Hi, if its a Birmingham Sun ( pre Raleigh/Carlton Sun from Worksop ), there is a rich history, below is some info from the Classic Rendezvous archives : -
Sun Cycles & Fittings Company Limited celebrated their 75th Anniversary in 1961. The original firm was started in 1885 as James Parkes and Son, Brass founders, in Alma Street, Birmingham. Amongst other things, they manufactured light fittings. It was the manufacture of these light fittings that finally gave the name of 'Sun' to the company. James Parkes was a famous Birmingham industrialist. In 1885 James Parkes took advantage of the new bicycle market and the company began to make frames and fittings for other companies. This new product proved very successful and the company moved to larger premises in Aston Brook Street, Aston, in 1886. Sun was in the same street as R.T. Shelley who owned Norton and very near to the back of the Norton factory, which was also in Aston Brook Street.
After the move the company changed its name to THE SUN CYCLE FITTINGS COMPANY. The founder, James Parkes died in 1896. In 1907, Joseph Parkes, James's son, changed the name of the company to THE SUN CYCLE AND FITTINGS COMPANY and the company was also incorporated as a limited company. It was about this time Sun started making their own bicycles using the name of SUN and SUN SPIDER. Prior to this the company produced lugs and fittings for bicycles, cutting and boring the early lugs out of solid steel. They also produced the Sun carbon lamp. The Sun as we know it as the huge lightweight maker from our youth really started in 1925 when F.C.Parkes and his son Peter were inspired after seeing a French lightweight bicycle. This gave them the idea to make and sell lightweight cycling to the British public. They set about improving these Continental designs. The first problem they tackled was to better the French design by making their frames more lively responsive and lighter. Sun were at that time one of the very few concerns manufacturing fittings for both sports and racing machines and had all the company's resources behind him. The wheelbase of the French made machines was much longer than the Sun Company wanted. So with the aid and co-operation of Austin Reynolds, Mr Parkes visited Reynolds Tyseley works, to instruct the fork blade makers on the exact bend and shape he wanted. This was a very important part of the Parkes idea and design, for he always contended that the fork should be designed according to the head angle of the frame. The results of his prototypes, experimentation and deliberations were the introduction of the first Sun Wasp bicycle with 70-degree parallel angles and a wheelbase of 42.5". This claimed Mr.Parkes was the first upright design, which was fully brazed up (Cycling's Show Report 192
. They first exhibited the Wasp at London's Olympia on Stand 17 and the press gave the new model rave reviews. It was inexpensive and had excellent equipment. Available in three sizes 20" 21" 22" with a bottom bracket height of 10.5". Its front forks were D to round with a small offset. Sun was very successful in the cycle industry, making many patented improvements to bicycles. In 1936 F.C. Parkes, grandson of the founder, with his son Peter Parkes, developed the lightweight Parkes sports cycle, which became the standard machine for cycle racing throughout the world. From the thirties to the fifties Sun had a separate company producing bicycles under the Parkes name. We also have all the other products and innovations from Sun Cycles to be thankful for: In the 1920's the self lubricating centrifugal action freewheel, oiled from an oil bath in the hub centre. In the 30's badge steel extensions way before Cinelli. The Sun Manx and Manxman TT models with either strutted bottom bracket to increase the rigidity of the rear triangle or the quirky USWB designed TT frame. The Jay and Apex fork and the modern resilient fork with its gradual fork rake plus those wonderful telescopic adjustable bag carriers, which were just great for touring with. In the 1940's Sun popularized the alloy brake calliper and hooded levers here in the UK, some even branded as Sun Wasp. They even made a derailleur gear guard in the late 50's.
For many years Peter Parkes was head of design at Sun and like his father disliked frames built with parallel angles but the finally had to succumb to fashion and they introduced the Sun Wasp Champion du Monde with 72 parallel angles but they always maintained that a frame of equal angles has a fixed top tube length and this cannot give the best results for every size of rider. Although the original Wasp was a parallel frame. They also made those wonderful cast Sun lug patterns for either solos or tandems. Builders like Jack Jones or Harry Ferris cut and created into something special and unique.
The company was taken over by Tube Investments, (Raleigh) in early 1958. The Chairman, Fred Parkes, announced the company would continue exactly as before but motorcycle production ceased in 1959. Sun badged pedal cycles continued to be produced by Raleigh until 1986. After 1963 Sun Cycles carried a Worksop name, presumably being built at the Carlton works. So the cycle side Sun's main period of fame was from the middle 1920s through to the fifties. The Wasp (which was also the name of a Sun motorcycle) was a popular budget clubman's lightweight. They also produced tandems. In 1959 Sun cycles (Parkes) became part of the British Cycle Corporation, which was absorbed by Raleigh in 1960. The Birmingham rider, Trevor Bull first professional shirt being emblazoned with Sun cycles, even though he was riding for Carlton!
There was a Sun-Truewel racing team in the late 60s The year that Sun celebrated their 75th Anniversary and it coincided with Raleigh shutting down the Sun Aston Brooks works and Fred Parkes retired at the same time.