For the record... I don't "work on bikes every day". In fact, I've never worked in a bike shop. But bikes are my hobby, obsession perhaps,... and the whole mechanic thing has kind of taken on a life of it's own I suppose.
But if there's anyone still following this, you must have more than a passing interest in wanting to know "how things work" and a desire to have your bike adjusted as perfectly as possible. I had the opportunity to play around with a bike before the chain was cut and with the Shadow Dura Ace derailleur and an 11/28 cassette. I thought I'd set it up perfectly and take a few pics what the arrangement should look like when all is set up as it should be. The drive train consists of standard 39/53 rings up front and 11 spd 11/28 cassette at the rear. I played around with the correct length chain and experimented with what would happen if the chain was a tad too long (didn't bother with too short as that would rip off the derailleur). It's a Di2 system so in order to be able to just manually move the chain from the big ring and the small ring, I just taped the front derailleur out of the way for a bit, so I could have the chain on small/small easily for purposes of some pics. Here's some pics of how things should look with the correct length chain, and the B-screw adjusted properly...
Combo 1: Small ring/small cog....
Combo 1 Closeup Small ring/Small cog: Note the interface with the cassette and chain and upper pulley... in all cases that I show note how far forward of the rear axle the upper pulley is, and also how close I can get it to the cogs themselves, regardless of the drivetrain combinations...
Combo 2: Small ring/Large cog...
Combo 2: Closeup Small ring/Large cog...
Combo 3: Large ring/Small cog...
Combo 3: Closeup Large ring/Small cog...
Combo 4: Large ring/Large cog...
Combo 4: Closeup Large ring/Large cog...
There you have it, a perfectly set up and adjusted Shimano drivetrain. No Direct Mount hanger... just the regular hanger and the provided B-Link from Shimano. The setup is identical in both cases, as the derailleur is positioned in the same exact place no matter if you have a DM hanger or a regular hanger plus the B-link (I suppose there could be very minor differences due to slight differences in the regular hangers' designs, but these should be very small). In conclusion, once again, the minor annoyance in rear wheel removal over previous versions is the tradeoff for having the derailleur top pulley so far forward of the rear axle, and that has nothing to do with whether a DM hanger or a regular hanger is used. But look at that wrap and engagement of the chain, all before the 6 o'clock position of the cogs. This makes for crisp, accurate and fast shifts. It's a delight on a fast road machine just clicking through the gears. I don't want to see the road bike morph into more mountain technology than road. Where technology is good under either scenario, then by all means share it. But don't just port if over carte blanche. Refine it for the road specifically. I'd be good with that. Don't force me to have 425mm and longer chainstays just so I can run fat tires, discs, and monster cassettes on my road bike. Please... don't do that. Lol Set up correctly, the new derailleurs from Shimano are great... just look at the pics above for evidence. They shift super smooth. There may be the odd frame here and there that really doesn't play well with the new stuff as far as wheel removal goes, so that should be paid close attention to for sure. On that note and before I forget, after playing with this one for a bit, and twisting and turning things without the chain on it and with the chain on it, I would strongly advise against any grinding away of the "stop" built into the B-link. I can see now why it's there... pulling the derailleur back farther than that stop puts a whole lot of stress on the pulley cage, and I was hearing unpleasant creaks and crackling noises when I experimented. That stop is there for a good reason. Paragon should have one on their hangers imo.
Having said all that, I have a very high end frame in front of me waiting for a build. Campagnolo EPS is going on it, but I've noticed that it may also fit most of the requirements for the "perfect storm" scenario I described earlier. So perhaps I'll slap a Shimano Shadow derailleur on it and just experiment a bit with it and report back here sometime over the next week or so.
Till next time...