Chain too close to bottom bracket!

PB Forum :: Mechanics' Lounge
Chain too close to bottom bracket!
  • Previous Page
  • Next Page
Author Message
flag Cesar-wldr666
Posted: Sep 10, 2022 at 19:55 Quote
I have a Scott ransom 910 2022, recently upgraded my rear cassette (12 speed) to a e*thirteen helix, also got a e*thirteen 30T chainring. (The bike came with a 32T )
Not sure if it’s normal but on my last cog (12) the chain is very close almost about to rub on my chainstay in my bb.
Is this normal?
Although I never use that gear I’d like to know to prevent further damage of there is any.
flag kiranseligman
O+
Posted: Sep 10, 2022 at 20:00 Quote
Cesar-wldr666 wrote:
I have a Scott ransom 910 2022, recently upgraded my rear cassette (12 speed) to a e*thirteen helix, also got a e*thirteen 30T chainring. (The bike came with a 32T )
Not sure if it’s normal but on my last cog (12) the chain is very close almost about to rub on my chainstay in my bb.
Is this normal?
Although I never use that gear I’d like to know to prevent further damage of there is any.

How close? There’s not usually a whole lot of room but the chain definitely should not be making contact with the frame. I have seen cases where the derailleur hanger was so badly bent that the chain was contacting the tire and frame, but that was not an issue other than aligning the hanger
flag Cesar-wldr666
Posted: Sep 10, 2022 at 20:10 Quote
If I had to put a number on it it’s perhaps about 1/16 of a inch away from touching, atleast rubbing on the protector the bike came with. My derailleur hanger is not bent that’s the first thing I checked
flag TimMog
Posted: Sep 11, 2022 at 0:46 Quote
Photos would help
flag kiranseligman
O+
Posted: Sep 11, 2022 at 5:32 Quote
Cesar-wldr666 wrote:
If I had to put a number on it it’s perhaps about 1/16 of a inch away from touching, atleast rubbing on the protector the bike came with. My derailleur hanger is not bent that’s the first thing I checked

How close is the chainring? Possibly if you forgot a spacer on the crankset it could cause the chainring to be closer to the frame and therefore pull the chainline closer to the frame which may cause it.
flag eshew
Posted: Sep 11, 2022 at 10:13 Quote
Is the cassette tightened to the correct torque? Very easy to under torque and leave it to far outboard.
flag privateer-wheels
Posted: Sep 13, 2022 at 7:40 Quote
eshew wrote:
Is the cassette tightened to the correct torque? Very easy to under torque and leave it to far outboard.

Helix cassettes do not torque onto the freehub body. They are just hand pressed on, and then a pinchbolt is used to secure the biggest ring to the freehub body inside splines.
flag eshew
Posted: Sep 13, 2022 at 7:59 Quote
Well I guess that's not the problem then Smile
flag privateer-wheels
Posted: Sep 13, 2022 at 8:09 Quote
photo

The issue is the chainstay is already very close to the chain with a 32t chainring. It's just the placement of the chainstay. So a 30t will naturally ride lower and closer to the chainstay.

Probably not the best bike to downsize the chainring on. Or run a smaller front ring with a smaller 9t cog in the rear, as you are closer to the chainstay on the front and rear then.
  • Previous Page
  • Next Page

 


Copyright © 2000 - 2024. Pinkbike.com. All rights reserved.
dv56 0.011518
Mobile Version of Website