Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take part in the January Giveaway for the DYU R1 20" City Electric Bike


Does the B limit screw cause grinding in the drivetrain if not set correctly?
#1
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.
  Reply
#2
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.
Take care,
Jesper

"I am become Death, the destroyer of bicycles." NJS
  Reply
#3
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.
  Reply
#4
(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!
Take care,
Jesper

"I am become Death, the destroyer of bicycles." NJS
  Reply
#5
No, the new Ultegra RX also feature the Shadow Clutch now.
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
Aloha!
Today 05:19 AM
Question about Leg Shaving
Today 04:51 AM
Brand New Rusty Steel Split frame Bike
Today 04:36 AM
What was your first bicycle?
Yesterday 05:32 PM
paralyzed in a bike crash: Sports Illust...
Yesterday 02:54 PM
How much do you bike per year?
Yesterday 01:12 AM
Identify
01-15-2022 09:19 PM
Breaking in Brooks B17 Imperial
01-15-2022 03:42 PM
Big Basso, Tiny Colnago
01-15-2022 03:26 PM
ebikes and regular bikes
01-15-2022 03:15 PM

[-]
Join BikeRide on Strava
Feel free to join if you are on Strava: www.strava.com/clubs/bikeridecom

[-]
Top 5 Posters This Month
no avatar 1. Jesper
26 posts
no avatar 2. ReapThaWhirlwind
15 posts
no avatar 3. Jake1
14 posts
no avatar 4. jeffg
13 posts
no avatar 5. JR Namida
10 posts