Originally Posted by
Miele Man
A Wolf Tooth Roadlik rear derailleur extender should allow you to use a bigger rear cassette cog with your present 105 rear derailleur. You'll probably need a longer chain though.
Cheers
I’ve used the Roadlink to extend the range of the rear derailer on my touring bike
Untitled by
Stuart Black, on Flickr
It works well and allows me to use a 36 tooth cog on the cassette without issue. On my Cannondale, I did have to do some file surgery to the hanger, however. The Roadlink doesn’t work on all derailer hangers.