Thousands of cyclists will set off from Millennium Square tomorrow as part of Bristol's Biggest Bike Ride.

They will be following one of five different routes, ranging from nine to 38 miles.

This is the 16th year the event has been held and anyone with a bike can take part in what is a free event for people of all ages and abilities.

People can enter on their own or as part of a team. Families are very welcome, but organisers recommend that any children under 14 taking part should be accompanied by an adult.

Registration will be open in Millennium Square before the different rides start between 9.30am and 11am.

Lots of those taking part will be raising money for charity. In previous years, thousands of pounds have been raised for good causes.

This year Bristol's Biggest Bike Ride is supporting the Lord Mayor's Appeal for Children with the Evening Post.

By donating £1.50, people can help raise money for the appeal, which helps underprivileged youngsters across the city.

Many of those taking part will also be representing their business or school. The challenge is to have the highest number of employees taking part, relative to the size of the employer, or as many pupils, teachers and parents as possible taking part.

Last year's business winner was UWE, and Henleaze Infants and Junior School won the schools' competition.

All the rides finish at the Harbourside, where you can join in the Family Fun Day, collect your ride certificate, meet up with others and enjoy a relaxing summer afternoon.

The Family Fun Day will be taking place around the Lloyds Amphitheatre from 11.30am until 6pm.

Activities will include an extreme mountain bike show, BMX competitions, whacky bikes, bicycle ballet, cycle try-outs, a chill-out zone, children's entertainment marquee, music stage, charity stalls, cycling information stalls, and food and drink.

Ed Plowden, Cycling City project manager at Bristol City Council, said: "This fantastic event is one of the many reasons that Bristol has been designated England's first Cycling City.

"We are really looking forward to a huge turnout on Sunday.

"The weather forecast is good, there is a range of rides to suit all abilities – and the fiesta and fun event in Millennium Square at the end of the rides offers something to enjoy for all the family, whether you're on a bike or not."

The Family Fiesta (about 9 miles)

Approximate start time: 11am

The ride is aimed at inexperienced riders and is suitable for families with young children.

This ride allows riders to enjoy the beautiful Avon Gorge. It goes out along the Portway, turns around at Sylvan Way and returns to Harbourside.

The Avon Gorge Loop (13 miles)

Approximate start time: 10.25am

The Avon Gorge Loop is suitable for families that are more experienced and used to cycling.

This route follows the Portway through the Avon Gorge, turns through Shirehampton and over the dramatic Avonmouth bridge, returning to Harbourside via the Pill path.

The Sustrans Ride to Portishead (24 miles)

Approximate start time: 9.50am

A classic example of how the routes you take when cycling can be much quieter and flatter than by car. Instead of the hilly A369, riders will travel out of Bristol along a largely traffic-free section beside the A4 into Shirehampton. They will then pedal over the River Avon on to more traffic-free trails and quiet country lanes into Portishead. Cyclists return through woodland along the traffic-free Pill to Ashton cycle path before crossing the finishing line in Harbourside.

The Failand Heights Ride (18 miles but hilly)

Approximate start time: 10.10am

A more demanding route suitable for experienced riders who are used to hills and riding on narrow country lanes.

Follows the Avon Gorge Loop but splits off at Pill, following the main road out of Pill, and crosses the A369. The route goes through Portbury with a series of challenging climbs up to Lower Failand, through country lanes to Long Ashton and through Ashton Court back to Harbourside.

The Clevedon Challenge (38 miles)

Approximate start time: 9.30am

Suitable for experienced cyclists wishing for a greater challenge who are used to hills and riding on roads for long distances.

Follows the Failand Heights Ride as far as Portbury, along the Gordano Valley to Clevedon then through Brockley Combe, Barrow Gurney, Ashton Court and back to Harbourside.

The Portway, which will be closed to traffic between 7.40am and 2pm.

Other roads that will be closed are Canons Way, Merchants Road, Brunel Lock Road, Smeaton Road, Hotwell Road, Bridge Valley Road and Cumberland Basin Road.