The imperative phrase get on your bike is an exhortation to take action.

In British English, since 1981, this phrase has been associated with the speech that the Secretary of State for Employment, Norman Tebbit (born 1931), delivered on Thursday 15^th October 1981 at the Conservative Party conference, in Blackpool. In this speech, with reference to inner-city riots in 1981, which were linked to unemployment, Norman Tebbit appealed to the memory of his father to exhort the unemployed to go and find work—as reported in The Press and Journal (Aberdeen, Aberdeenshire, Scotland) of Friday 16^th October 1981:

“I grew up in the 30s with an unemployed father. He did not riot. He got on his bike and looked for work.”

Norman Tebbit was immediately associated with the imperative phrase get on your bike. These are two examples:

1-: From A glaring flaw in the aid argument, by Rod Chapman, published in The Guardian (London and Manchester, England) of Tuesday 20^th October 1981:

The hardline attitude towards this week’s Cancun summit is best encapsulated in the “trade not aid” mantra heard so often on the lips of Whitehall and Washington officials. In Conservative parlance, this is meant to codify the view that the process of international aid should be privatised, with industry speaking unto industry.
Apart from the lack of compassion implied—the policy could be the distaff side of Mr Norman “on yer bike” Tebbit’s Blackpool homily on unemployment—there is a glaring flaw in this argument. It is that Britain’s trade with the Third World flows predominantly one way, which is not South to North.

2-: From The Journal (Newcastle upon Tyne, Northumberland, England) of Friday 27^th November 1981:

A spoke in the wheel

Employment Secretary Mr. Norman Tebbit must already be regretting that anecdote about how his father had fastened on his cycle clips, got on his bike and set off in search of work.
“Get on your bike” has become one of those catchphrases that will haunt him for years to come.
Many people who uprooted their families to find work elsewhere and are now facing the prospect of going back into the dole queue, may find cause to quarrel with Mr. Tebbit’s famous dictum.
For example, the craftsmen from the North-East, who responded to advertisements from the Ministry of Defence for jobs at Chatham and Portsmouth dockyards, will be pondering their future now that Chatham is to close.
Yesterday Moss Evans, general secretary of the Transport and General Workers’ Union, accused the Government of “a shabby confidence trick” over the issue.
It was an allegation that brought a quick and welcome response from the Ministry of Defence, which disputed some his claims.
An MoD spokesman admitted that the Chatham men from the North-East had been given undertakings about job security. So, he added, those men will be given “special consideration” when the dockyard closes.
There is the added consolation that none of the redundant workers will be summarily removed from their Ministry-owned homes. When the dockyard shuts, they may be allowed to stay on as tenants—albeit jobless ones, far from their original homes.
The Ministry’s assurances will be a relief to worried families—but the whole experience is hardly likely to encourage bike-riding, Tebbit-fashion.

In The broad attack on Thatcher ¹, published in The Guardian (London and Manchester, England) of Monday 8^th April 1985, the British historian Eric Hobsbawm (1917-2012), who was a Marxist, placed the phrase get on your bike in the context of Margaret Thatcher’s policies:

Thatcherite policies clearly represent a style of politics, of ideology, and right-wing demagogy, which is new in British governments, though it has long been found in some press lords. It represents, with unprecedented frankness, the will to wage the class struggle against the workers (“the enemy within” ²) and a contempt for those who need help, for human and social considerations in policy, combined with flag-waving: one might call it “I’m all right, Union Jack.” It represents the feelings of social climbers and hardfaced people who have done, or hope to do, well out of free enterprise (“get on your bike”).

¹ The British Conservative stateswoman Margaret Hilda Thatcher (1925-2013) was the Prime Minister from 1979 to 1990.
² Cf. some British uses of ‘the enemy within’.

In October 2010, the British Conservative politician Iain Duncan Smith (born 1954) expressed an idea reminiscent of Norman Tebbit’s speech—as explained by Jo Adetunji in The Guardian (London and Manchester, England) of Friday 22^nd October 2010:

Iain Duncan Smith tells unemployed they should get on the bus to find work
Work and pensions secretary’s comments recall 1980s advice from Norman Tebbit

Iain Duncan Smith, the work and pensions secretary, was derided today for having called on the unemployed to get on the bus in order to seek work.
Duncan Smith said he wanted people to make a “reasonable effort” to take available work, even if it had to be found elsewhere.
His comments were similar to those of Norman Tebbit, who in 1981 as employment secretary in Margaret Thatcher’s government, said that his unemployed father had “got on his bike and looked for work, and kept looking ’til he found it”.
Speaking on BBC2’s Newsnight, Duncan Smith said: “There was a very good programme the other day that talked about Merthyr Tydfil and the fact there were jobs in Cardiff. But many of them [the unemployed in Merthyr] had become static and didn’t know that if they got on a bus for an hour’s journey, they’d be in Cardiff and could look for the jobs there.
“My point is we need to recognise the jobs don’t come to you.”