What can happen if the chain is too tight?

[SuZuki10]

I recently took my 04 gs to the dealer for the 600 mile service and he practically barked at me that my chain was too tight and I shouldn't have done that.  But I didn't touch it.   He said I may have ruined something, but I don't really know what.  Do any of you know what can happen after riding a couple hundred miles with your chain too tight?

~Amanda

[VTNewb]

All I can think of is faster wear on the chain and the sprokets...

[tkm433]

The bearings on the output shaft of the motor and also the beaings on the rear wheel could be damaged and the chain and sprockets would also tend to wear quicker.  If the chain was way to tight it could break and end up killing you by causing the bike to crash or by hitting you when it beaks and causing the bike to crash.

[pixelmonkey]

good points made so far..

and to add to this

If the chain was way to tight it could break

sometimes if a chain is too tight and snaps it wraps around the front sproket and  bust the case, but it doesnt commonly happen on a street bike. most instances include bikes with more travel *dirt bikes, and even quads have this problem.

chirs<pixelmonkey>

[luksi]

When I got my bike, I checked the chain freeplay while on it's sidestand and it was about 30mm....as far as I know that's the max slack it's supposed to be.  A friend of mine saw my bike one day and said the chain was too loose...so I tightened it up to the min slack of 20mm listed in the both Haynes & Clymer...

I had no noise or problems until a few weeks later when I was caught out in the rain...when I got home, and started to park the GS in the garage, rolling the bike forward/backward in neutral, the front sprocket started making these strange grinding noises.  Got on this forum and decided several things must have happened.

The front sprocket grinding noises might have been due to the chain being too tight (my 210 lbs added to the min slack of 20mm too tight), or the chain was misaligned, or  the chain links sticking due to the rain (I also read somewhere that rusty chains actually tighten up somewhat...adding to my tight chain theory).

I cleaned the chain link by link, I loosened the chain back to the max slack of 30mm, I very carefully aligned the chain (marks on both side of swingarm)....no more grinding noise from the front sprocket area.

I'm guessing I rode around with the chain too tight for about 5 weeks before the chain got wet and the noise started.  I visually checked both sprockets and I can't discern any noticeable wear.

I personally wouldn't worry about the dealer...while I'm sure his point was valid...he probably was having a bad day and just over-reacted a little.

[dsmirnov83]

Please Check the chain free play wihile the bike is on the CENTER STAND.
Those are the numbers in the manual, not side stand.
-Denis S.

[Runner]

I've read somewhere (here?) that someone should be sitting on the bike when you check the slack, or you will be getting a seriously false reading.  I also read that most people tend to adjust the chain way too much.  Many years ago, I had a Honda CB350 and adjusted the chain WAY too frequently and kept it WAY too tight (which I didn't realize at the time) -- but I never had a problem of any kind in 12,000 miles of riding.

[bikenut]

Well, it seems we have some knowledgeable folks out there and I need some help.

I just tightned my chain for the first time.  I've always placed my other bikes on the centerstand when tightning, but the manual, although unclear, seems to indicate that the sidestand should be used.

I put it on the centerstand anyway.  Aren't we moving the rear wheel back and need it on the centerstand to take the weight off of it ??

Also, when I tightned the axle nut, it would never get to the torque recommended in the manual.  Once it got to about 25 ft/lbs the bolt started to turn.  I put in a new (little smaller, cause the original was a Buddha Loves You to get out) cotter pin and she feels fine on the road.

Am I ok ?  Did I do something wrong?

[mjm]

Since the center of the sprocket is not the same as the center that the swingarm pivots from, the chain will tighten and loosen depending on where in its travel the rear wheel is - You want to adjust the chain to have sufficient slack when the chain is at its tightest point.  "some" slack is really all that is needed at this point.

The tightest point is, convieniently, the point where a line drawn through the center of the front sprocket to the rear axle crosses the center of the swing-arm pivot.  On our bikes things are closer to that ideal state when the bike is on the side stand than when it is on the center stand - thus the directions in the manual to adjust it on the side stand.  It is not lined up then - but it is reasonably close - might even line up after the spring sags from a few thousand miles - I do not know because I replaced my shock with a GSXR unit.  Anyway, stock shock, any preload, and it is close enough that the spec in the manual will put you in a good range when all those points are lined up.

Once you install a different shock  and adjust sag, the bike sidestand probably won't  be very close to the right position.  Depending on whether you raised or lowered the bike with the new shock and by how much you changed the distance between the sprockets at that ride hieght, the stock specc might be good or might be too loose or too tight.

To really know, grab a couple heavy duty rachet type tie downs (or a friend of suitable wieght) and crank it down (have them put wieght on) until a straight edge or string along the swingarm shows that the sprockets and pivot are all lined up - then adjust for a small amount of slack - the chain will never be tighter than that amount during its travel.  So long as it is not so loose (at the extremes of travel) that it can jump a sprocket all will be well.

