Go Back  Bike Forums > Bike Forums > Road Cycling
Reload this Page >

Dura ace 7800 long cage ?

Notices
Road Cycling “It is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.” -- Ernest Hemingway

Dura ace 7800 long cage ?

Old 06-13-16, 09:13 PM
  #1  
sinjun
Senior Member
Thread Starter
 
Join Date: Dec 2006
Location: cinti. oh
Posts: 65

Bikes: Workswell Carbon road bike and flyxll Carbon hard tall

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Dura ace 7800 long cage ?

Where can I buy a long cage for a dura ace 7800?
sinjun is offline  
Old 06-13-16, 11:01 PM
  #2  
leicanthrope
Senior Member
 
leicanthrope's Avatar
 
Join Date: Mar 2013
Location: Atlanta, GA
Posts: 799

Bikes: 1975 Fuji Professional • 1988 Bianchi Campione d' Italia • 1982 Fuji Team • 1986 Trek 1000 • 2007 Trek Madone • 1991 Schwinn Paramount PDG Series 3

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Likes: 0
Liked 1 Time in 1 Post
eBay or the like is going to be your best bet.
leicanthrope is offline  
Likes For leicanthrope:
Old 06-14-16, 01:51 AM
  #3  
T Stew
Senior Member
 
T Stew's Avatar
 
Join Date: Jun 2012
Location: Central Ohio
Posts: 865

Bikes: All 80s Schwinns: 88Prologue, 88Circuit, 88Ontare, 88KOM, 86SS, 88Tempo, 88V'ger, 80V'ger, 88LeTour, 82LTLuxeMixte, 87 Cimarron, 86H.Sierra, 92Paramount9c

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 188 Post(s)
Liked 0 Times in 0 Posts
Originally Posted by sinjun View Post
Where can I buy a long cage for a dura ace 7800?
I think that would be custom since they were not available in long cage. 7800 was available in SS (short cage) and GS (medium cage) but not SGS (long cage). Generally speaking the long cages were for triple chainsets, which didn't exist in DA back then. DA seemed to be more about having minimum weight for racing, not about triples and long cages...
T Stew is offline  
Old 06-14-16, 01:18 PM
  #4  
SSRI
Senior Member
 
Join Date: Aug 2005
Location: NYC
Posts: 839
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 92 Post(s)
Likes: 0
Liked 1 Time in 1 Post
http://www.bikeforums.net/bicycle-me...atibility.html

Dura ace did make a triple group for 7800's
7803 .

If you insist on a D/A it will likely have to hunt one down on ebay.
SSRI is offline  
Likes For SSRI:
Old 06-14-16, 01:23 PM
  #5  
Corbin
Senior Member
 
Corbin's Avatar
 
Join Date: Oct 2015
Location: N. Valley, AZ
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 48 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by sinjun View Post
Where can I buy a long cage for a dura ace 7800?
$250 beans: New Shimano Dura Ace RD 7800GS Long Cage Rear Derailleur 10 Speed | eBay

Another: Shimano Dura Ace RD 7800 GS Long Cage Rear Derailleur 10 Speed | eBay
Corbin is offline  
Old 06-14-16, 01:25 PM
  #6  
TimothyH
- Soli Deo Gloria -
 
TimothyH's Avatar
 
Join Date: Aug 2015
Location: Northwest Georgia
Posts: 14,779

Bikes: 2018 Rodriguez Custom Fixed Gear, 2017 Niner RLT 9 RDO, 2015 Bianchi Pista, 2002 Fuji Robaix

Mentioned: 232 Post(s)
Tagged: 0 Thread(s)
Quoted: 6814 Post(s)
Liked 634 Times in 403 Posts
@SSRI is correct. They did make a DA 7800 triple. I know a guy who had that setup on a Calfee.

There is a brand new Dura-Ace 7800 long cage derailleur on Ebay right now.

New Shimano Dura Ace RD 7800GS Long Cage Rear Derailleur 10 Speed | eBay

TimothyH is offline  
Old 06-15-16, 09:14 PM
  #7  
T Stew
Senior Member
 
T Stew's Avatar
 
Join Date: Jun 2012
Location: Central Ohio
Posts: 865

Bikes: All 80s Schwinns: 88Prologue, 88Circuit, 88Ontare, 88KOM, 86SS, 88Tempo, 88V'ger, 80V'ger, 88LeTour, 82LTLuxeMixte, 87 Cimarron, 86H.Sierra, 92Paramount9c

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 188 Post(s)
Liked 0 Times in 0 Posts
Originally Posted by TimothyH;18844914
There is a brand new Dura-Ace 7800 long cage derailleur on Ebay right now.

