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A65 Crank to Main Shaft Distance #764257
02/02/19 9:11 am
02/02/19 9:11 am
Joined: Jul 2004
Posts: 71
Gold Coast, Australia
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Bougor Online content OP

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Gold Coast, Australia
Hi,
Does anyone know the distance between the crank and the gearbox main shaft centre to centre on an A65.

Thanks in advance.

Nigel

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Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764287
02/02/19 6:26 pm
02/02/19 6:26 pm
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Posts: 3,972
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DMadigan Online content
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Crank to mainshaft is 6.70"

Re: A65 Crank to Main Shaft Distance [Re: DMadigan] #764291
02/02/19 6:48 pm
02/02/19 6:48 pm
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Posts: 71
Gold Coast, Australia
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Bougor Online content OP

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Thanks David

Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764331
02/03/19 2:17 am
02/03/19 2:17 am
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NickL Online content
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It changes with temperature that's why the primary chain always tightens up a fair bit when running on the A65.


No-one expects the Spanish Inquisition................
Bring in the 'Comfy Chair'
Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764440
02/03/19 10:45 pm
02/03/19 10:45 pm
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Gold Coast, Australia
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Bougor Online content OP

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Thanks Nick, yep that's the problem. Running a belt. It's pretty tight to start with so trying to find solutions before it gets messy.

Cheers

Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764442
02/03/19 11:42 pm
02/03/19 11:42 pm
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DMadigan Online content
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Is that due to the case or aluminum sprockets?
The problem that I found on using a belt on the A65 was a reasonable set of sprockets to get a belt to fit. At 8mm pitch the only sets close were 29/63 with a 90 tooth GT-2 which is 0.010" short, a 28/64 with 90 tooth belt at 0.043" long or a 28/46 with 80 tooth at 0.007" long. GT-2 only come standard in 80 and 90 tooth.
Of course the 28/46 is a big change in the primary ratio and with a 4.6" clutch basket pitch diameter it would be hard to find existing plates.
Going to 10mm Syncro-Power belt there is the T10 with 27/58 and 78 tooth with 0.0072" long.
More lengths available in the Syncro-Power than the GT-2.

Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764443
02/04/19 12:00 am
02/04/19 12:00 am
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NickL Online content
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The cases change shape in lots of directions when they get hot,,,,, primary side tightens up a lot.
I'm talking about standard with a chain, that was a problem when i ran a 33 tooth engine sprocket,
i had to use pre- stretched chain or run a half link to accommodate it. I knew too many blokes who
had big trouble with belt drives on A65's to want to 'go there'. But once again it was a long time ago.
Apparently the dry set up with the fancy clutch that's sold now works well, Newby i think.


No-one expects the Spanish Inquisition................
Bring in the 'Comfy Chair'
Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764474
02/04/19 10:57 am
02/04/19 10:57 am
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Gold Coast, Australia
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Bougor Online content OP

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Dave,
The situation was locally made with AT10 30/56 pulleys, the problem for me is that when the end feed was done I asked for a spot of weld to be put over the oil gallery so that it had a "body" to accept an interferance fit pipe for the end feed transfer. Unfortunately they filled the whole area leading to case distortion and thus the main shaft is not where it should be.

Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764616
02/05/19 11:13 pm
02/05/19 11:13 pm
Joined: May 2013
Posts: 5,287
West Yorkshire
Allan Gill Offline

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The bob Newby is an excellent clutch, i was put on to it by Pushrod Tom, best belt clutch on the market by far! I have an old tony Haywood, all looks fine but needs a new belt, yet still retains the standard useless 3 spring clutch centre.... couldn’t see any gain at all with that one so it’s stayed in a bag


beerchug
Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764646
02/06/19 6:17 am
02/06/19 6:17 am
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The 3 and 4 spring clutches are fine if you keep them in good nick. Don't malign them totally.
With a decent end plate and 7 plates they work very well. Even with 6 they are OK.
I used one racing for years and i never ever saw a primary chain snap like the
countless belts i have seen. The haywood belt drive can run wet which is
an advantage sometimes as well.


No-one expects the Spanish Inquisition................
Bring in the 'Comfy Chair'
Re: A65 Crank to Main Shaft Distance [Re: NickL] #764649
02/06/19 10:21 am
02/06/19 10:21 am
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Kristiansund. Norway
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Arnstein Offline
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NickL.. I have exactly the same experience with the 3 and 4 spring clutches. Even if the end plate has some wear, the 7-plate conversion will usually make it work very well and for a reasonable price compared to the belt conv. This experience has been stated several times by people that have 800 - 900cc high comp engines with the "useless" 3-spring clutch and the very strong triplex chain which, by the way, is the same as in the 1000 -1200cc Laverda triples.

The other small conversions that can be made to these clutches to make them work just as good as any modern ones has been pictured and explained several times.


Arnstein

BSA Spitfire MK3.800cc
Honda CB450T -71
Laverda RGS 1130cc -85
Ducati 1098 -08
Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764651
02/06/19 11:38 am
02/06/19 11:38 am
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West Yorkshire
Allan Gill Offline

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A good quality chain isn’t a problem, it’s like the cam chains being problematic on Honda 400/4’s, same chain is faultless on the z1000...

