72andsunny

Another stupid question.

I bought a new cassette for the new wheels, and the smaller 4 or so cogs are rumbling. I figured I needed a new chain, so after ordering one, decided to put the old cassette on the new wheels. Then I noticed it has 5 spacers instead of 3 on the new one. I had doubled confirmed that everything was in the correct order.

Old cassette is 105 (R6800, I think) 11-32

New cassette is Ultegra (R-8000) 11-32

I’ve got UDI2 shifters, couple years old, not sure of the number at the moment.

Alright, so do I need more spacers for the new cassette, or what’s the story? My attempts at adjusting the UDI2 shifting did not improve anything (with the new cassette). Any advice would be appreciated, especially if it’s the correct advice.

shelbyfv

Where are you putting spacers?

72andsunny

As in the R-8000 diagram here:

https://si.shimano.com/pdfs/dm/DM-RACS001-03-ENG.pdf

(After cogs 6, 7, and 8)

shelbyfv

You don't need more spacers. Notice cogs 10,11 and 5 have spacers built in. You do need to be sure the loose cogs are assembled with the marking facing out (away from the wheel.)

Iride01 

On the smaller cogs sometimes you'll feel the chain "rumble" as the rollers engage the cog. So what you are feeling might be normal. I typically will notice it the few times I clean the gunk from my cassette and am riding on a very smooth and very peaceful part of my route.

Not that you shouldn't check for other causes, but this is one.

zacster

Hold on here. You shouldn't need any extra spacers at all with a new cassette, it should just slide right onto the freehub without anything else. Whatever spacers are there in the cassette in the box should just stay where they are on the cassette. You should not have to even think about this.

Run through the rear derailleur adjustment, assuming you didn't muck up the spacers already. The Park Tool guy does a great job: Watch the video!!!

MudPie

Don't underestimate the importance of proper torque when securing the lockring. It's probably 40 N-m, which is about 32 lb-ft of torque.

72andsunny

Thank you for that. My largest socket is 24 mm and the Park Tool is an inch (or possibly 25 mm), so I put it on with an open wrench. I’ll pick up a bigger socket and check my torque.

72andsunny

These are just the spacers that came with the cassette. I’m sure a better mechanic can put the entire cassette on in one piece, and never see them. But I’ve been unable to do that. Everything is in the correct order as per the Shimano manual.

MudPie

Correct, I use a 1" socket to fit my Park cassette tool.

zacster

My Campy cassette has 8 spacers in 4 different sizes, 2 of which look identical. That is confusing. And confuse them I did when reassembling after cleaning not realizing the 2 were different. But then I couldn't get the shifting right. I could either get the large cogs right but then the middle/small ones were off, or the other way around. With just 3 spacers it should be easy on your Shimano. Improper torque sounds like it could be an issue as the small cogs are all metal against metal without having spacers. If it isn't tight you'll hear it.