[URL="http://www.ebay.com/itm/NEW-Shimano-Dura-Ace-RD-7800GS-Long-Cage-NIB-Rear-Derailleur-10-speed-/331880104137"
New Shimano Dura Ace RD 7800GS Long Cage Rear Derailleur 10 Speed | eBay[/URL]
Interesting, but why is it called a GS and long cage, the two are contradictory, shimano long cage where designated SGS correct? (GS for medium cage).
T Stew is offline  
Old 06-15-16, 11:40 PM
  #8  
Corbin
Senior Member
 
Corbin's Avatar
 
Join Date: Oct 2015
Location: N. Valley, AZ
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 48 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by T Stew View Post
Interesting, but why is it called a GS and long cage, the two are contradictory, shimano long cage where designated SGS correct? (GS for medium cage).
You're right no sgs for 7800. The gs was a long cage for it. Here's a shimano document: https://www.google.com/url?sa=t&rct=...j_rH94s6baLAqQ

To clarify there was a short cage (ss) and a long cage (gs) no medium cage.
Corbin is offline  
Old 06-16-16, 12:35 AM
  #9  
T Stew
Senior Member
 
T Stew's Avatar
 
Join Date: Jun 2012
Location: Central Ohio
Posts: 865

Bikes: All 80s Schwinns: 88Prologue, 88Circuit, 88Ontare, 88KOM, 86SS, 88Tempo, 88V'ger, 80V'ger, 88LeTour, 82LTLuxeMixte, 87 Cimarron, 86H.Sierra, 92Paramount9c

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 188 Post(s)
Liked 0 Times in 0 Posts
Ahh I had the GS/SGS terms backwards darnit.
T Stew is offline  
Old 06-16-16, 12:42 AM
  #10  
Corbin
Senior Member
 
Corbin's Avatar
 
Join Date: Oct 2015
Location: N. Valley, AZ
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 48 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by T Stew View Post
Ahh I had the GS/SGS terms backwards darnit.
No you are right. sgs is typically long cage. Just not that year.
Corbin is offline  
Old 06-17-16, 12:41 AM
  #11  
redlude97
Senior Member
 
Join Date: Sep 2011
Posts: 4,383
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 1772 Post(s)
Liked 72 Times in 55 Posts
Originally Posted by Corbin View Post
No you are right. sgs is typically long cage. Just not that year.
regardless of what they call it, the RD-7800GS is a medium cage based on the specs with only a 37t total capacity. Shimano doesn't make any road long cages. A long cage sgs has a 40+T total capacity
redlude97 is offline  
Old 06-17-16, 01:10 PM
  #12  
merlinextraligh
pan y agua
 
merlinextraligh's Avatar
 
Join Date: Aug 2005
Location: Jacksonville
Posts: 30,375

Bikes: Wilier Zero 7; Merlin Extralight; Co-Motion Robusta; Schwinn Paramount; Motobecane Phantom Cross; Cervelo P2; Motebecane Ti Fly 29er; Calfee Dragonfly Tandem

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 903 Post(s)
Liked 13 Times in 9 Posts
We have Dura Ace 7800 triple on our Co-Motion Tandem. Gearing is 53-39-26, and an 11-28 cassette in the rear. So a 44 tooth difference and it works fine.
__________________
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
merlinextraligh is offline  
Old 06-20-16, 05:13 AM
  #13  
T Stew
Senior Member
 
T Stew's Avatar
 
Join Date: Jun 2012
Location: Central Ohio
Posts: 865

Bikes: All 80s Schwinns: 88Prologue, 88Circuit, 88Ontare, 88KOM, 86SS, 88Tempo, 88V'ger, 80V'ger, 88LeTour, 82LTLuxeMixte, 87 Cimarron, 86H.Sierra, 92Paramount9c

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 188 Post(s)
Liked 0 Times in 0 Posts
Originally Posted by merlinextraligh View Post
We have Dura Ace 7800 triple on our Co-Motion Tandem. Gearing is 53-39-26, and an 11-28 cassette in the rear. So a 44 tooth difference and it works fine.
Does it shift all the way from big/big to small/small? You can certainly run gears that exceed your total derailleur capacity as long as you don't mind loosing some on the end, but those you wouldn't really ever need to use / shouldn't use anyhow. Shimano has been known to underrate by a few teeth though.