I did a lot with my 3 spring unit, apart from at the time replace the rubbers. At that time I didn’t have an old clutch centre that I was willing to sacrifice in a vice. I would get it working then do something which gave the bike more power and it would begin to slip again under acceleration. I did in the end get t pretty reliable but lost patience with it. I also believe the “NOS” (supposedly) Renolds chain wasn’t much cop either. Recently someone else complained of similar problems with what looked like a similar chain from the same style box. It was constantly needing adjustment. A friend later on began having issues with his on the 600 mile ride to Denmark, like mine it started slipping, the centre was a new unit. I had the 7 plate it and the SRM pressure plate.... just prefer the Newby, it handles a lot of abuse, being slipped in high gear from a standing start (too tired, causing me to forget I had recently switched to rear sets) sure the clutch smelled a bit immediately after but it didn’t slip or drag once.


beerchug
Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764690
02/06/19 7:48 pm
02/06/19 7:48 pm
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Bolton Lancs UK
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Originally Posted by Bougor
Dave,
The situation was locally made with AT10 30/56 pulleys, the problem for me is that when the end feed was done I asked for a spot of weld to be put over the oil gallery so that it had a "body" to accept an interferance fit pipe for the end feed transfer. Unfortunately they filled the whole area leading to case distortion and thus the main shaft is not where it should be.


If the welding has caused so much distortion that the crankshaft and mainshaft are no longer in the correct positions relative to each other I would not consider riding the bike, it is an engine explosion waiting to happen


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Re: A65 Crank to Main Shaft Distance [Re: Allan Gill] #764742
02/07/19 2:38 pm
02/07/19 2:38 pm
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Kristiansund. Norway
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Arnstein Offline
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Mr. Gill. Of course isn´t the triplex chain a problem being able to cope with Laverda power. The reason mentioning it is that it is very strong so why change it for a belt which is nowhere near as strong.
As long as the 3 or 4 spring clutch easily can be modified to work as a modern clutch there is no need to go for the belt conv. I believe Mark Parker is still using the modified 4-spring 7-plate clutch in his 80 hp+ 883cc and my 800cc high comp uses the 3-spring 7-plate working excellent and with the tallest gearing possible, 22 - 46 chainwheel / close ratio g.box. As I said, modifications has been pictured and explained several times.. I would think this is proof enough for anyone that the original clutch will work ok if understanding what has to be done.. and for a reasonable price.

When it comes to the 400-4 Honda I believe it is the tensioner that fails an causes problems with the chain, not the chain itself.

Last edited by Arnstein; 02/07/19 2:55 pm.

Arnstein

BSA Spitfire MK3.800cc
Honda CB450T -71
Laverda RGS 1130cc -85
Ducati 1098 -08
Re: A65 Crank to Main Shaft Distance [Re: Arnstein] #764784
02/07/19 10:54 pm
02/07/19 10:54 pm
Joined: May 2013
Posts: 5,287
West Yorkshire
Allan Gill Offline

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Originally Posted by Arnstein
Mr. Gill. Of course isn´t the triplex chain a problem being able to cope with Laverda power. The reason mentioning it is that it is very strong so why change it for a belt which is nowhere near as strong.
As long as the 3 or 4 spring clutch easily can be modified to work as a modern clutch there is no need to go for the belt conv. I believe Mark Parker is still using the modified 4-spring 7-plate clutch in his 80 hp+ 883cc and my 800cc high comp uses the 3-spring 7-plate working excellent and with the tallest gearing possible, 22 - 46 chainwheel / close ratio g.box. As I said, modifications has been pictured and explained several times.. I would think this is proof enough for anyone that the original clutch will work ok if understanding what has to be done.. and for a reasonable price.


The chain will be stronger but if it does let go will make a huge mess, some belts are also better than others and the ones on the Bob Newby are not only proverb in racing but aren’t made of the same [***] material that many other aftermarket ones are made of.

As I say I had the 3 spring working well by the time i came and replaced it. It was using T120 springs at that point from lp Williams (some crap springs on the market) I tried T140 springs but the extra tension wasn’t much fun in town traffic.

For me I just find the Newby a good strong reliable unit. If I need to change final drive sprockets it quickens the whole job and makes it cleaner. One less chance of oil leaks and if there is a problem easier to sort on the side of the road. It’s a big plus if you do a lot f touring.

Originally Posted by Arnstein

When it comes to the 400-4 Honda I believe it is the tensioner that fails an causes problems with the chain, not the chain itself.


That was exactly my point and reason for mentioning it. However the problem with the tensioner eventually effects the chain much quicker than it wears on the bigger bike.


beerchug
Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764821
02/08/19 8:47 am
02/08/19 8:47 am
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Kristiansund. Norway
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Arnstein Offline
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Mr. Gill. How can the 400 4 cam chain tensioner problem be "exactly your point" comparing it to the Kawa 1000 with no tensioner problem and then comparing this with my statement that the a65 / Laverda triplex chain is the same.. both with no tensioner problem.. in fact the tensioners are the same type. And I never heard of a a65 triplex chain breaking.

