Difference in rear derailleur on a bike?

Question

More specifically what is the major difference between the Shimano LX and XT both of which are 9 speed or the SRAM-7 and the SRAM-9?

No ****...i would like to know why it is considered better! Like what makes it a better one over the other?

Answer 1

Don't know if I'd agree that lighter components shift gears better. I mean, more expensive derailleurs ARE lighter and DO shift gears better. But one doesn't cause the other. It's more a case of better manufacturing and hardware involved means lighter weight, and better shifting.

So basically, the more you pay for a derailleur, the lighter it will be, and the more precise it's shifting will be.

In terms of strength, I don't think lighter means weaker either. Think about it - would a derailleur manufacturer (of which there really only are 2 at the moment worth considering - Shimano & SRAM), make their products weaker as they increase in price?? "Here's our bottom of the range Deore, but for just 10 times the price, we can give you an XTR that's much much weaker!!"

From the top down it goes:
Shimano:
XTR, Deore XT, Deore LX, Deore (more from here, but really crap)
SRAM:
X0, X9, X7 (I think that's it)

Shimano also have Saint and Hone in their mix, but I don't know where you'd place them. I think Saint (which is for DH, Freeride) is about XT level, and Hone (All Mountain apparently) is about LX Level. They also have a BMX range too, don't know much about that.

The diff between SRAM and Shimano is ... well ... they're just different ways of achieving the same outcome - to shift gears. I think their actuation ratios are different (ratio of cable/shifter travel to derailleur movement and subsequent gear change), but I certainly don't think one way is better than the other. SRAM has had quite a rise in popularity over the last few years. But that doesn't make them better. I honestly think you'd be hard pressed to find one better than the other. Perhaps keep an eye on the SRAM vs Shimano test in AMB magazine over the next few issues.

Personally - I'm a Shimano man (XT mechs & brakes, LX crank) and always have been. Mainly because they do rapid rise (low-normal) rear derailleurs - which just make more sense in my opinion (having the bigger cogged/low gears, as the return sprung position, rather then the other way round).

If you're going to get XT - get the new 2008 XT. Looks awesome! (see below)

Answer 2

SRAM uses different leverage than Shimano. Shimano uses 2:1, while SRAM 1:1.

From everyone I've heard that went from Shimano to SRAM, they're in love with SRAM and happy of the change. I still ride Shimano, but I want to try SRAM.

About the differences between LX and XT (2007), I believe it's a tiny bit of weight, and a tiny bit in performance, as well as the difference between X.7 and X.9 in SRAM.

If you buy SRAM, you need their shifters, Shimano won't work (or viceversa).

Answer 3

Aside from the amount of cogs (speeds)- and price- the main difference you will find is in the weight of the components. The lighter the component is, it shifts gears easier and faster. However, light components have finer adjustments and are affected more quickly by things such as cable stretch than their heavier cousins are. XT is Shimano's second best line, after XTR, and LX is the next level down, and thus is heavier and shifts slightly slower than XT. As for the SRAM derailleurs, I do not know the difference between the models (I ride road, not mountain), but I would assume the differences follow the same pattern.

Answer 4

XT and sram X-9 change gears more smooth and more accurate, that's all and the only differences

Answer 5

the higher models are lighter and do their job better. if your going from tiagra to 105, theres not much difference. if you go from tiagra or 105 to Dura Ace, you will notice a significant difference in weight, durability, and performance, especially if the entire is decked out with it. on a road bike, you only need that high performance crap if you race. other wise tiagra or 105 works great. unless you have lots of money and you can afford the big bucks for the best just to have fun, then go for it, it is worth it. i should also add that the more expensive, the more precise the components get as well. the average rider may have trouble operating them. for example, expensive shifters have a "half-shift" on the front derailleur which can cause headaches if you dont have the proper riding techniques down.

Answer 6

i've had great luck with both. the main difference is the cable attaches to the sram derailleur with less cable and more easily. as far as quality goes i've mountained biked with both and had no problems at all. go with whichever costs less and just keep it in good condition

Answer 7

just quality