Topic: My 'primary' concern right now... is 'linked' to the bottom end.

[Doctor_D]

Same chain I have, and a nice one at that.  However, it appears that chain is installed incorrectly. The sideplates should alternate between the two chains -- outer plates on one next to inner plates on the other.

CCC has a picture of a correct install, here: http://www.classiccyclecity.com/gallery/displayimage.php?pid=1411&fullsize=1

[mick7504]

Same chain I have, and a nice one at that.  However, it appears that chain is installed incorrectly. The sideplates should alternate between the two chains -- outer plates on one next to inner plates on the other.

CCC has a picture of a correct install, here: http://www.classiccyclecity.com/gallery/displayimage.php?pid=1411&fullsize=1

Dave

That has always been a curious point, and there have been varying opinions on whether the links should be be staggered or aligned.
I honestly don't know the benefits or drawbacks either way but I would like to know.

I have put the subject up several times here on the board and there really hasn't been a definative answer either way.
There have been varying opinions and ideas but really nothing concrete.
Originally I picked this up from Axl, (Satanic Mechanic) which is when the curiosity began.

Mick

[mec]

"The sideplates should alternate between the two chains -- outer plates on one next to inner plates on the other."

would like to have an explanation for that.

for me it seems to be nonsense, copied one from the other.
the OEM manual shows several drawings: the chains side by side regularly, one photo with alternate plates.
nothing mentioned in the assembling chapter.

mec

[MCRider]

Yes MEC and Mick, when I went to assemble mine I put out a request for opinions/facts as to how they should go. i had remembered reading somewhere they should alternate, but couldn't find the source or reasoning.

I PMd several who might know. I don't remember the exact results. The consensus result was no one knew for sure either way.

So I flipped a coin and put them in aligned. I figure either way, they'll likely outlive me.   

PS: I wish I'd paid attention to how they came out of my parts bike. That would have been factory original.  Wasn't an issue back then.

[Doctor_D]

I got it from the Hondaman book, but my dealer service manual is silent on the issue.  That doesn't mean a whole lot, as the manual is silent on many, many things.

However, if MEC, fabricator and engineer extrodinaire, calls it bogus, I will scrub it from my knowledge-base and move on.

 

[mick7504]

I got it from the Hondaman book, but my dealer service manual is silent on the issue.  That doesn't mean a whole lot, as the manual is silent on many, many things.

However, if MEC, fabricator and engineer extrodinaire, calls it bogus, I will scrub it from my knowledge-base and move on.

 

It's probably one of those curiostities that will never have an answer mate. 
But I must say that it bugs me a bit when I think about it not knowing either way.
Might just go and crack a cold beer. 

[MCRider]

I got it from the Hondaman book, but my dealer service manual is silent on the issue.  That doesn't mean a whole lot, as the manual is silent on many, many things.

However, if MEC, fabricator and engineer extrodinaire, calls it bogus, I will scrub it from my knowledge-base and move on.

 

Doc: Did you see it in print in Mark's book? I've looked and can't see it. Several pictures of the chains, but none that are clear enough to tell for sure. Maybe one is and it has the links synched up, not alternate. Give us a page number if you have one.

Mark does say that if you are using old chains over, to keep them on the same sprockets and in the same direction of rotation. Makes sense. If 40+K miles better to replace while you're in thre.

I thought that I had PMd all parties that would have an educated opinion. I remember APE for example did not have an opinion as they don't assemble engines.  I think i included Mark in my canvas,  but maybe not. Had he told me I'd give it more weight, but again, I may not have asked him.

[Doctor_D]

My copy of the book is down at the shop.  I'm a "read the f'ing manual" type of hobbyist, and have to believe that I got it from a credible source, but now I'm uncertain and awash in self-doubt.

Apologies to Mark if it didn't come from him.

[simon#42]

There are more ways leading to Rome. I came up with the preload plate back in the mid-70's. I first tried to 'open up' the spring by forcing it open.........bad idea. After a few miles the spring broke and had to open the engine again. Back then with my very small paycheck, not good. So had to find something different and came up with this plate. It has been in every engine I build and honestly never heard of problems with it. Do not misunderstand it is no miracle and the chains will wear out, but it will keep 'following' the chains better and for a longer time.

Rob

Hey Rob

I'm fairly certain that we have all been through the very smallpaycheck thing at one time or another.
This is probably why we have come up with these different ideas to improvise and improve on what was already there.

With the HD chains and and a bit if extra preload on the tensioner, I think that the possibility of a chain breakage would be less than that of winning the lotto. 

This afternoon, I assembled a set of cases with HD chains and a modified tensioner, and I just cannot see how those chains are going to whip/snap and cause internal damage.
They really do look bulletproof.

Mick

mick as you have got the motor apart it is very easy to see how much chain slack you are going to have on over run , just remove the tensioner from the engine and then check how much play you have got in the chains , allow for a bit more for when the chains are run in .

[mick7504]

There are more ways leading to Rome. I came up with the preload plate back in the mid-70's. I first tried to 'open up' the spring by forcing it open.........bad idea. After a few miles the spring broke and had to open the engine again. Back then with my very small paycheck, not good. So had to find something different and came up with this plate. It has been in every engine I build and honestly never heard of problems with it. Do not misunderstand it is no miracle and the chains will wear out, but it will keep 'following' the chains better and for a longer time.

Rob

Hey Rob

I'm fairly certain that we have all been through the very smallpaycheck thing at one time or another.
This is probably why we have come up with these different ideas to improvise and improve on what was already there.

