Hi hope all are great... I have looked, I have googled now I am here to get the straight dope.
What was is a great rear derailleur for road bikes with say a Sram 11-32 tooth cassette?


thanks a ton rc

Use a long cage derailleur. Roger

Shimano XTR, XT, LX, or Deore (MTB)

I'm not aware of any road derailleurs that will technically work with a 32 tooth.

That being said, I used a Tiagra rear derailleur with a 34 tooth on my Marin.

So a Dura Ace long cage WILL work with a 32? I've never tried it, and it isn't something we get asked for a lot. lol

I have a Shimano Deore LX with a long cage, that would work ?


rc

Sometimes there are specific issues having to do with a cog being just too huge, but most of the time a derailer is limited by the amount of slack it can take up-- the difference between the number of teeth in the two biggest rings and the number in the two smallest rings.

If you have a "road triple" derailer, you can probably run a double and an 11-32 cassette with no problem if you avoid cross chaining. 1x9 would be bombproof. Sheldon Brown's got a more detailed explanation somewhere...

Hi thanks a ton for the info
I plan to use a 11-32 rear and a 47/30t double front

what do you think ?

rc

LX will work with any combination.

Shimano rear derailers for the road-bike market are all rated to a max cog of 27t. In practice, they can work with larger cogs, but 32t would really be pushing it.
Unless you have a road rear derailer sitting around that you may as well test on your setup, you should just buy a Shimano mtb-marketed rear derailer, nearly all of which are now rated to 34t large cog.

I like your proposed setup, that's a super gearing range for a double.
With that wide of a gearing range, you'd need a long-cage rear derailer to take up the chain slack anyway so you're not giving up anything by going with a "mountain" rear derailer instead of a "road".

My Schwinn commuter runs a 40t single chainring over a 13-32 7-speed cassette for a simple but very effective commuting drivetrain. I use a mountain bike rear derailer, although with the single chainring I don't actually need the long cage to take up that much chain slack. You will with a 17t difference in chainrings.

thanks for that info... I am using a Stronglight model 99 with that 47/30t. I am in upstate SC and do have lots of hills. I am 51 too and just want something to ride with my wife on longer rides... I ride an old single speed I made up mostly. Campy crank with a 55t ring and 21t white industies freewheel... I enjoy it alot, but know I need a geared bike for longer rides with lots of hills....

again thanks a ton

rc

Yeah, you'll be fine with your LX rear derailer. Happy riding with the wife.
I live in central NC and it's rolling hilly here, nothing too long so I can get by on my fixed-gear but for longer rides (and most rides with other people) it definitely pays to have gearing range.

Hi there rc... just curious. What FD have you got. How is the jump from 30T to 47T. I am thinking of a 30/44 front and 11-28 rear setup for our tandem. I'd like to go 30/48 front but afraid the gap might be too big for an ultegra FD to handle.

FWIW, I run 24-48 on the front and 11-28 on the back with a sora FD and it works just great.

Well as far as front derailleurs I just looked and I have a Suntour SuperBe Pro or a Cyclone II
I'll try the SuperBe first if it works ok will keep it.

rc

I've ran these combinations and it has always shifted flawlessly:

A) Shimano 105 8sp brifters + 53/39 crankset + 105 FD + XT M772 long cage (SGS) + 11-32 8sp cogs
B) Shimano Dura Ace 9sp downtube shifters + 44/36 crankset + the same 105 FD + the same XT M772 + 11-32 9sp cogs

It was the late great Sheldon Brown that told me the brifters would work with the XT RD and large cassette. The 53/39 with a 12-23 cassette was killing me before the switch to A)

What cranks are you using? I'm searching for a reasonably elegant way to run the same gearing (ok, a 34 in back, but it's on a touring bike), but the only things i can come up with are 2 of 3 on a triple and a TA.

The 2 of 3 would work, but I hate the look of the bare chain ring tab.

TA's and their clones are just expensive.

Do you have some brilliant idea I just haven't thought of? Please tell me you do.

This is my touring/commuter too. It's old (92ish) deore triple cranks 110x5. Why can't you run a triple?

I could run a triple, but it's just a waste of the middle chainring. On most terrain I stay in my 48, but there are those times when you just need lower gears. The middle chainring doesn't help me any, so why should i bother with it?

Assuming you have Shimano shifters you need a Shimano mountain bike rear derailleur.
If you have SRAM shifters with a 1:1 ratio you will need a SRAM mountain bike rear derailleur.

Al

My Bianchi San Remo has the old "half-step" triple setup. It's a Sugino crank with a 52-48-30 on it. I use a 12-27 ultegra cassette with a Deore rear and a Shimano 600 front. All is controlled by a set of Dura-Ace 10 speed bar ends. Obviously, the 52-27 or 52-25 are impossible. All of the other combinations work, though.

I have a "touring" setup that I am running on my road bike with a 10spd Centaur triple Group. I am using a long cage Centaur Road RD with a 11-34t SRAM 9spd cassette. I found a Centaur hub with a Shimano hub body on eBay. I know there are some aftermarket hub bodies available. The combination works like a champ. The remainder of the specs are: Campy Triple crankset 28/39/50t (28 and 39t chain rings are T/A Specialties), Centaur Ergo shifters 10speed setup for the 9 spd cassette using the limit set screws (pitch is nearly identical to the DA / Ultegra 9spd cassettes). I am using a SRAM 995 chain. Although this setup sounds strange it is smooth as glass once it is set up.

I helped a friend setup a similar setup with Shimano using a 105 group with a Longcage RD. Works very well. The 105 was from a setup he had since the mid 90s. I don't think Shimano has a Road RD other than the Mid Cage type. A neighbor had an LX derailluer installed with her Ultegra 9 speed group. A good starting point for compatibility information is Sheldon Brown's site (RIP).

Wow! Thats a 24T jump. I guess I am over thinking the 18T jump I had in mind. I will go for it and give it a shot.

Just remember, although a larger jump may mean slightly poorer shifting, it also means your going to be shifting a lot less, so its less of an issue. Do it and never look back!

To be fair, there's a 38T in the middle, although I've seen some old touring doubles with a similar jump.

Hi thanks a ton for all the great info...
What I am trying to do is set something up that will give me some go when I need it and help me climb hills as well. I really am not one that needs to go 40 miles an hour down a hill My wife likes that lol, but me too many old bones that hurt when they break I don't need more pins in my body
I think I am going to try a 45 / 30 double. I have a 45 and a 47 for this stronglight 99 crankset and if that is not what I want I'll try the 47 or the 52 lol i have a 36t chainring as well so i can mix and match til i get it right... I just want a double. I don' do alot of shifting.... I am a smell the roses bike rider now days over "wow man I just blew right by that guy" bike rider

thanks a ton again

rc