Topic: Drive Chain Adjustment

[kach_me]

I have checked my Haynes manual and I cannot find anywhere that it talks about Drive chain tension or adjustment.  What is the proper amount of "play" in the drive chain and how do I adjust the chain if it is too loose or too tight? 

I checked the forums but couldn't find a thread specific to making the actual adjustments.  Sorry if this is a repeat question.

Shannon

[nickjtc]

On the CB650 the slack is 15-25mm (5/8"-1") at mid-run, after checking the chain for tight spots.

Take out the cotter pin holding the axle nut. Loosen the axle nut. Loosen the chain adjuster lock nuts, both sides. If the chain is too loose tighten the chain adjuster bolts by an equal number of 'flats' each side. You will only have to turn a bit to tighten the chain a lot. If the chain is too tight loosen the adjuster bolts by a few flats, equally, both sides and tap the adjuster bolt ends with a hammer to move the axle forward. Spin the wheel to check tension at several points around the chain. When ok tighten the adjuster lock nuts and axle bolt (58-72 pounds feet torque) and replace the cotter pin.

You may want to check the alignment of the front/rear wheels at this point.

Ride the bike a bit to warm up the chain and then lube it with your favourite lube. 

If, after adjustment, you can pull the chain off the rear sprocket to show half the depth of a cog the chain and sprockets need to be replaced. Replace as a set, even if the sprockets look in reasonable condition.

[SohcCBs]

750...Honda Manual states 1/2 to 1", I find 1", no less - no more to work properly on my '76, with 630 "O-ring" chain.  I think I remember when I had a regular chain it was best at 3/4 to 7/8s.


nickjtc, how long you had your Norton?  I used to have the '71 Interstate model, with that big "conical" front brake....worked extreemly well and 5 gallon tank.  Sure wish I still had it!!!

[mic-57]

This is out of the 750 manual

[SohcCBs]

750...Honda Manual states 1/2 to 1", exactly.

[kach_me]

This is out of the 750 manual

Mic, what manual have you got there (i.e. what years does it cover, etc)?  If possible, I would be interested in a copy (PDF or otherwise), if you are willing to do so...

[Kev Nemo]

Can somebody tell me where you measure the play? Top chain, bottom chain? Would you hold a straight edge paralell with the chain and measure up from there?

[MCRider]

Can somebody tell me where you measure the play? Top chain, bottom chain? Would you hold a straight edge paralell with the chain and measure up from there?

There is lots of argument about this, so you decide. First, use the lower run, and tighten up the upper run by putting it in gear and turning the wheel. Then...

If you'll notice, if you adjust it on the centerstand, as it is most convenient, when you drop it off the stand and have someone else sit on it it will be too tight. This is because as the swingarm travels up the rear wheel gets further away from the countershaft sprocket.

So with trial and error you can find the point at which the proper slack exists with weight on the bike. On the centerstand it will be looser.

That's my experience.

What happens when the chain is too tight? It bears on the sprocket carrier bearing and the give in the drive cushes. Without the drive cushes, one can do damage to the countershaft bearing as well.

[SohcCBs]

I can't say who's right, but I can say I've done it by adjusting the bottom middle to the recommended spec for all the motorcycles I've owned for 35 years.  On the centerstand with no tension and in neutral....spin it or run it for a few seconds and check it again.

I've never had any problems this way with German, British or Jap bikes..all of which I've owned.

I have found though, that each bike depending on the sprokets and chain may vary from the spec a little.
My '76F likes 1 inch, but I have 15/43 sprokets and 630 o-ring. 

[feliz]

I can say who's right, but I can say I've done it by adjusting the bottom middle to the recommended spec for all the motorcycles I've owned for 35 years.  On the centerstand with no tension and in neutral....spin it or run it for a few seconds and check it again.

I've never had any problems this way with German, British or Jap bikes..all of which I've owned.

+1

[Dave Wyatt]

I've found that adjusting it to the loose end of the specs gives me more miles between re-adjustments.  Porbably due to the previously mentioned tightening effect when it is on the ground and rider seated.  Starting out loose give it some room to tighten up without it getting too tight.  Too tight wears out the chain and sprockets pretty fast.

[Kev Nemo]

So a thousand miles between when I put the chain on and now is about right for adjustment,right?

I don't think the chain is bad, I just think I've put alot of miles on it in a short time- as it should be!

[Dave Wyatt]

I get 5-6 thousand out of an adjustment, but I've got a Hondamatic and they are easy on chains.  I keep it well lubed and run an O ring chain too, which helps.  If your banging gears, I could see 1000 mile, or less, adjustments being needed.

[333]

I've always checked it whist sitting on it.  That takes the "trial and error" out of the process.  And unless you take the chain guard off, the bottom run is exposed and handy.