Mountain Biking - Shimano Rear Derailleur DEORE XT M750 and M760

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Alastair
05-14-04, 01:21 AM
Hi

I have just managed to break my Shimano Rear Derailleur M750 :mad: and it was replaced in a good bike shop by the M760.
Are they backwards compatible?
I have noticed that when changing up it goes down and when changing down it goes up.
This makes the useful function of jumping 2 or more gears to a much lower gear unavailable.
What is going on :o

Any ideas ?


Hunter
05-14-04, 01:38 AM
They put a rapid rise derailleur on your bike. Rapid rise is a reverse spring. In essence the der. works in reverse. Shimano claims that by doing so the spring works to shift up so it is easier to climb hills. Downside is no multiple gear shifts.

catatonic
05-14-04, 02:55 AM
I thnk it was either this month's or last month's Mountain Bike Action magazine that had an article on the whole "low-normal" and "high-normal" shifting systems. it was a pretty good read and if you find that issue, I reccomend at least giving that article a llok at.


hanshananigan
05-14-04, 01:34 PM
I made a similar change about 3 months ago. 'Still misshift sometimes! I miss the multiple downshifts, but have become faster at shifting down with the rapid rise 760. In the end, I think it's made me more conscious of how I'm shifting, and maybe improved my shifting.

Raiyn
05-15-04, 12:31 AM
Bah the only thing that should be "Rapid Rise" is yeast

Maelstrom
05-15-04, 12:36 AM
Hehehehehe...thanks raiyn you made my night. And I agree...

Raiyn
05-15-04, 12:48 AM
Hehehehehe...thanks raiyn you made my night. And I agree...
That's what I do:D

catatonic
05-15-04, 03:15 AM
Found the issue of MTB action that had it, it was may `04 issue. The "10" issue for those that go by articles and not months (it had tons of top 10 lists...)

TimB
05-16-04, 07:31 AM
rapid rise is brilliant and is the way all derailleurs should work

seely
05-16-04, 11:03 AM
Ahh I despise rapidrise... its much more useful to be able to "grab a handful of gears" IMHO but to each their own. I know most of the pros at the NORBA this year were bemoaning the fact they had rapidrise on their new rigs... many swapped it for a 750 but if it works for you and you like it, leave it. I'm not sure if the 750 is still really available or not.

catatonic
05-16-04, 02:16 PM
I noticed for hill climbs "rapid-rise" is pretty nice, especially combined with shimano's strange gear design. I really do think that the rapid-rise was posibly made for their mega-range gearing...since I do see how hard it can be going from an 18t to a 34t gear...my diamondback has one of those strange cassettes, and it's super easy to shift into that 34t gear, possibly from this derailer design.

Phatman
05-16-04, 02:45 PM
I can see the value of a rapid rise system. a few months ago, my rear derailleur cable snapped on my road bike. I was stuck in the 12T cog until the end of the ride, and I'll tell you, I was not a happy camper. to get up hills, I had to switch to the 39T ring, and man, that made a racket, and probably took 1000 miles off the life of my chain.

TimB
05-17-04, 08:30 AM
Idon't see the point in grabbing a whole load of downshift gears at all.

the gearing range on an MTB is so big that one cog usually make a big difference in gear ration. two gears even bigger difference and two flicks of the dual control lever is dead easy and accurate.
also you can shift under load with a rapid rise so even if you find yourself in that one off situation you can still power laong and let the rear mech do the work.

I have the impression that people who don't like RR either have'nt tried it or really don't understand how they use their own gears...

Maelstrom
05-17-04, 12:38 PM
Man thank god I have the ignore feature on. I don't miss being insulted by a shimano worshipper. Its like dealing with the stepford wife of shimano.

seely
05-17-04, 01:01 PM
I have the impression that people who don't like RR either have'nt tried it or really don't understand how they use their own gears...

:rolleyes:

I'm not even going to reply to that one.

catatonic
05-17-04, 03:15 PM
At least to me both sides have their merits. I'll never understand why some folks Bash shimano the way they do, but I've had bikes with either shimano gearing or generic garbage my entire life, so I have had no experience with any quality drivetrain components outside of them.

So far I see how some like to do fast drops to a high gear on the high normal derailer setups, since that is often an easy way to get to a gear quickly, especially on a downhill, so you get maximum speed before you hit levle of inclined ground.

But, I see for the rapid rise (low normal) that you can shift under load with less abuse on your drivetrain (especially when used with hyperglide cassettes), and that in event of a cable breakage you will be left in a slow, but somewhat more usable gearing than if you were on a high normal derailer setup.

I guess it's all a matter of preference really.

Chuckie J.
05-17-04, 08:39 PM
Ahh I despise rapidrise... its much more useful to be able to "grab a handful of gears" IMHO but to each their own. I know most of the pros at the NORBA this year were bemoaning the fact they had rapidrise on their new rigs... many swapped it for a 750 but if it works for you and you like it, leave it. I'm not sure if the 750 is still really available or not.

I have both but use the Dual Control Shifters for the Rapid Rise derailleur and Rapid Fire Shifters for the regular derailleur. I don't confuse the two because of the shifters but I can see how someone could easily go mad trying to think of what standard their using. Doing things subconsciously is a good thing-- could you imagine the accidents that would happen if auto-makers decided to switch the break and gas pedals on a 2004 cars? Yikes!

a2psyklnut
05-17-04, 09:59 PM
A better analogy would be to reverse the shifting patterns on manual transmissions. i.e.

5th gear would be up and to the left with 1st being down and all the way to the right!

Yikes!

L8R

Maelstrom
05-17-04, 10:20 PM
I guess it's all a matter of preference really.

Thats usually the point I take. Both should be the option. While they still offer both for now, they are slowly removing the good stuff from the market...

Maelstrom
05-17-04, 10:20 PM
A better analogy would be to reverse the shifting patterns on manual transmissions. i.e.

5th gear would be up and to the left with 1st being down and all the way to the right!

Yikes!

L8R

Oh good...now my brain hurts even more after dealing with network problems all day ;)...

Raiyn
05-18-04, 12:45 AM
rapid rise is brilliant and is the way all derailleurs should work
Still taking those kickbacks I see.

TimB
05-18-04, 05:51 AM
Still taking those kickbacks I see.

:roflmao:

some funny comments here re kick backs and insults.


I use both systems, Shimano XTR and SRAM X.9.
The XTR is fitted with a Rollamajig from Avid. Differences in shifting:

shimano smooth and less affected by bad adjustment; SRAM quicker but more affected by bad adjustment
Shimano is low normal ; Sram is high normal
Shimano is Dual control ; SRAM is Gripshift (Tried triggers and they don't suit me. They do work well though)
Shimano is 2:1 ; SRAM is 1:1

Overall impressions: The Xtr is more accurate and provides less drivetrain friction than the SRAM. ie spin the pedals backward and see the difference.

Both systems have their merits, it's just that SRAm still has a few more demerits.


Tip for not being insulted:
Don't take this forum personally.


Shimano worshipper?! :rolleyes:

Xtreme Biker
05-18-04, 07:19 PM
rapid rise is brilliant and is the way all derailleurs should work

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:p
Sounds like a Viagra competitor....
:p