This is an "is it worth it" idea. In my mind I'm 98% sure it'll work. First, I have an early 80's Univega road bike that has a 52 X39 crankset (square taper) and a 14-28 freewheel (6spd); 700c wheelset. Second, have a Sugino road triple crankset (52/42/30) that I'm considering to convert as a double with 42/24 rings (I have the rings). From what I can gather, it should work. Chain and line will need to be adjusted but I'm not sure about the FD. Will I need to change the FD to a road triple FD or do you think the old FD will work? The bike has downtube friction shifters (Shimano DuraAce). Your input, comments, suggestions would be appreciated. I'm sure I'm overlooking something. PG.
A road double should work fine. For extra geekiness you could set up 24-39-42 or 24-42-45 and you will have 'half step plus granny' gearing. I use a 105 FD-5501 to shift over 24-39-42 (with STI, even, and no trimming) and only had to adjust the chainring spacers.
It does take some finessing the height and angle of the FD so if you have a braze-on it would be harder.
I've been lusting after a TA crankset because I want a crank set up like this. I just never thought of this. I assume your going to run your large chainring on the inside of the crankarm, so what are you going to do about the funny looking tabs on the outside of the crankset? Maybe a 110bcd bash guard?
Spec' Tarmac (road), Spec' Secteur Disc (commuter & tourer), Salsa Mamasita (MTB), CoMo Speedster (tandem), Surly Big Dummy (cargo), Airnimal (folder), a train pass, and NO car :)
On my commuting/touring bike ('03 Trek 520) I'm running 26-42 chainrings on the inner two positions of a 105 triple crankset. I'm using a mountain bike FD, which is working just fine with an old down-tube 105 front shifter. I then have a 9-speed 105 brake/shifter to control the 12-27 cassette. It's an awesome setup. Chainline is fine since I stay in the 42 (middle position) 95% of the time. I'm planning to get a Salsa crossing chain guard to mount in the big-ring position.
On my road/racing bike ('07 Trek Madone) I'm running 28-46 chainrings on an Ultegra triple crankset paired with a SRAM 10-speed 11-26 cassette, which also works great. Shifting is the similar to the tourer: Dura-Ace down-tube for the front and Ultegra brifter for the back, which is like Lance used to run back in the old days (I expect that he won't use this setup during his comeback because the new Madone frames don't have the mounts for downtube shifters). I'm leaving the outside chainring position blank on that one, and the empty tabs just help to show off my red chainring bolts. Chainline is improved by the fact that I have a dropstop chain retention device mounted on the bottom bracket, which makes the chainline for my two rings virtually as it would be with a standard double crankset.
'''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Originally Posted by Chris_W
Dura-Ace down-tube for the front and Ultegra brifter for the back, which is like Lance used to run back in the old days (I expect that he won't use this setup during his comeback because the new Madone frames don't have the mounts for downtube shifters).
Just for the record, Lance, and a few other riders, did this on some mountain stages because the setup was slightly lighter than using two STIs.
These days with the UCI mandated minimum weight requirement and bikes that have to be ballasted just to reach that weight, saving a few grams by using a downtube shifter is a non-issue.