Shimano Rear D XTR RR and Long?

What's the question?

I noticed this post was out here a couple days and I was trying to figure out what it is you're asking - you don't actually ask any questions, which is why maybe no one has posted anything yet. I'll take a shot at it.

Rapid Rise is Shiamno terminology for a derailleur that works "backwards" from a normal derailleur. Most deraillers, if you disconnect the cable, will return to the highest (smallest) cog. This is called high normal, and it's what almost all derailleurs have been for decades. RapidRise is low normal, meaning it will return to the largest cog. If you're familiar with rapidfire shifters, you know that the rear shifter upshifts with the finger and downshifts with the thumb. Rapidfire is backwards.

Long cage derailleurs are pretty much the standard and go with big cogsets and triple rings. Ever notice how short the cage is on most road derailleurs? That's because they run closely spaced cogsets and only two chainrings. Mountain bike riders typically prefer wider range and they need a longer cage to take up all the slack in the chain.

So if you want to be consistent with what you have in place now, stay away from RapidRise and get the long cage. If you are looking for maximum racing performance, get the RapidRise and the shortest cage you can, but understand that it may limit your gear selection options.

I hope I answered your question.

slaterbike said:

Thank you for your reply. That helps clarify things a lot for me and I didn't think I knew exactly what to ask.

I am putting together a bike for the first time. Epic comp frame, RF deus crank, RockShox WC and some Avid 7 brakes so far but I dont have any components and there were too many options for me!

It sounds like I should go with the XTR long and skip out on the RR for the rear derailler.

Now how about the front d? Do you know what size clamp I will need for an XTR front d? I also don't understand the top side sweep, etc. options for the front d.

Thanks again for the help!

Click to expand...

Specialized uses 34.9mm front derailleurs on most of their bikes. Some of the older models required the special shimano E-Type which clamped with a plate on the bottom bracket. Swing refers to how the derialleur swings in relation to the clamp. Bottom swing also known as traditional is what you've probably seen on most bikes all your life. The clamp is on top with a little arm that swings the cage underneath. Top swing is a low profile derailleur where the clamp actually sits below (more like right next actually) where the cage swings. A very large portion of most modern full suspension frames require top swing for clearance issues. For a Specialized you usually need a 34.9mm top swing with bottom cable pull. The cable pull refers to what direction the cable is routed on the frame. If the cables run along the top side of the frame (top tube) and attand to the front derailleur from the top, then you need top pull. If the cables are routed along the downtube and attach from the bottom it bottom pull. Specialized has traditionally used bottom pull. Most modern front derailleurs will work in either pull direction.