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illf8ed
Joined: 30 Dec 2003
Posts: 472
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 Posted: Tue Jul 06, 2004 10:47 am Post subject: Reynold vs Diamond final drive chain |
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| At the beginning of the season I replaced my Reynold chain that had over 10,000 miles with a Diamond at nearly half the cost. My reasoning was why pay for shipping a British made chain when a US made should work the same. Since then I've been told the Diamond doesn't fit quite right, the link pitch is slightly different. Why would this be the case if the chain size is the same? So far there haven't been any problems. |
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debby
Joined: 15 Apr 2004
Posts: 890
Location: Boulder, CO
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| Posted: Tue Jul 06, 2004 11:20 am Post subject: |
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I thought the pitch was always supposed to be the same, regardless of brand. Ditto for the roller width. I've heard that some of the "heavy duty" chains have thicker sideplates which could cause clearance problems on our Nortons. If not, would be useful to know which brands are non-standard!
Debby |
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Guest
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| Posted: Tue Jul 06, 2004 5:33 pm Post subject: |
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Illf8ed,
I echo Deb's comment.
Pitch is the distance between the chain rollers. If the advertised chain pitch is, say, .600" then that's would it will be, regardless of who manufacturers the chain.
Regards,
Jason |
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Ron L
Joined: 27 Feb 2004
Posts: 1101
Location: Ohio
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| Posted: Wed Jul 07, 2004 3:09 am Post subject: |
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I have run Diamond chains for 25 years. No problem, no premature sprocket wear. This sounds like some one wants to unload their stock of Renold chain. Don't get me wrong, Renold is excellent chain. I just don't want to throw money away just because "it's genuine Renold".
As far as pitch. 530 chain means it is 5/8" (.625) pitch by 3/8" width. That's a standard, so why would any one market a chain that is any different?
By the way, 420 is 4/8" X 2/8", 520 5/8" X 2/8". You get the idea. |
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Philippe
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| Posted: Tue Jul 13, 2004 3:11 pm Post subject: speaking of chain |
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Does anyone know the exact size, links wise, of the rear chian on 1973? (too lazy to count them !)
Philippe |
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Jason Curtiss
Joined: 14 Jun 2003
Posts: 661
Location: HOUSTON, TEXAS
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| Posted: Tue Jul 13, 2004 5:55 pm Post subject: |
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Philippe,
According to my Norton factory shop manual, your rear chain should have 100 pitches (links) unless your gearbox has a 20-tooth sprocket, which would be unusual and pretty darn small. This smaller sprocket calls for a chain with only 99 links.
Jason |
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Ron L
Joined: 27 Feb 2004
Posts: 1101
Location: Ohio
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| Posted: Wed Jul 14, 2004 3:03 am Post subject: |
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| Actually, for the U.S., the 750's came with a 19 tooth countershaft sprocket for the Roadster and a 20 tooth for the Interstate. The 850's jumped up to 20 and 21 respectively. |
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Jason Curtiss
Joined: 14 Jun 2003
Posts: 661
Location: HOUSTON, TEXAS
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| Posted: Wed Jul 14, 2004 3:55 am Post subject: |
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Philippe,
Well, it sounds like you better start counting.
If you buy a chain that is a little long, you can easily shorten it to your exact needs with a chain breaker.
Jason |
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debby
Joined: 15 Apr 2004
Posts: 890
Location: Boulder, CO
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| Posted: Wed Jul 14, 2004 7:19 am Post subject: 20 or 21? |
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Yes, best to count the links yourself. No fun buying a chain that's a couple of links too short.
Speaking of gearing - my 750 Roadster is geared way too low for the highway. I assume it has the std 19 tooth sprocket though I haven't checked yet. Would a 20 or a 21 be better? Was wondering if the 750 would be too sluggish and overgeared with the 21...