I do a lot of long distance touring on my A65 ( last 5 years the digital Smiths says 32577km ) and I never had to open the primary and no oil leaks. Besides when having outrigger bearings behind the clutch and outside the alternator it better to have these open and oil lubricated than sealed. As stated several times there is no problem to modify the 3 - 4 spring clutches to work very well and not being heavy to operate either.. just ask Mark Parker and his A65 superbike, it is just a matter of knowing what to do.. and for a reasonable price.


Arnstein

BSA Spitfire MK3.800cc
Honda CB450T -71
Laverda RGS 1130cc -85
Ducati 1098 -08
Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764827
02/08/19 10:57 am
02/08/19 10:57 am
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Bolton Lancs UK
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A lot of triplex primary chain problems are due to alignment issues. Triplex chains cannot tolerate any misalignment, unfortunately the sprockets are on unsupported shafts outboard of the bearings. During acceleration the crankshaft end is deflected backwards and the gearbox mainshaft is deflected forwards. Add a wobbly clutch into the mix and the chain cries "HELP"


BSA B31 500 "Stargazer"
Greeves 200 "Blue Meanie"
Greeves 350
Greeves 360
Suzuki GSX1100 EFE "Sorcerers Apprentice"
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Jawa 500 "Llareggub"
Aprilia RSV Mille "Lo Stregone"
'35 & '36 OK Supreme
Kawasaki ZZR1400 "Kuro no senshi"
Re: A65 Crank to Main Shaft Distance [Re: Andy Higham] #764831
02/08/19 12:30 pm
02/08/19 12:30 pm
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Yes the triplex chain cries HELP but I never heard of one breaking. When both shafts are supported with outrigger bearings it only sings. I have seen belts stripping teeth or jumping off when shafts are deflecting.. friends with belts always carry one in spare when touring and have had to change it during trips, especially on Gold Stars with the long gearbox shaft.

The belts has of course become better, but for the price of the conversion I think it is better to have the chain.


Arnstein

BSA Spitfire MK3.800cc
Honda CB450T -71
Laverda RGS 1130cc -85
Ducati 1098 -08
Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764915
02/09/19 5:43 am
02/09/19 5:43 am
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NickL Online content
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All i know is that i raced a sidecar outfit with up to a 920cc a65 motor with a 4 spring clutch and never broke a chain.
In the early days i did have problems with clutches but is was all my fault and taught me to have some patience with them.
Like so many of these things, putting one together is not just a matter of 'bolting it on'.
I always preferred the 4 spring unit, it was better made, but i used 3 spring ones on my bike as a 750 and they were ok.
As i always like to have the engine breath into the primary side, a chain is the most feasible option. I used Duplex ones
which are more tolerant to the flexing which goes on in the primary side.


No-one expects the Spanish Inquisition................
Bring in the 'Comfy Chair'
Re: A65 Crank to Main Shaft Distance [Re: NickL] #764921
02/09/19 9:11 am
02/09/19 9:11 am
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Originally Posted by NickL
All i know is that i raced a sidecar outfit with up to a 920cc a65 motor with a 4 spring clutch and never broke a chain.
In the early days i did have problems with clutches but is was all my fault and taught me to have some patience with them.
Like so many of these things, putting one together is not just a matter of 'bolting it on'.
I always preferred the 4 spring unit, it was better made, but i used 3 spring ones on my bike as a 750 and they were ok.
As i always like to have the engine breath into the primary side, a chain is the most feasible option. I used Duplex ones
which are more tolerant to the flexing which goes on in the primary side.


Oooh that's interesting.
So you were racing an duplex chains and not suffering chain problems ?
was this because you changed them very regularly or are you sating the triplex is overkill ?


Bike Beesa
Trevor
Re: A65 Crank to Main Shaft Distance [Re: Bougor] #764955
02/09/19 3:34 pm
02/09/19 3:34 pm
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West Yorkshire
Allan Gill Offline

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I was under the impression that the triplex chain wasn’t as tolerant to flex as the duplex chain. Or in some cases 2x single row chains fitted to triplex sprockets


beerchug
Re: A65 Crank to Main Shaft Distance [Re: Bougor] #765003
02/09/19 11:09 pm
02/09/19 11:09 pm
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NickL Online content
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Running a duplex chain was fine, in my application, it was changed before every 5th race meeting.
The duplex chain did not wear as badly as the triplex in this application, i found the triplex chain would
be clapped after 2 or 3 meetings, i mean totally knackered. I was unable to run an engine outrigger
bearing on the large engines as i had a 33 tooth engine sprocket and had machined the casting off to clear.
I did have a clutch/gearbox outrigger, that's normal if you want the box to last more than a few minutes.
Bare in mind this was racing, NOT road use, and this was a sidecar which is probably about the worst
stress on a drive train.
The standard triplex setup is more than adequate for road use, a duplex one would probably be suitable
i must admit i've never tried one on my road bike.


No-one expects the Spanish Inquisition................
Bring in the 'Comfy Chair'

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