Chain goes slack when I stop pedalling, what's that about?

[Mitford]

It's a hybrid bike with a 15 speed derailleur, it seemed to be working ok before but now the chain goes slack when I stop pedalling.

 

[rusky]

If the chain is being pushed by the cassette, then it's probably a sticky freehub/freewheel. Also, I'm guessing you mean 16 speed - 8 sprocket cassette, 2 chainwheels.

What bike is it?

 

[Mitford]

hi Rusky,

It is 3 chainwheels x 5 sprockets, a Giant CRS 4, but the gears may not be original. I sprayed a selection of choice lubricants around the freewheel and I think that may have solved the problem, but I'll read up on it and see if there's anything else I need to do. Thanks for your help.

 

[rusky]

How old is it? it's pretty much unheard of these days for an adult bike to have a 5 speed cassette.

 

[Mitford]

It's pretty new but I bought it second hand Rusky, maybe the previous owner put the cassette on. It has a 5 speed gripshift thingy though.

 

[festival]

The lube may have done the trick, it happens more often than you might think.
Has it got a plastic spoke protector on, its a disc between the last cog and the spokes? If so, this sometimes moves and jams the freewheel stopping it from doing its job with the same affect.