Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Singlespeed & Fixed Gear "I still feel that variable gears are only for people over forty-five. Isn't it better to triumph by the strength of your muscles than by the artifice of a derailer? We are getting soft...As for me, give me a fixed gear!"-- Henri Desgrange (31 January 1865 - 16 August 1940)

User Tag List

Reply
 
Thread Tools Search this Thread
Old 11-06-07, 06:43 AM   #1
lukeC
Senior Member
Thread Starter
 
Join Date: Feb 2007
Bikes:
Posts: 135
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Maximum Allowable Chainline Deviation?

There are a lot of discussions about correcting Chainline, but I can't find any discussing what is an acceptable deviation. on a single speed, Fixed gear or internally geared Hub bike obviously

If its close to straight, (say a few mm out) is it worth the trouble of respacing and re-dishing a wheel just to get those last couple of mm in line?

How much mis-alignment or deviation in Chain line is acceptable?

I searched and couldnt' find an obvious thread.

Last edited by lukeC; 11-07-07 at 03:26 AM.
lukeC is offline   Reply With Quote
Old 11-06-07, 06:49 AM   #2
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Bikes: 1987 Bianchi Campione
Posts: 28,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It's acceptable when you can tolerate the noise, the extra drivetrain wear and when it doesn't drop the chain on every bump. I accept no less than near perfection for noise reasons.
operator is offline   Reply With Quote
Old 11-06-07, 07:35 AM   #3
rudetay
Senior Member
 
Join Date: Dec 2006
Location: Columbus, Ohio
Bikes: Serotta Colorado III Track (Renyolds Ouzo Pro Aero Fork, Dura-Ace to Mavic CXP-14 wheels, Sugino crank, Thomson and 3T the rest), Steelman Cyclocross (Campy Record 10, Deda Newton & Thomson stuff)
Posts: 445
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If this is for a freewheeling bike just add a tensioner that is aligned correctly and get the best of both worlds. It still will be louder than a straight chain, but should be ok. It won't wear your cog and chainring down as much.

The "safe" deviation would depend on cog/chainring type, size, wear, trueness, etc. The chain itself will have a huge role in this, most 1/8" chains have much less latitude for side to side motion than a 9 speed chain would (as you could guess). The safe latitude is just whatever the range is that you won't drop the chain.
rudetay is offline   Reply With Quote
Old 11-06-07, 08:15 AM   #4
teiaperigosa
Banned.
 
teiaperigosa's Avatar
 
Join Date: Oct 2005
Location: 40th, up in the 30th
Bikes:
Posts: 1,694
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
1mm
teiaperigosa is offline   Reply With Quote
Old 11-06-07, 08:27 AM   #5
mihlbach
Senior Member
 
mihlbach's Avatar
 
Join Date: Dec 2005
Location: Long Island, NY
Bikes:
Posts: 6,407
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
My singlespeed mountain bike chainline is off about 6-7mm because of a seriously mismatched BB and crank (will fix this soon). Anyway, its still fairly quiet and I've never dropped the chain. Road bikes function well with the chainline off by several cm. You can't get away with that with a SS chain, but you can still get away with a lot of slop in your chainline. Nonetheless, I'd still aim for getting it to within 1-2 mm. If you are measuring your chainline with just a tape measure or even a digital calipers, you're measurement error is going to amount to 1-2 mm anyway, so don't expect it to be absolutely perfect.

Last edited by mihlbach; 11-06-07 at 08:32 AM.
mihlbach is offline   Reply With Quote
Old 11-06-07, 08:45 AM   #6
queerpunk
aka mattio
 
queerpunk's Avatar
 
Join Date: May 2005
Bikes:
Posts: 6,023
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 39 Post(s)
you can have plenty of chainline deviation. there may be some increased wear - may or may not be noticeable. same goes for noise - may or may not be noticeable. if your chain tension is proper and your chainring is close to round (out of round chainrings lead to unevenly tensioned chains - tight spots and loose spots in the rotation), you won't throw a chain.

teiaperigosa, most people can't accurately measure their chainline to within 1mm.

i'd say that within 10mm, you're fine, but that's just a guess. i've certainly ridden setups with bad chainlines - with absolutely no problems.

