Dr Karen was MD and chief designer at Ogle Design from 1962 to 1999, responsible for 60s and 70s icons such as the Reliant Scimitar and Bond Bug cars, folding rear car seats and the Bush TR130 radio. Karen also designed the Aston Martin DBSV8.
Raleigh has long held to the belief that the Chopper was the brainchild of Alan Oakley, who sketched out the design on the back of an envelope.
This version of events is the line taken in the Chopper re-launch press release, available on Raleigh's website.
Dr Karen poo-poohs Raleigh's story:
"I can assure you that I have got all the evidence. I have diaries going back to 1966 and a record of 20 meetings I had with people from Raleigh, including Alan Oakley."
Dr Karen told The Cambridge Evening News he had written to Mr Oakley twice since first learning about Raleigh's claims in 1999 but had never received a reply.
"From that day I challenged them, starting with the chairman of Raleigh and working down the hierarchy.
"Alan Oakley is a very able guy and did all the engineering and put it into production, which is good stuff, but the envelope story is a lie."
Dr Karen's claim is backed by the Design Council, which gave Dr Karen a special commendation in 2002 for his lifetime achievements, including the Chopper.
At the time the Design Council called him "a pioneer in product design. His Raleigh Chopper bike is a design classic."
The direct forerunner of the Chopper was Schwinn's Orange Crate from the 1960s, itself an adaptation of bikes cobbled together by West Coast USA teenagers to look like 'chopped up' Harley Davidson 'Kustom Kruisers'.
1950's motorcycle customisers in America were the first to use 'ape-hanger' handlebars.
But what about the use of banana seats on bicycles?
Enthusiast website raleighchopper.info traces this to US saddle manufacturer Persons Majestic, until just recently the Brooks saddle importer in the US, a company founded in 1892 (and, incidentally, the president of which is a regular reader of BikeBiz.com...)
"Pearsons (sic) Majestic had developed a seat for bicycle polo. The seat was long and thin, and needed supporting at the rear by a tube hoop attached to the rear wheel nuts. [The] Californian younger brothers [of the motorcycle customisers saw] the potential of the seat, the rear support hoop looked like a motorbike sissy bar, and as motorcycles and bicycles shared a similar handlebar thickness, fitting 15 inch high apehanger handlebars was easy....Some unknown Californian kids back in the very early 1960s produced, in their back yards, the first bicycle to bear the name 'Chopper'."
This street-design was picked up by Al Fritz, concept designer for Schwinn, the Raleigh of the USA. He created the Stingray, released in June 1963.
Raleigh USA saw the success of the Stingray and in 1966, brought out a lookalike, the Raleigh Rodeo. Unlike the Stingray, the Rodeo had a Sturmey Archer 3-speed rear hub changed by a gearshift stick on the cantilever frame and used the seat that would later be used on the Chopper, rather than the Persons Majestic polo seat.
The Rodeo was available in the US only. In 1968, Raleigh USA launched the Fireball, a tougher version of the Rodeo.
Also in 1968, Schwinn fitted a 16-inch front wheel to its Stingray, keeping the 20inch rar wheel. This was known as the Orange Krate and is the design used by Ridgeback for the 2003 Thunderbird.
According to raleuighchopper.info, Raleigh's chief designer, Alan Oakley, was "put on a 'plane for the west coast of America to have a look at what was going on, and cast a fresh, unprejudiced eye over the youth bike scene. Legend has it that Alan sketched the Raleigh Chopper on the back of an envelope on his return flight. This may or may not be true, but if the Fireball was the daddy of the Chopper, Allan Oakley was its midwife...The Raleigh Chopper is born. Not so much a Schwinn clone any more, but still having the Schwinn family trait of twin thin top tubes. [Oakley] simply squared up a Schwinn cantilever frame, fitted the Fireball seat, and lowered the headstock to fit standard 16 inch forks, for economy, to a wide front 16 inch rim."
The Chopper seat has a metal back plate, with a registered design number stamped upon it - no 934257 - because, says raleighchopper.info, "Raleigh were so pleased with the eventual design of the Chopper seat, they didnÂ’t want anyone else using it, unlike the majority of U.S. concerns who used the Pearsons banana-seat style."
What does Raleighchopper.info say about Dr Tom Karen and Ogle Design?
"Raleigh had used the Ogle design studios to submit designs for the eventual Chopper, and despite many wild claims by Ogle`s chief designer at the time, Tom Karen, the modified Rodeo seat design was one of the few parts they actually designed. They claimed the 20/16 wheel layout, despite the bike being built to compete with the U.S. new fashion for 20/16 bikes, and also claimed to have invented the spoke guard, in order to look like a rear disc brake, despite it having been used on the R.S.W. Range of Raleigh [Shoppers] for 5 years previous."
Raleigh released the Chopper in the UK in September 1969. The company sold 500 bikes to IBDs in Croydon, Newcastle and Manchester. They sold out quickly.
"Safety issues dogged the Chopper on both sides of the Atlantic, but over in the UK reached monstrous proportions," says Raleighchopper.info:
"The main item of public scorn was the seat. If you sat too far back the front wheel raised up and, horror of horrors, two young people could sit on the seat at one time! The indignation reverberated throughout the country. One legitimate safety issue, that most complainers missed altogether, was the fact that the frames were falling apart under their riders...quite literally...the rear stays commonly came unstuck from the rest of the bike, and Raleigh dealers were kept extra ... Article continues below
Surrounded by controversy, what became known as the MK 1 Chopper was quietly withdrawn from sale in late 1971.
Raleighchopper.info: "The MK2 was a redesign of the MK1, with several safety issues addressed. First, the seat had been shortened, this was accomplished by bending the rear seat stays in towards the frame, making the frame almost arrow shaped from the side view. The seat got a warning written on the white strap, telling anybody who could be bothered to read, that the seat was not designed to carry more than one rider... perhaps the most ignored warning in the history of the bicycle?"
The Raleigh Chopper lasted until 1980, although "along the way several special editions were tried, all without exception being marketing disasters," says raleighchopper.info.
Chopper history adapted from text at: