Good Rear derailer for touring

[livinday2day02]

I'm taking a x-country tour this summer.  I'm making some changes to my Jamis Aurora Elite.  I'm in the process of giving the bike gearing more suitable for touring.  I'm switching the front chainrings out to be 48-36-24.  And I'd like to change the rear cassest for something with a range of 12-34.  One of the problems is the aurora elite comes with  an Ultegra rear derailleur which only gives me a range of 11-27 on my casset.  Are there any recommendations on a rear derailleur that would give me at least equal or preferably better quality and also give me the range I'm looking for? Help please

[livinday2day02]

By the way this is a 2009 model of the aurora elite...major changes in frame design over last years basically cyclocross bike geometry.  The 2009 is much more touring specific frame but poor component choices...like this derailleur.

[staehpj1]

Check out http://www.sheldonbrown.com/harris/k7.html#10 wide range 10 speed cassettes (Interlock Racing Designs 10-speed Cassettes ).  They recommend a long-cage (SGS) rear derailer, such as Deore, LX, XT, XTR.

Like quality would probably be XTR, but even Deore is good enough and the more expensive XTR models are rumored to be less rugged.  Personally I just buy Deore or XT at most.

[livinday2day02]

when you say long cage what do you mean? Also I know that these are typically MTB derailleurs, and this brings me to another question...what is the difference between typical road derailleurs, and MTB?  I mean i guess it must be the range, but is there any other difference?  I have noticed that they like to use these derailleurs on newer cyclocross and even the surly LHT. The XT does seem like a good choice, XTR always seemed like it was for the gram counters.

[staehpj1]

when you say long cage what do you mean? Also I know that these are typically MTB derailleurs, and this brings me to another question...what is the difference between typical road derailleurs, and MTB?

The following link explains that better than I could:
http://www.sheldonbrown.com/harris/derailers-rear.html

[bogiesan]

People toured for decades on only a double front and a five cog rear cassette.

The tradeoffs between climbing gear inches and quality of the mechs is secondary to the compatibility between the front and rear mechs and the rest of the hardware. A ten-speed cassette requires a ten-speed deraileur, ten-click shifter, and ten-speed chain. For touring, this can mean less durability. Some ten-speed grupos are a bit flimsy compared to seven-and eight-gear systems.

And know that in many cases, switching to 10-speed transmissions gains nothing on the extremes, you've just divided the intervening options into finer slices. If you add a huge cog and a tiny chainwheel, you must swap out the mechs to accommodate the huge swings. The lang cage rear mech has the ability to suck up all that extra chain when you drop into the lowest granny or ratchet up to the tallest gear.

david boise ID

[DaveB]

People toured for decades on only a double front and a five cog rear cassette.

That's right and they also toured on a single fixed gear or even on a high wheeler because that's all that was available. We don't have to.  There has been progress in equipment and it's foolish not to take advantage of it. 

A ten-speed cassette requires a ten-speed deraileur,......

That's wrong.  A 9-speed rear derailleur works fine on a 10-speed cassette.  The "speeds" are in the shifter, not the rear derailleur.  You are correct that a 10-speed drivetrain does require a 10-speed shifter, cassette and chain.

One problem the OP will have is that Shimano and SRAM don't make 10-speed MTB range cassettes, only 9-speed so if he wants to go to a Xx32 or Xx34 cassette he will need a 9-speed.  IRD does make 10-speed MTB range cassettes but I've heard mixed reports about their quality. One "cure" for having 10-speed brifters and wanting to use 9-speed everything else is Jtek's "Shiftmate".  These things are relatively cheap (~$35) and work wonderfully well.

And know that in many cases, switching to 10-speed transmissions gains nothing on the extremes, you've just divided the intervening options into finer slices. If you add a huge cog and a tiny chainwheel, you must swap out the mechs to accommodate the huge swings. The lang cage rear mech has the ability to suck up all that extra chain when you drop into the lowest granny or ratchet up to the tallest gear.

True, road 10-speed cassettes tend to provide more intermediate cogs instead of a wider range. 

A long cage MTB rear derailleur is required on wide range cassettes for two reasons:

1. To provide the chain wrap needed to accomodate the wide range of cog and chainring sizes.
2.  To clear the large cog on a MTB cassette.  Shimano road derailleurs are rated to clear a 27T maximum cog.  They will usually accept up to a 30T but a 32 is very iffy and a 34 almost never works.  An MTB rd is made to work with these wide range cassettes.

[paddleboy17]

A do not think that an SRAM derailleur will not work.  My understanding is that a SRAM derailleur will work only with a SRAM shifter, something about the proportions of the parallelagram being different.