Debby |
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bill50cal
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| Posted: Wed Jul 14, 2004 1:43 pm Post subject: |
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I just put a 21 on my 750 combat. yes it took some of the snap out of it but it also lowered the RPM by 500 on the road  . it is a lot better @70MPH now. it was about 4750 with a 19 now its 4200 with a 21.
bill |
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Jason Curtiss
Joined: 14 Jun 2003
Posts: 661
Location: HOUSTON, TEXAS
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| Posted: Wed Jul 14, 2004 1:53 pm Post subject: |
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Debby,
As you pointed out, the larger the gearbox sprocket, the faster the bike will travel at a given RPM. Or put another way, the less the engine has to spin to maintain the same speed.
I currently have a 21 tooth sproket on my '75 Commando and find it works quite well.
I assume your concern about a larger sprocket is sluggishness during take-off from a fully stopped position. The 21 tooth sprocket does give up some snap on take-off but it's very liveable, considering the lower revs at highway speeds, which reduces engine wear and increases gas mileage.
Hope this helps.
Jason |
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Jason Curtiss
Joined: 14 Jun 2003
Posts: 661
Location: HOUSTON, TEXAS
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| Posted: Wed Jul 14, 2004 1:57 pm Post subject: |
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Oops!
Sorry for the duplicate reply; Bill's reply must have popped up without me knowing it when I was typing my response to Debby.
Jason |
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Ron L
Joined: 27 Feb 2004
Posts: 1101
Location: Ohio
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| Posted: Thu Jul 15, 2004 3:44 am Post subject: |
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It depends on the type of riding you plan on doing. The 19 tooth tops out the Commando at 107 mph at redline (7000 rpm). And it will pull usually pull top gear to redline in fourth! A 20 tooth will give 113 mph, a 21 tooth 119 mph, and a 22 tooth 124 mph. This assumes your using a 4.10H-19 tire.
As you can see this is pretty low. In the 70's the US market wanted that quick jump so 750 Roadsters were fitted with 19's.
I have a 22 tooth on my 850 Interstate and that is as tall as I'd want to go. It definitely saps some acceleration, but cruises nicely at freeway speeds. My 850 Production Racer replica is quite happy with a 21 tooth. A good compromise for a bike with a ported head, oversize valves, cam, carbs, and head mill. My stock 750 MkV still has the 19 tooth, but next time I have the primary off, I have a 20 tooth waiting to go on. |
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Norton Commando Forum by Corporate Pages Web hosting using phpbb
The Unapproachable Norton Commando
At the end of 1967 the Norton Commando was announced.
The Norton Commando was greeted with a certain amount of scepticism because on first sight the commando appeared to comprise of the old Norton Dominator twin cylinder engine mounted at an inclined angle in a set of new cylinder parts.
It was not realized that the new Norton Commando Isolastic method of engine suspension damped out all engine vibration and produced a machine which had uncanny smoothness for a vertical twin. In due course the critics were silenced and the Norton Commando had the distinction of being regarded as the first of todays so called superbikes. There can be little doubt that the original design concept of the Norton Commando has proved correct, since comparatively few modifications of any real consequence have been made since production commenced during 1968.
Now nearly 40 years later Norton Commando riders like us are a breed of our own, and as far as we are concerned its still more fun to go for a blat on the old Norton Commando, and fast. As a Norton Commando owner and enthusiast, my goal here is to promote and give credit to those who keep the Norton name going.
It is more deserving to give credit to the Commando itself, for after all these years it continues to be respected. The original Commando designers like John Favill are those who deserve the credit for developing this incredible motorcycle.
The Norton Commando Roadster and Interstate of the late seventies, never died. Although the Norton Villiers factory dispersed the tradition lived on. Today Kenny Dreer in the USA is developing the new 952 CC Norton. What a great looking bike this is, and its engineering is still based on the original layout. It will be interesting to see how the new 952CC Norton does in todays tough motorcycle market. One thing is for sure, I would own one if I could afford it.
