Broken deraillur - upgrading groupo

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Hey !

I have been so "fortunate" to have the rear deraillur break off my bike, and do some fun around the rear of my MTB - thus I need to replace it. As I wished to upgrade to better groupo, now is the time. In this regard, I have some doubts, where I hope you can help ... :)

I am running the Felt FS-600 bike, equipped with Shimano Acera 7-speed gears and a custom crank. I am looking to do the "small" leap, to go XT (M750 serie) equipment and in doing that, choosing a 9-speed option. (rough price in my currency is 30.000Y while a new bike is 200.000Y, so yes, it's worth it)

So the question goes :
1) What is the main difference between the RD-M750-GS and RD-M750-SGS models ? (one is lighter and more expensive, any other differencies - aka one makes shifting smoother, longer lasting ... ?)
2) As I want to change the crankset to the FC-M752 180mm, do I need an new "bottom bracket" ?
3) I have tried to gather the spareparts I need, have I forgot any - is there better or more optimal choices, keeping durability in mind ?
- ST-M750, RD-M750-SGS, FD-M750, FC-M752, CS-M750, CN-HG93
4) As I go from 7-speed to 9-speed, I need the new Casette Sprocket - I figure it would not fit my current 7-speed "unknown" wheel. Which wheel solution would fit an allround rider, with focus on long-distance rides and light offroad. I weigh about a 100kg and is thus not in the low-range. 26" size.

Many thanks,

/ Lars
http://www.ljweb.com



PS. Courious about how a deraillur also can look ?
http://cycling.devarea.dk/photos/19_2.jpg

The SGS version uses what is known as a long cage. It picks up more chain slack in order to use it with cassettes that have a 34 tooth cog. The GS or medium cage is designed for a maximum 32 tooth cog in the rear.
You can't just take your bike and start upgrading bits and parts to XT 9 speed. You will have to do it all the way. That will mean replacing both derrailleurs, crankset, bottom braket, shifters and possibly wheels. The only think you can do now is use an XT rear derrailleur with a 7 speed system because that doesn't matter. The shifter is what determines the movement of the derrailleur. As long as the derrailleur can cover the range of the 7 speed it will work.

Originally posted by Hecubus
The SGS version uses what is known as a long cage. It picks up more chain slack in order to use it with cassettes that have a 34 tooth cog. The GS or medium cage is designed for a maximum 32 tooth cog in the rear.

Ahh, then the SGS for me ;) thx

You can't just take your bike and start upgrading bits and parts to XT 9 speed. You will have to do it all the way. That will mean replacing both derrailleurs, crankset, bottom braket, shifters and possibly wheels. The only think you can do now is use an XT rear derrailleur with a 7 speed system because that doesn't matter. The shifter is what determines the movement of the derrailleur. As long as the derrailleur can cover the range of the 7 speed it will work.

As I posted, I was planning to buy the full set, and thus the 30.000Y excluding rear wheel - that includes the Mega9 STI Leverset, Rear/Front deraillur, crankset, chain and casette sprocket (though it seems it comes with the wheels)

Thx for the help so far

/ LJ
http://www.ljweb.com

Cassette sprockets never come with the wheels. Unless its some sort of combo offer from the vendor.