And I made jury rig chain whip by drilling a chain-sized hole in a plywood 24" square, pinning a length of old bike chain to its backside, then standing the wheel on edge over the hole, wrapped the chain around the cassette large cog and then was able to undo the splined nut with
this simple Park tool and a breaker bar. The stock cassette is great! unless...you want a lower low gear!
Someone should invent a super stiff helper spring to augment the very weak OEM cage-arm spring of the stock derailleur.
That would really be a fix, too, imo. My stock CCS setup got worse over time. So I shortened the chain to cause more pre-tension of the spring. Helped a lot for a very short time, only...
Chain would usually drop outside the chainwheel if I was in a higher gear and if I was NOT pressing hard on the pedals. If I coasted over, say, a little speed bump. There goes that chain drop again @(#$!
The chain was so slack, so untensioned by the stock derailleur, it was always jouncing and striking the chainstay.
Why would Shimano make units deliberately like that?
OTOH,
with a very strong spring there would have been no problem. I make that as a bolded statement of fact because I do not need to use the clutch feature of the Shadow Plus, because its spring is super strong.
Bike shifts require a bit more effort than stock today. But because of the high, basic tension the chain does not whip around so much as it did with the stock weak sister derailleur. I have used the friction clutch and I have not used the friction clutch. No chain drops in my riding, either way. Today I generally leave the clutch ON, just for insurance, because a chain drop is so unpleasant.
As basis, all chain drops from the chainwheel are caused in our CCS bikes by wild undulations, by the whipping up and down and side to side sometimes like a jumprope, of chain permitted to swing wildly over bumps if it is not under pedal pressure.
Under pedal pressure the chain won't jump the chainring. Ergo, if we are coasting on rough terrain, a strong derailleur arm tension is required to control chain jouncing because the tension side of the chain is slack and the cassette freewheels.
We don't, for instance, suffer chain drops with single speed setups. The basic difference is that no wild chain whipping is possible in a single speed setup because there is no spring loaded, chain-retensioning arm on the slack half of the chain.