Long story but I have a Cotic Simple frame I’d like to convert to run gears

Does anyone have a good frame builder recommendations? I know several people have converted vertical dropouts to track ends but would be grateful to know if anyone had done the reverse and who with?

If I’m missing a trick and there is an easy way to do this without butchering the frame I’d like to hear it

Any sensible ideas welcome!

(No I can’t just buy a Solaris, unless anyone has an XL going spare…!)

Ta muchly

This will be a lot cheaper: http://singletrackworld.com/forum/topic/removable-gear-hanger-for-slot-dropouts