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An alternative to using a compact crank set - Page 4

post #46 of 143
Thread Starter 

Hi alfeng, swampy1970 and Peter@vecchios, do the following alternatives look correct :-)

 

  1. 11-32T 10spd MTB cassette with a crankset (39-52/53T) and a GS RD (depends on dropout length)
  2. 11-32T, 11-34T 10spd MTB cassette with a crankset (39-52/53T) and a GS RD with the 11T pulley wheels changed to 10T pulley wheels (11-34T depends on dropout length and 11-36T might be possible)
  3. 11-32T 10spd MTB cassette with a crankset (39-52/53T) and a GS 9spd SLX/XT/XTR MTB RD (M662, M770, M772, M970, M972)
  4. 11-32T or 11-34T 10spd MTB cassette with a crankset (39-52/53T) and a SGS 9spd SLX/XT/XTR MTB RD (M662, M770, M772, M970, M972)
  5. 11-32T, 11-34T or 11-36T 10spd MTB cassette with a crankset (39-52/53T) and a SGS 9spd SLX/XT/XTR MTB RD (M662, M770, M772, M970, M972) with the 11T pulley wheels changed to 10T pulley wheels
post #47 of 143

Hello,

Thanks for interesting & useful discussion.

I too, am fed up of pushing my bike in steep hills (11-23).

I'm getting the XT 11-34 cassette but keeping my ultegra 6600 GS

Could you tell me what jockey pulley you've got? (model/brand)

On several website, they mention 11t for shimano and 10t for campagnolo. But they don't say if they are interchangeable

Thanks again,

Oliver

post #48 of 143
Thread Starter 
Quote:
Originally Posted by digifant View Post

Hello,

Thanks for interesting & useful discussion.

I too, am fed up of pushing my bike in steep hills (11-23).

I'm getting the XT 11-34 cassette but keeping my ultegra 6600 GS

Could you tell me what jockey pulley you've got? (model/brand)

On several website, they mention 11t for shimano and 10t for campagnolo. But they don't say if they are interchangeable

Thanks again,

Oliver

Hi digifant, the 10T campagnolo pulley wheels can replace the 11T shimano pulley wheels, just swap them over, they fit perfectly, and it is easy to do.  If you can wait, I am doing this tomorrow using an XT 11-34T 10spd cassette, DA GS RD with 10T Token alloy pulley wheels, and I am also going to use an Avid Rollamajig to remove the rear bend in the cable.  Hopefully I should have a pic or two to show :-)

 


 

post #49 of 143

That is to use one of the new MTB XT Dyna Sys 10 spd 11-34 cassettes with a MTB 9 spd XT(M772) or XTR(M972) GS/SGS RD (which should be index compatible with my DA 7800 STI lever).  I am not sure, though,  whether to use a GS Medium Cage or a SGS Long Cage?

post #50 of 143

 

Quote:
Originally Posted by frankiemuniz01 View Post

That is to use one of the new MTB XT Dyna Sys 10 spd 11-34 cassettes with a MTB 9 spd XT(M772) or XTR(M972) GS/SGS RD (which should be index compatible with my DA 7800 STI lever).  I am not sure, though,  whether to use a GS Medium Cage or a SGS Long Cage?

 

FWIW.  IMO, the longer the cage, the better ... so, I would probably choose the SGS because it would allow more crankset-cassette combinations ...

 

  • I did use an XTR 950 SS rear derailleur on my Olmo before changing to a 10-speed 105 GS rear derailleur -- I dd install a 13t LOWER pulley wheel on the XTR rear derailleur to increase the chain capacity.

 

The GS cage, however, is certainly long enough for most chainring-and-cog combinations you will encounter ... a GS cage may-or-may-not let you use an 11-34 or 11-36 with a "Compact" crankset without having some chain slack.

 

FYI. 'GS' is the label for the length of long cage Road rear derailleurs which Shimano specs for use with Triple cranks.

 

 
 

post #51 of 143
Quote:
Originally Posted by alfeng View Post

 

Quote:
Originally Posted by frankiemuniz01 View Post

That is to use one of the new MTB XT Dyna Sys 10 spd 11-34 cassettes with a MTB 9 spd XT(M772) or XTR(M972) GS/SGS RD (which should be index compatible with my DA 7800 STI lever).  I am not sure, though,  whether to use a GS Medium Cage or a SGS Long Cage?

 

FWIW.  IMO, the longer the cage, the better ... so, I would probably choose the SGS because it would allow more crankset-cassette combinations ...