With the HD chains and and a bit if extra preload on the tensioner, I think that the possibility of a chain breakage would be less than that of winning the lotto. 

This afternoon, I assembled a set of cases with HD chains and a modified tensioner, and I just cannot see how those chains are going to whip/snap and cause internal damage.
They really do look bulletproof.

Mick

mick as you have got the motor apart it is very easy to see how much chain slack you are going to have on over run , just remove the tensioner from the engine and then check how much play you have got in the chains , allow for a bit more for when the chains are run in .

Hey Simon

I've got the cases glued together now which was the mission for today.
The metal strip that I welded onto the tensioner base is 4mm thick and the HD chains have laid together quite well.

It is a bit of a trial and error thing with how much to load it all up but these chains are the Bees Knees.

Looking at one of the smashed and welded up top cases in the collection (Mick/Steptoe), I can remember the punishment and neglect that was metered out on stock chains well before that happened.
That was back in the days when it was "Go Hard or Go Home" - A long time ago now.

I really think that these HD Primary Chains are a force to be reckoned with for the 750 SOHC's and they'll eat 100+HP for breakfast - Throttle On, Throttle Off.
I may be wrong but time will tell mate. 

Mick

[simon#42]

i think your probably right mick , im just being fussy .... i bloody hate that tensioner arrangement !

[Retro Rocket]

i think your probably right mick , im just being fussy .... i bloody hate that tensioner arrangement !

A slipper tensioner that is adjustable from underneath the engine would be ideal....

[simon#42]

yes mick it would , even if you had to take the sump off to adjust it . if the new chains are as good as people think they wouldn't need adjusting very often . oh and as the chains tend to wear at different rates one for each chain would be nice .

[voxonda]

yes mick it would , even if you had to take the sump off to adjust it . if the new chains are as good as people think they wouldn't need adjusting very often . oh and as the chains tend to wear at different rates one for each chain would be nice .

Regardless of what, this is the biggest flaw in the design. One tensioner for two chains. Chains will never ever stretch at the same rate, so the tensioner can only follow the one that is the tightest.

[fang]

Regardless of what, this is the biggest flaw in the design. One tensioner for two chains. Chains will never ever stretch at the same rate, so the tensioner can only follow the one that is the tightest.

I always assumed that the adjuster would wear a little to accommodate the difference in chain wear.  lol!

For whatever its worth, I also first started installing an aluminum spacer for my primary chain tensioner around 10 years ago.  I just used some generic 3mm thick plate, trimmed to a correct fit.  It just seemed like the right thing to do, and I also have never had a problem with mine.  It quieted those chains, which seemed like a big improvement. 

I also have noticed a wide discrepancy in the slack and play between the left and right sides of my primary clutch gears.  Some are tight as can be, and many are soft or sloppy.  It should be remembered that those are perhaps wearing differently side-to-side, which also can provide an illusion of uneven chain wear. 

For the record, I received my HD primary chains from CCC.  They arrived fast and packaged well.  I am pleased with them, and just holding them in my hand makes me excited to get this motor buttoned up.  I can't wait for the last few expensive bits to arrive in the mail. 

I have every intention to shim the primary tensioner in this motor with these chains.

-Fang

[Ricky_Racer]

Glad you've received the chains and are excited about them, Fang. Thanks for the feedback.

Just a quick observation... with a tested 0.2% (two tenths of one percent) stretch at 60,000 miles of use, these chains certainly ought to reduce concerns about the tensioner significantly favoring one chain over the other. And they may bring into question whether shimming the tensioner arm is even necessary, unless there's an inherent weakness in the Honda tensioner spring.  RR

[kos]

I have never, ever set up the dual primary chains that were not matched up at the side links.
They must be aligned.

Not to put anyone down or in their place BUT how many chains have any of you broken?

And as Mike R has indicated the tensioner is not really doing anything when you are accelerating, but is really needed when on deceleration.
What is really needed and what we are working on at M3 Racing for a proper tensioner for primary drive system on the CB750 is one that has a dampener (or a shock absorber) if you will, to control the rapid up and down motion of the tensioner on engine decel.

Mark

[MCRider]

I have never, ever set up the dual primary chains that were not matched up at the side links.
They must be aligned.

Not to put anyone down or in their place BUT how many chains have any of you broken?

And as Mike R has indicated the tensioner is not really doing anything when you are accelerating, but is really needed when on deceleration.
What is really needed and what we are working on at M3 Racing for a proper tensioner for primary drive system on the CB750 is one that has a dampener (or a shock absorber) if you will, to control the rapid up and down motion of the tensioner on engine decel.

Mark

Thanks I feel a lot better now!

[voxonda]

My primary idea about shimming the tensioner was not increasing the springload if you will, but to increase the travel of the tensioner as can be seen in the pictures. On decelleration the oem setup has trouble 'following' the chains. With shim this is certainly much better. BTW I agree with Mark about the number of broken primary chains seen. During my lifespan I've seen it once happening on a all out racer while under having braking, and that was at the end of the season. And seen one topcase which had scares but that was from neglect by the owner.
In my latest engine I have made a slider in the topcase, using a addepted slider from a 900 DOHC engine.

Rob

[MCRider]

Man you guys are hard on equipment! I love it! Real world testing.

[kos]

Just to clarify...we have broken at least 6 sets of chains...so we know all about the proper way to get around this problem.

and never once was it under acceleration.

Mk @ M3