of going to Oxford,—Exeter College, where he read a course of engineering. During his first year at Oxford Riddoch came into possession of one of the few Zenith-Gradua machines, fitted with a 500 c.c. twin J.A.P. with vertical overhead valves and bore and stroke of 76m.m. x 54m.m. respectively—in fact a smaller edition of the famous " 90-bore " models. This machine was ridden in the Inter-Varsity hill climb of 1920 but failed to distinguish itself particularly: later in the year, however, it won a race at the Public Schools M.C.C. Brooklands meeting at 62i m.p.h. At this time Riddoch's tutor was L. P. Openshaw, a then famous rider of big twin Zeniths and, strange though it may seem to present undergraduates, " Dons " were actually allowed to represent their universities in the annual speed contests. In 1921 this privilege was abolished and Openshaw went abroad, (though not

because he could no longer ride !). It was _then that I. P. Riddoch really began to distinguish himself as.a big twin exponent, since Openshaw's dreaded" 90 bore" Zenith-Gradua became his property.

Much experimental work was carried out by Riddoch and his friends on this machine, aluminium pistons were designed and made, while several ingenious methods of catching the heads of broken valves, were devised.

These labours were destined to bear ample fruit, for in the two Inter-Varsity speed events of 1921 Riddoch made fastest time of the day both solo and sidecar, thus insuring comfortable wins for Oxford.

The first of these contests was at Aston Clinton, a hill which calls for great riding skill, especially for the rider of a fast and unwieldy machine like the big Zenith. The other event was a flat speed trial in the wilds near Thetford and it is interesting to note that Riddoch, finding that Oxford must score another point to win the contest, hurriedly fitted his own carburettor to another "90 bore" Zenith, which had not travelled quite quickly enough, thus enabling its rider, Mr. Davies, to score the necessary points.

Riding in open competition during the same year Riddoch won a sidecar event at Kop Hill, and if memory deceives us not, a broken valve prevented a similar victory in the unlimited solo class. Soon after these events Riddoch experimented with a Blackburne-engined Hawker machine, and being struck with the mechanical excellence of this engine and still being a big twin devotee, he induced the various firms concerned to build him a pair of racing machines which

in those days represented the last word in speed. The machines, which are now famous, had 1,000 c.c. o.h.v. Blackburne engines and Sturmey Archer gear boxes mounted in Zenith racing frames, as used on the track by the majority of riders in the 1,000 c.c. class.

Previously Riddoch had always been a strong believer in the belt drive in conjunction with the gradua gear, and indeed he still believes that up to a point this combination is almost ideal for speed.hill climbing, but what with the enormously increased power output of the modern engine, together with the unreliability of the belt and the wet weather problem, he wisely realised that chain drive was the only possible transmission for his new motors.

During 1922 the two Zeniths were ridden by their owner with great success, the most notable performance perhaps being the winning of the sidecar race at the Royal Race meeting organised by the Essex Club at Brooklands. This win was distinguished by the enormous distance between Riddoch and the runner up, and by the fact that the 5-mile record was handsomely beaten. Unkind friends never fail to point out that many prominent track men were absent in the Isle of Man for the T.T. races ! After a year of successful racing as a private owner Riddoch joined the staff of Burney & Blackburne in the capacity of competition manager, thus demonstrating that a persevering amateur may very well attain important appointments in the trade. Though still owning and riding the two Zeniths, Riddoch now had

the very definite advantage of a complete factory backing so that during the ensuing years, even greater successes attended him in the numerous events entered.

One outstanding achievement during 1923 was at Clipstone Drive when I. P. Riddoch was the first rider to attain 100 m.p.h. on the road in this country.

Numerous speed trials and hill climbs were won by Riddock during 1923 and 1924 but it gradually became evident that as the power of the engines was increased, so it became more and more difficult to control the machines at speed. A nasty crash at Kingsdown Hill in 1924, caused by a wet road and thoughtless spectators, decided Riddoch not to ride solo unless the course was reasonably straightforward.

At the end of the 1924 season the Zenith won the championship races for 1,000 c.c. machines, both solo and sidecar, ridden in the former by 0. M. Baldwin and in the latter by the owner, which performance probably represented the peak of these machines' performance.

During the following year, 1925 however, the ZenithBlackburnes appeared on the track in the hands of 0. M. Baldwin again, while other riders to perform credibly were J. L. Emerson and T. R. Allchin. When being ridden by the latter at Kop Hill one ot the machines enhanced its reputation as a " dangerous motor" by throwing poor Allchin at some 85 m.p.h.—a crash which seems to have caused both the retirement of Allchin from competition riding and the abandonment of speed hill climbs in this country. I. P. Riddoch continued to drive the machines in

sidecar events and on one occasion, at the Mont Theux Hill Climb in Belgium he established a solo record for the course which still stands. His speed was 87i m.p.h. for a kilometre of 1 in 10 gradient and Riddoch thinks it will be long unbeaten, modestly attributing his fine speed to complete lack of control and inability to shut off !

In 1925, too, Riddoch won the Cup for the best aggregate performance in class G. at Brooklands, during the season. 1926 though not devoid of success, was not such a good year for Riddoch as those before and motorcyclists will doubtless be sorry to hear that he is disposing of the two Zenith-Blackburnes at last. He considers them out of date and not particularly safe and feels that more useful

information is to be had by endeavouring to extract high speeds from a small engine, possibly with the aid of a supercharger.

Like many well known racing men Riddoch has little use for a motorcycle apart from sport ; as a means of transport he favours an Austin 7 and an Essex Coach while he contemplates the purchase of an M.G. Super Sports as a compromise between fast travelling and elegance !

As a proof of the high esteem in which he is held by the racing world we need only state that I. P. Riddoch has for four years been elected a member of the B.M.C.R.C. committee and we feel sure that universal regret will be felt, if by any chance his name fades from the select band of speedmen.