Author Topic: A65 primary chain  (Read 2218 times)

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DAVID.FORSYTH@VIRGIN.NET

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A65 primary chain
« on: 16 February, 2017, 14:03:56 »
Has any one had any difficulty fitting a new Renold primary chain to an A65. The chain looks to be to short.  The part number on the box is 116038, it's a 0.375" pitch and it has 80 links. The clutch basket has 58 teeth and the crank sprocket has 28 teeth. everything looks right but the chain won't fit.  Any suggestions?

bikerbob

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Re: A65 primary chain
« Reply #1 on: 16 February, 2017, 17:29:51 »
You have the correct sprockets as they are all the same for the A65 also you have correct chain,as it is an endless chain you have to  take both sprockets off then fit the chain around the sprockets then slide sprockets on together.

DEREKANDERSON8

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Re: A65 primary chain
« Reply #2 on: 16 February, 2017, 19:17:52 »
Have fun with that! the woodruff key on the output shaft can be a pain to line up.  ;)

AWJDThumper

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Re: A65 primary chain
« Reply #3 on: 16 February, 2017, 19:54:52 »
Has any one had any difficulty fitting a new Renold primary chain to an A65. The chain looks to be to short.  The part number on the box is 116038, it's a 0.375" pitch and it has 80 links. The clutch basket has 58 teeth and the crank sprocket has 28 teeth. everything looks right but the chain won't fit.  Any suggestions?
Does the chain fit with the tensioner removed?

DAVID.FORSYTH@VIRGIN.NET

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Re: A65 primary chain
« Reply #4 on: 16 February, 2017, 21:09:04 »
Thanks for the help. I've now got the primary chain on. But still have problems. The key on the clutch shaft doesn't protrude out of the shaft by very much.it dosent look right. Also when I tighten the clutch centre nut the centre doesn't spin freely inside the clutch basket, it's locked up. Time to call it a night I think before I break something.

JulianS

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Re: A65 primary chain
« Reply #5 on: 16 February, 2017, 22:30:20 »
Worth checking the thrust washer if the clutch centre does not spin freely.

Sometimes the washer may need thinning or it may be slightly distorted, thus causing dragging when nut tightened.

If it is causing the dragging you will probably see rub marks on the bearing surface.
« Last Edit: 16 February, 2017, 22:38:49 by JulianS »

AWJDThumper

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Re: A65 primary chain
« Reply #6 on: 17 February, 2017, 07:53:18 »
Thanks for the help. I've now got the primary chain on. But still have problems. The key on the clutch shaft doesn't protrude out of the shaft by very much.it dosent look right. Also when I tighten the clutch centre nut the centre doesn't spin freely inside the clutch basket, it's locked up. Time to call it a night I think before I break something.
You have to check that the clutch centre has fitted correctly on to the shaft - sometimes, if the Woodruff key isn't a good fit, it can slip in its slot and prevent the clutch centre from fitting properly. I assume that there is now slack in the primary chain otherwise this might cause problems when you try to re-assemble the clutch?

DAVID.FORSYTH@VIRGIN.NET

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Re: A65 primary chain
« Reply #7 on: 17 February, 2017, 08:49:37 »
There is a little bit of slack on the chain now.  All these parts look new as they were covered in a protective grease. The bike was in boxes when I bought it so the origin of the new parts are not known. it does have an alloy pressure plate with SRM on it so it must be one of there's, not sure if the whole clutch is one of there upgrades or not.  I will buy a new woodruff key today and I am away to do some space out  measurements. Does anyone know how thick the thrust washer should be?  is it normal to have to thin these down to get a proper fit?

AWJDThumper

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Re: A65 primary chain
« Reply #8 on: 17 February, 2017, 10:01:22 »
I would buy a new thrust washer to be absolutely sure - they only cost a few pounds.

JulianS

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Re: A65 primary chain
« Reply #9 on: 17 February, 2017, 10:08:08 »
The thrust washer 57 3931 fitted to 1970 on models is 0.05 inch thick and 2 5/8 inch outside diameter. That is a genuine Vandervell one measured this morning.

It is worth checking for flatness on a surface plate before fitting.

No it should not be normal to have to thin the washer , but sometimes we are left with no choice.

DAVID.FORSYTH@VIRGIN.NET

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Re: A65 primary chain
« Reply #10 on: 17 February, 2017, 13:54:56 »
Ive measured the thrust washer and its 0.053" thick. its flat but the back face of the clutch basket is appears to be concave as the rub marks are on the outer edges of the thrust washer.  Ive used Emery paper and a flat surface to thin down the thrust washer and I can now get the centre to turn within the basket. I am going to remove another 0.001" to make it turn a little easier. I don't want it to heat up and lock up when running the bike though.

bikerbob

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Re: A65 primary chain
« Reply #11 on: 17 February, 2017, 17:33:46 »
This problem with the clutch basket being difficult to turn when tightened up reminds me of the same problem that I had some years ago on my early A65 which does not have the thrust washer fitted this came in later, It turned out that some of the new rollers were a few thou longer than the originals which caused the basket to tighten up I had to buy another set of rollers and measure each one to make sure they were the correct length they all looked the same but it was only a few thou that made all the difference.

AWJDThumper

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Re: A65 primary chain
« Reply #12 on: 17 February, 2017, 18:49:28 »
Ive measured the thrust washer and its 0.053" thick. its flat but the back face of the clutch basket is appears to be concave as the rub marks are on the outer edges of the thrust washer.  Ive used Emery paper and a flat surface to thin down the thrust washer and I can now get the centre to turn within the basket. I am going to remove another 0.001" to make it turn a little easier. I don't want it to heat up and lock up when running the bike though.
It sounds to me that you need to address the problem with the clutch basket - if you simply thin down the thrust washer, it might get the clutch basket turning freely at this point, but the washer is then likely to wear quickly because the mating surface on the clutch basket is effectively not very wide.

DAVID.FORSYTH@VIRGIN.NET

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Re: A65 primary chain
« Reply #13 on: 17 February, 2017, 21:14:51 »
I agree, I need to address the clutch basket. I will also measure the length of each roller as suggested. Thanks guys for your help. Much appreciated.