Dura Ace Di2 noisy on the way down the block

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ParisCarbon
Posts: 1920
Joined: Mon Feb 05, 2007 5:39 am
Location: Winnipeg Canada

by ParisCarbon

Hey all,
11-25 block 53X39 Dura Ace SRM unit.. shifts up perfectly fine, but in the big ring if in the upper 4 cogs, the down shift seems to not really work well.. lots of grinding sounds.. small ring doesnt do this...but if I back pedal even slightly then come forward, the noise disappears. rest of the cogs work perfect.. its all brand new stuff... Id think I should be able to ride at least up to the 3rd cog from the top in the big ring without crossover?

Im taking it the shop on Monday, but just wondering if there is anything I can try..tried micro adjusting on the 5th cog and its perfect.. limit screws seem bang on..

Thanks

salesguy
Posts: 136
Joined: Tue Mar 28, 2006 9:27 pm

by salesguy

2 words: Hanger Alignment

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ParisCarbon
Posts: 1920
Joined: Mon Feb 05, 2007 5:39 am
Location: Winnipeg Canada

by ParisCarbon

salesguy wrote:2 words: Hanger Alignment


I had it in yesterday quick and the hangar is aligned... the Di2 expert had gone home for the day already.

Ive noticed a few more things:

1) Works perfect on the 39 ring
2) If I don't shift it up to the 53X25 cog its not noisy coming back down... 53X25 is a massive crossover and I will never be in that gear.. but I should still be able to shift up there and down you'd think?

MoreRideTime
Posts: 128
Joined: Sun Sep 17, 2006 9:09 pm
Location: Canada

by MoreRideTime

If the hanger is aligned properly, check that the chain has been installed in the correct direction; the new ones from Shimano are symmetrical. Only other thing I can think that could cause this is very short chain stay length.

Argh! I really need to have my coffee before posting.. Shimano's chains are asymmetrical.. doh!
Last edited by MoreRideTime on Tue May 03, 2016 3:32 pm, edited 1 time in total.

ParisCarbon
Posts: 1920
Joined: Mon Feb 05, 2007 5:39 am
Location: Winnipeg Canada

by ParisCarbon

Its a Tarmac... will check chain direction... chain direction is OK.. being a former Campy user, does shimano have a different way of determining chain length?? Campy used small ring, smallest cog and then I think 5mm from pulley?

MoreRideTime wrote:If the hanger is aligned properly, check that the chain has been installed in the correct direction; the new ones from Shimano are symmetrical. Only other thing I can think that could cause this is very short chain stay length.

salesguy
Posts: 136
Joined: Tue Mar 28, 2006 9:27 pm

by salesguy

Chain length was my next reco - if it's a factory setup they tend to make the chains 1 link shorter than I would do.

Follow the Shimano DI2 dealer manual to the letter including chain length.

ParisCarbon
Posts: 1920
Joined: Mon Feb 05, 2007 5:39 am
Location: Winnipeg Canada

by ParisCarbon

So I dug up the doc for the chain and it says pulleys should be 90 degrees when big ring, smallest cog.. so when I go 53X11 the RD is angled back behind 90.. if I double the chain over to pull out 2 links it pulls it to 90 degrees..

salesguy wrote:Chain length was my next reco - if it's a factory setup they tend to make the chains 1 link shorter than I would do.

Follow the Shimano DI2 dealer manual to the letter including chain length.

salesguy
Posts: 136
Joined: Tue Mar 28, 2006 9:27 pm

by salesguy

Huh - Usually longer chains are quieter, shorter (too short) are noisy in the top few gears.

Possibly remove 1 link and see - but I'd re-do the entire front and rear adjustment from scratch before I did that. And just because I'd re-check alignment and hanger tightness (those tiny little bolts). While you are at it remove the hanger, clean, apply a little grease to the surfaces and then drop of locktite to those tiny bolts.

Also B-adjustment (though honestly it has never moved the needle for me, like ever)

Other ideas:

-Different wheel
-Different cassette
-Different wheel and cassette

fh8425
Posts: 132
Joined: Fri Dec 04, 2015 3:20 pm

by fh8425

check shift cable/housing to ensure no restriction and also for smoothness during operation ..

Nefarious86
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Joined: Sun May 25, 2014 4:57 am

by Nefarious86

Di2 shift housings dont really foul up....
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ms6073
Posts: 4290
Joined: Fri Jul 23, 2004 8:24 pm
Location: Houston, Texas

by ms6073

fh8425 wrote:check shift cable/housing to ensure no restriction and also for smoothness during operation ..

Post is asking about Di2, so no shift cable/housing to check. :mrgreen:
Last edited by ms6073 on Mon May 02, 2016 2:16 pm, edited 1 time in total.
- Michael
"People should stop expecting normal from me... seriously, we all know it's never going to happen"

fh8425
Posts: 132
Joined: Fri Dec 04, 2015 3:20 pm

by fh8425

lol .. my bad

salesguy
Posts: 136
Joined: Tue Mar 28, 2006 9:27 pm

by salesguy

The OP PM'd me that it was hanger alignment. From now on that will be the only acceptable answer for these things, until it's been 100% eliminated as a possibility!

So:

-Hanger alignment
-Completely fresh setup from scratch, according to dealer manual

Rarely a DI2 shifting problem can't be solved by this procedure, front or rear. Unless you are using non-shimano rings, etc.

964Cup
Posts: 195
Joined: Tue Dec 18, 2012 1:31 am

by 964Cup

Why has no-one mentioned Di2 trim adjustment? http://www.artscyclery.com/learningcent ... leurs.html

by Weenie


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grover
Posts: 1302
Joined: Mon Jul 26, 2004 1:06 pm

by grover

As already stated

1 hanger alignment
2 chain length
3 b-tension
4 trim adjustment
5 limit screws

If di2 is still noisy in select rear gears after those steps something is faulty or worn out.

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