I currently have a low quality Shimano Acera on my Trek 4100 and it´s really starting to annoy me when I want to change gears going up hills. I can never anything close to crisp in the shift. So I was considering anything better, LX, XT, even an XTR. But the problem is that they are all 9 speed. Would I need to get a new cassete or hubs or a new chain, if I wanted just to change the derailleur? Could I just run the 9 speed in 7 speed?

Edit: Or could something like this be a good solution?
http://www.pricepoint.com/detail/112...ble-Device.htm

Thanks

the avid thing has been known to help. You are not going to get super good shifts going uphill if your pedaling hard, you have to ease a bit regardless the model.

Acera and Alivio deraileurs are made with relativley soft metal in the pivots. This leads to a short service life before they develop play, which causes awkward shifting. A step up to Shimano LX would be the easiest and most noticeable, the other levels above that(XT and XTR) are incrementally refined above LX but are more money. If you feel up for a little longer term, get an XT. Aceras almost never last more than a few hundred miles before this play sets in. These three types are rated to go at least 4,000 miles or more. XTR has been known to exede 12,000 miles.
The Avid Rolamajig is a good device, but you want to be careful if you deal in a lot of mud and grit. They are advantageous in most conditions since it is a pulley instead of a sliding surface. I am a fan of a teflon housing that is propperly lubed and greased, due to its durability, but I have had freinds who loved them.

you could also try SRAM stuff, but you will need to have sram shiftes becuaese of the 1:1 thing. I have an x7 i got the derailleur+shifter for 80. Works flawlessly, i have a good thousand miles off them

Agreed. I have both and SRAM makes a good product. But for drop in capability, shimano is the cheapest.

I just realized we overlooked a major part of the question. 9-speed rated reraileurs are reverse compatible. They just have an added range of motion, there are minor details, but that is the gist of it. 8-spd chain and 9-spd deraileurs are fine for the job.

Where do you find this fantasy stuff?

Doubt is all of them are, and the correct term you are grasping for is 'low normal'.

Well actually, there are sram shifters/RDs that are shimano compatible.

That is true, but the move is well well worth it. 80 bucks for the x.7 rd+shifters is amazing for what you get.

Hmm, I love how you people answer questions so fast, though it causes me to come up with more questions.

So LX will work fine, as well as XT and XTR? Can you explain me the difference between rapid rise and non RR? As well as whether I´d need a long cage or short cage?

Also how does an x7 compare to a XTR?

Thanks

Well i have not tied XTR but personally i believge XTR is too percent marketing hype. THe price of my shifters and derailleur are still less than the xtr derailleur. My x7 shifts so smoothly that when i first got it installed and all and shifted up i could not hear or feel it so i actually looked back becasuse i did not believe it. :). Now its got 1000 miles and keep in mind i keep my drivetrain fairly clean, but its working like new still. I couldnt imagine XTR be any better, after a certain point what separates these components is the materials used. Some higher end stuff might throw in some carbon fiber or ti hardware for weight savings.

I have run Xt for several seasons of racing and XTR for the last 2. The difference is very minor but it is there. It only becomes apparent in really rough conditions such as one sees on a hardcore xc track. In addition it has real oilite and bronze bushings, to increase the service life.
RapidRise is a matter of debate. I preferred Suntour's reverse front der. The rapid rise design is supposed to be superior in action, but it requires a fair bit of getting used to, and I like being able to pull the cable to downshift when muddy.
On another note:
Syd, when I refer to the construction of these, look for yourself. Can you possibly tell me an Acera uses bushings? It uses the aluminum body, which can be bent by hand.
When I say these are reverse compatible, that is not a RR reference. It is a term we mechanics use to note a part can be used in lesser or older systems.
:rolleyes:

Try backwards compatible.

You say "TOMAYTA" I say "TOMARTO", let's call the whole thing off!

Got my vote.

I have to disagree there, i think thats what the market wants us to believe but i have read many reviews about this stuff, it is my expirience that x.7 and x.9 have the same performance however i believe x7 is 20 or so grams lighter and a different color scheme. The shifters are the same. I suspect x.0 will not show any difference

Im not sure about this year's set but the shimano ders are available in a couple cage lengths. One should only buy the longer unless running single ring anyway.

Bull. Do the wrap caculation,then decide. The shorter cages can work even with some triple setups.

Or just buy same lenghth as was on it initially.

Isn't possible that he's just got gummed up housing or old cables? My advice would be to replace your cables and housing first (unless you've done that in the last 6 months - stainless is a good option) and if it's still crummy, then pony up for the high $ components.

you'll want the fresh cables and housing for the new derailleur anyway so it's a zero cost option. I recently helped a friend get a 15+ year old mtn bike riding like new by cleaning, lubing, replacing cables and re-packing his bb and headset. No compatibility issues because there were no new parts, except the PW grease and some $20 in cables.

it's higher than $0 if he doesn't need it.