|"Downgrading" Triple to Double (Ultegra)||the_gormandizer|
Jun 25, 2001 11:50 AM
|I am seriously considering changing from a triple to a double. My current setup is 52-42-30 with a 12/25 cassette, but I seldom feel the need for the granny gear and I would prefer not having to deal with the triple. |
My questions are:
1) Is it feasible to use a 12/27 with a 39-53? I have been told that it's quite difficult to get shifting right for the 27 tooth cog using a short-reach derailleur. If that's the case, would I be better off keeping the long-reach derailleur?
2) Is it true that I would not have to switch the STI levers? Do you need to reset the front derailleur's lever from a 3-click setup to match the double? If so, how?
3) Is the chain for the double with sort-reach derailleur shorter? Can one just shorten an existing chain, assuming minimal wear?
|re: "Downgrading" Triple to Double (Ultegra)||Larry Meade|
Jun 25, 2001 1:33 PM
|1) It is perfectly feasible to use a 12/27 with a 39-53. I have done it numerous times. You don't need to keep the long reach derailleur but there is no reason to change it either. All you really need to change is the bottom bracket and crank. Everything else will work OK but I would also change the front derailleur to a double for crisper shifting.
2) You don't need to do anything to the STI lever. You will get the best shifting performance if you use a double front derailleur but it is not absolutely neccessary.
3) If I were putting on a new crank and a new rear cluster, I would go ahead and spring for a new chain. That way all the important parts of the drivetrain are new and grit free. A good way to size it is to stretch it between the large ring and the largest cog without threading it through the derailleur. Then add about an inch, or one inner link and one outer link of the chain. If you don't change the rear derailleur and deal with all the fun that it entails, the current chain will probably work with the 27. Test it on a stand in the big/big combo before riding it for the first time to make sure it will handle this as you will undoubtably end up in this combo accidently.
|Swapped out my triple yesterday||sidley|
Jun 26, 2001 1:22 PM
|Just swapped out my Ultegra triple and Specialized BB for Dura Ace double with Ultegra BB. I tried to save a few bucks and not get a new front derailer which was a mistake. The chain rubs in almost every gear and the shift is really sloppy. Your drivetrain will work but not well unless you get a short cage derailer.|
|Swapped out my triple yesterday||the_gormandizer|
Jun 26, 2001 1:39 PM
|I'm just about to place an order for front and rear derailleurs, BB, crankset, chain and the required tools. I'll stick to Ultegra, and will keep my 11/25 cassette for now. I've got Zinn's book on order, but am wondering what special tools I'll need. From looking at the Park tool site, it looks like all I need is the BB tool (Park BBT-2), a torque wrench, plus loctite and anti-seize compound. Does this sound right?|
|Swapped out my triple yesterday||xyz|
Jun 26, 2001 2:33 PM
|You don't need a torque wrench (although I will get flamed for saying so...) - just thread it in Tight. Remember, if its an english thread the drive side is lefthanded. Also use anti-seize compound but NOT the loctite. (For that matter, I can't think of a single component of a road bike that should EVER have loctite applied). "Required" tools for your other components are a 5mm allen head for the derrailleurs, 8mm allen head for the crank bolts, chain tool, and a 'fourth hand' tool sure makes cable installs easier.|
|re: "Downgrading" Triple to Double (Ultegra)||xyz|
Jun 25, 2001 1:38 PM
|1. Yes. Keep the long cage. Although, a short cage may work just fine. Try it. You can swap out the 2 long side plates that make up the cage with 2 short plates w/o purchasing a new derailleur.
2. True. You do not 'reset' the shift levers at all. The adjustment is at the derailleur - the 2 limit screws.
3. Your current chain length may change by a full link or 2. You stated your going from 52 > 53. Also a function of which derailleur cage you choose. Yes, you can shorten the existing chain - with the proper tool.
4. You will also need a shorter length bottom bracket for optimal shifting up front. (Triples have longer b/b spindles)
5. Triple to a double is NOT a downgrade.
|re: "Downgrading" Triple to Double (Ultegra)||the_gormandizer|
Jun 25, 2001 2:45 PM
|Thanks (to you and others for the advice). BTW, I used quotes for the word "Downgrade", since I've seen quite a few posts that call going the other way an "Upgrade"!|
|re: "Downgrading" Triple to Double (Ultegra)||Crash|
Jun 25, 2001 2:13 PM
|I was wavering on the double/triple when I bought my new bike (Ultegra) and I ended up going with a double 52-39, 12-27. It has really worked out well, I don't use it that often but it's nice to have the 39-27 as a bail-out gear. But, if I already had a triple on the bike I don't think I would spend the money to change it to a double.|
|did this very thing||terry b|
Jun 25, 2001 2:36 PM
|changed front derailleur, crank, BB. left everything else alone. works just fine.|| |