Help with eTap rear derailleur hitting the spokes (on Canyon CF SLX)

Discuss light weight issues concerning road bikes & parts.
SIMOSBRAZ
Posts: 5
Joined: Thu Aug 09, 2018 12:55 pm

by SIMOSBRAZ

Hi to Everyone,


i hope someone can help me about this issue cuz is Long time that im searching for a solution .- (sram Manual, video , forum , but no information about this kind of config )

me too i have the same "issue" when the chain is not installed and i think that unfortunately is normal for all of Us
but anyway i have a major issue :

i have a Sworks VEnge Vias with the Etap SHORT CAGE RD but i have replaced the original Xg1190 11-28 with a Dura Ace Cs-r9100 11-25 cassette and it is impossible for me to understand how i can setup the Distance between Pulley and Cogs with B screw , it must be measured from the 25 theet sprocket ? of like in the sram manual but seems only for Long CAge derailleur , from the 11 theet sprocket with 4-6 mm distance?
iv tried to search on gogole for long time. but all the SRAM instruction refer to 11-28 cassette setup or 11.26 but with Long cage , that is not my case.
so which is the correct distance for this configuration? 11-25 and Short cage derailleur , from where i have to measure the distance? im asking due to little noise withe pedaling but not from all Sprocket but just from 13 and 14 theet cog , from all the otther no relevant Noises , the gearing shift is ok, no rattle or hesitation the derailleur hanger is new and totally straight , iv tried to rotate the B screw on a stand and if i can hear that i can attenuate the noise on a single cog , the noise switch to another randomly on the cassette.that is very strange
i have also a little play if i genlty touch the derailleur lever when is totally "closed" but i have seen that is like other people who own so i think is normal for this derailleur

thanks in advance for the HElp.

sungod
Posts: 1644
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

red mechanical could also touch the spokes without a chain, nothing new that etap does it too, it's how sram chooses to do it

b adjustment is very clear in the etap instructions https://www.sram.com/sites/default/file ... nual_0.pdf
Use a 2.5 mm hex wrench to adjust the B-adjust screw so there is 6-8 mm between the teeth of the pulley wheel and the largest cog.
yes there is slight play in the rd if you manually push it

by Weenie


SIMOSBRAZ
Posts: 5
Joined: Thu Aug 09, 2018 12:55 pm

by SIMOSBRAZ

sungod wrote:
Thu Aug 09, 2018 4:34 pm
red mechanical could also touch the spokes without a chain, nothing new that etap does it too, it's how sram chooses to do it

b adjustment is very clear in the etap instructions https://www.sram.com/sites/default/file ... nual_0.pdf
Use a 2.5 mm hex wrench to adjust the B-adjust screw so there is 6-8 mm between the teeth of the pulley wheel and the largest cog.
yes there is slight play in the rd if you manually push it

HI sungod,

thx for ur answer but iv read thousand of times the SRAM manual
the issue is that with a 11-25 CAsette, that gap 6-8mm on the largest sprocket is not optimal due to Chain not tensioned properly , that in the smaller cog touch the chainstay so i had to remove 2 links, and i think is not so good config. for that reason i thought that maybe is better to check the gap in the smaller cog. but is not clear in the Manual so i was trying to understand with the Short cage + 11-25 cassette where i have to check for the gap.

sungod
Posts: 1644
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

you first said...
11-25 and Short cage derailleur , from where i have to measure the distance?
...which is clearly stated in the manual, 6-8mm from largest cog, 25/26/28 makes no difference, the largest cog is the largest cog

now you say the issue you have is something touching the chainstay, exactly what touches the chainstay? in what condition? maybe post a photo to show what is wrong

fwiw i use the short cage with 11-28, the b-screw and chain length all set exactly as sram's instructions, the chain tension is fine

SIMOSBRAZ
Posts: 5
Joined: Thu Aug 09, 2018 12:55 pm

by SIMOSBRAZ

sungod wrote:
Thu Aug 09, 2018 4:57 pm
you first said...
11-25 and Short cage derailleur , from where i have to measure the distance?
...which is clearly stated in the manual, 6-8mm from largest cog, 25/26/28 makes no difference, the largest cog is the largest cog

now you say the issue you have is something touching the chainstay, exactly what touches the chainstay? in what condition? maybe post a photo to show what is wrong

