What ‘modern’ dual pivot roady brake has upto a 50mm drop?
Shimano long-reach calipers do.
You can get the Ultegra brakes in long reach (code BR-R600)
Max: 67
Min 47
Expensive though.
Those Shimano ones are 47-57, not 47-67.
If you need serious drop, get Tektro R556/R365, 55-73mm drop, perfect for 700c in 27" and fenders.
Otherwise, there’s the R538, 47-57mm and clearance for bigger tyres. They also make R358/R316 (47-57mm) and the R730/R736 (47-57mm)
http://www.tektro.com/02products/08521ag.php
http://www.tektro.com/02products/10sb-1.php
http://www.tektro.com/02products/10qb-1.php
Thanks guys, the R538’s look the goods as I think I need around 45-55mm. I guess you can get them from the usual place or is there anywhere specific one should look?
Try Bicycle Recycle. I got a set of long reach Tektros for a 27" there.