Help & FAQs    Search BCF    Members    Groups    Events Calendar
Resend my activation email : Register : Log in 
BCF: Bike Chat Forums


Chain stretch

 Reply to topic
Bike Chat Forums Index -> The Workshop
View previous topic : View next topic  
Author Message

Arfdog
Crazy Courier



Joined: 17 Aug 2006
Karma :
PostPosted: 13:16 - 07 Nov 2006    Post subject: Chain stretch Reply with quote
Hi guys,

I cannot understand it. I find my chain has about 4 cm or more of play, of which 2 cm is TOTALLY free (slack) play, every 3 weeks or so. I tighten it JUST enough so that the slack is taken out of it, and then it's got about 2 cm of play. Not free flopping about slack play, but play under very slight tension.

Trouble is, I've done this 4 or 5 times already! my chain seems to be stretching at one hell of a rate... I still have about 15% usable space before I reach the end of my tensioning adjusters...

What you think? New chain? Or how can I check the problem is not with bearing on engine side of driving sprocket?

Cheers me dears
____________________
I'm a lover, not a fighter.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Kickstart
The Oracle



Joined: 04 Feb 2002
Karma :
PostPosted: 13:19 - 07 Nov 2006    Post subject: Reply with quote
Hi

How well is the chain lubed? Is the rear wheel in line? Are you setting the chain tension to the recommended amount of slack?

Chains do wear out, and old sprockets wear them out even quicker (one reason why chain wear accelerates with age).

What bike is it?

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Arfdog
Crazy Courier



Joined: 17 Aug 2006
Karma :
PostPosted: 13:28 - 07 Nov 2006    Post subject: Reply with quote
Hi Kick,

It's an ancient yamaha RXS100. I've lubed the train only twice (about once every 6 weeks). Prolly not enough.

I keep the tensioners on either side of rear wheel in line with each other, so the wheel must be pretty straight. When I set the chain, I set to manufacturers guidelines (2cm play). The sprocket looks like its in pretty good condition....
____________________
I'm a lover, not a fighter.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Kickstart
The Oracle



Joined: 04 Feb 2002
Karma :
PostPosted: 13:31 - 07 Nov 2006    Post subject: Reply with quote
Hi

Suspect it is a small chain on that (420?). Likely to stretch rapidly. Check the front sprocket (just in case someone ignored that when they fitted the chain.

However you do need to lube your chain more often. That is likely to be the main culprit. With wet weather you could easily need to lube it a couple of times a week.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

0ddball
World Chat Champion



Joined: 15 Jul 2005
Karma :
PostPosted: 13:44 - 07 Nov 2006    Post subject: Reply with quote
Just sounds like a chain on it's last legs. Mine stretched so much it needed adjustin on a daily basis for about 2 weeks before it snapped.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Trixie
World Chat Champion



Joined: 27 Jul 2005
Karma :
PostPosted: 13:58 - 07 Nov 2006    Post subject: Reply with quote
Arfdog wrote:
I keep the tensioners on either side of rear wheel in line with each other, so the wheel must be pretty straight. When I set the chain, I set to manufacturers guidelines (2cm play). The sprocket looks like its in pretty good condition....


When you say about the tensioners either side of the rear wheel in line with each other, do you mean the adjustment marks on the swingarm? If so, it's possible your wheels are out of alignment, as these marks are very rarely accurate - don't use these to line everything up!
____________________
Dead nobodies in company cars...
 Back to top
View user's profile Send private message Visit poster's website You must be logged in to rate posts

Arfdog
Crazy Courier



Joined: 17 Aug 2006
Karma :
PostPosted: 15:21 - 07 Nov 2006    Post subject: Reply with quote
Think I'll get a new chain (and lube it regularly).

yep I mean those adjustment marks..

Could you advise on a more accurate method please, Trix?
____________________
I'm a lover, not a fighter.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Kickstart
The Oracle



Joined: 04 Feb 2002
Karma :
PostPosted: 15:23 - 07 Nov 2006    Post subject: Reply with quote
Hi

If you are replacing the chain then replace the sprockets as well.

Once you get the wheel in line (use a long straight bar against the rear wheel and check how close it comes the the fron wheel, repeat on the other side and compare), just adjust the chain the same number of turns / partial turns on the adjuster nuts on each side.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Trixie
World Chat Champion



Joined: 27 Jul 2005
Karma :
PostPosted: 15:33 - 07 Nov 2006    Post subject: Reply with quote
Arfdog wrote:
Think I'll get a new chain (and lube it regularly).

yep I mean those adjustment marks..

Could you advise on a more accurate method please, Trix?


Pretty much what Kickstart says. Make sure the wheel is in alignment, then when you adjust the chain, make sure you turn the nut the same amount on each side; I normally use either a quarter or half a turn at a time. Thumbs Up
____________________
Dead nobodies in company cars...
 Back to top
View user's profile Send private message Visit poster's website You must be logged in to rate posts

Finglonga
World Chat Champion



Joined: 27 Jul 2004
Karma :
PostPosted: 19:40 - 07 Nov 2006    Post subject: Reply with quote
2cm doesn't sound like enough slack, I would imagine its getting tight when the suspension is compressed. Just sounds like it would need at least double that.

