72’ Final drive chain. DID?

mean gene said:
At the time I was in charge of pumps, gear boxes and water plants in a steel mill. We were investigating belt drives vs chain. sorry fifteen years ago. Our regular chain was 5,200 lbs tensile another brand was 7,500 and UST was advertised 10,000. These figures are for conversation not exact from memory. Some of this came out because we supplied the steel for UST links! But seriously in the 100 inch Sportster a primary wouldn't last, stretched, UST with stood the power. Searched web and DID is 8,500 EK is 9,000. Tsubaki Omega O-ring chain listed at 7,500 and a racing chain at 38kN good for 200 hp EK has one, 520 ZZZ with 9,400.
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"Strength" is never going to be an issue for a Commando (or any other road bike). No bike is capable of breaking a chain. The term "stretch" is simply a euphemism for wear. A bike can't "stretch" a chain! The side plates and pins are the same for 520, 525 & 530.
Resistance to wear is paramount.
Sealed chains definitely have the edge here - particularly X and Z profiled o-rings (much tighter radii)
Then it comes down to how you minimise sliding friction with sprockets - plenty of good options out there (I use Motul C4)
...oh, also how you clean the chain without damaging the polymer seals. If you don't do this then you are simply leaving the "grinding paste" to do its evil job.
 
robs ss said:
"Strength" is never going to be an issue for a Commando (or any other road bike). No bike is capable of breaking a chain. The term "stretch" is simply a euphemism for wear. A bike can't "stretch" a chain! The side plates and pins are the same for 520, 525 & 530.
Resistance to wear is paramount.
Sealed chains definitely have the edge here - particularly X and Z profiled o-rings (much tighter radii)
Then it comes down to how you minimise sliding friction with sprockets - plenty of good options out there (I use Motul C4)
...oh, also how you clean the chain without damaging the polymer seals. If you don't do this then you are simply leaving the "grinding paste" to do its evil job.
Click to expand...
If i could have a £ for every time someone has said my "chains stretched" .....spoiler alert they don't stretch!!
 
vidar hjelm johansen said:
This fits my MK3 perfectly.
Have driven with it for two seasons. It has not touched the gear box, but it is only approx. 1 to 2 mm. clearance

VidarView attachment 99064
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I installed this chain last night on my Mk III and it went on perfectly and is very smooth with no audible clearance issues. I had a 530 O-ring chain on my '73 850 and maintenance was negligible. I am running a belt drive primary on the '73 so was able to shim the case to get the clearance necessary. That bike is now running a 520 x-ring which I'm very happy with.
 
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72’ Final drive chain. DID?
 
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