Mountain Biking - 1:1 vs Rapid Rise derailleurs

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pyroguy_3
02-03-08, 08:56 PM
I am looking to upgrade the stock alivio RD and am curious about the differences in the 1:1 and the rapid rise systems. I think I know the rapid rise RD has a return spring that helps with downshifting? So does that mean the 1:1 doesn't? Also, will a 1:1 RD work with rapid rise shifters? and vice versa. Basically should I be looking specifically for a rapid rise system (that's the shifter setup I have), or is it a universal thing and only matters on the derailleur end?
On another note, how do the XT's ride? I want to keep it under $100USD so the XTR/X.O parts are out of the question. Any others I should look at?
Fat Boy
02-03-08, 09:24 PM
You're completely confusing these 2 things.
1:1 is the actuation ratio of the SRAM stuff. 1 mm of cable pull on the shifter moves the derailler 1mm. It's the 1:2 on the Shimano stuff. In theory, this gives the SRAM stuff a greater tolerance for being out of whack and still working right.
If you take the cable off of a normal derailler, the spring will pull it towards the smallest cog. By pulling on the cable you move it to bigger cogs on the cassette or lower gears. On a Rapid Rise, it works the other way. The springs pull it towards the big cogs and the cable pulls it towards the little ones (or higher gearing). For the life of my I can't figure out why Rapid Rise exists, but if someone likes it, then good on 'em.
If you were going to use a SRAM rear derailler, then you'd also have to change the shifter because of the different actuation ratios. For that reason, it's going to be out of your budget (except on a sweet Ebay deal, maybe). XT is really, really good stuff. The only difference is that it'll be a pinch heavier than XTR. My advice is to stick with an XT rear derailler.
But if it's better shifting you're after, the shifters will make a far greater difference than your derailleur. If you have Alivio shifters, maybe you could find a deal on some deore or LX shifters on ebay.
pinkrobe
02-03-08, 10:36 PM
But if it's better shifting you're after, the shifters will make a far greater difference than your derailleur. If you have Alivio shifters, maybe you could find a deal on some deore or LX shifters on ebay.
+eleventybillion The shifters make a much bigger difference than the dérailleurs, IMHO.
And sadly the cables and housing make an even greater difference. How on earth am I to justify spending money on nice stuff :(
I run XT rapidfire shifters with an XTR 960 rapid rise derailluer and it all works just fine. Takes some getting used to the shifting pattern reversing but overall I'm very happy.
pyroguy_3
02-04-08, 07:31 AM
Awesome, thanks for the info. Basically I should either stick with shimano's 1:2 if I'm not replacing shifters, which would mean either heavy modification of my damn integrated shift/brake or replacing of the brake levers also, or replace almost the whole transmission system. I think I will probably go XT and just suffer with the shifters for a while. Probably time to switch out cables anyway.
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