What length chain do you CB500 owners fit: 98 or 100 links?

[Bryanj]

The reason the rear sprocket size changed on the 550 is because the primary drive ratio changed and not for any esoteric reasoning of chain to sprocket ratio

[Oddjob]

Got to say I disagree with that Bryan. At the time the 550 was in real competition with stuff like the GT550 and the kwack 500 and most of the motorcycle mags tended to be fixated on standing quarter times, so Honda tried to counter that with a bigger sprocket to get that time down.

That’s my take on it.

[Bryanj]

Ken, if you look at the overall ratio the 500 and 550 are almost identical

[deltarider]

I have the feeling I have not been able to communicate what I meant. There are two things: if a bike can do it with a 98 links chain, why not. The second is: after some time not all links are equal in souplesse. From a designer's pov, you don't want that less supple link to hit the very same spot on a sprocket every rotation (hammering effect). Better is to have it arrive at all spots in turns, so the wear is spread evenly.

[Bryanj]

A98 link wont fot with the 37 tooth rear

[Oddjob]

Easy enough to test though. Mark a link and a tooth on the rear sprocket and see if it lands on it everytime. Get someone to test the 550 and see if it does it on that.

I had a test lined up Bryan to test your theory. Unfortunately my illness meant it has been delayed until I can get back to working on the bike. What I intend doing is fitting a 500 clutch basket on my 500 as standard, do some tests on revs versus speed etc, maybe mpg and then replace the clutch and primary gear with one off a 550. I have a 550 rear gear on a 500 basket so it’s a simple swap, same engine etc so no bias should be apparent. Then do the same tests and see how they compare.

As you know it’s not possible to fit a full 550 clutch on a 500 engine due to crankcase differences. Hence why I designed the test this way.

[Bryanj]

Sounds god Ken, i was working from the workshop quoted figures

[deltarider]

Johnwebley came closest. I am well aware of the differences between CB500 and CB550 transmissions.
Please do a test by marking, but I predict that with a final reduction of exactly two, which is what you have with a 17/34 teeth configuration, the same link will always land in the same spot of the sprockets. That's why it is best to have a 98 link chain on a CB500. Over the years I had to persuade a seller sometimes to shorten a 100 link chain to a 98 one.
What is nice about the CB500 set up, is that in top gear 5000 RPM equals 100 km/h, 6000 120 km/h, 7000 140 km/h, 8000 160 km/h, 9000 180 km/h and 9250 a theoretical top speed of 185 km/h. The circumference of the tyres fitted - both by size and wear - play a role however and will lead to some deviation.

[mickwinf]

Am I missing something here? If the 500 with standard sprockets needs a 98 link, then the 550 uses a bigger sprocket on the rear and all other dimensions are the same then a longer chain is required due to the bigger diameter? Also the amount of adjustment available is a factor.

[Johnwebley]

Just to complicate matters slightly,

When I started fitting modern tyres, the rear only available as 4.00 width, it also had a larger diameter and circumference

So I reduced my gearbox sprocket by one tooth



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