"Who owns the bicycle?"
The bike and equipment remain the property of the employer throughout the hire period.
"Who is responsible for maintaining the bicycle?"
It is the employee’s responsibility to maintain the bike.
Fair enough - but how come I have to pay for replacement parts?
Brake blocks, tyres etc. Who owns the replacements?
If it was a car owned by the company they'd pay for all spares and replacement parts wouldn't they? So why's it different with a bike?