Advice re wheels please

[Eichers]

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

 

[Eichers]

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

 

[alfeng]

Originally Posted by KLabs .

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 ([COLOR= #808080]it's older & primitive[/COLOR]) ... but, here's the information which I presume you want:

• As pictured ([COLOR= #808080]previously[/COLOR]), the Colnago's chain length is set for a 12-25 cassette ... when the chain is on the 39t chainring, it is [COLOR= #ff0000]just[/COLOR] 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 [COLOR= #ff0000]just[/COLOR] 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 ([COLOR= #808080]remember, the derailleur hanger has a minimal drop because it was designed for a vertical Campagnolo Nuovo Record [and/or similar-type] rear derailleur[/COLOR]):
  

[COLOR= #808080][/COLOR]​

IMO, two-and-probably-three more inches of chain ([COLOR= #808080]if the frame would allow for a 34t with the Road rear derailleur[/COLOR]) 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.

​

Hope that helps.

 

[Motobecane]

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!

 

[Eichers]

Originally Posted by alfeng


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 /img/vbsmilies/smilies/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

 

[Motobecane]

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

 

[alfeng]

Originally Posted by KLabs .

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 /img/vbsmilies/smilies/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 ...

http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946​

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 ([COLOR= #808080]or possibly, using THAT information from Sheldon Brown's site[/COLOR]) ... 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:

​

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 ([COLOR= #808080]e.g., [/COLOR][COLOR= #ffa500]¿[/COLOR][COLOR= #808080]older[/COLOR][COLOR= #ffa500]?[/COLOR][COLOR= #808080] 8-speed Shimano cassettes[/COLOR]).

• 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 ([COLOR= #808080]I presume that is what you are doing[/COLOR]) 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

 

[Eichers]

Hi alfeng, your short chain sounds like a reasonable excuse to me, but can be a bit dangerous and you are very aware of that already, so no worries

It is interesting looking at the action of the Road and MTB RDs. The Road RD moves backward and across but the MTB RD moves forward and across.
My current observation suggests that the MTB RD is superior because ...
1. there will always be more chain on a sprocket because the guide pulley sits in front of the sprocket which should mean less chain and sprocket wear
2. the mech action is more compact and as such the mech/cage are less likely to be damaged
3. and the change seems to be just as quick due to spocket ramping (as you have mentioned in your post)

Actually, spocket ramping is definitely one of the reasons that the MTB RDs say that they can be used with 7, 8, or 9spd cassettes, along with consistent/similar actuation, which would mean that cable movement(pull) controls the distance that the cage moves.

Yes, regarding the strength of the Epoxy, the B screw does seem to grind into it a bit. Perhaps I should put a dab of epoxy onto the bottom of the B screw. I didn't think of that at the time

 

[davereo]

Are you trying to get more clearance for the larger cogs in your new cassette? If so maybe by making a new hanger you could shift the position of the derailuer back by 1 or 2 mm and solve your issue. I may be way off base but offering this up for discussion. Any Machinist with access to a shop could bang these out very easily. If you know someone....

 

[Eichers]

Originally Posted by davereo .

Are you trying to get more clearance for the larger cogs in your new cassette? If so maybe by making a new hanger you could shift the position of the derailuer back by 1 or 2 mm and solve your issue. I may be way off base but offering this up for discussion. Any Machinist with access to a shop could bang these out very easily. If you know someone....

Hi davereo, what you have said is absolutely correct

If the hanger was about 3-5mm vertically longer then there would be no issue, but the RD hanger on my bike only comes in one size. For my RD hanger the extended B screw adjustment is necessary.

Yes, having one machined a little longer is an alternative (and I have been thinking of just that). Have a piece of alloy laser cut to the required shape, then have the cut outs milled as required, then have the holes drilled and tapped

 

[davereo]

Originally Posted by KLabs .



Hi davereo, what you have said is absolutely correct

If the hanger was about 3-5mm vertically longer then there would be no issue, but the RD hanger on my bike only comes in one size. For my RD hanger the extended B screw adjustment is necessary.

Yes, having one machined a little longer is an alternative (and I have been thinking of just that). Have a piece of alloy laser cut to the required shape, then have the cut outs milled as required, then have the holes drilled and tapped

These guys make custum hangers. Maybe they can help. http://webmountainbike.stores.yahoo.net/derhan.html

 

[Eichers]

Originally Posted by davereo .

These guys make custum hangers. Maybe they can help. http://webmountainbike.stores.yahoo.net/derhan.html

Thanks davereo, they don't show the one I have but they do custom hangers, so maybe
I will see how my mod goes, first (sorry I have been away and busy) ...


A question, is it possible that the Shimano SLX Rear Derailleur Shadow M663 10 Speed is compatible with the 10spd STI lever? The specs look like they are more flexible than the XT or XTR?

 

[Eichers]

Well the epoxy did not stick well enough to the alloy and it broke after a short while, but everything looked very promising upto that point. So, I will have to try something else, maybe Chemical Metal

 

[oldbobcat]

Somebody remind me what the perpetrators of this thread are trying to accomplish?

