Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Chainring "Boss": What Is This Thing?

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Chainring "Boss": What Is This Thing?

Old 04-15-06, 05:40 PM
  #1  
Coyote!
Guest
 
Posts: n/a
Mentioned: Post(s)
Tagged: Thread(s)
Quoted: Post(s)
Chainring "Boss": What Is This Thing?

I just replaced a couple of worn chainrings on my old TREK 930. The new large one [46 tooth; 110 mm] had a little cylindrical stainless part thatís threaded on one end. Sure enough, the old one had one of these too that faced outboard and perpendicular to the flat plane of the chainring. When screwed in and tightened, the exposed cylinder is 6mm in diameter and stands out 7mm.

I want to call this little thing a ďbossĒ, but bosses generally guide another part in the right direction.

All I can think is that it somehow aids the experienced biker to somehow re-mount a chain thrown to the outside.

So what is this thing?

Thanks.
 
Old 04-15-06, 06:01 PM
  #2  
khuon
DEADBEEF
 
khuon's Avatar
 
Join Date: Aug 2002
Location: Catching his breath alongside a road near Seattle, WA USA
Posts: 12,234

Bikes: 1999 K2 OzM, 2001 Aegis Aro Svelte

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 3 Times in 1 Post
Perhaps you could post a picture? If you're describing what I think you're describing then it's to prevent the chain from lodging itself between the crankarm and the outer chainring should the chain get thrown outboard. The crankarm should be over that "nub".
__________________
1999 K2 OzM 2001 Aegis Aro Svelte
"Be liberal in what you accept, and conservative in what you send." -- Jon Postel, RFC1122
khuon is offline  
Old 04-15-06, 06:27 PM
  #3  
RegularGuy
I am a lonely visitor
 
RegularGuy's Avatar
 
Join Date: Feb 2002
Location: Where even Richard Nixon has got soul
Posts: 2,630

Bikes: Michelle Pfieffer, the Carbon Fiber Wonder Bike: A Kestrel 200 SCI Repainted in glorious mango; Old Paintless, A Litespeed Obed; The Bike With No Name: A Bianchi Eros; RegularBike: A Parkpre Comp Ltd rebuilt as a singlespeed.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
That little nub will indeed allow an experienced cyclist to pedal a chain, thrown to the outside, back onto the large chainring.

In fact, it will allow an inexperienced cyclist to do the same thing. It is easier to do then you might think. Just keep pedaling and shift gently.

Like Khuon said, mount it so that it is under, or behind the crankarm.
__________________
Religion is a good thing for good people and a bad thing for bad people. --H. Richard Niebuhr
RegularGuy is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.