British police get 93-page guide to riding bikes

British police chiefs came under fire Thursday over a 93-page guide telling officers how to ride their bikes, including how to brake and how to balance to avoid falling off.

The Police Cycle Training Doctrine also warns policemen not to try to tackle suspected criminals while still "engaged with the cycle" -- on the bike -- and gives a diagram on "deployment into a junction" -- turning left or right.

The guide was produced by the Association of Chief Police Officers (Acpo), which insisted it had not been fully approved for publication after the document was reported in the Sun newspaper.

Other advice includes to wear padded shorts for "in-saddle comfort," while officers must always remember to "rear-scan" -- look over their shoulders.

Undercover police are advised that they may have to cycle without a protective helmet to avoid being found out.

But, underlining the importance of sometimes-criticised health and safely laws, it warned: "This lack of protection must be noted and a full risk assessment of the required role... be undertaken."

The Sun -- which noted that the original US constitution ran to only four pages, and the Bible takes less than a page to recount God's creation of the universe -- said the guide had cost thousands of pounds.

Critics said it was a waste of money.

"I am sure it is of great value... but I think you can do this kind of thing much, much more cheaply," said London mayor Boris Johnson, a keen cyclist who has sought to boost bike use since taking office last year.

"This is an absurd waste of police time and thousands of pounds of taxpayers' money," added Mark Wallace, head of the Taxpayers' Alliance lobby group which campaigns against misuse of public money.

But Dave Holladay of the National Cycling Organisation rejected the charge that the guide was too long, and defended its contents.

"I would quite expect a manual on police cycling to tell police officers how to turn corners correctly," he said, adding: "The advice of getting off the bike is actually included in most police bike training."

"Police cyclists have to be exemplars," he told the BBC.