Engineering:Triumph TR6 Trophy

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Short description: British motorcycle
Triumph TR6 Trophy
Triumph Trophy TR6R 1964.jpg
ManufacturerTriumph
Also called'Desert Sled'
Production1956–1973
PredecessorTR5
SuccessorTR7 Tiger
Engine649 cc (39.6 cu in) four-stroke, parallel-twin
Compression ratio8.5/9:1
Power34–46 bhp (25–34 kW) @ 6,500 rpm (claimed)[1]
Transmission4-speed (5-TR6RV)
Wheelbase55 in (140  cm)
DimensionsL: 84 in (214  cm)
W: 27½ in (70  cm)
Seat height32.5 in (82.5  cm)
Weight365 lb (166 kg) (dry)
Fuel capacity3 gal / 4 gal
RelatedT120 Triumph Bonneville

The TR6 Trophy is a motorcycle that was made by Triumph, in Meriden, from 1956 to 1973, when it was replaced by the five-speed 750-cc Triumph Tiger TR7V.[clarification needed] During this time, it was a successful model, particularly in the US. The competition variant, popularly known as the "desert sled", won numerous competitions throughout the late 1950s and 1960s. Steve McQueen's fondness for the model is well known, as is his participation in the 1964 ISDT on a TR6 Trophy.[2]

Background

The genesis of the model came with the introduction of the 650-cc Thunderbird Model in 1950. This was released to meet the demand for higher-capacity motorcycles, particularly from the United States, Triumph's largest export market. In 1954, the T110 model was introduced, a higher performance version of the Thunderbird. The success of these models and the 500-cc TR5 Trophy led to the creation of a 650-cc TR6 Trophy model.[3] The TR6 was developed and produced specifically for the US market, in particular, California desert racing.[4]

Pre-unit models

The model was introduced in 1956 and named the TR6 Trophy-bird, borrowing its name from the Thunderbird model.[5] The model used the same engine as the T110, but with the new "Delta" alloy cylinder head. The cast iron barrel was retained, but painted silver. The engine used 8.5:1 compression ratio and developed 42 bhp. The power delivery made the mount ideal for off-road competition, for which the model is well known. The bike sported a 'siamese' (two-into-one) exhaust system and a 7-inch front brake.[6] Another feature taken from the TR5 was the quick-detachable headlamp, which was ideal for bikes ridden to competitive events and back again. This used a multipin connector which plugged into the bottom of the headlamp shell.

For 1957, the front brake was enlarged to 8 inches. The TR6 was now fitted with a Lucas Red Label Competition Magneto as standard.[7] This was the first year of the "Harmonica" tank badge. For the 1959 model year, the Trophy was offered in two variants, the TR6/A and TR6/B. The TR6/A was the roadster model with low pipes and the TR6/B was the high-piped street-scrambler.[8] After Edward Turner, the fabled Triumph designer, witnessed the death of a young rider on a TR6, at the 1960 Big Bear Run, due to frame failure, it immediately received a stronger steering head. For 1961, the "Trophy-Bird" name was replaced with simply "Trophy". The home model was named the TR6, whereas the US export models were named TR6C for the competition model and TR6R for the road model. Ruby Red and Silver were used for all models. For 1962, the US models were renamed TR6SR and TR6SC.[9] Introduced in 1962 and offered through 1966 was the TR6SS model, which sported a two-into-one exhaust, but was otherwise similar to the road model. The TR6SS used the cheaper K2F magneto rather than the competition K2FC used previously.

Unit construction, before oil-in-frame models

Like the other 650-cc models, the Trophy gained unit construction in 1963. Coil ignition replaced the magneto. For 1964, the bike received stronger front forks, which improved handling. The Smiths Chronometric instruments were replaced by the magnetic type. In 1965, a locating pin for finding top dead center was added to allow timing without the use of a dial gauge.

In 1966, the tank badge style changed from the "Harmonica" style to the "Eyebrow". Confusingly, the model designators for the US now reverted to TR6R and TR6C. The electrics changed to 12 volts, and a bigger 6-pint oil tank was added. The front brake drum was redesigned to allow a larger braking surface.[10] TR6C models had a smaller teardrop 2.5-imperial-gallon (11 l; 3.0 US gal) tank without the parcel grid.

For 1967, the TR6 received some engine changes.[11] Compression was raised to 9:1. and Bonneville exhaust valves and camshaft were adopted, resulting in a 5-bhp increase. This year was the beginning of the shift to unified threads. The TR6C got twin high pipes on the left side.

The twin leading shoe brake was adopted in 1968.[12] This year had the introduction of the Amal Concentric carburettor.[13] The TR6R was the "Sport" version with low pipes, and the TR6C was the "Trophy Special" with high pipes and folding footpegs. The TR6C Trophy Special was built at the request of Triumph's sole US distributor at the time, Johnson Motors in southern California, as a way to target the growing number of desert riders. It was fitted with Dunlop Trials Universal block-tread tires and was the model referred to as the "Desert Sled".

1968 650-cc TR6C Triumph Trophy

The TR6 and TR6R were renamed Tiger for 1969, leaving the TR6C model with the Trophy name. The front brake used a modified actuating lever to avoid snagging of the cable on the front mudguard. Other changes included the larger RM21 alternator and twin Windtone horns. The signature parcel grid was finally dropped for all models.

The last year before the 'oil-in-frame' was adopted was 1970. The exhausts on the TR6C received the "barbecue grill" heat shields.