Mountain bike derailleurs work under more abusive conditions than a road derailleur, that is why they are more expensive.  XTR is deep into the gram consciousness (as was previously posted), so it is not appropriate here.

Touching up the back end of this bike is likely to snowball.  The conversion could lead to 9 speed cassette, mountain derailleur, and new shifters as well.  Brifters (those integrated brake/shifters) are really expensive.  Going to separate brake levers and barcon shifters would probably be cheaper, and it would let you use those auxillary brake levers that Cane Creek makes. 
http://www.canecreek.com/component-other?product=road-crosstop
I put them on my Waterford and I don't know how I ever made it through life without them.

There was some discussion about this bike on another thread.  I still think the bike should be ridden under load to see if its owner has the leg strength to ride the bike as is. 

I have had mixed results replacing the granny gear on cranks with a smaller one.  For me, I don't think they shift that well.  I previously suggested leaving the back end of the bike alone and putting a mountain crank up front.  It would be great for touring, but probably limited for regular riding.  There are no easy or cheap changes here.

Should livinday2day02 want to go the 9 speed brifter route, I have a pair of used, 9 speed Tiagra brifters in my parts bin.  I relubed them last summer before I put them in the bin, so they should be in good shape.  Contact me off list if you are interested at daniel.merchant@sbcglobal.net.

[SweetLou]

A do not think that an SRAM derailleur will not work.  My understanding is that a SRAM derailleur will work only with a SRAM shifter, something about the proportions of the parallelagram being different.

That would depend on what SRAM derailer you get. SRAM makes both 1:1 and 2:1 pull ratio derailers. Shimano uses the 2:1 ratio. If you get the SRAM 2:1, it will work fine.

[staehpj1]

I previously suggested leaving the back end of the bike alone and putting a mountain crank up front.  It would be great for touring, but probably limited for regular riding.

That is probably the smartest approach at this point and can probably work out well.  Personally I would have never bought the bike with 10 speed as a touring bike now.  Down the road when/if 10 speed becomes mainstream for MTB and touring that may change.  I think that both Cannondale and Jamis are off their rockers WRT how they spec'ed their higher end tourers.

The OEM gearing may work OK in the Cascades and Rockies, but I wouldn't want it in the Ozarks and Appalachians.  Then again there are a limited number of really steep climbs on a route like the TA and they are short enough that they could be walked if need be.  Depending on your route this may not be a big problem.  What route are you riding?  Also are you riding E-W or W-E?  If on the TA and W-E I would just start out with what you have and see how it goes.  You will have plenty of time to evaluate before you get to the Ozarks and Appalachians.  Swap the crank out in Kentucky if you think you need it.  If you need it in the Cascades and Rockies you probably need a more drastic change than just a crank.

An MTB crank with a 22t inner ring can be found for a decent price and if you want the old ratios back after the tour, just swap it back to the OEM one when you are back home.

[livinday2day02]

So I'm going with the idea of leaving the back end and the brifters alone for now.  I'm going to take it out with the new gearing in the front, load it up and go find some big climbs....Another question....?  I hear people mentioning switching out the whole front crank for an MTB crank....is that necessary?  My LBS seems to think I should Leave the FSA Mega EXO cranks and just change the chain rings...Makes sense to me. The FSA cranks are pretty sweet and it doesn't seem necessary to change out the whole crank....right?

[livinday2day02]

I'm going to be going West to east starting in San Fran to do the western express to pueblo, then picking up the TA.....

[staehpj1]

My LBS seems to think I should Leave the FSA Mega EXO cranks and just change the chain rings...Makes sense to me. The FSA cranks are pretty sweet and it doesn't seem necessary to change out the whole crank....right?

The reason a MTB crank makes sense is because since you only have a 27 on the back you are likely to want to go as low as possible on the front, hence an MTB crank that takes a 22t.  I think the smallest the FSA takes is 30t which you already have, right?

[whittierider]

I think the smallest the FSA takes is 30t which you already have, right?

If it has a 74mm BCD for the tiny ring, it will go down to 24T, which we put on our tandem since my wife is definitely not a strong climber and we've done long 10% grades.  Sheldon Brown's BCD crib sheet is at http://www.sheldonbrown.com/cribsheet-bcd.html .  58mm goes down to 20T.

[livinday2day02]

I was under the impression that I could fit a 24t sprocket on the FSA.  I chose 3 new chain rings 48-36-24 to replace the OEM 50-39-30.  I think this will get me in the ballpark for a good climbing gear......24 front 27 rear.....that works out to 24 gear inches....Not that bad even for the Appalachians.