cranks

I'm not strong enough to push a big ring up proper hills, so I'd like to swap my dura ace chainset for an equivalent compact.

It's 7800, in very good nick - a few of the usual scuffs but nothing bad. Teeth look good too, hasn't done too many miles. Crank length is 172.5mm.

I'm looking for 7850, or similar - I'll consider SRAM, FSA etc . gotta be compact though.

Pictures here:
http://www.flickr.com/photos/bashthebox/sets/72157628816098477/

Shimano Tiagra triple cranks and BB Tiagra triple cranks and BB by cnarborough, on Flickr

170mm, square taper axle, 53/42/30 rings. Aluminium outer, steel middle and inner. Used - done about 2000 miles but in pretty good condition. Includes UN54 68x113mm english BB. £20 posted for the set, will split.