Cycling man
Read the bit in Sheldon Brown I linked about chain line. Heres the link again. https://sheldonbrown.com/chainline.html
There is a diagram which shows you what chain line means, and a table which tells you your road inner ring should be 41mm chainline, and a road triple middle ring is 45mm chainline.
So your front mech. would need to go 4mm further out for the Spa triple crank to work
It may not do this, and even if it does the chain will be out of line in commonly used ratios.
Will These Cran Arms Fit My Bike?
Re: Will These Cran Arms Fit My Bike?
Bike fitting D.I.Y. .....http://wheel-easy.org.uk/wp-content/uploads/bike-set-up-2017a.pdf
Tracks in the Dales etc...http://www.flickr.com/photos/52358536@N06/collections/
Tracks in the Dales etc...http://www.flickr.com/photos/52358536@N06/collections/