Split Link Primary Chain

Gerald

Gerald

Hero member
Removed the primary side cover to replace primary chain and found a triplex chain with split link.
Never seen one before, anyone know when these were around?
Bike came to me without speedo or recorded mileage, so I don't know when it was installed.

Gerald
 

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One of the triplex on my SF that let go had a split link, and it was that which failed. Cannot remember from where or what brand, but would have been bought from a Lav dealer in Australia. The next one did not have a split link and it let go at the track, plates broken through, also from a dealer in Australia.
 
All Laverda triple engines were originally fitted with Regina triplex endless primary chains up to around 1983 when the 120 engine was produced with twin duplex chains (again endless).
Having a split link primary chain seems a daft idea far too risky.
Alan.
 
From my perspective, the main problem is the use of inferior quality chain just because it is the same size. Also, if using a split link, using incompatible ones, or ones which have been clipped already. The spring clip is a single use item in an ideal world. I won't use a split link (on a camchain) unless it's still in the plastic bag with the part number on it, so I know it is correct for the given chain and the clip is unused.
I did run clip link single row primary chains on road bikes for a while back when I couldn't easily source the correct ones, I used Regina C121HCS chain and links and touch wood never had an issue.
These days with the Iwis G76HP endless chains so high quality and fairly easy to get, it's a no brainer. Either two single row ones on a 120 or a duplex on anything earlier.

I broke a triplex primary chain in my 750 racebike after purchasing it from Chris, it was a clip link chain but it broke away from that link. It was a shit quality chain. At Phillip Island back in 08 I arrived with hope of using the belt drive which failed in short order so I had to source some Tsubaki industrial triplex chain from Melbourne (thanks Ian!) and robbed the sprockets from the genuine SFC on the day. I put a new chain in each day just to be on the safe side and it worked. Later when running the bike more regularly the Iwis G67HP duplex had become available and I used that without incident, initially still changing it daily, eventually comfortable to leave it in for the duration of a three day meeting. There was never any perceptible wear or signs of trouble, they would probably last much longer but a new chain is cheap insurance in the context of a multi-thousand dollar weekend even if things go smoothly.
 
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I'll take your 3-day old IWIS duplexes off your hands, Steve! 🤣 Jokes aside, if couldn't source a new one, I would be happy to fit one to my 880 - I doubt very much they've been compromised, but understand that racing is a different world. I have to confess that I've also reused my camchain split link several times :eek:
 
You take a conservative approach when you've punched one out through the bottom of your crankcases (though not a Merc duplex). :D

Re camchain split link, I recall Andychain saying that you re-use the original split link (as it has aged with the chain) and only fit the new spring clip. Interesting perspective I hadn't thought of before. Hair-brained theory or wisdom from someone who knows the intricate details of a very specialised industry? It seemed plausible to me so I went with the latter.
 
The primary chain, removed from a 750, was in pretty decent condition when removed.
Split link clip was pretty tight fit, a camchain clip is easier to remove.
I was just astonished to see a primary chain with a split link.
 
Gerald said:
The primary chain, removed from a 750, was in pretty decent condition when removed.
Split link clip was pretty tight fit, a camchain clip is easier to remove.
I was just astonished to see a primary chain with a split link.
Click to expand...
Probably sourced and fitted by a DPO. Don't think any dealer would risk supplying an open primary chain with a spring clip... except maybe a certain Herr N. (?)!

piet
 
The bike is not DPO'ed, has run very well since aquired.
Who knows why and when the primary chain was fitted.
Now replaced with a chain from reputable source.

Gerald

Hope that a certain Herr N. Is not at large anymore......
 
I also reuse the split link on the cam chain. The reason they recommended you not reuse it is they assume it was stretched too far on removal. If you pay attention and gently slide it off then you have not damaged it. They don't wear out as it is a piece of spring steel. The one on my 3CL has been reused probably 6 times without issue.

As for primary chains with a split link, I don't have problems with that either. If the split link is such a bad idea then why do the manufactures even make them? Back when just about every bike had a separate gearbox with a single row primary chain, they all had a split link and many had a half link. I have seen a number of primary chains fail on British bikes, but never because of the split link. My Norton Commando has had a split link triplex chain in it for 38 years without problems.
 
I also reuse the split link on the cam chain.

I would no do it and it is just a two cents item, I never would risk any engine trouble. I can agree to your argument but will not reuse link.
 
breganzane said:
Re camchain split link, I recall Andychain saying that you re-use the original split link (as it has aged with the chain) and only fit the new spring clip. Interesting perspective I hadn't thought of before. Hair-brained theory or wisdom from someone who knows the intricate details of a very specialised industry? It seemed plausible to me so I went with the latter.
Click to expand...

I tend to agree. I'm not as chain savvy as Andy, but what he says makes sense to me.

I think it's less risky to re-use the original split link than to mix and match. Don't buy a new one if you can't be 100% certain that the new one is a perfect match to the chain. If you don't know the correct manufacturer and part number of the original link. Stick with what you've got.

Not all 06B chains are the same. Whilst the basic dimensions of pitch and width are standard, they can vary slightly in pin diameter, roller diameter and side plate thickness. A generic split link may not have exactly the same dimensions as the chain you're using.

The spring clip also has to be a perfect fit. Using your original split link with a spring clip from another link of unknown provenance is asking for trouble. If you're gentle removing and replacing the spring clip, it shouldn't get bent out of shape. Slide it off lengthways as 1200ts says above. Check that it fits snugly when re-fitting. A spring clip that's a bit loose on its pins should be discarded.

Anecdote:
Once, a few years ago, while I was in a bike shop waiting for a tyre to be fitted to a wheel I'd brought in, I was watching the shop "mechanic" do a rear tyre change on someone's bike. For some reason that escapes me, he split the chain to remove the rear wheel. He removed the spring clip on the drive chain by spreading the legs apart with a screwdriver and levering one of them over the head of the pin so the clip swivelled off sideways. When it came off it was all bent and twisted. The chain was staying on the bike, so using a vice as an anvil, he hammered the clip flat again, then squeezed the legs together with a pair of pliers and re fitted it. Nice job.
 
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