FWIW here is a screenshot from the 7800 installation guide of the specs:

Attached Images
File Type: jpg
7800RD-specs.JPG (17.9 KB, 219 views)
T Stew is offline  
Old 06-21-16, 11:27 AM
  #14  
merlinextraligh
pan y agua
 
merlinextraligh's Avatar
 
Join Date: Aug 2005
Location: Jacksonville
Posts: 30,375

Bikes: Wilier Zero 7; Merlin Extralight; Co-Motion Robusta; Schwinn Paramount; Motobecane Phantom Cross; Cervelo P2; Motebecane Ti Fly 29er; Calfee Dragonfly Tandem

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 903 Post(s)
Liked 13 Times in 9 Posts
Originally Posted by T Stew View Post
Does it shift all the way from big/big to small/small? You can certainly run gears that exceed your total derailleur capacity as long as you don't mind loosing some on the end, but those you wouldn't really ever need to use / shouldn't use anyhow. Shimano has been known to underrate by a few teeth though.

FWIW here is a screenshot from the 7800 installation guide of the specs:

Yes. It runs fine in the 53-28. The 26-11 combo is a bit noisy because of interference from the middle chainring, but the chains' not overly slack.

In my experience, Shimano is pretty conservative in their specs. It has to work to their standard on every bike (regardless of chain stay length, and other variables from bike to bike) So, most of the times, Shimano derailleurs will work well past their official specs.
__________________
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
merlinextraligh is offline  
Old 09-10-19, 09:42 PM
  #15  
malcala622
Senior Member
 
malcala622's Avatar
 
Join Date: Oct 2014
Location: Pico Rivera, CA
Posts: 2,087

Bikes: Bianchi Trofeo/Limited/Giro.Tommasini Prestige. Bottecchia Cromor. Gios Torino. Torelli Strada?

Mentioned: 60 Post(s)
Tagged: 0 Thread(s)
Quoted: 570 Post(s)
Likes: 0
Liked 65 Times in 50 Posts
Instead of a new thread i figure id get info here. Being that its on the topic of a mid cage 7800 rear derailleur.

Would I be able to run a 11-32 or larger cassette?

I currently have a 12-25 with 53-39 front chainring.

Cost me a shiny penny some 5 years back for this 7800 derailleur

malcala622 is offline  
Old 09-10-19, 09:49 PM
  #16  
Kimmo
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 8,276

Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 558 Post(s)
Liked 74 Times in 63 Posts
Suck it and see. If not, get one of those wolf tooth things.
Kimmo is offline  
Likes For Kimmo:
Old 09-10-19, 10:25 PM
  #17  
Dave Mayer
Senior Member
 
Join Date: Dec 2006
Posts: 1,836
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 635 Post(s)
Likes: 0
Liked 28 Times in 18 Posts
Get a XTR 9-speed rear derailleur. The 9-speed versions can be had for much less than $100. I've seen a few pass through our local bike Co-op - donated.

The XTR units are made to the same level of quality of workmanship and materials as the contemporaneous Dura-Ace 9-speed units.

Of course, Shimano road and MTB derailleurs and shifters of this era were cross-compatible.

Last edited by Dave Mayer; 09-10-19 at 10:32 PM.
Dave Mayer is offline  
Likes For Dave Mayer:
Old 09-10-19, 10:36 PM
  #18  
malcala622
Senior Member
 
malcala622's Avatar
 
Join Date: Oct 2014
Location: Pico Rivera, CA
Posts: 2,087

Bikes: Bianchi Trofeo/Limited/Giro.Tommasini Prestige. Bottecchia Cromor. Gios Torino. Torelli Strada?

Mentioned: 60 Post(s)
Tagged: 0 Thread(s)
Quoted: 570 Post(s)
Likes: 0
Liked 65 Times in 50 Posts
Originally Posted by Dave Mayer View Post
Get a XTR 9-speed rear derailleur. The 9-speed versions can be had for much less than $100. I've seen a few pass through our local bike Co-op - donated.

The XTR units are made to the same level of quality of workmanship and materials as the contemporaneous Dura-Ace 9-speed units.

