Right, cut to the chase, this is regarding the DHi's custom MRP: origianl weight: 570g 1) without bottom roller: 480g I lost my bottom roller on a ride 2-3 years ago, and was lazy in replacing it. In fact I never replaced it, and in those 2-3 years I've NEVER dropped a chain. I put this down to a combination of running my chain as tight as I can, having a small block on the back (11-26), the DHi's limited chain growth, and having a chainring smaller than the chaindevices max capacity (40t on a 40-44 world cup guide). Only recently got around to removing the mount for the roller too. Result? About 90g saved (those rollers are heavy!) 2) slalom carbon instead of alu WC: 360g I'm doing the megavalanche this summer, and decided I want a smaller chainring for that. Then I thought about how often I get to crank at 40/11 and it's hardly ever, so figured I may as well make a permanent switch. The world cup guide can only go down to 40t without a lot of rubbing, and I wanted to run a 36t. Bought a (carbon) slalom outer, and a alu. C-plate inner. Result? 120g saved 3) system1 & trimming: 274g Someone bought to my attention the idea of converting the bike to system 1. I.e. two rotating plates. With that there'd be (obviously) no need for the C-plate, which in turn means there's no need for the backplate, almost. Unfortunately the backplate controls the position of the top roller, and can't be eliminated due to the eccentric's movement. However... you CAN trim a lot off of it. Bought a second carbon plate for the inner, and got busy with a hacksaw and dremel. The bottom two corners were completely redundant, but I got a bit keen and removed some of the top section as well. It's THICK aluminium, and does very little, so in my opinion definitely well overbuilt for the job. Result? Another 86g saved, and now 300g total saved compared to the original guide. Plus it looks a feck-load sexier! (Though I forgot to take a pic of it on the bike ) PS: yes, I know, my hacksawing and dremmeling sucks, I got bored! (And I broke the dremel). Disclaimer: I am having to run longer chainring bolts (which I only have in steel at the moment) and some hacked-up-from-an-old-chainring spacers, so that has added 20g.