Does the B limit screw cause grinding in the drivetrain if not set correctly?

[Caden R Stirtz]

It happens only when I’m pushing a big gear up a slight gradient in the saddle. My first thought was the BB needed to be replaced but I took it to the shop and they said it was fine. They thought they fixed the problem with adjusting the b limit but it only helped it maybe a little. It didn’t solve the issue. Would there be any other causes?

I have Shimano GRX 810. Happens when the clutch is on and off. It doesn't make any noise, I can only feel it.

[Jesper]

I hope someone comments to the OP's query since I am unfamiliar with a "clutch" on a derailleur. Probably commonly known to many, but I live in the dark ages of friction shifting; even my indexed systems have no clutch.

[ReapThaWhirlwind]

Yes, it does, because your derailleur pulleys are too close to the cogs.

The clutch will make this worse, as it locks the derailleur's pivot mechanism.

It's recommended to unscrew the b-limit as much as possible until you have smooth transition into the pro gear and back. You may have to adjust the size of your chain depending on much this ends up being.

If you notice any skipping on the chain, then you may need to dial it back in a touch.

[Jesper]

(07-30-2021, 05:07 AM)ReapThaWhirlwind Wrote:  The clutch will make this worse, as it locks the derailleur's pivot mechanism.

Hey Reap,
Please excuse my ignorance; is this clutch feature only an mtb derailleur feature?
Just trying to educate myself since I never heard of it. Certainly don't know why I would need it on a road bike (maybe when riding cobbles?).

Thanks!

[ReapThaWhirlwind]

No, the new Ultegra RX also feature the Shadow Clutch now.