Those donut things just prevent the cable rattling against the frame when you go over bumps. The guide missing from the entry point into the chainstay sounds like more of a problem though.

I'm not familiar with the 11 speed requirements but I see mentioned use of a nosed ferrule. You might want to check the instruction manual on them.

Hi John,
Yes, I have a bike stand. It has proved quite useful these last few weeks! I'm going to buy a chain whip, the proper cassette removal tool, and a pair of cable cutters. I might buy a chain tool as well, in case it's needed in the future when I buy a new chain to size it correctly. It's time I did my own work on my bike, as I know I'm the only one who cares about it as much as I do.

Choddo, you're referring to full or segmented housing/cabling, mine is internal. There isn't a "guide" where the cable goes into the chainstay, but there does need to be a cable donut to keep it from rubbing on the frame. The donut slides onto the cable and fits into the hole just right.

I think the word you are looking for is "grommet". A bare cable (i.e., not within housing) runs through a grommet when the cable enters or exits via a small hole in the frame. The grommet is inserted into the hole in the frame, both to protect the edge of the hole and to bring the cable away from the internal surface of the frame.

The smoother the derailleur cable path, the better the shifting. Maximize the radius of any bends and avoid kinks.

FWIW the donuts are purely for cosmetic protection and have no effect on function. EXCEPT if they slide all the way to one end and get trapped, possibly causing cable friction.

Thinking about your issue, I came up with another possible suspect. Namely the ferrules on the ends of the housings, and how they pocket into the frame.

Index housing requires ferrules with flat (inside) bottoms. The conical bottom of poor quality ferrules suitable for brake cables cause the ends of the steel wires to pinch in with valuable tension causing friction and poor shifting.

Also important is how those ferrules pocket into the frame. If not solidly bottomed out, or if the housing pulls to the side, that bit of wiggle undoes all the effort to make a compressionless cable system.

One of the first things I look at with erratic shifting is housing --- usually the rear loop --- that moves sideways as I shift.

So, I took the jockey wheels off one at a time, to make sure they were super clean and in good shape, no cracks, etc. I did find some gunk built up on 1 of them. But here's my question. When I took off the jockeys, both of them had the back cover pop off when I removed it.
Should that be happening? My gut tells me no. Every video I've watched says no. Are my jockeys wheels toast if they do this? These are supposed to be sealed, right? I've replaced bearings before, and every time the cover should be sealed to keep contaminates out.
https://cimg3.ibsrv.net/gimg/bikefor...49bb8ed8eb.jpg

Actually, no, it's not a grommet. At least not according to the official documentation. It's a cable frame protector. However, that being said, you are also right. I'm starting to wonder, if there should be a rubber/plastic protector where the cable goes into the chainstay. There is one for the FD, where the cable comes out of the frame. There was not one for the RD cable. So I put the donut in there. That's why there was so much wear on the cable, it had no protection from the frame.

Where this donut is placed, there is no cosmetic issue. It's buried underneath the cable guide. Something should be there to protect the cable, and I'd hate to think that the bike mechanic did something shady because he was mad at me when he put on the Bontrager shift kit. I know when I got the bike home (said this previously), I found a donut on the floor underneath the bike. It could be it got cut because the cable was improperly routed and too much tension, or? Anyhoo, there needs to be something in that hole in the chainstay to protect the cable. I got a video, I'll share it, easier than typing right now haha.

By the way, thank you all for continuing to assist me with this problem. I appreciate your input and ideas, and I am learning from what we are discussing. Thanks!

Ask yourself,

Why would a donut be under the cable guide?
What purpose would it serve there?

The cable doesn't need protection. It's made of the hardest, strongest material found anywhere on your bike.

What it wants are clear unobstructed runs with only the minimal bends needed to follow the frame.

Basically clear freedom to move with no motion lost to flex anywhere, so every 1mm movement at the lever end causes EXACTLY 1mm movement at the RD end.

As you continue, think, What does this part do? Why is it there? How does it work?

Any part without a specific purpose is pure waste. Since manufacturers cost stuff down to fractions of pennies, you can trust that each part is a critical element of the system, so you need to ask yourself what that role is.

I get what you mean about the entry hole to the chainstay but surely if the cable was scraping the frame material at the edge of the hole enough to fray the coating, it’s now going to cut through that donut thing?
The fact it’s octagonal rather than circular might mean something.
I don’t think that housing is too long. I could live with that. Are you using the Shimano OT-RS900 housing that’s specific to that job?

There is no problem here.

+1. Most/Every Shimano jockey wheel is like this. Put them back on and enjoy another 30k miles or so before they need replacing.

FB and choddo, you both have valid points that I wasn't thinking about. I guess I was viewing the cable as a weak part, not a strong part. Look how I butchered my cable by simply pulling on it with a pair of needle nose pliers, it doesn't seem all that strong to me. But choddo is probably right, that donut will probably just get cut by the cable. I'm going to just leave it be for now, ride it, and see how it goes.
(Edit: I called a few Trek bike shops this morning and asked mechanics about this, and they said that hole is indeed bare, with no cover/protection. OK then!)

Thanks to the 2 folks that said the jockey wheels are fine, I appreciate it. I had no idea. This is all very much a learning process.

If you have Ultegra pulleys, both pulleys have ball bearings. Whereas, for 105 pulleys, one has ball bearings while the other only has a bushing; I forgot which one because I upgraded to Ultegra pulleys as soon as I learned this fact.

With reference to this picture -- which I hope shows a towel and not the carpet :D -- the silver / grey metal piece is only the outer cover, which often falls off when removing pulleys from the RD; the black donut shape piece (between the two silver circles) is the actual bearing seal, which can be carefully pried off to access, clean, and lubricate the ball bearings.

Yes, it's a piece of towel haha! I have a large towel that I use as a mat when cleaning my guns, and I cut a few pieces off of it for bike work. OK, that's cool, and good to know. That does line up with the videos I watched about jockey wheels. I just didn't expect the cover to fall off haha.

[QUOTE=choddo;23181938]I get what you mean about the entry hole to the chainstay but surely if the cable was scraping the frame material at the edge of the hole enough to fray the coating, it’s now going to cut through that donut thing?
The fact it’s octagonal rather than circular might mean something.
I don’t think that housing is too long. I could live with that. Are you using the Shimano OT-RS900 housing that’s specific to that job?[/QUOTE]

The OT-RS900 is intended for the 'Shadow' type RD, which often has a short bend. It is a 'coiled' construction housing and is able to handle the bend better, but at the expense of having a little compression. For most modern frames with the housing stop closer to the RD, the more vertical entry to the RD and shorter 'run', this is necessary.

With the older style RD, with a longer 'run' and full 180* +/- of curve, the standard 'linear' strand housing is preferable.

[QUOTE=KCT1986;23182633]Aha, thanks. I didn’t realise that was introduced with the shadow mechs but now you mention it, that was the first time I noticed Shimano being specific about it.