triplex chain upgrade N15CS

gpzkat

gpzkat

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In my parts pile I got with the bike there's a triplex clutch assembly that looks to be from '71 or newer Commando. It's complete except for a missing diaphragm plate. My N15CS original setup is single row and complete. Is it a worthwhile upgrade to go with the triplex setup? I'd have to get a crankshaft sprocket and the diaphragm to make the switch. Either way I'll need a new chain so it won't be too much more. Just wondering if I should bother, it's not going to be a daily rider, a fun bike to ride now and again along with my other 3.
 
Quite a few years ago I spoke to the owner of a mid '60s Atlas, he told me he had fitted a Commando triplex primary set up of course with the longer Commando main shaft, he told me that he broke several said main shafts until he reduced the primary chain to duplex!
 
The std primary case of an N15 is not wide enough for a triplex chain.
I did that conversion on my N15 before I switched to a belt drive, but with a duplex chain.
Removed the unused row of teeth. Mercedes camshaft chain, Commando main shaft.
Still have the parts.
If you lived any closer, you could have them.
The case isn't wide enough for a belt either, but I believe it is a better option.

triplex chain upgrade N15CS
 
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Thanks for the info, very helpful. Though I love the idea of running a belt, my job in the avionics field went kaput thanks to Covid, so I'm on a tight budget. Heck we had layoffs a month before all the fun started.
 
What about an iwis chain feom Andy the chain man? I believe he can supply one for that single row which is stronger thatthe original.
 
That little single row bicycle chain in the primary can take a surprising amount of abuse on a fun to ride street Norton. I would not bother with all the work required to change it myself.

An N.E.B single row chain clutch might be a nice upgrade for an N15CS, but I really don't know how much better it would be than the stock clutch. It would be lighter weight, so possibly less stress on the crank and quicker spin up.

What I'd like for my P11 is leak proof Matchless primary cases. I'm OK with the single row chain. :)
 
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cjandme said:
What about an iwis chain feom Andy the chain man? I believe he can supply one for that single row which is stronger thatthe original.
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Yes I'll be doing that, will need all the chains on the bike replaced I'm sure.
 
Years ago I converted my Atlas primary to a Commando Clutch with a triplex chain. Long story short: I have since gone back to the AMC clutch. I did not like the flywheel effect of the heavier Commando clutch and chain, besides there is no cushion in the hub of the Commando clutch; you risk gear failure without a cushion somewhere in the drive line.

Moreover, as others have stated, the work involved due to the wide chain is not worth it.

Slick
 
As previously stated I am currently assisting with a N15CS, even with a single row primary the chain is extremely close to the inner primary case.
 
gpzkat said:
In my parts pile I got with the bike there's a triplex clutch assembly that looks to be from '71 or newer Commando. It's complete except for a missing diaphragm plate. My N15CS original setup is single row and complete. Is it a worthwhile upgrade to go with the triplex setup? I'd have to get a crankshaft sprocket and the diaphragm to make the switch. Either way I'll need a new chain so it won't be too much more. Just wondering if I should bother, it's not going to be a daily rider, a fun bike to ride now and again along with my other 3.
Click to expand...
You can only fit a single row primary chain in the alloy AMC chain case. Some people have fitted a belt drive but you need to add a special spacer between the inner and outer cover, then you would need to alter the riders footpeg bracket, keep it simple, stay with the original setup.
 
OK thanks all, good info. I'll just stick with stock and get a new top quality chain.
 
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