Primary chain: tight control

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Nov 10, 2012
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Hi All.
Commando is very easy to take a control of the primary chain thighten: remove the outer cover cap and you can see and touch the chain.
But if you remove the P11 cap you can see only a part of the chsin in the bottom side.
What do you do to control the chain?.
Thank you.
Piero
 
Hi All.
Commando is very easy to take a control of the primary chain thighten: remove the outer cover cap and you can see and touch the chain.
But if you remove the P11 cap you can see only a part of the chsin in the bottom side.
What do you do to control the chain?.
Thank you.
Piero

Piero,
The large center inspection plug not only allows you to look down on the primary chain, it also gives you access to the top chain row where you should be able to judge it's tension pretty accurately just by putting your finger in there and feeling for looseness or tightness. Just make sure the motor's not running, (laughing hard). You can also look down on the bottom chain row with a flashlight and you should be able to see oil just touching the bottom chain row at the rear, near the clutch chain wheel
C-ya, Jer
 
Piero,
The large center inspection plug not only allows you to look down on the primary chain, it also gives you access to the top chain row where you should be able to judge it's tension pretty accurately just by putting your finger in there and feeling for looseness or tightness. Just make sure the motor's not running, (laughing hard). You can also look down on the bottom chain row with a flashlight and you should be able to see oil just touching the bottom chain row at the rear, near the clutch chain wheel
C-ya, Jer

Hi Jerry.
My finger doesnt come to the top!!
May be is too short??.
If i put the finger i can only touch the central spacer, that is between the inner and outer cover trough goes the stud that holds the foot peg to the gearbox plate.
I will need a crooked finger to the right or to the left of almost twenty cm. long.
What finger do you have?
Piero
 
Piero is right. The inspection plug is located above the lower chain row and is only intended for filling up the chaincase with a lubricant, not for measuring chain tension (which should be done at the top chain row). For chain adjustments, the outer cover needs to come off, unless you have a clever tool of some sort.

-Knut
 
Hmmn, time for me to rethink this. I have a P11 primary apart at the moment and I'll recheck how I used to get it done. Perhaps a right angle length of thin tubing instead of a finger? I'll see what I can figure out.
 
Hmmn, time for me to rethink this. I have a P11 primary apart at the moment and I'll recheck how I used to get it done. Perhaps a right angle length of thin tubing instead of a finger? I'll see what I can figure out.
Hi Jerry,
let us know.
Piero
 
owners manual any help

Primary chain: tight control
 
I don't recall having difficulty using this lower large plug for oil fill and tension.

of course maybe I don't recall very well.

the difficulty was finding a tool to loosen and tighten the plug.

See how flat the angle is between the rubber foot peg and the new brake lever. This new angle, rather than the pedal being bent up 2", seems to work well for me so far.


Primary chain: tight control
 
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,straight from the manual
Hi Jerry,
let us know.
Piero
P.

Looks like P400 has it right, straight from the manual. As a further check you should be able to test the tension on the lower run with a piece of sturdy wire bent into a small hook to lift the chain up and down, You could also make up some sort of bent tubing or sturdy wire to try and detect movement on the top row? In any case a little loose is better than too tight. Good luck, Jer
 
Hi.
I use the tool to pool the kickstart shaft spring.
But is not the same take a control of the cahain up or down side.
Even if you have a new chain the botton side will be ever tight that upper side.
Piero
 
I will check my P11 primary chain this weekend to relive this adjustment.

I think I will need to lift rear wheel off ground....but maybe just neutral will work.
I would not be happy removing the outer cover.

I am not understanding, from a mechanical perspective, how you cant check primary chain slack at the top or bottom with equal success.


Primary chain: tight control
 
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I am not understanding, from a mechanical perspective, how you cant check primary chain slack at the top or bottom with equal success.

Length of the tangent line is identical at top and bottom run of chain. The procedure and accessability makes the difference. As per manual, you are advised to check slack/whip along the entire chain at half length of the longest run of the chain, and the opening is not in this position at the lower run, I believe. Checking the entire length of chain requires the engine to be turned. I can't imagine how you can perform this operation reliably through the oil filling opening. Measuring 3/8" (10mm) or a ratio thereof through the opening and at the same time ensuring the top chain run is tight will be difficult. Yes, undoing the primary cover is a pain but on the other hand, having fitted a good chain it should be done every 5000 miles only.

-Knut
 
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Personally, I won't be pulling my outer cover to check chain tension every 5,000. It's an easy approximation to make. 3/8" is not very difficult to estimate. And the manual gives enough information to tension the chain correctly. I'm going to fit a high tensile strength "O"-ring chain if there's enough clearance as I've done on my Atlas models. I'll be long gone before I accumulate 5,000 miles on my current P11.
 
Hi.
Take a control of primary chain of a Commando.
The bottom side is ever more tight than upper dide.
And the P11 too.
This means that the bottom side, the only thst you can see and touch, must be less than 3/8 slack.
Piero
 
An approximation of a fraction of the recommended slack/whip at a location where you can't see what's going on? Ahh .. ... well, maybe you are cleverer than me! :)

Isn't the O-ring chain made for free running chains in order to prolong maintenance intervals? A chain running in oil bath has no benefit of the O-ring chain, IMHO.
However, a high tensile chain available in a suitable dimension would be of interest. JWIS chains is probably the best chain for single row primary drives.

There are 3 reasons for chain failure apart from material failure: Misalignment of sprockets, neglect of tensioning to spec (sic!), and loss of lubrication.

-Knut
 
The bottom side is ever more tight than upper dide.
And the P11 too.

Piero,
if your mainshaft and countershaft are straight, there is no reason why the bottom chain run should be tighter than the top run. Have you observed this with your freshly restored N15?
Could there be some misalignment of the gearbox causing this?
The Commando Mk3 tensioner acts on top and bottom chain runs ....

-Knut
 
Piero,
if your mainshaft and countershaft are straight, there is no reason why the bottom chain run should be tighter than the top run. Have you observed this with your freshly restored N15?
Could there be some misalignment of the gearbox causing this?
The Commando Mk3 tensioner acts on top and bottom chain runs ....

-Knut

Hi Knut.
I undersatnd.
But my commandos have all a little difference between up and down.
Piero
 
ck chain today.
used a "dent pull rod" hook tool as shown.


Primary chain: tight control
 
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pulled up chain to ck tension, worked fine.

Seems to be 3/8" to 1/2" primary chain slack as I rolled it thru random locations.


Primary chain: tight control
 
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