I have to replace the rear derailleur on my MTB and would want some help for choosing it.
I actually have a Shimano Deore XT RD-M735 (model from about 1993).
I looked at Shimano website for a replacement model and was surprised to see that there is 4 models of Deore XT rear derailleur. (RD-M751-GS, RD-M751-SGS, RD-M760-GS and RD-M760-SGS)
My front sprockets are 28, 38 and 48. I have 7 rear sprockets ranging from 13 to 30.
I suppose I need a SGS model because (48-28)+(30-13)=37 and the total capacity for GS is 33T. The difference between RD-M751 and RD-M760 seems to be the link length but I don't understand what it means.
Also, I don't know if theses derailleur designed for 9 rear sprockets will work with my 7 rear sprockets and shift lever.
Any tips on derailleur choice would be welcome.