 

[Eichers]

perpetrators? There is no need to comment if you are not interested or cannot read ... thanks /img/vbsmilies/smilies/mad.gif

There are certainly some who are interested and can read ...

Also, isn't wonderful that there are helpful people on this forum /img/vbsmilies/smilies/wink.gif

 

[Eichers]

Hi alfeng, what 10spd 11-34T cassette did you use?


I was talking to a bike mechanic today, who does extreme bike setups, who said using a 9spd XT Shadow SGS RD (ie. M772, etc) with a any SRAM 11-32T or 11-34T 10spd cassette (ie. PG1050, PG1070, PG1080, etc), will work perfectly with 10spd STI road shifters (ie. 5600, 6600, 7800 and the new ones). He also said that the 9spd XT SGS RD/STI combination will change/work better and faster than the DA7800 GS RD/STI combination /img/vbsmilies/smilies/smile.gif In fact he (almost) guaranteed it.

He also said that you cannot use the Shimano MTB 10spd cassettes with a 9spd XT SGS RD/STI combination. The Shimano 10spd Road cassettes have different sprocket spacing to the Shimano 10spd MTB cassettes /img/vbsmilies/smilies/frown.gif

He also said his his favourite DA group was the 9spd 7700, although he likes the new 7900 group, also. The bit he didn't like with the 7800 was the RD and shifters, which he said was too soft and the shifters chew through cables. Although I had not had cable issues to date.

He has an interesting bike setup for riding/touring. He has a 26er MTB on which he runs 700c wheelset c/w discs and 28c tyres. The tyres run flat with the rim edge so that they don't bulge, which means because the rim is supporting the edge of the tyre he can run lower tyre pressure but still achieve the same rolling resistance as a 23c with 120psi ... very interesting (I compared this to low profile tryes but achieving a more comfortable ride). This approach has certainly turned his 26er MTB into an awesome road rider/tourer /img/vbsmilies/smilies/smile.gif Nice, I might do that to my MTB, also ...

 

[Peter@vecchios]

Originally Posted by KLabs .

Hi alfeng, what 10spd 11-34T cassette did you use?


I was talking to a bike mechanic today, who does extreme bike setups, who said using a 9spd XT Shadow SGS RD (ie. M772, etc) with a any SRAM 11-32T or 11-34T 10spd cassette (ie. PG1050, PG1070, PG1080, etc), will work perfectly with 10spd STI road shifters (ie. 5600, 6600, 7800 and the new ones). He also said that the 9spd XT SGS RD/STI combination will change/work better and faster than the DA7800 GS RD/STI combination /img/vbsmilies/smilies/smile.gif In fact he (almost) guaranteed it.

He also said that you cannot use the Shimano MTB 10spd cassettes with a 9spd XT SGS RD/STI combination. The Shimano 10spd Road cassettes have different sprocket spacing to the Shimano 10spd MTB cassettes /img/vbsmilies/smilies/frown.gif

He also said his his favourite DA group was the 9spd 7700, although he likes the new 7900 group, also. The bit he didn't like with the 7800 was the RD and shifters, which he said was too soft and the shifters chew through cables. Although I had not had cable issues to date.

He has an interesting bike setup for riding/touring. He has a 26er MTB on which he runs 700c wheelset c/w discs and 28c tyres. The tyres run flat with the rim edge so that they don't bulge, which means because the rim is supporting the edge of the tyre he can run lower tyre pressure but still achieve the same rolling resistance as a 23c with 120psi ... very interesting (I compared this to low profile tryes but achieving a more comfortable ride). This approach has certainly turned his 26er MTB into an awesome road rider/tourer /img/vbsmilies/smilies/smile.gif Nice, I might do that to my MTB, also ...

He is correct. Use a shimano 10s STI with any shimano MTB 9s rear der and that will work great(done it).

shimano 10s MTB cogsets are spaced the same as sram and road 10s cogsets tho. You could use a shimano 10s MTB cogset, shimano 9s MTB Rder and shimano 10s STI-that would work fine.

 

[alfeng]

Originally Posted by KLabs .

Hi alfeng, what 10spd 11-34T cassette did you use?

That's a [COLOR= #ff0000]9[/COLOR]-speed, 12-34 XTR ([COLOR= #808080]CS-M953[/COLOR]) cassette.

The only 10-speed cassettes that I have are over-priced Campagnolo cassettes whose largest cog is considerably smaller than 34t ([COLOR= #808080]e.g., 26t[/COLOR]).


I was talking to a bike mechanic today, who does extreme bike setups, who said using a 9spd XT Shadow SGS RD (ie. M772, etc) with a any SRAM 11-32T or 11-34T 10spd cassette (ie. PG1050, PG1070, PG1080, etc), will work perfectly with 10spd STI road shifters (ie. 5600, 6600, 7800 and the new ones). He also said that the 9spd XT SGS RD/STI combination will change/work better and faster than the DA7800 GS RD/STI combination /img/vbsmilies/smilies/smile.gif In fact he (almost) guaranteed it.

