Shimano is the major company making Brake / Shift levers for mountain use. Please read these reviews in the order presented, so we can avoid explaining the same principles with each of the three items. We chose top write about the XTR first because it is the longest in production of the 3 and wanted to discuss how the Rapid Fire shifter has changed in the current Optical Gear Display version. Incidentally this the last year the M900 will be made. For 1995 Shimano will introduce an OGD version of the XTR brake/shifter.
We want to remind you that all indexing systems for shifting reside only in the shifter. Any rear derailleur can be used with any indexed shifter, there are some very fine adjustments that are invisibly built into "systems" but the indexing will function with any index shifter. Some makers of bike parts have chains and rear gears that might add speed to achieving the shift. These Shimano shift systems are designed to use the industry standard of 4.8mm spacing on-center between rear sprockets. They will work with any rear changer, chain, or cassette...no matter who made it.
In the 1995 model year Shimano will introduce an 8 speed version of the LX Rapidfire brake/shift lever set. As we've pointed out in the above images the differences between them from a manufacturing point of view are insignificant in materials and time, (in fact we've hinted that it may take more time to keep a separate assembly line running). Frankly, the 8 speed version should cost no more than the 7 speed model because it will probably be the XT shifter used inside the new LX mechanism, but we expect the 8 speed to cost more.
Remember, you can upgrade the 7 speed version merely by ordering an 8 speed M737 right shifter replacement which will replace just the lower shifter component of the lever not the brake functions or the OGD. Shimano will be selling both the 7 and 8 speed models of the LX levers in the 1995 year and probably phase out the 7 speed version 1996.