Once you have performed this ideal adjustment - like Suzuki did - you can put it on the side stand or center stand or hang it from the ceiling and   measure the slack at that point - so long as you always adjust the same way after that you are fine.

[Kerry]

As far as I can tell, you did everything right.  However, 25 ft-lbs seems a little low.  (I don't have a manual on hand, so I can't check for sure.)

It sounds like you have a torque wrench and a 21(?)mm socket.  Can you scare up a 17mm wrench and a buddy to hold the bolt motionless while you tighten the nut further?

[bikenut]

Kerry,

The manual calls for 45 lbs. and the nut is 22MM.  My torque wrench is 20 years old Craftsman, maybe it's no longer accurate?  I'm not that concerned about the sprocket alignment, more so that the wheel might be loose.  She feels fine on the road up to about 60mph.  I didn't want to exceed that speed until I checked with all these helpful, knowledgeable folks on the board.

I don't want to mess with something so vital, and will take it in to the shop if it's suggested.  BTW, I don't like the Suzuki dealership in my town, think taking it to the Yamaha dealer is a problem?

[Kerry]

The manual calls for 45 lbs. and the nut is 22MM.

Ah, 22mm.  Thanks - I can never remember that one.  I just about ALWAYS grab the wrong socket (21mm I guess) and then have to go back and get the 22.

My torque wrench is 20 years old Craftsman, maybe it's no longer accurate?

Hmmm.  I don't know for sure, but that would surprise me.  But if you could only prove it maybe you could get a brand new one!  

This is definitely a DIY job.  What's the motivation behind taking it to the shop?  Is it because you don't have a 17mm wrench to apply to the head end of the axle bolt?  You could probably buy more than one nice hand tool for the minimum shop charge.  :dunno:

BTW, I do find it interesting that your axle turns when you get up to 25 ft-lbs.  I have never needed to use a wrench on both ends of the axle, but maybe I'm just lucky.  Still, I wonder - is it possible that a spacer or a washer is missing?  If so then the two sides of the swingarm might refuse to come any closer together (at 25 ft-lbs) before they both make a solid landing against the shishkabob of hardware between them.  Does that make any sense?



I once left out item #9 in the diagram above, but luckily I caught it before I rode the bike.  (So I don't know how it would have felt going down the road.)  Perhaps the axle DID turn on me that time....  :dunno:

[bikenut]

Kerry,

I'd think of going to a dealer, 'cause I have no confidence in my mechanical ability, especially where my safety is concerned.  It seems when I try to do a simple thing (like adjusting the chain), it gets complicated and then I'm lost. If a washer is missing, they must have left it on the factory floor.  The bike's 3 months old, and unless the dealer removed the rear wheel during the 600 mile service, the wheel's never been off.  

I've had it up to a speedo reading of 115mph before the chain adjustment and she felt fine.  No hint of anything circumspect.

I've got the 17mm, but I wonder why I would need to do something so unusual just to tighten the chain.  It is under warranty.

[Kerry]

I've got the 17mm, but I wonder why I would need to do something so unusual just to tighten the chain.  It is under warranty.

Hmmmm.  It's unusual to have to exert torque on both a bolt head and the nut on the other end to get it sufficiently tight?  I have always marveled that I haven't had to do that.  :dunno:

But I'm not trying to start an argument.  You have every right to do what you deem necessary for your safety.  

Let us know how it comes out.

[bikenut]

Well, I went out to check out the size of the bolt on the exhaust side of the bike and what I saw embarrasses me.  The bolt runs through a triangular "A" shaped piece of metal that had turned and was not in the position that it should be.  I loosened everything up and put it in its proper position and then tightned everything and it torques fine now.  Ya see why I have little confidence in my mechanical ability??

Thanks for your help.  Now I can ride with confidence and that's the important thing.

[Kerry]

Now I can ride with confidence and that's the important thing.

Amen!  I'm glad you figured it out.  

[John Bates]

........... I have no confidence in my mechanical ability, ...... It seems when I try to do a simple thing (like adjusting the chain), it gets complicated and then I'm lost.......

Don't sell yourself short.  Adjusting the chain is much more complicated than it sounds.  It's not simple.  

For one thing the slack in the chain varies depending on how it is positioned.  Adjust it, then roll the bike to check your adjustment and it's changed.

Some say use the side stand, others say use the center stand.  My owners manual doesen't say which stand.

My owners manual says tighten the axle nut "securely".  
Clymer says "36 - 59 ft-lb".

I don't think a dealer could do it any better than you or me.

No matter who does the work, you or a dealer, do two things.

1. Before adjusting, ride the bike, get some speed up, pull the clutch in, cut the engine and listen to the chain. (no helmet on so you can hear it)

2. Then after adjusting the chain repeat the above.  If the chain is too tight you should be able to hear it grinding.