Impact of changing inner chainring
05-03-08, 06:24 PM
#1
Newbie
Thread Starter
Join Date: May 2008
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Impact of changing inner chainring
So heres the deal:
I switched out my inner chaining (on a triple set). I went from a 28 to a 22. Now when i am in the smallest ring up front and the smallest cog in back my chain rubs the the outermost side of my front derailer.
I do not believe i shifted the derailer position while working on the chainring.
To fix this should i be looking at the length of my chain or derailer adjustments or what?
thanks
steve
I switched out my inner chaining (on a triple set). I went from a 28 to a 22. Now when i am in the smallest ring up front and the smallest cog in back my chain rubs the the outermost side of my front derailer.
I do not believe i shifted the derailer position while working on the chainring.
To fix this should i be looking at the length of my chain or derailer adjustments or what?
thanks
steve
05-03-08, 06:29 PM
#2
Pwnerer
So heres the deal:
I switched out my inner chaining (on a triple set). I went from a 28 to a 22. Now when i am in the smallest ring up front and the smallest cog in back my chain rubs the the outermost side of my front derailer.
I do not believe i shifted the derailer position while working on the chainring.
To fix this should i be looking at the length of my chain or derailer adjustments or what?
thanks
steve
I switched out my inner chaining (on a triple set). I went from a 28 to a 22. Now when i am in the smallest ring up front and the smallest cog in back my chain rubs the the outermost side of my front derailer.
I do not believe i shifted the derailer position while working on the chainring.
To fix this should i be looking at the length of my chain or derailer adjustments or what?
thanks
steve
On certain bikes, the chain may tend rub and rattle against the front rings while riding in certain gear combinations. This is common on many bike when riding in the so-called "cross-chaining" combination of the smallest front ring, and the smallest rear cog. An example of a gear combination that is likely to rub is shown below.
Last edited by Wordbiker; 05-03-08 at 06:34 PM.
05-03-08, 07:51 PM
#4
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2026 Post(s)
Likes: 0
Liked 1,095 Times
in
741 Posts
+1. There is absolutely no reason to ever use that gear combination.
05-03-08, 08:21 PM
#5
Guest
Posts: n/a
Mentioned: Post(s)
Tagged: Thread(s)
Quoted: Post(s)
It's also likely that the chain is rubbing the front derailruer "cage" because the derailruer is no longer close to the smaller ring as it was on the 28.
Last edited by kellyjdrummer; 05-03-08 at 09:29 PM.
05-03-08, 08:42 PM
#6
My bikes became Vintage
Why not, if it works without noise? I do it often, but I don't have a triple. The opposite "forbidden" combination (big-big) however, is usually quite noisy due to the high chain tension and I never use it, even accidentally, because I'm off the big ring long before I need those bigger rear cogs.
05-03-08, 08:50 PM
#7
Senior Member
Join Date: Jul 2007
Posts: 2,114
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Because the angle is too great for the chain. It will cause greater wear and strain. You really want the chain to be as straight as possible. It would be better to find a different gear combo that gives you the same or close to that one that will give you a better chain line.
05-04-08, 08:22 AM
#8
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2026 Post(s)
Likes: 0
Liked 1,095 Times
in
741 Posts
Because, if you calculate the gear chart, you will find there is at least one combination of middle chainring and larger cog that gives the same ratio and is easier on the chain.
Also, if the OP has exceeded the rd's capacity by going to the smaller granny ring, the chain will be completely slack in the small small combination if the chain is long enough to safely allow big-big as it must be.
Also, if the OP has exceeded the rd's capacity by going to the smaller granny ring, the chain will be completely slack in the small small combination if the chain is long enough to safely allow big-big as it must be.
05-04-08, 08:33 AM
#9
Senior Member
Join Date: Mar 2007
Location: West Dorset, UK
Posts: 908
Bikes: 1983 Dawes Galaxy, 2006 Raleigh Airlite, 1982 Sun Solo (fixed)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Less Stress on the chain, therefore increasing lifespan
__________________
A group for all Dawes Galaxy owners to give and recieve information about them
https://flickr.com/groups/dawes_galaxy/
i jam my thumbs up and back into the tubes. this way i can point my fingers straight out in front to split the wind and attain an even more aero profile, and the usual fixed gear - zen - connectedness feeling through the drivetrain is multiplied ten fold because my thumbs become one with the tubing.
https://flickr.com/groups/dawes_galaxy/
05-04-08, 09:25 AM
#10
Senior Member
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225
Bikes: Catrike 559 I own some others but they don't get ridden very much.
