Bosses at the airport recently released a promotional video extolling the cycling facilities available and encouraging more employees to make use of them.
But Lewis Cornwell, who pedals from Ashford to work at Terminal 4 each day, believes the film glosses over the difficulties encountered by many existing cyclists.
He complained of treacherous moss-covered cycle paths leading to terminals, and poorly-lit cycle-storage facilities which had been targeted by thieves.
"For me personally working at T4, the riding experience is varied. The cycle paths leading to the terminal are badly maintained and usually consist of litter, overgrown bushes, broken glass and even fallen trees threatening to block your path," he told getwestlondon .
"The green moss that has collected on most paths is on cold mornings a slip hazard even to the most experienced cyclist.
'The green moss... is a slip hazard even to the most experienced cyclist'
"The cycle lock-up area itself at T4 hasn't been touched for years, is poorly lit and I'm aware of three staff members having bikes stolen with little or no effort from Heathrow to seek CCTV evidence etc.
"If it rains then your bike will be wet and we even had a purge on locks being left on railings last year."
The 39-year-old also said security measures made it difficult for staff to bring essential cycle tools to work, and although he praised the cycle hub where staff can get their bikes fixed for free, he said this was of little use to employees working on the other side of the airport.
"I don't want this to sound all negative. I want more people to ride to work. It's just that the efforts so far don't speak to the cyclists that already use the facilities so why should it encourage new ones?" added Mr Cornwell.
'This year we will establish a dedicated cycle officer – the first of its kind for an airport'
Heathrow estimates that only 800 employees currently cycle to the airport, despite around 16,500 workers living within 5km.
It says it is determined to increase this as part of its commitment to reduce air pollution, which is one of the biggest obstacles to a third runway .
A Heathrow spokeswoman said: "We know cycling is important to our colleagues and it's important to the airport as well. This year we will establish a dedicated cycle officer – the first of its kind for an airport.
"As the largest local employer too, we know we have an opportunity to encourage many more people to take up cycling.
"We are currently working on a new cycling strategy because we know we can deliver a better cycling experience that will attract people to this sustainable mode of transport."