 

  • I did use an XTR 950 SS rear derailleur on my Olmo before changing to a 10-speed 105 GS rear derailleur -- I dd install a 13t LOWER pulley wheel on the XTR rear derailleur to increase the chain capacity.

 

The GS cage, however, is certainly long enough for most chainring-and-cog combinations you will encounter ... a GS cage may-or-may-not let you use an 11-34 or 11-36 with a "Compact" crankset without having some chain slack.

 

FYI. 'GS' is the label for the length of long cage Road rear derailleurs which Shimano specs for use with Triple cranks.

 

 
 


Can GS be used with standard and compact doubles or just SS?
 

post #52 of 143

 

Quote:
Originally Posted by davereo View Post

Quote:
Originally Posted by alfeng View Post

 

Quote:
Originally Posted by frankiemuniz01 View Post

That is to use one of the new MTB XT Dyna Sys 10 spd 11-34 cassettes with a MTB 9 spd XT(M772) or XTR(M972) GS/SGS RD (which should be index compatible with my DA 7800 STI lever).  I am not sure, though,  whether to use a GS Medium Cage or a SGS Long Cage?

 

FWIW.  IMO, the longer the cage, the better ... so, I would probably choose the SGS because it would allow more crankset-cassette combinations ...

 

  • I did use an XTR 950 SS rear derailleur on my Olmo before changing to a 10-speed 105 GS rear derailleur -- I dd install a 13t LOWER pulley wheel on the XTR rear derailleur to increase the chain capacity.

 

The GS cage, however, is certainly long enough for most chainring-and-cog combinations you will encounter ... a GS cage may-or-may-not let you use an 11-34 or 11-36 with a "Compact" crankset without having some chain slack.

 

FYI. 'GS' is the label for the length of long cage Road rear derailleurs which Shimano specs for use with Triple cranks. 
 


Can GS be used with standard and compact doubles or just SS?
 

 

Yes -- you can use a derailleur with a GS or SGS cage with either a standard or compact Double ...

 

Using a rear derailleur with a longer cage simply means that you may be moving a few MORE links of chain than you would if you installed a rear derailleur with an SS cage ...

 

Of course, you could theoretically have the same length chain with all three cage lengths ...

 

  • if the chain is long enough for a Triple (for example) then with the SS cage the chain will be slack in some chainring & cog combinations
  • if the chain is short enough for a Double with a 12-25 cassette (for example), then the cage arm will not be cocked all the way back when in the small-small combination.
  • et cetera

 

A longer cage is more practical, IMO, if you are not racing AND may want to use a cassette with larger cogs from-time-to-time ... a cassette with a smaller largest cog can be swapped in without making any changes whereas a SS cage probably won't have enough chain capacity to use a cog larger than 27t-or-28t..

 

A longer cage is not acceptable if you are a weight weenie due to the additional links in the chain.

 

 

 

 

post #53 of 143

kLabs,

please keep us updated. Can't wait to know how it turned out.

If yours is conclusive, I'll replicate your setup

Thanks!

post #54 of 143
Thread Starter 

Hi digifant, just a short note, but I have good news and bad news, and I will provide more details later :-) 

 

The short news though, is that a Road GS RD with a 10T Guide Pulley Wheel will work with an 11-32T and 11-34T cassette but I have an issue with the Dropout ledge that the B screw sits on for adjustment. The Dropout ledge on my bike is not quite long enough and it appears to be a unique shape, so I will look more closely at it today :-(

 

Also with an 11-34T cassette you need to ensure that when the chain is on the large sprocket (34T) and large chain wheel (52/53T) that the the RD cage reasonably vertical or only slightly forward. This will prevent too much strain being placed on the RD mech and Dropout. If the chain is too short and angles the RD cage too far forward this could actually damage the RD mech and Dropout. Hope this makes sense :-)

 

More details later and the saga continues, hopefully only good news prevails :-)

post #55 of 143
Thread Starter 

Hi digifant, I have worked out what the problem is ... hmm.  The problem is that the B screw gets very vertical with the DA GS RD that I am using, but the RD Dropout (hanger) ledge (could be called the B screw Seat) itself is quite vertical. As such the B screw is only held onto the ledge by the B screws thread, not the bottom of the B screw. A picture would be better but I do not have one for you at the moment.  I think I have an answer to this and the answer that I am thinking of is adding epoxy to the Dropout ledge and shape it so that it is less vertical and closer to horizontal :-)  Does anybody know an epoxy that sticks to alloy and is shapeable. We have Selleys alloy epoxy here, perhaps that will do the trick :-)

 

The good news is I know how you can test your GS RD.  Simply wind the B screw in completely and see how well it sits on the RD Dropout ledge (Seat).  If there is good contact then you should not have any issues doing this, just as alfeng has done and kindly shown us. 