Are you checking the tension on its tightest spot?
____________________
Andy Sez....
F.Y.Y.F.F.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Pete.
Super Spammer



Joined: 22 Aug 2006
Karma :
PostPosted: 20:16 - 07 Nov 2006    Post subject: Reply with quote
Check your wheel alignment with a straight-edge about 4 inces off the floor. It should touch at four points - front and rear of the front tyre and front and rear of the rear tyre. If it doesn't, you need to adjust it until it does. You can use string, or something like a long timber batten but make sure you sight along it before you do to be sure it's perfectly straight.

Another way is to use a tape measure and measure both sides from the swingarm pivot to the axle.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good Very Happy
 Back to top
View user's profile Send private message Visit poster's website You must be logged in to rate posts

Arfdog
Crazy Courier



Joined: 17 Aug 2006
Karma :
PostPosted: 08:22 - 08 Nov 2006    Post subject: Reply with quote
Finglonga wrote:
2cm doesn't sound like enough slack, I would imagine its getting tight when the suspension is compressed. Just sounds like it would need at least double that.

Are you checking the tension on its tightest spot?


Well, I've tried to sit on the bike and check the play then, but it seems to not change at all. I've also revolved the wheel to try find if the chain is tighter on some stretches, but it ain't.

When it comes to play, I am uncertain whether PLAY means SLACK, or if it means the amount you can move the chain up and down with your fingertips, whilst there is no slack.

So, if I tighten chain up as much as I can, I cannot budge the chain at all. It is taut, NO PLAY, certainly NO SLACK. I loosen it a bit, so that while it is still taught, I can move it up and down a little. This to me is PLAY. I loosen the chain further, which increases the PLAY, and I find when the play is about an inch, this is the point where SLACK begins to appear - the chain has no tension on it at rest, and can 'flop about. This is where I normally adjust the chain to, to the point where there is the tiniest amount of slack. Under this setting, about 0.5 cm movement up or down on the lower stretch of chain is enough to remove the slack, and a further cm or so brings it to the end of play, to the pint where it can no longer be moved. So the total range of movement would be 3cm top to bottom, of which 1 cm would be slack zone.

Now, maybe I am reading the specs wrong and actually need 2 cm of SLACK, but that makes the chain pretty loose! When it has that much slack I can actually feel a bump when I blip the accelerator. I would have thought slack in a transmission system would be very bad for the driving sprockets and gearbox bearings if it means NO LOAD for a tenth of a second before hitting to FULL LOAD, everytime you accelerate..

I bet no-one has posted such a long post about tensioning a chain before! Confused
____________________
I'm a lover, not a fighter.
 Back to top
View user's profile Send private message You must be logged in to rate posts

feef
Energiser Bunny



Joined: 11 Feb 2002
Karma :
PostPosted: 08:48 - 08 Nov 2006    Post subject: Re: Chain stretch Reply with quote
Arfdog wrote:
Hi guys,

I cannot understand it. I find my chain has about 4 cm or more of play, of which 2 cm is TOTALLY free (slack) play, every 3 weeks or so. I tighten it JUST enough so that the slack is taken out of it, and then it's got about 2 cm of play. Not free flopping about slack play, but play under very slight tension.


Sounds to me like your chain is actually too tight..

As soon as the suspension moves, it's going to start stretching that chain.

a
____________________
Mudskipper wrote: feef, that is such a beautiful post that it gave me a lady tingle Laughing
Windchill calculator - London Bike parking
Blog and stuff - PlentyMoreFish dating
 Back to top
View user's profile Send private message You must be logged in to rate posts

Walloper
Super Spammer



Joined: 24 Feb 2005
Karma :
PostPosted: 13:23 - 08 Nov 2006    Post subject: Reply with quote
Measure 'Stretch' over several Link/Bushing Assemblies.
The OEM will provide a spec.
Usually five. This is the 'PITCH'
This adds up much more 'measurable' wear and determines if chain is reusable.
Also I (have to say it) Check that the adjustment isn't just backing off cause the axle nuts arn't tightening properly.
I don't think the chain would stretch and stretch and stretch. It might only do that once then snap.....

I had one of those silly light weight sprocket on a bike and the chain wore out within weeks of eating the hardened sprocket teeth.
____________________
W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair
 Back to top
View user's profile Send private message You must be logged in to rate posts
Old Thread Alert!

The last post was made 19 years, 81 days ago. Instead of replying here, would creating a new thread be more useful?
  Display posts from previous:   
This page may contain affiliate links, which means we may earn a small commission if a visitor clicks through and makes a purchase. By clicking on an affiliate link, you accept that third-party cookies will be set.

Post new topic   Reply to topic    Bike Chat Forums Index -> The Workshop All times are GMT
Page 1 of 1

 
 You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum

Read the Terms of Use! - Powered by phpBB © phpBB Group
 
Debug Mode: ON - Server: birks (www) - Page Generation Time: 0.08 Sec - Server Load: 0.27 - MySQL Queries: 13 - Page Size: 86.45 Kb