Keo Classic Creak and Chain Slips

[Squarewheels]

So, I have a new pair of RED Look Keo Classic pedals. The cleats are on Scott Comp road shoes. When I am powering up hills, out of the saddle, the cleat feels as though it is coming off of the pedal (but not unclipping), almost as though the pedal isn't tight enough and isn't clamping the cleat down.

And I also have a problem with my chain skipping. The chain is new but the cassette is not. The new chain was put on along with new chainrings and jockey wheels.  The chainrings were 52-42 but were changed to 50-39. The chain is about 1-2 links shorter than it was with the 52-42 (with stretch taken into account). Why does it skip and slip? I can make it do it any gear under enough power and load etc.

 

[Bledlow]

Almost certainly, your old cassette is too worn for a new chain. You have to change chains more often to avoid needing a new cassette (though you will eventually), or reconcile yourself to changing 'em both when the chain goes.

[Biggsy]

Try blobs of grease on the middle of the tops of the pedals, and/or try "bi-material" cleats if you just have plain ones.

Yes the cassette probably need replacing to work with a new chain, but first check the chain for stiff links.

Put the old chain back on if you want to ride the bike before the new cassette arrives.  In fact you could just carry on with the old chain for a few thousand more miles if you don't mind wearing out the chainrings.

[Squarewheels]

So it isn't to do with chain length? I was going to upgrade to 10 speed soon anyway so I might just go ahead and do that and keep the chain as a spare for my other bike.

Will try the pedal suggestions...

Thanks

[Biggsy]

No, nothing to do with the number of links in the chain.  That would only affect extremely crossed-over gears anyway, if any.