 

The next check is with the chain on the large sprocket (34T) and large chain wheel (52/53T). You need to ensure that the RD cage should be reasonably vertical or only slightly forward.  You should not do this while you are riding but should it happen you don't want the chain tension to rip the derailleur off the Dropout and it ending up in the spokes.

 

Hi alfeng, with your setup, is it possible for you to show us a photo of your RD cage when the chain is on the large sprocket (34T) and large chain wheel :-) 

post #56 of 143

 

Quote:
Originally Posted by KLabs View Post

 

Hi alfeng, with your setup, is it possible for you to show us a photo of your RD cage when the chain is on the large sprocket (34T) and large chain wheel :-) 


My camera needs new batteries (it's older & primitive) ... but, here's the information which I presume you want:

 

  • As pictured (previously), the Colnago's chain length is set for a 12-25 cassette ... when the chain is on the 39t chainring, it is just long enough to wrap around the 34t cog.

 

With four additional inches of chain, the Colnago's rear derailleur pulley cage will be close to horizontal when the chain is on the Small-Small combination, but I don't think the chain would roll back against itself.

 

  • As pictured, the Olmo's chain length is just long enough to wrap around the 53t chainring & 32t cog ... the B-screw was adjusted to facilitate the 10t pulley wheel clearing the 32t cog (remember, the derailleur hanger has a minimal drop because it was designed for a vertical Campagnolo Nuovo Record  [and/or similar-type] rear derailleur):
     

OLMO_9u29gn.jpg

 

IMO, two-and-probably-three more inches of chain (if the frame would allow for a 34t with the Road rear derailleur) woud not cause the chain to roll back against itself when in the Small-Small combination; so, five additional inches of chain should still be "okay" on the Colnago.

 

If I switched back to a 9-speed XTR rear derailleur, I would need to hubbub the rear derailleur cable when using the 10-speed Campagnolo shifters ... OR, switch to 11-speed Campagnolo shifters to get the 9-speed Shimano rear derailleur to replicate 9-speed Shimano index.

 

Campagnolo_Shimano_shift-ratios.jpg

 

Hope that helps.

 

  

post #57 of 143

Shimano stuff is very compatible all around.  I have long been using a 9 speed 11/32 with an Utegra long cage with no issues using both a triple upfront as well as a compact.  If i' m not mistaken, the new Dyna-SYS MTB RD's will NOT work with your road shifters, I think they changed the cable pull ratio.  But if you don't want to go with an Ultegra GS, you could go with almost any other Shimano MTB RD.

 

i suspect you wouldn't want to change to a triple because that would necessitate getting a new left side shifter?  I recently went to an ultegra compact on the 11/32 casette and while it's great for climbing hills, I find that I have to shift a helluva lot more than I ever did on the triple.  for the most part on the triple I would be in the middle ring (I'm a clyde so I don't get it going crazy fast on the flats) and could usually climb most reasonable hills with my 42/32 combo.  For really crazy huge hills, then I would need to drop it down to the small ring up front. 

 

Likewise, going downhills the 42/11 would usually be more than enough but if I had long extended downhills then I would go to the big ring.  With the compact crank, the big ring is consistently too much to get up hills and the small ring is consistently not enough when I'm on the flats!  lots of shifting!

 

post #58 of 143
Thread Starter 

Originally Posted by alfeng 

 

Campagnolo_Shimano_shift-ratios.jpg


Hi alfeng, where did you get the above chart from and would you happen to know where one can get RD Actuation Ratios from, per chance :-) 

Also, does old Dura Ace refer to pre 7800 and does Shimano refer to every other STI Shimano makes?

 

If you are running a short chain you would have to be very careful not to shift to the large sprocket while you are in the large chainring eek.gif

 

Also, I have modified the RD hanger using Steel-Reinforced Epoxy Paste, and I am in the process of shaping it. My RD hanger was designed for race cassettes (11-21, 11-23, 11-25).  Lets see if it is all worth the effort :-) 

 

Also, I know that an RD SGS M662 or M772 mates, with only minor issues, to an 8spd STI and 11-32T 8spd cassette.  I did this to my friends bike and all is working perfectly :-)

 

post #59 of 143

fyi, sheldonbrown.com has a similar chart to the above, i don't think it lists ratios just what is compatible with what and whether or not you need alternate cable routings

post #60 of 143

 

Quote:
Originally Posted by KLabs View Post


Hi alfeng, where did you get the above chart from and would you happen to know where one can get RD Actuation Ratios from, per chance :-) 

Also, does old Dura Ace refer to pre 7800 and does Shimano refer to every other STI Shimano makes?

