The two 'drivers' are very different in terms of size! It would need to be UK bases.
ta
cc
We had more trouble trying to find a tandem that was the same size front and rear.
Nicholai do custom build tandem frames. Well they would do if the UK importer ever answered the emails i sent them. 😐
Assuming you mean a tall pilot and a short stoker, you could look at a "childback" tandem. Major sources of info would be the "double forte" mailing list, or the tandem specialist shops St John St Cycles in That London and JD Cycles in Ilkley
Ventana
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UK bases
oops sorry missed that bit
You would be suprised what you can get off the peg - but yes custonm are available
Da vinci IIRC and of course alex at MTB tandems in the states
http://www.mtbtandems.com/CustomFrames.html
JD cycles in Ilkley have a Ventana tandem test bike. Any size can be made to order, takes about a month. Ventana only make FS tandems.
St John street cycles are in Somerset, about 170 miles away from London.
There used to be a frame builder in Warwickshire who built tandems, can't remember the name though.
Try George Longstaff up near Stoke. Fantastic quality bespoke tandems and trikes. Sadly George himself is no longer around to do the build but the bikes are still really nice.
Roberts do, seen some nice ones in their shop over the years;
http://www.flickr.com/photos/robertscycles/
They also do the S&S couplings which may be useful.
Thanks eveyone.I will look into the suggestions.
cc
bob jackson in leeds
Mercian Cycles in Derby