Of course, Shimano road and MTB derailleurs and shifters of this era were cross-compatible.
I would like to keep using this 7800 10 speed derailleur since its a match to the groupset.
malcala622 is offline  
Old 09-10-19, 10:44 PM
  #19  
Dave Mayer
Senior Member
 
Join Date: Dec 2006
Posts: 1,836
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 635 Post(s)
Likes: 0
Liked 28 Times in 18 Posts
OK... Then transplant a cage assembly from the 9-speed XTR (only) derailleur over to the Dura-Ace derailleur body.
Dave Mayer is offline  
Old 09-10-19, 11:00 PM
  #20  
malcala622
Senior Member
 
malcala622's Avatar
 
Join Date: Oct 2014
Location: Pico Rivera, CA
Posts: 2,087

Bikes: Bianchi Trofeo/Limited/Giro.Tommasini Prestige. Bottecchia Cromor. Gios Torino. Torelli Strada?

Mentioned: 60 Post(s)
Tagged: 0 Thread(s)
Quoted: 570 Post(s)
Likes: 0
Liked 65 Times in 50 Posts
Originally Posted by Dave Mayer View Post
OK... Then transplant a cage assembly from the 9-speed XTR (only) derailleur over to the Dura-Ace derailleur body.
This already has a "long" cage but in that era it was called Mid
malcala622 is offline  
Likes For malcala622:
Old 09-11-19, 06:46 AM
  #21  
shelbyfv
Senior Member
 
shelbyfv's Avatar
 
Join Date: Jun 2007
Posts: 5,529
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1201 Post(s)
Liked 201 Times in 133 Posts
The cage isn't going to change whether the 32 clears the pulley. It's unlikely that it will, but depends on the configuration of the dropout. Try it and see. If it doesn't work, Wolf Tooth, MTB derailleur or reversed B screw are some options. Why not go to a compact crank if you need easier gearing?
shelbyfv is offline  
Likes For shelbyfv:
Old 09-11-19, 07:32 AM
  #22  
cycledogg
Senior Member
 
cycledogg's Avatar
 
Join Date: Dec 2012
Location: Tennessee
Posts: 1,134

Bikes: Cannondale CAAD4, CAAD5, CAAD7 (Optimo), '07 SystemSix, '08 Trek TTX 9.0, 2015 Cannondale Supersix Evo - ZIPP

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 333 Post(s)
Likes: 0
Liked 9 Times in 8 Posts
Keep in mind that the parallelogram design of the rear derailleur governs how wide the rang is for the mech to shift. The cage will not guarantee the size of the cassette to be used.
cycledogg is offline  
Old 09-11-19, 08:56 AM
  #23  
Davet
Licensed Bike Geek
 
Davet's Avatar
 
Join Date: Oct 2002
Location: Los Barriles, Baja Sur, Mexico
Posts: 1,230

Bikes: Kirk Terraplane, Serotta Ottrott, Spectrum Super Custom, Hampsten Carbon Leger Tournesol

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 54 Post(s)
Liked 11 Times in 8 Posts
Originally Posted by malcala622 View Post
I would like to keep using this 7800 10 speed derailleur since its a match to the groupset.
Your Dura Ace rear derailleur will not clear a 32t rear cog in its stock configuration.

Last edited by Davet; 09-11-19 at 09:20 AM.
Davet is offline  
Old 09-11-19, 09:20 AM
  #24  
malcala622
Senior Member
 
malcala622's Avatar
 
Join Date: Oct 2014
Location: Pico Rivera, CA
Posts: 2,087

Bikes: Bianchi Trofeo/Limited/Giro.Tommasini Prestige. Bottecchia Cromor. Gios Torino. Torelli Strada?

Mentioned: 60 Post(s)
Tagged: 0 Thread(s)
Quoted: 570 Post(s)
Likes: 0
Liked 65 Times in 50 Posts
Originally Posted by Davet View Post
Your Dura Ace rear derailleur will not clear a 32t rear cog.
Thanks for this straight up answer. 2nd option was going 12-28 cassette and 50t big chainring. Theyre easily avaipable.

@shelbyfv thanks for that suggestion. It was a option i had in mind.
malcala622 is offline  
Old 09-11-19, 12:23 PM
  #25  
mercator
In the wind
 
mercator's Avatar
 
Join Date: Aug 2006
Location: Calgary AB
Posts: 1,196

Bikes: Giant TCR Advanced Team, Lemond Buenos Aires, Giant TCX, Miyata 1000LT

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Likes: 0
Liked 1 Time in 1 Post
I'm using that derailleur with a 12-30 cassette with zero problems. I don't think anything larger would fit.
mercator is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.