Topic: The front wheel spindle clamp - knowledge test

[scottly]

I have personally decided to do it some way and never tell anyone.

I think I'll take the same route this time around.

[CycleRanger]

What manual CycleRanger?

The Honda manual.    Either 750 or 360. Might be from the setup guide, I don't remember.
Here's another picture from the CB360 shop manual.

[Schnell]

This is riveting. Will there be a resolution? Is there a correct answer?

[seanbarney41]

I've actually experimented with putting it both ways, probably even had it different from side to side...and could not discern any difference, and nothing broke...but yeah, just put the gap to the back

[MoMo]

This is riveting. Will there be a resolution? Is there a correct answer?

Unless Honda is wrong  in every manual the answer would be...............................................................................

[70CB750]

I dont believe Honda couldnt make precise enough it to clamp down full force without gap.

And HM quote is from sohc faqs. I wonder why he would say it.

[MoMo]

I dont believe Honda couldnt make precise enough it to clamp down full force without gap.

And HM quote is from sohc faqs. I wonder why he would say it.

There has to be a gap, it allows the axle( handlebars use the same principle) to be locked into place so they do no rotate-see TT's post 15...Larry

[Whaleman]

I just changed mine back to the gap in the rear where I had it for the first 25 years. Dan

[Raul CB750K1]

My two cents...

Only when the spindle diameter is slightly oversize with regard of the clamp diameter, is when you can be positive you clamp is actually clamping.

Honda did it that way, and for that reason there is a gap.

In my "modern" CB Seven Fifty -built in 1993-, I found that the master cilinder clamp has the "top" marking pointing downward. I also discovered that the handleblar clamps has some small indentation that serves to install the clamp in a given direction.

For the life of me I can't see any reason as to why marking a "top" sign in the M/C clamp, or an indentation in the handlebar clamps. But I can tell you that I was getting mad at riding while seeing a "top" engraving facing downwards. So one day I got my sockets and installed it the "right" way.

Long story short: I find no reason why there should be any difference in the orientation of the clamps. But my theory is that the japanese, being a conscietous and perfectionist type of people, found strange to leave, in the shop manual, something to be decided by the assembly operator. Everything must be specified, clear, and with no hint of improvisation.


Back to the front spindle clamp, it is necessary that the diameter is smaller to make sure there is clamping force. As long as there must be a gap, in Honda decided it was either leaving the decision where to leave it to the operator, or specifying where to do it.... and they chose the latter.

It is the only reasonable explanation I can find for that. Apart from what TwoTired says about preventing the front side to get exposed to water and debris, the actual force is performed by the bolts, not the clamp itself, so I don't see any structural difference between leaving the gap in the front or in the back.

[Don R]

I'm going to rotate mine every 500 miles. Does it matter which way you  turn most often?

[bryanj]

Just make it a whirling dervish mate,

If i can be bothered to get my arse into gear and find the bulletin book there is a proper bulletin on this

OK did it now stop bickering

[70CB750]

Thank you

Now I have to go back and change it again since I followed Hondaman FAQ.  Oh well, live and learn. 

It would be good to  fix it in FAQ - post 37 @  http://forums.sohc4.net/index.php?topic=7401.25

[Raul CB750K1]

Bryan, that bulletin explains a lot.

So it is not that the diameters are different- in fact they are the same, but one of the clamp sides has been milled in order to leave room for clamping.

This definitely would explain the reason for the markings in master cylinder and handlebar clamps. Guess I'll have to go and take a look....

Other thing that comes to my mind is that, even when the rotating momentum in the spindle is almost nil, in that way the clamp tends to tighten itself with the rotation of the spindle, while if the gap was in front, the rotational momentum would tend to loosen the clamp.


Never expected that a subject such as a front spindle clamp would raise so much discussion....

[CycleRanger]

Other thing that comes to my mind is that, even when the rotating momentum in the spindle is almost nil, in that way the clamp tends to tighten itself with the rotation of the spindle, while if the gap was in front, the rotational momentum would tend to loosen the clamp.

Now you're thinking like an engineer.

[Raul CB750K1]

Other thing that comes to my mind is that, even when the rotating momentum in the spindle is almost nil, in that way the clamp tends to tighten itself with the rotation of the spindle, while if the gap was in front, the rotational momentum would tend to loosen the clamp.

Now you're thinking like an engineer.

There is a big hammer in my workshop drawer. If I ever think like an engineer again, hit me hard in the head! 

[ncstatecamp]

Does it matter that much?

[City Boy]

Hi gang.I have always mounted front axles with cap clamp gap to rear just as I was taught while apprenticing and as Honda decreed in their various manuals without giving any thought as to why.However,I can't see that it makes a scintilla of difference to the reliability of the assembly as all forces that matter are directed away from the clamp and studs anyway.     Rock On

[TwoTired]

Other thing that comes to my mind is that, even when the rotating momentum in the spindle is almost nil, in that way the clamp tends to tighten itself with the rotation of the spindle, while if the gap was in front, the rotational momentum would tend to loosen the clamp.

I think that is a very good point.  In addition, if the wheel bearings ever began seizing (or non-rolling) on the shaft, the tightening clamp would help prevent the slippage.

[70CB750]

To wake up this dead horse    - I have a complete front end from 78 CB750F - and there is no gap under the clamp, front or back.

Apparently it was not so critical to keep it up in later production.

[TwoTired]

To wake up this dead horse    - I have a complete front end from 78 CB750F - and there is no gap under the clamp, front or back.

Apparently it was not so critical to keep it up in later production.

Perhaps the horse is dead.  But, it died without ever knowing the true nature of the universe. 

Either you are mistaken, it was assembled incorrectly, or there are some non-stock modifications.  All three of my F2/F3 bikes have that gap and it is toward the rear.  Pictures on request.  A black gap in black painted forks might be tricky to discern.

Below excerpt from the Honda Common Service manual.

[70CB750]

Interesting, I will take a picture tonight.

[TwoTired]

Interesting, I will take a picture tonight.

Do show the markings on the cap.  In fact, ensure it was assembled properly (per Brian's service bulletin) before taking the pictures.  Honda built it 35 years ago.  And, there are a multitude of wrenches out there which it may have encountered since.

Cheers,

[70CB750]

Here are pictures.  I will take it apart to see what is what.

[70CB750]

Details. The arrow apparently points backwards.

[crazypj]

There must be a gap so the clamp can apply full pressure.  The gap always goes toward the rear, out of the way of oncoming rain, dirt, grime, bugs, etc.  Same is true for bar clamps, and control group clamps onto the bar, and for the same reasons.

Cheers,

 That's the way I've always set them, for those exact reasons (as the set up guide doesn't tell you why )
 The clamp can stretch if fitted wrong and over tightened (as on the F2 front end)
I'm sure that if you check carefully you'll find the 'gap'  is angled as shown in service bulletin.
Just becasue it was fitted wrong 35 yrs ago, doesn't mean it's right today
BTW,
I worked at various Suzuki dealers for a number of years, they had equal gaps front and rear on many models Studs/bolts got pretty badly corroded as dirt/bugs/water got in the front 'opening' of wheel and handlebar clamps
Handlebar bolts are easy to change but doing studs in fork bottoms was a major ordeal