Road Bike, Cycling Forums banner

1 - 20 of 38 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
What could be causing a groaning noise when I'm in the highest gears? I noticed this when I spin the crank while the back is on the rack. It sounds like marbles jumbling around. Is something out of alignment with the rear derailleur?
 

·
Banned Sock Puppet
Joined
·
12,976 Posts
Are you sure you aren't hearing chain rub against the front derailleur?
 

·
'brifter' is f'ing stupid
Joined
·
15,347 Posts
If it's in the large cogs it's most likely the b-tension as tlg posted. Turn in the b-tension screw until the chain isn't being pinched between the upper pulley and the cog. If it's actually the large cogs it would the first, second, third...not ninth, tenth, eleventh.
 

·
Banned Sock Puppet
Joined
·
12,976 Posts
What could be causing a groaning noise when I'm in the highest gears? I noticed this when I spin the crank while the back is on the rack. It sounds like marbles jumbling around. Is something out of alignment with the rear derailleur?
Going my tlg's reply, I now assume you meant the lowest gears (largest cogs)? Sort of a "rumbling" or "motor boating" sound?
 

·
Registered
Joined
·
14 Posts
Discussion Starter #8
If it's in the large cogs it's most likely the b-tension as tlg posted. Turn in the b-tension screw until the chain isn't being pinched between the upper pulley and the cog. If it's actually the large cogs it would the first, second, third...not ninth, tenth, eleventh.
It's in the smallest cogs, 9th, 10th, and 11th based on my shift display (Di2)
 

·
Matnlely Dregaend
Joined
·
4,868 Posts
Is the chain sized correctly? You may be getting slack if you're trying the small/small combination, which you shouldn't be doing anyways.
 

·
Banned Sock Puppet
Joined
·
12,976 Posts
Is the chain sized correctly? You may be getting slack if you're trying the small/small combination, which you shouldn't be doing anyways.
There should be some tension if you are in the small/small combo. If it is slack, your chain is too long.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #13 (Edited)
I tried posting a video of the sound and rear derailleur so you guys could help assess but I got banned for spamming. I'll try it again. Hopefully you guys have seen this before.

The chain is the same Dura Ace one that I had before when I was running the 50/34 and then switched to 53/39. I've since changed it to 52/36 so I don't believe there is any slack with the chain.
 

·
Banned Sock Puppet
Joined
·
12,976 Posts
Damn, that is one irritatingly noisy freewheel!
 

·
Banned Sock Puppet
Joined
·
12,976 Posts
Hahah so what should I do?
At this point, without seeing the bike in person, I wouldn't try to guess.

Does your rear derailleur look aligned?

What happens if you turn your rear derailleur barrel adjuster in one direction or the other?

Does the derailleur pulley look like it's touching the cassette cogs of any of these noisy gears?
 

·
Registered
Joined
·
14 Posts
Discussion Starter #17
At this point, without seeing the bike in person, I wouldn't try to guess.

Does your rear derailleur look aligned? Yes

What happens if you turn your rear derailleur barrel adjuster in one direction or the other? It's Di2 and I've re-indexed it and it's quiet in all other gears except those last 3

Does the derailleur pulley look like it's touching the cassette cogs of any of these noisy gears? No, plenty of gap in the highest gears.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #18
I forgot to mention I installed a new 11/28 Ultegra R8000 cassette and that's when this sound came about
 

·
Registered
Joined
·
860 Posts
I forgot to mention I installed a new 11/28 Ultegra R8000 cassette and that's when this sound came about
Are you sure you got the cassette installed correctly? Spacers in all the right places (no spacers in all the right places), and that you got the last cog aligned and the lock ring snug ?
 

·
Registered
Joined
·
14 Posts
Discussion Starter #20
Are you sure you got the cassette installed correctly? Spacers in all the right places (no spacers in all the right places), and that you got the last cog aligned and the lock ring snug ?
That I'm not sure anymore. Any guide to review? I thought I lined all the gears correctly by way of the wider slot on the hub. I used all the spacers as is. I did use a proper torque wrench to tighten it to the 40Nm. Anything I miss?
 
1 - 20 of 38 Posts
Top