1/8" chains have plenty of side to side movement, though not as much as a 9 or 10 speed chain, obviously. try this. remove your chain from your bike. hold it at one end, let the rest dangle. move it from side to side. feel how much movement it can handle. plenty.
queerpunk is offline   Reply With Quote
Old 11-06-07, 09:39 AM   #7
dizzy101
Senior Member
 
Join Date: Sep 2007
Bikes:
Posts: 369
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'd say it could be in the 6-7-8mm range without big problems.
dizzy101 is offline   Reply With Quote
Old 11-06-07, 10:49 AM   #8
dobber
Perineal Pressurized
 
dobber's Avatar
 
Join Date: Oct 2003
Location: In Ebritated
Bikes:
Posts: 6,557
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Unless you've got the proper measurement tools, the ability to get the chainline within +/- 1mm is doubtful.
__________________
This is Africa, 1943. War spits out its violence overhead and the sandy graveyard swallows it up. Her name is King Nine, B-25, medium bomber, Twelfth Air Force. On a hot, still morning she took off from Tunisia to bomb the southern tip of Italy. An errant piece of flak tore a hole in a wing tank and, like a wounded bird, this is where she landed, not to return on this day, or any other day.
dobber is offline   Reply With Quote
Old 11-06-07, 10:50 AM   #9
dobber
Perineal Pressurized
 
dobber's Avatar
 
Join Date: Oct 2003
Location: In Ebritated
Bikes:
Posts: 6,557
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by dizzy101 View Post
I'd say it could be in the 6-7-8mm range without big problems.
I think a chain 1/4" - 1/3" of an inch off might be noticeable.
__________________
This is Africa, 1943. War spits out its violence overhead and the sandy graveyard swallows it up. Her name is King Nine, B-25, medium bomber, Twelfth Air Force. On a hot, still morning she took off from Tunisia to bomb the southern tip of Italy. An errant piece of flak tore a hole in a wing tank and, like a wounded bird, this is where she landed, not to return on this day, or any other day.
dobber is offline   Reply With Quote
Old 11-06-07, 11:03 AM   #10
lyledriver
Electrical Hazard
 
Join Date: Oct 2005
Location: Manhattan / Vancouver
Bikes: a bunch.
Posts: 974
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by dobber View Post
Unless you've got the proper measurement tools, the ability to get the chainline within +/- 1mm is doubtful.
A ruler and a pen and paper?
lyledriver is offline   Reply With Quote
Old 11-06-07, 11:40 AM   #11
dizzy101
Senior Member
 
Join Date: Sep 2007
Bikes:
Posts: 369
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
A caliper is the best. With rulers, you're always eyeballing somewhat (you can't exactly put the ruler flush with the elements that you're measuring).
dizzy101 is offline   Reply With Quote
Old 11-06-07, 01:08 PM   #12
dddave
Senior Member
 
dddave's Avatar
 
Join Date: Oct 2006
Location: los angeles
Bikes: 2012 redline conquest pro / 2008 yeti 575 / motobecan fantom cross uno
Posts: 2,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
i have no clue as to how to measure this.
dddave is offline   Reply With Quote
Old 11-06-07, 01:20 PM   #13
DDYTDY
Senior Member
 
DDYTDY's Avatar
 
Join Date: Nov 2006
Location: Methuen, Massachusetts
Bikes:
Posts: 519
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I've been eyeballing my chainline. I put a yard stick against the chain and look to see if it seem parallel to the downtube.

I'm finding that 3/32" 8 speed chains make much less noise then 1/8" It must be because derailer chains are designed to flex and so can take more misalignment?
DDYTDY is offline   Reply With Quote
Old 11-06-07, 01:20 PM   #14
andre nickatina
not actually Nickatina
 
andre nickatina's Avatar
 
Join Date: Oct 2006
Location: OR
Bikes:
Posts: 4,447
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Yeah, you can't get correct chain line measure without calipers. How I do it is measure the seattube width, than the distance from center of ring to the far end of the seat tube (farthest away from you) and than take that number and subtract it with one-half the seat tube.
andre nickatina is offline   Reply With Quote
Old 11-06-07, 01:26 PM   #15
jdms mvp
Senior Member
 
Join Date: Jun 2007
Location: four 1 OHHH , Maryland
Bikes: nagasawa, fuji track pro
Posts: 2,801
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Quote:
Originally Posted by lyledriver View Post
A ruler and a pen and paper?
digital caliper.
jdms mvp is offline   Reply With Quote
Old 11-06-07, 08:44 PM   #16
calf man
Senior Member
 
calf man's Avatar
 
Join Date: Apr 2007
Location: Atascadero, CA
Bikes:
Posts: 169
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Just eyeball it until you can't tell if it is off to one side or the other.
calf man is offline   Reply With Quote
Old 11-06-07, 08:53 PM   #17
humancongereel
live free or die trying
 
humancongereel's Avatar
 
Join Date: Oct 2005
Location: where i lay my head is home.
Bikes: bianchi pista workhorse, cannondale r1000, mountain bike fixed conversion
Posts: 6,999
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
5mm. i wish i could remember the guy's name, an olympic mechanic who said that, and i think it's pretty much always worked for me.

