I've got a brand spanking new Mercier Kilo TT Pro running 48 x 18. It's a bit to much gear for this 60 year old guy. I've done a little Googling and it appears that going to a 19 cog is as high as I can go.

A couple of questions.

1. Is 19 the largest cog available? If not, where do I find more cog teeth online?

2. Am I going to have to go with a smaller chain ring? If so, where is a good source for Sugino rings online?

I'm not seeing a lot of options with smaller Sugino's except the Messenger.

Opinions and advice please