 

If you are running a short chain you would have to be very careful not to shift to the large sprocket while you are in the large chainring eek.gif

 

Also, I have modified the RD hanger using Steel-Reinforced Epoxy Paste, and I am in the process of shaping it. My RD hanger was designed for race cassettes (11-21, 11-23, 11-25).  Lets see if it is all worth the effort :-) 

 

Also, I know that an RD SGS M662 or M772 mates, with only minor issues, to an 8spd STI and 11-32T 8spd cassette.  I did this to my friends bike and all is working perfectly :-) 


This is the web site ...
 
 
The author (Chris Juden) of the web page has updated the compatibility tables as drivetrain options have evolved.
 
FWIW.  The actual "RD Actuation ratios" are probably proprietary ..
 
I interpret the "shift ratios" (1.7, 1.9, 1.6) to be what I presume are the "Actuation ratios" which you are looking for ...
 
As far as I can tell, the "shift ratios" were calculated by measuring the cable pull for each shifter AND the measuring the cog spacing (or possibly, using THAT information from Sheldon Brown's site) ... and then, calculating the posted ratios --  the displayed "shift ratio" values at the top of their respective columns are not precise and were simply rounded off to the nearest tenth. 
 
By my recollection, the information for the 11-speed Campagnolo shifters was added in just the past six months and I believe they are the consequence of interpolations using the previously calculated "shift ratio" values.
 
As far as I can tell, the chart still refers to 8-and-9-speed Shimano rear derailleurs.
 
  • as I have previously noted, and singularly declare(d), the geometry of the 10-speed Shimano rear derailleurs is different from the geometry of the 8-and-9-speed Shimano rear derailleurs ...
 
As used by the article's author, the term "old Dura Ace" refers to attaching the rear derailleur cable in the manner which Shimano prescribes by using the Alternate derailleur cable postion:
 
 
DuraAcemech.gif
 
By MY RECKONING, using the "old Dura Ace" anchoring on a 10-speed Shimano rear derailleur turns it into a 9-speed rear derailleur ... HOWEVER, some continue to insist that a 10-speed Shimano rear derailleur works as-is with 9-speed shifters ... 
 
Maybe, they are right?!
 
BUT, as I have stated before, I can recreate 9-speed Shimano indexing while using a 10-speed Campagnolo shifter & using a 10-speed Shimano rear derailleur without hubbubing the rear derailleur cable.
 
Consequently, I will continue to contend that if people have been able to interchange a 10-speed Shimano rear derailleur for a 9-speed Shimano rear derailleur, and vice-versa, without making any cabling accommodations then it is in part due to the ramping which Shimano introduced to with their 9-speed cogs which makes the rear shifting very forgiving compared to shifting with non-ramped cogs (e.g., ¿older? 8-speed Shimano cassettes).
 
  • In the past, I have been able to mis-match 9-speed Shimano cassettes with 9-speed Campagnolo shifters and smoothly engage 8-of-the-9 cogs because the ramping on the cogs makes up for a lot of improper indexing sins and the chain simply jumped past one of the intermediate cogs during the chain's left-right & right-left passage ... that is, there is a lot of open-space between the plates, so perfect indexing isn't necessary to get the chain to rest on the cogs once it is in place ...
  • when I later tried a ramped 8-speed SRAM cassette with some 9-speed Campagnolo shifters, THAT worked, too ...
  • but, I found that the unramped 8-speed XT cassette which I had previously used successfully with a 10-speed Campagnolo shifter & non-hubbub'd 9-speed Shimano rear derailleur was barely functional with the same 9-speed Campagnolo shifters ...
  • so, I reckon that the ramping on the cogs found on Shimano cassettes made in the past dozen years can create the illusion that two rear derailleurs with a different "shift ratios" have the same ratio when they don't.

 

FYI.  Yeah, I know that I should put a longer chain on that bike!  The continued presence of the short chain is a consequence of being BOTH cheap AND lazy ...
 
So, here's my lame excuse for the short chain -- the 30t & 34t cogs are bailout cogs and if the chain has made it to the 26t then I've already shifted the chain onto the inner chainring!
 
BTW.  If amending the tab on your rear derailleur hanger (I presume that is what you are doing) with a blob of epoxy proves to be too fragile, then CAP the edge which the B-screw rests against with some "scrap" metal ...
 
  • you will probably only want to adjust the B-screw when the derailleur is OFF the bike because the tip of the B-screw will probably grind into the hardened epoxy

  

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