Hi all: I am doing a mild bit of gear freaking, and want to change my Norco's stock 52/40 x 13/15/17/19/21/24 gearing to add a lower low: I've decided on 52/38 and have sourced a 27T Uniglide cog for the back.

Question #1 - bike has 600EX rear derailleur, and according to Velobase will wrap 26T and take a max of 28T cog. Chain wrap using the parts I have above is 28T - is this significant enough to worry about?

Question #2 - thinking the best spacing comes with a 13/17/19/21/24/27 rear (big jump to high gear!) but would welcome other opinions.

Thoughts?

Mark

ps. Velobase gets better and better all the time - thanks to all who are contributing.