Why is tight-ish chain different than pedaling hard?
11-11-16, 01:16 PM
#1
Senior Member
Thread Starter
Join Date: Jun 2012
Location: harrisburg, pennsylvania
Posts: 351
Bikes: 1976 Schwinn Super Le Tour, tricked out with modern components. Shimano Alfine 11 internal gear hub. Dynamo hub. Titanium racks and bottle cages. Mercier Kilo Wide Tire dropbar singlespeed
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 44 Post(s)
Liked 8 Times
in
1 Post
Why is tight-ish chain different than pedaling hard?
Can somebody explain the physics that differentiates the effect of having a too-tight change from just pedaling hard? Everybody makes a big deal that a too-tight chain wears the freewheel bearing and bottom bracket bearings. But how are the forces created by a too-tight chain any different than the forces on those same bearings created by pedaling hard?
11-11-16, 01:21 PM
#2
Your cog is slipping.
It has nothing to do with "forces" and everything to do with the way the chain interacts with your chainring and cog. Too tight and the chain binds as it passes over the gears, causing both the teeth and chain to wear out faster.
The rollers in your chain links are supposed to (you guessed it) roll, not scrape.
The rollers in your chain links are supposed to (you guessed it) roll, not scrape.
11-11-16, 01:37 PM
#3
- Soli Deo Gloria -
Join Date: Aug 2015
Location: Northwest Georgia
Posts: 14,779
Bikes: 2018 Rodriguez Custom Fixed Gear, 2017 Niner RLT 9 RDO, 2015 Bianchi Pista, 2002 Fuji Robaix
Mentioned: 235 Post(s)
Tagged: 0 Thread(s)
Quoted: 6844 Post(s)
Liked 736 Times
in
469 Posts
Did somebody say roll?
Last edited by TimothyH; 11-11-16 at 01:40 PM.
11-11-16, 02:11 PM
#4
Senior Member
Join Date: Sep 2009
Location: PHL
Posts: 9,948
Bikes: Litespeed Catalyst, IRO Rob Roy, All City Big Block
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1332 Post(s)
Liked 398 Times
in
194 Posts
Pedaling hard makes you go faster. A tight chain makes you go slower.
11-11-16, 04:42 PM
#6
Your cog is slipping.
11-11-16, 04:55 PM
#7
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,716
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5788 Post(s)
Liked 2,580 Times
in
1,430 Posts
The difference is important because of the huge differences in the forces involved. Top chord tension from the driving forces are limited by rider power, bike/rider weight and terrain. As such they're not all that high at the peak, and most of the time pretty low.
OTOH - sprockets are nearly always slightly eccentric. As the high spots come around, the chain tension can hit extreme levels, determined by flex in the rear axle or chain stays. This is constant, and pulses with every revolution, and is added to whatever the rider introduces.
OTOH - sprockets are nearly always slightly eccentric. As the high spots come around, the chain tension can hit extreme levels, determined by flex in the rear axle or chain stays. This is constant, and pulses with every revolution, and is added to whatever the rider introduces.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
11-11-16, 08:51 PM
#8
Senior Member
Super tight chain and you ask for trouble
Talking about bearing worn out, I believe its all about "pre-load" and correctly setup of bearing, you want every parts of bearing to be "even" in term of loads so its not worn out too fast
Tight chain rarely have effects on bearing, its just eat your drivertrain for breakfast that way if you set up super tight chain, and you asking for trouble!
Talking about bearing worn out, I believe its all about "pre-load" and correctly setup of bearing, you want every parts of bearing to be "even" in term of loads so its not worn out too fast
Tight chain rarely have effects on bearing, its just eat your drivertrain for breakfast that way if you set up super tight chain, and you asking for trouble!
11-11-16, 08:52 PM
#9
Senior Member
Join Date: Sep 2009
Location: PHL
Posts: 9,948
Bikes: Litespeed Catalyst, IRO Rob Roy, All City Big Block
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1332 Post(s)
Liked 398 Times
in
194 Posts
Oh yeah also I've never heard a person say that running a chain too tight has any effect on bottom bracket bearings.
11-11-16, 09:21 PM
#10
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,716
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5788 Post(s)
Liked 2,580 Times
in
1,430 Posts
In reality, the rear axle flexes, acting like a stiff idler arm spring, and unless the sprockets are eccentric enough to bend the axle, the only consequence is excess chain wear until the chain stretches (wear, not like taffy) enough to solve the problem.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
11-11-16, 09:42 PM
#11
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,629
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3871 Post(s)
Liked 2,568 Times
in
1,579 Posts
Thread
Thread Starter
Forum
Replies
Last Post
nivv
Singlespeed & Fixed Gear
10
07-19-14 12:56 PM
ScrawnyKayaker
Alt Bike Culture
25
06-21-10 11:41 AM
