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Dura Ace 7803 or Ultegra 6700

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Dura Ace 7803 or Ultegra 6700

Old 09-06-11, 11:38 AM
  #1  
merlinextraligh
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Dura Ace 7803 or Ultegra 6700

Our Robusta has the 7800 generation Dura Ace 10 speed with a triple crankset.

We need to replace the rear derailleur. My understanding is that Shimano doesn't make a 7900 triple RD.

So, should I go with another 7803, which appear to be a bit hard to find, or a new Ultegra 6703.

The 6703 RD is supposed to be compatible with 7803 DA shifters, it would be cheaper, and I'm guessing likley shifts as well or better than 7800 generation DA.

But it wouldn't say Dura Ace on it.
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Old 09-06-11, 02:02 PM
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I found a new 7803 rd on eBay and it works great with the 6703 shifters.

Wayne
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Old 09-06-11, 08:12 PM
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Shimano SS & GS RD's

With the popularity of compact cranks and the demise of triples, Shimano is making fewer GS RD's. RD 7800 GS (suitable for triples - RD 7803) is available but rare. Shimano says that the 7900-SS has an improved chain wrap -33 teeth. If the following specs meet your set up, RD7900-SS, might meet your requirements.

Shimano Dura-Ace RD-7900-SS Rear Derailleur
CAPACITY: 33T
COMPATIBILITY: 9/10-speed
MATERIAL: Carbon/Aluminum
MAX. COG: 28T
MAX. FRONT DIFFERENCE: 16T
MIN. COG: 11T
WEIGHT: 166g
Shimano Dura-Ace RD-7900-SS Rear Derailleur
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Old 09-06-11, 08:32 PM
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So, if you need/want a triple, you are probably doing some terrain. If you are doing that, then why not go XTR? Shift's like a dream for us (9spd and SRAM 11-32 cassette), so no need for DA.
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Old 09-07-11, 10:32 AM
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We replaced our DA triple with a XTR (9speed version) SRAM 11-32 10 speed cassette and never looked back as it shifts better then ever. We leave Friday to do Cycle Oregon so it will get another good workout.
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Old 09-08-11, 07:04 AM
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I ride XTR myself, but don't like the lack of an adjuster screw on the new ones. If I'd been happy with the old dura ace 7803, I'd look for one on ebay.
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Old 09-08-11, 12:41 PM
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Originally Posted by tredlodz View Post
I ride XTR myself, but don't like the lack of an adjuster screw on the new ones. If I'd been happy with the old dura ace 7803, I'd look for one on ebay.
I put a Jagwire adjuster at the rear derailleur to solve that issue.
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Old 09-08-11, 01:46 PM
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Why not buy a new short cage and add your long cage to it. Will that work?
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Old 09-08-11, 01:50 PM
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Here is a place that claims to have 3 of the 7803's just like you need. https://www.ebay.com/itm/SHIMANO-DURA...#ht_2897wt_804
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Old 09-08-11, 07:02 PM
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More info than you could ever want comparing Ultegra and Dura Ace is here.



Originally Posted by merlinextraligh View Post
But it wouldn't say Dura Ace on it.
The essay linked above demonstrates that the esthetics are more than just the label, the DA has a finer finish.





The trouble with the DA 7803 is that looooong derailleur cage drooping half way to the ground shouting Triple! evaporates any performance pretensions, which the subtle logo whispering Dura-Ace cannot rehabilitate.




Another reason I prefer the Campy 11-speed. Exclusivity, esthetics, and performance pretensions.
  • Campagnolo > Shimano
  • Super Record > Dura Ace
  • Carbon > Alumimum
  • Black > Silver
  • 157 grams > 180 grams
  • 11-speeds > 10
  • and...one-size short cage RD even for triple. No drooping long cage!


Last edited by Ritterview; 09-08-11 at 11:15 PM.
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Old 12-13-19, 03:16 PM
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I realize this is a very old thread....Bueller, Bueller? Wondering if this DA7803 would handle a 34 rear or is 32 probably the max?
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Old 12-15-19, 04:14 PM
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Originally Posted by smoore View Post
I realize this is a very old thread....Bueller, Bueller? Wondering if this DA7803 would handle a 34 rear or is 32 probably the max?
In my experience working in a bike shop near the Alps where we do a lot of cassette changes, the 7803 deraileur often struggles to clear a 30 or 32 tooth cog, 28 tooth is often the limit. There's almost no chance that it'll clear a 34-tooth without some serious modification or hanger extender.
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Old 12-15-19, 10:18 PM
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Originally Posted by Chris_W View Post
In my experience working in a bike shop near the Alps where we do a lot of cassette changes, the 7803 deraileur often struggles to clear a 30 or 32 tooth cog, 28 tooth is often the limit. There's almost no chance that it'll clear a 34-tooth without some serious modification or hanger extender.
Thanks much for the very helpful response.
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