Oil-in-frame models

In 1971, the TR6R Tiger and TR6C Trophy adopted the P39 frame like the other 650 models. The twin high pipes were retained on the left side.[14] The main improvement over the previous models was the handling, helped by the stronger frame and improved front forks. However, many problems occurred with these new models. The oil capacity was reduced, causing the engine to run hot and the new 'conical' hub front brake required frequent adjustment to avoid fade. The new electrics proved unreliable. Mid-year changes attempted to correct these problems. For 1972, a five-speed was offered as an option, thus creating the TR6RV and TR6CV models. The TR6 model ended in 1973 when it was replaced by the 750-cc TR7 model.

Police models

Before using the Trophy, UK police forces successfully deployed Speed Twin and Thunderbird models. The Trophy version, codenamed the TR6P, carried the model name "Saint" (Stop Anything In No Time).[15] These had a special petrol tank which typically accommodated a PYE radio telephone. It had panniers, a fairing or leg shields.[16] These were sold between 1967 and 1973. The factory varied the specification slightly according to the needs of the individual police force.

A rare TR6SS model was produced for the US police. It is not known if these were ever used for police duties.[17] In 1967, Triumph marketed the Saint model to the US public as a replacement for the beloved but discontinued Thunderbird model.

Model production quantities

Listed here are the production quantities for the various models for each year.[16]

Model 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73
TR6 1 1678 1691 1691 1254 1221 1220 637 262 357 377 682
TR6B 402
TR6C 310 192 543 2042 1573 2772 1880 3056 1150
TR6CV 2
TR6P 570 977 852 1323 154 752 25
TR6R 1108 963 1529 4706 2673 4900 6246 7527 3607
TR6RV 1 2047 122
TR6SR 478 922 1631
TR6SS 1266 1685 447 182 83
TR6SC 60 346 260
Totals 1 1678 1691 1691 1254 1623 1418 1266 1685 2140 2670 4683 7580 5580 8091 10131 10468 7558 147

Competition

Listed here are all known competition wins with the TR6 Trophy.[18]

Year Event Winner(s)
1956 Big Bear Run (Open Class) Bill Postel (1st), Bud Ekins, Alvin Cox
1956 ISDT (750cc Class) [5] John Giles
1956 Catalina Grand Prix (Open Class) Bill Postel
1957 Big Bear Run (Open Class) Bud Ekins
1957 Catalina Grand Prix (Open Class) Bob Sandgren
1957 Greenhorn Enduro Eddie Day
1957 California State TT Championship Ed Kretz Jr.
1957 California State Scrambles Championship Dick Dorrestyne
1957 AMA Scrambles National Championship Bud Ekins
1957 AMA National Hare and Hound Championship Buck Smith
1958 ISDT (750cc Class) John Giles
1958 Big Bear Run (Open Class) Roger White
1958 Catalina Grand Prix (Open Class) Bob Sandgren
1958 Peoria TT (80cu.in. Class) Dick Dorrestyne
1958 California State Hare and Hound Championship Bud Ekins
1958 AMA National Hare and Hound Championship Buck Smith
1959 Big Bear Run Bud Ekins
1959 Greenhorn Enduro Buck Smith
1959 East Coast Scrambles Championship Jim Hayes
1960 Southern 500 Jim Hayes
1962 ISDT (750cc Class) Bud Ekins
1962 Hi-Mountain 200-mile (320 km) Enduro Al Rodgers
1963 Greenhorn Enduro Mike Konle
1963 AMA Cross Country Championship Eddie Mulder
1964 ISDT (750cc Class) John Giles
1964 Greenhorn Enduro Buck Smith
1964 Corriganville Grand Prix Eddie Mulder
1965 Hi-Mountain Enduro Eddie Day
1965 AMA Cross Country Championship Ron Nelson
1965 Corriganville Grand Prix Eddie Mulder
1965 Stone Mountain Enduro Leroy Taylor
1965 Greenhorn Enduro Jim Burleson
1966 Iowa State TT Championship Dick Schmidt
1966 Hare Scrambles National Championship Dick Vick
1967 Barstow to Vegas 150-mile (240 km) desert race Dusty Coppage
1970 Barstow to Vegas 150-mile (240 km) desert race Mike Burke
1970 World Championship Hare and Hound Bob Ferro

Steve McQueen and the 1964 International Six Day Trials

In 1964, the US ISDT team, including the Ekins brothers and Steve McQueen travelled to East Germany. Brand new TR6SC and T100SC models were collected from Meriden for the competition. Cliff Coleman achieved third place in the up to 750 cc class and Dave Ekins gained fifth place in the 500 cc. Bud Ekins and Steve McQueen both crashed on the third day, Ekins with a broken ankle. The Steve McQueen bike has been rediscovered and is now owned by Sean and Catherine Kelly of Johnson Motors.[19]

Appearance in The Great Escape

Replica of the motorcycle used by Ekins for stunts in the film The Great Escape.

The motorcycles used during chase scene in film The Great Escape were 1961 Triumph TR6 Trophy models disguised as German BMW R75 motorcycles.[20][21] The star of the movie, Steve McQueen, did much of the riding for the film himself, although Bud Ekins performed the famous jump scene as McQueen's stunt double.[19] Pin-striper and artist Von Dutch converted the motorcycles for the movie while working at Ekins' shop.

Notes

References