Potenza rear derailleur adjustment help

Discuss light weight issues concerning road bikes & parts.
flying
Posts: 1834
Joined: Mon Dec 19, 2005 9:16 am

by flying

Hi all

Just built a new bike yesterday & installed Potenza

Everything works great except I cannot seem to get rear derailleur indexed properly

I have not seen this problem before...Anyone know what its cause could be?

I set up as normal setting high & low range limits
Set smallest cog with cable not attached to run silent/aligned
Set largest cog limits to not interfere with spokes
Then when running thru gears lower gears/larger sprockets wants some cable tension via barrel adjuster for smooth running

But...Opposite on high gears/small sprockets which then run noisy or skip 2nd gear unless I slack cable barrel adjustment
But of course if I do I then get noise due to out of aligned cage on low gears

No problems on setup all cables friction free etc no binding
Front derailleur no probs :D

This is baffling me as I have not encountered this before on any other RD
11-32 cassette

Any ideas?
Thanks

by Weenie


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spookyload
Posts: 1055
Joined: Wed Feb 23, 2005 6:47 am
Location: Albuquerque, NM

by spookyload

Did you check your derailleur hanger for alignment?

flying
Posts: 1834
Joined: Mon Dec 19, 2005 9:16 am

by flying

spookyload wrote:
Wed Jan 09, 2019 6:38 am
Did you check your derailleur hanger for alignment?
Yes I know that is a possibility but do not have the tool
Visually RD cages seen parallel to wheel

It is a new aluminum frame & hanger...but I do know it is possible to be out on a new frame

But this problem seems odd to me & I have never seen this before
where one end of range is wanting opposite of other end of range as far as cable tension goes.

I guess it could also be the horizontal alignment of the hanger? Heheh my brain is fired after tinkering for
too many hours.

Thanks will see if I can find or make an alignment check tool

bm0p700f
in the industry
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Location: Glermsford, Suffolk U.K
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by bm0p700f

Hanger alignment is probably off. You can tell by looking at the hanger.

flying
Posts: 1834
Joined: Mon Dec 19, 2005 9:16 am

by flying

bm0p700f wrote:
Wed Jan 09, 2019 7:47 am
Hanger alignment is probably off. You can tell by looking at the hanger.

Yes looks pretty good as I said but will make or buy an alignment check tool

I did get things pretty close now only one gear mid cluster still acting finicky

I found the campy cable wiper rubber was a bit too much friction I guess?
Removed & things did get better albeit still not perfect

mattr
Posts: 4606
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

You can just screw a threaded wheel axle into the hanger and use that as a guide. Or a whole wheel.

And at a guess, bm0p700f means you *can't* tell by looking at it. Cos you can't.

wilwil
Posts: 329
Joined: Thu Sep 23, 2010 5:47 pm

by wilwil

Buy a hanger alignment tool and learn how to use it. You wont regret it. You can't tell by looking. Potenza on my wifes bike worked great until a friend knocked her bike over. The hanger still looked straight but it wasn't.

PokojniToza
Posts: 202
Joined: Mon Nov 26, 2018 10:41 pm

by PokojniToza

Just an idea - 11 to 32 is also a rather "wide" range. Can the cage handle it?

AJS914
Posts: 3223
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

When I first set up 11 speed, I had inconsistent RD indexing problems. It turned out to be sharp cable bends going through internally routed handlbars. I recut every cable so that they were perfectly filed flat and triple checked all the routing and bends and that fixed it.

flying
Posts: 1834
Joined: Mon Dec 19, 2005 9:16 am

by flying

mattr wrote:
Wed Jan 09, 2019 8:44 am
You can just screw a threaded wheel axle into the hanger and use that as a guide. Or a whole wheel.

And at a guess, bm0p700f means you *can't* tell by looking at it. Cos you can't.
Yes will look into it just in case
Thanks
PokojniToza wrote:
Wed Jan 09, 2019 3:26 pm
Just an idea - 11 to 32 is also a rather "wide" range. Can the cage handle it?
Yes made for it a medium cage derailleur no problems there

flying
Posts: 1834
Joined: Mon Dec 19, 2005 9:16 am

by flying

AJS914 wrote:
Wed Jan 09, 2019 6:44 pm
When I first set up 11 speed, I had inconsistent RD indexing problems. It turned out to be sharp cable bends going through internally routed handlebars. I recut every cable so that they were perfectly filed flat and triple checked all the routing and bends and that fixed it.

I think this was a big part of it & I have it narrowed to just one mid cluster gear now. Will work it further.
In my case it was the last section before the derailleur. Not the loop itself but the wiper seemed to have too much drag

with cable disconnected from RD I could feel a lot of drag but nor caused by outer housing.
So removed wiper & it fixed a lot of the problem

Thanks will continue to check for last bit of problem

AJS914
Posts: 3223
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

I'd really like to try some 12 speed "maximum smoothness" cables in my 11 speed housing. I haven't seen anyone selling just replacement cables yet.

shimmeD
Posts: 487
Joined: Thu Jun 28, 2012 10:52 pm
Location: eNZed

by shimmeD

Last I checked, only bmOp700f stocks max smoothness.
Less is more.

robertbb
Posts: 904
Joined: Thu Jul 23, 2009 3:35 am
Location: Melbourne, Australia

by robertbb

Stupid question, but, you are running Potenza shifters too, right?

Chorus/Record/SR shifters *won't* work well with a Potenza RD. I tried it and it simply won't, something to do with the strength of a return spring I think.

by Weenie


bm0p700f
in the industry
Posts: 4775
Joined: Sat May 12, 2012 7:25 pm
Location: Glermsford, Suffolk U.K
Contact:

by bm0p700f

Actually I can spot bent hangers by eye. They just look wrong, small deviations need the tool to spot definitively.

My daughter dropped her bike on the mech ( orange zest) and the hanger bent. Look away Erika and bingo I had it fixed and shifting properly in a jiffy. No alignment tool. Its 1*11 too. She's 7 and loves her bike.

It might be cable friction that normally shows as hesitant shifting when going down the cassette. If it's friction you can get it shift going up normally but double shifting going down.

Hanger alignment normally shows up if it a slight bend as reasonable shift at the start but as you get to the middle of the cassette it gets nosey and double shifts or fails to shift depending on the direction of the bend.

Don't forget the "b tension" adjustment. That moves the top jockey wheel and needs to be fine tuned to get it to shift properly if fitting an 11-32t from say a 12-27t that screw will need a fettle.

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