Using a road front derailleur on a MTB to save weight

Dura-ace FD7800 front derailleur , plus Speen Umlenker , plus carbon cycles eXotic Carbon Front Derailleur Clamp with a few aluminium bolts thrown in for good measure weighs 82g.

Dura ace FD tuned for MTB use

This is much, much lighter than any readily-available MTB front derailleur. For example, the latest XTR front derailleur weighs around 150g.

Related articles:

XT M771 Front Derailleur tuning

These derailleurs start out at around 160g, but with a bit of creative whittling and some alu bolts you can drop the weight down to around 130g:

Shimano XTR Di2 M9050 11 speed rear derailleur

This has got to be one of the most expensive rear derailleurs you can hang off the back of your MTB (and part of the super expensive XTR Di2 group).

Shimano XTR RD-M980 10 speed rear derailleur

Weight: 180g for long cage (SGS) version.

Shimano XTR 11 speed rear derailleur - M9000

Quick facts:

Shimano XT Shadow+ rear derailleur with short cage

There are various iterations of the Shimano XT 10 speed rear derailleur .  However, none are available with a short cage like what the Zee rear derailleur has.

Can you fit a road front derailleur to the Anthem X?

The short answer is "no". It'd be "yes" if you could get a low mount road FD, but you can't. Road front derailleur's are either top mount or braze on. You can normally use a braze-on ...