He also said that you cannot use the Shimano MTB 10spd cassettes with a 9spd XT SGS RD/STI combination. The Shimano 10spd Road cassettes have different sprocket spacing to the Shimano 10spd MTB cassettes /img/vbsmilies/smilies/frown.gif

He also said his his favourite DA group was the 9spd 7700, although he likes the new 7900 group, also. The bit he didn't like with the 7800 was the RD and shifters, which he said was too soft and the shifters chew through cables. Although I had not had cable issues to date.


I am pretty sure that the Rapid Rise Shadow rear derailleur will work, too -- better, perhaps, BECAUSE the "dwell" which I say is the nemesis which precludes efficient downshifting by Shimano's STI shifters when under load is circumvented by having the RETURN SPRING move the parallelogram rather than having the dwell-burdened eccentric take-up spool effect the chain transfer between cogs OR chainrings.

So, it will work better than a standard pull rear derailleur being shifted by a Shimano STI mechanism, HOWEVER, I am not certain that any mechanical Shimano Road shifter + Rapid Rise rear derailleur would work any better than using Campagnolo shifters + most readily available rear derailleurs ...

• I do not know the specs on the Shimano Road cassette cog spacing vs. MTB 10spd cassette cog spacing ...

• I can't compare the stiffness of the different Shimano rear derailleurs ... your mechanic may be right ... the fore mentioned "dwell" is probably amplified when using some rear derailleurs and mitigated when using others ... the difference between various Shimano rear derailleurs isn't apparent enough (to me) when using Campagnolo shifters for me to have noticed BUT now that the idea has been planted in my mind I may notice!

• The GOOD THING about Shimano shifters having "dwell" is that rather than abandon the eccentric take-up spool for a concentric spool, the engineers in Osaka have spent 16+ years trying to mitigate its effects ... ramping, pinning, asymmetrical chains, progressively stiffer chainrings which have resulted in the current, super expensive hollow chainrings ...

• While Campagnolo shifters certainly benefit from ramping-and-pinning, my first hand testing revealed that Campagnolo shifters with a Shimano front derailleur can shift BETTER ([COLOR= #0000ff]more easily[/COLOR]) onto an old 6-/7-speed outer chainring than an Ultegra 6500 shifter could move the chain onto a ramped-and-pinned chainring .

He has an interesting bike setup for riding/touring. He has a 26er MTB on which he runs 700c wheelset c/w discs and 28c tyres. The tyres run flat with the rim edge so that they don't bulge, which means because the rim is supporting the edge of the tyre he can run lower tyre pressure but still achieve the same rolling resistance as a 23c with 120psi ... very interesting (I compared this to low profile tryes but achieving a more comfortable ride). This approach has certainly turned his 26er MTB into an awesome road rider/tourer /img/vbsmilies/smilies/smile.gif Nice, I might do that to my MTB, also ...



FWIW. Here's an old picture of one of my old Hardtail frames which I rebuilt with 700c wheels:



The Road fork lowers the front end so the resultant head tube angle is approximately 73º ...

I changed the pictured ISIS BB & crankset for an 118mm Octalink BB & crankset ...

• I forgot (!?!) that I have an English threaded 111mm Chorus BB ... I should probably put THAT on the bike + a Record crankset just to confuse some of those people who are overly fixated by the components on a person's bike ([COLOR= #808080]their own & other people's bikes[/COLOR]) with some ridiculous conspicuous consumption.

BTW. Here's a wheelset with 700c rims on XT disc hubs that I laced up about 10+ years ago:



Sometimes I wish that I still had those wheels ...

 

[alfeng]

Originally Posted by KLabs .

Well the epoxy did not stick well enough to the alloy and it broke after a short while, but everything looked very promising upto that point. So, I will have to try something else, maybe Chemical Metal

BTW. If you are handy, then you can fabricate your own derailleur hanger from suitably thick aluminum stock ...

Take your existing hanger ...

• lay it on the stock ([COLOR= #808080]outside face down[/COLOR]) ... cover the bottom HALF ... spray with some FLAT BLACK paint ...
• move the hanger "down" by the amount of additional extension that you want ... cover the top HALF ... spray with FLAT BLACK paint
• remove the excess metal indicated by the paint ([COLOR= #808080]i.e, cut out[/COLOR]) ... drill holes ([COLOR= #808080]AND, counter sink on the outside face[/COLOR]) as marked by the paint ...
• thread the derailleur hanger hole with a 10x1 tap.

Clean the paint off your original deraileur hanger with some mineral spirits.

In addtion to the aluminum stock, you'll need a hand drill & bit(s), hand files, 10x1 tap, spray paint, tape.

 

[swampy1970]

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

This sounds most bizarre. Any chance you could post a picot two from the side and directly above?