I have just bought a new bike with Ultegra SL groupset.

I am finding that sometimes it will shift two gears at a time on the cassette. Also, on some gears it makes that loose sound as though it's not properly in. Do the cables just need the slack taking out? Or is it something more complex?

I'd really appreciate any advice on just general maintainence of gears...

Thanks

Yeah, it sounds like your rear derrailer cable tension is little off. View the cassette from the rear, the RD top pulley should line up below a cog. If it does not, turn the tensioning barrel to line it up. That is your starting point. Now ride it, if everything is ok, you got lucky. If not, you will have to fine tune it. Turn the tension barrel in small increments in one direction only and take it for a ride between each adjustment. If it gets worse, you are turning the wrong way. I do not use the largest or smallest cogs when doing this, as I don't want my high and low DR stop screws to complicate the adjustment process.

Great!

Many thanks.