fwiw i use the short cage with 11-28, the b-screw and chain length all set exactly as sram's instructions, the chain tension is fine
SOrry but in the manual iv never seen the mention to 11-25 or 26 cassette. the setup is only explained for 11-28 ...
the only setup that mention the 11-26 is ONLY for the Long CAge. and the manual say that the gap must be measired from the Little Cog and non to the Big anyway
in fact the issue is that if i measure the chain like the manual say. with cross chain in the big+big +2 link
is impossible to me. with a 11-25 to have a proper chain tension. mantaining that gap 6-8 mm because the chain will be not tight enough if i put the small rear and small front.. the CHAIN is rubbing the Frame chainstay, so i have to rotate the B screw for more tension but the gap obviously will increase and will not be not be correct.
i know that with the 11-28 there are no issue but the isue is with the 25 cuz the diameter is minor that a 28 theet

sungod
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Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

it is 4-6mm irrespective of largest cog, that is how to do it

set the chain length a instructed by sram, not some other way

do not run small-small!!! there is no reason to do so, many systems will be too slack in small-small

i'm using 11-28, you are using 11-25, my chain is longer than yours, it works fine when used correctly, but if i was to try using small-small the chain would of course be too slack

DO NOT USE SMALL-SMALL, THE CHAIN WILL BE TOO SLACK

SIMOSBRAZ
Posts: 5
Joined: Thu Aug 09, 2018 12:55 pm

by SIMOSBRAZ

ok really thanks for ur answer, if really is not important how much is capable the cassette. so then always 6-8mm on 11-28 or 11-26 or 11-25 then ( the manual say 6-8mm gap in the big and 4-6 mm is the distance in the small cassette cog with long cage DR) ... i was in doubt cause never seen mentioned in the SRAM Manual
the chain is in the correct lenght like manual said. i was only trying to explain that in case of small + small the chain really touch the chainstay not only a little slack.
then i had tryied to remove 2 link and was ok. but really tight on the last two big cog on the cassette.that i dont use so much with 52 chainrig that have
anyway i'v read on google that the new DUra Ace cs-r9100 is not so silent ., just in the 13 and 14 that is like the mine is doing now. i have to try to change cassette with my old DA cs 9000 i remember was really silent ...

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Calnago
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by Calnago

sungod wrote:...
do not run small-small!!! there is no reason to do so, many systems will be too slack in small-small...
Can’t speak to SRAM, and there are good reasons to avoid the small/small combo with any system, but as for both Campy and Shimano, too much slack is not one of them.
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sungod
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by sungod

Calnago wrote:
Fri Aug 10, 2018 3:43 pm
sungod wrote:...
do not run small-small!!! there is no reason to do so, many systems will be too slack in small-small...
Can’t speak to SRAM, and there are good reasons to avoid the small/small combo with any system, but as for both Campy and Shimano, too much slack is not one of them.
facts are as i stated

SIMOSBRAZ
Posts: 5
Joined: Thu Aug 09, 2018 12:55 pm

by SIMOSBRAZ

Sure.,but im not using at all small + small...was just a consideration
i m just wondering to know how much and where i have to measure the GAP on a 11-25 cassette with the Etap Short cage
i have a 52-36 front. and the chain if measured on big big + 2 link in some situation seems to be not tensioned enought
and is impossible to set a gap of 6-8 mm if i dont tension the B screw , just only if i remove 2 link the tension is fine but difficult to go on 23 and 25 in cross chain . but was not an issue for me.....i dont use this combination.
was just also to understand if the tension can make the cassette noising or not in just some of the sprocket not in all...

Jugi
Posts: 109
Joined: Sun Jun 24, 2018 8:10 am

by Jugi


SIMOSBRAZ wrote:Sure.,but im not using at all small + small...was just a consideration
i m just wondering to know how much and where i have to measure the GAP on a 11-25 cassette with the Etap Short cage
None of the problems you have described are in any way special to SRAM eTap. Not even SRAM's groupsets in general. We are talking rear derailleur setup 1-0-1 here.

B-screw adjustment is essentially always done with the biggest sprocket and bigger chainring in use. Yes, the eTap setup manual has a special instruction for WiFLi RD and a 11-26 cassette, but the objective is always to adjust the RD's upper pulley far enough from the largest sprocket that the chain has enough room to shift between the two largest sprockets. On other sprockets, the gap to the upper pulley is always something else than at largest sprocket, just because of the chain tension difference and RD cage's geometry through it's available range of movement.

So far, not seeing pictures of your setup etc., my virtual diagnostic tool is pointing at a too long chain. Although there is very little chain tension available at small-small combo when correctly setup, it should be enough to ride that combination (but just not recommended, like was said) with every common cassette and chainring combination.

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