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Old 04-30-08, 07:21 PM   #1
bradchu
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Quick question: Dura Ace FC-7400 with 10 speed?

I am working on upgrading a 90's 6-speed to 10-speed. I was hoping to get away with changing just the shifters, rear wheel, rear derailleur and chain. I wanted to keep the existing front derailleur (FD-7300) and crankset (FC-7400), but now I'm thinking this might not work. Do I have to upgrade the crank and FD as well? Does it have to be 10 speed, or can 8 or 9 speed work?
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Old 04-30-08, 07:28 PM   #2
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I am in the same exact boat. From reading sheldon brown's excellent website and doing some research, my understanding is that you will need a new rear derailleur....and cassette....and chain...and shifters. You might need new chainrings (opinions differ, the 6 speed rings might be too thick).

It goes without saying, that you will need a new rear hub (i.e. wheel) and have to stretch your rear triangle from 126 mm to 130mm....not a problem if your frame is steel (like mine) but a MAJOR issue if you have carbon fiber or aluminum. See also sheldon brown's site about this as well.

The cheaper alternative (which I am also considering) is to keep the RD-7400 and go for 8 speed shifters....then you would only need the shifters (about 100 bucks used on Ebay), cassette, and chain.

Good luck!!

Doug

ps Most likely what I will end up doing, to save money, is to get ULTEGRA RD, brifters, chain and cassette, which more reasonably priced, especially from probikekit.com

feel free to drop me a message if you want to discuss this further
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Old 04-30-08, 07:38 PM   #3
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Originally Posted by datlas View Post
The cheaper alternative (which I am also considering) is to keep the RD-7400 and go for 8 speed shifters....then you would only need the shifters (about 100 bucks used on Ebay), cassette, and chain.
If you run a pre-9-speed Dura-Ace rear derailleur you'll need pre-9-speed Dura-Ace Shifters. Non-D-A 8-speed shifters are not compatible with with a pre-9-speed D-A rear derailleur.

The older crankset and front derailleur will probably work with a 10-speed drive train.

Al
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Old 04-30-08, 11:33 PM   #4
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Datlas - Well, I already did all the research and purchasing and got an Ultegra 10speed RD, 10 speed chain, 10 speed cassette on a new wheelset, and Ultegra 10 speed brifters. I'm planning to just pry the seatstays open by 4mm on a temporary basis (it's an old columbus steel frame). All said and done (all thru ebay) it cost me about $400 ($200 considering the return I got on my old parts).

Good to hear that there is one vote for using the old crankset and front derailleur. I just don't want to build it all up and realize that the front end of the drivetrain doesn't run smoothly. I also don't want to pour another $200 into this project.

This is my first full build, though I've been tinkering on this hand-me-down road bike for the past few years. I'll build it up next week when I have time and post the results.
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Old 04-30-08, 11:35 PM   #5
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btw - I wish I had found probikekit before now, their prices are absolutely insane.
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Old 05-01-08, 06:11 AM   #6
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brad....please let us know how it works once you are done. I am curious to know if you can get by with your old chainrings....you might need to get new ones of those also....but I believe the FD can stay.

Yeah, probikekit has amazing prices.
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Old 05-01-08, 02:07 PM   #7
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The ten speed chain will probably find a nice comfy spot between those two chainrings to hang out in. You'll have better luck if you also buy two ten speed chainrings. The teeth are offset towards each other to work with the very narrow ten speed chain.

The shifters will also probably not work with the front derailleur. Even if the throw is correct, the wide spacing between the two plates will probably mean STI front shifting won't work. Front STI is very fussy about everything working well together. While I haven't tried the specific combination of parts you list, I've tried enough to think this won't work. The thickness of the spider tabs has been 3.5mm on Dura Ace cranks since the beginning, so any DA crank can be ten speed compatible just by using the correct chainrings.
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Old 05-01-08, 03:15 PM   #8
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[/quote] so any DA crank can be ten speed compatible just by using the correct chainrings.[/quote]

Interesting.

But could we get ULTEGRA (or, shudder, 105) 10 speed chainrings to put on our D-A 7400 crankset? I imagine so but you cant take anything for granted when it comes to these matters.
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