edit: whoops, not asking about fixed. carry on.
humancongereel is offline   Reply With Quote
Old 11-06-07, 09:02 PM   #18
trons
yo yo yo yo yo
 
Join Date: Nov 2005
Location: delaware
Bikes:
Posts: 2,518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by dizzy101 View Post
I'd say it could be in the 6-7-8mm range without big problems.
yeah i would agree... just make sure your chain tension isn't totally off and you shouldn't have any problems..
trons is offline   Reply With Quote
Old 11-07-07, 12:24 AM   #19
Landgolier
THIS SPACE FOR RENT
 
Join Date: Jan 2006
Bikes:
Posts: 2,849
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
2mm is where it starts to get too loud for my taste, though my general answer to this question is "get it exactly right." Measuring with calipers works pretty well, but you are assuming that your frame is perfectly aligned. Wooden yardsticks are guaranteed to be off at least a little. I have a good steel carpenter's square that I use by laying it flat against the chainring, then I check against the calipers. There used to be a park chainline gauge, but they don't make it any more and it was kind of jingus anyway.
Landgolier is offline   Reply With Quote
Old 11-07-07, 03:32 AM   #20
lukeC
Senior Member
Thread Starter
 
Join Date: Feb 2007
Bikes:
Posts: 135
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Sorry, but I did mean - Fixed Gear, Single Speed or Hub geared (without using a chain tensioner).

I was just curious abotu what peopel consider too much. - My last two fixies were pretty rough and ready conversions... I didn't worry much abotu the chain-line. I just eyeballed it from the rear and thought - yeah thats 'kinda straight' I think... although it was noticably off a little.

it may have even been say 10 mm off - I don't really know. but it was pretty quiet and the chain never fell off.

but then yesterday i was watching the new Bobs Garage video which covers chainline and i thought - hmm maybe I shoudl be more concerned?

http://www.fixedgeargallery.com/colu...age/indexb.htm
lukeC is offline   Reply With Quote
Old 11-28-07, 05:12 AM   #21
lukeC
Senior Member
Thread Starter
 
Join Date: Feb 2007
Bikes:
Posts: 135
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I think getting it down to 1 - 2 mm out is enough isn't it? ther eis quite abit of lateral movement in most chains.
lukeC is offline   Reply With Quote
Old 11-28-07, 06:38 AM   #22
teiaperigosa
Banned.
 
teiaperigosa's Avatar
 
Join Date: Oct 2005
Location: 40th, up in the 30th
Bikes:
Posts: 1,694
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by queerpunk View Post
teiaperigosa, most people can't accurately measure their chainline to within 1mm.
but most gully people can
teiaperigosa is offline   Reply With Quote
Old 11-28-07, 06:39 AM   #23
captsven
Spawn of Satan
 
Join Date: Mar 2003
Location: Grand Rapids, Michigan, USA
Bikes:
Posts: 765
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The closer your chain is to perfect, the less chance you will have to throw a chain. When I first started riding a fixed, I would break chains and occasionally through them. I remember my cog was about 15 mm off from my CR. I still rode the **** out of the bike and 99.9% of the time life was good.

My cog and CR are now dead on because of an adjustable bb. I have not broke or thrown a chain in about 4 years.

I do not know what my chainline is. I use the method Landgolier mentioned about lining up a straight edge (I use a three foot aluminum carpenters level) on your CR. This is most important to me, having the cog and CR perfectly in line.
captsven is offline   Reply With Quote
Old 11-28-07, 08:02 AM   #24
ralphm2k
Lamb of God
 
Join Date: Oct 2007
Bikes:
Posts: 447
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
From.... http://sheldonbrown.com/gloss_ca-m.html#chainline

Chainline Measurement
Chainline is measured from the centerline of the frame to the center of the chain.
You can measure the front chainline directly with a simple ruler. Simply hold the ruler against the seat tube or down tube and measure the distance to the middle of the chainring teeth. In the case of triple chainwheel sets, measure to the middle chainring. In the case of doubles, measure to the halfway point between the two rings.
To measure rear chainline, the easiest way is to measure the distance from the inside of the rear fork end (or the outside of the axle locknut) to the middle of the sprocket. Double this, subtract it from the over-lock-nut dimension of the hub (or the frame spacing , which should be the same), then divide the result in half, and you have the rear chainline.
ralphm2k is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 07:38 PM.