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 643 Times
in
364 Posts
05-04-08, 09:58 AM
#11
Newbie
Thread Starter
Join Date: May 2008
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I get the point about crosschaining, but even if i am going to avoid using the small small combo I would like for the chain not to rub in that combo. Before I switched rings (see original thread at top) it did not rub. I would like to be make it not rub again, even if I never use the combo.
In the meantime and in the future though I will not use the small-small. I dont think I really used it before anyway. But I still want it to work!
In the meantime and in the future though I will not use the small-small. I dont think I really used it before anyway. But I still want it to work!
05-04-08, 10:11 AM
#12
Pwnerer
Then switch the chainring back.
You are obviously dealing with the effects of pushing the chain capacity of the derailleurs to the limits. When doing so, concessions must sometimes be made, one of which is giving up the crosschained gears.
I've done a fair amount of pushing the limits myself and have built drivetrains that exceed the limits to the point that certain gears couldn't physically be shifted into. I was a big boy about it and took full responsibility for what I'd done and took care not to use those combos. If you want to have a perfectly working drivetrain, run it within spec. Anything outside of that will be a "Class-B" fit and will come with some issues.
You are obviously dealing with the effects of pushing the chain capacity of the derailleurs to the limits. When doing so, concessions must sometimes be made, one of which is giving up the crosschained gears.
I've done a fair amount of pushing the limits myself and have built drivetrains that exceed the limits to the point that certain gears couldn't physically be shifted into. I was a big boy about it and took full responsibility for what I'd done and took care not to use those combos. If you want to have a perfectly working drivetrain, run it within spec. Anything outside of that will be a "Class-B" fit and will come with some issues.
05-04-08, 10:13 AM
#13
hello
I get the point about crosschaining, but even if i am going to avoid using the small small combo I would like for the chain not to rub in that combo. Before I switched rings (see original thread at top) it did not rub. I would like to be make it not rub again, even if I never use the combo.
In the meantime and in the future though I will not use the small-small. I dont think I really used it before anyway. But I still want it to work!
In the meantime and in the future though I will not use the small-small. I dont think I really used it before anyway. But I still want it to work!
05-04-08, 10:28 AM
#14
Senior Member
Join Date: Sep 2007
Location: Helsinki, Finland
Posts: 69
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
It's true that big-big is far noisier than small-small on most drivetrains. However, assuming you pedal at the same cadence and power, chain tension is smaller in the big ring and greater in the small ring. So the reason for the noise is something else.
05-04-08, 11:13 AM
#15
My bikes became Vintage
Just to set the record straight, I don't deliberately always use the small/small combination as a matter of course. However, when descending a mild hill, I might inadvertently go to it and not even realize because it's so smooth. So I leave it there temporarily rather than double shifting to a more "correct" combination. If it sounds and feels smooth, it can't be doing much damage for a few seconds. The thing about riding bikes is that if it doesn't feel "right", you're probably doing something wrong. That's whey so many people give up when they find it too hard.
05-04-08, 11:26 AM
#16
Senior Member
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225
Bikes: Catrike 559 I own some others but they don't get ridden very much.
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 643 Times
in
364 Posts
Yup. I understand the OP's concern. I feel that way too. The reality, however, is that roadfix and Wordbiker are right. That's probably why the bike didn't come with a 22 ring in the first place. If you want the 22 ring you're going to have to put up with the class B fit.
05-05-08, 01:29 AM
#18
Senior Member
Join Date: Dec 2005
Location: Boulder, Colorado
Posts: 1,383
Bikes: Cinelli Supercoursa 69, Ritchey Breakaway Cross, Mondonico Diamond Extra 05, Coors Light Greg Lemond (built by Scapin) 88, Scapin MTB, Stumpjumper 83, Specialized Stumpjumper M4, Lemond Poprad 2001
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked 2 Times
in
1 Post
Put your bike on a stand and shift to the smallest ring in front then start on the largest rear cog and change down until you see where the rubbing starts then file it away and don't use anything but the good combinations.
I have a campy triple and changed my 30 down to a 28 on my road bike and 26 on my cross bike. I just never use anything but the 5 largest cogs with the inner ring. I never shift out of my middle chain ring unless I really need the lowest gears...90% of the time I ride my triple as a double.
I have a campy triple and changed my 30 down to a 28 on my road bike and 26 on my cross bike. I just never use anything but the 5 largest cogs with the inner ring. I never shift out of my middle chain ring unless I really need the lowest gears...90% of the time I ride my triple as a double.
