The BSA A7-A10 Forum

Technical => Clutch, Primary, Gearbox => Topic started by: bikerbob on 25.01. 2015 14:18

Title: Six spring clutch bearing
Post by: bikerbob on 25.01. 2015 14:18
I have been overhauling the A7 it has the 6 spring clutch and decided to replace the clutch bearing and the replacement provided by the dealer Draganfly is as you see in the attached photos, whilst the new one looks to be an improvement on the old one I am a little concerned if it will get enough lubrication the old one being 2 separate bearings is of a more open construction whereas the new one is much more compact. The internal size of the clutch housing is 1.887" whilst the outer dia of the new bearing cage is 1.882".  The bearing cage is made of what looks like some type of aluminium alloy. Your comments please
Title: Re: Six spring clutch bearing
Post by: chaterlea25 on 25.01. 2015 16:05
Hi,
Quote
The internal size of the clutch housing is 1.887" whilst the outer dia of the new bearing cage is 1.882".  The bearing cage is made of what looks like some type of aluminium alloy. Your comments please

THe cage has to be smaller than the outer bearing race and larger than the inner
the ball bearings will be (or should be) of a larger diamater than the thickness of the cage
Other than that it would be a bush not a bearing

HTH
John
Title: Re: Six spring clutch bearing
Post by: bikerbob on 25.01. 2015 16:42
I understand that the cage has to be smaller than the outer bearing race and the balls are slightly bigger they are the same size 3/16" as the original bearings I listed the sizes to point out that there is only.007 difference as this is where the lubrication will have to go through.
Title: Re: Six spring clutch bearing
Post by: chaterlea25 on 25.01. 2015 19:11
HI Bob,
Put some high temperature grease on the bearings if you are worried
On Ariels theres a needle roller bearing and a bronze cage, this sits between the chaincase which has oil in it and the clutch which runs dry, The bearing never seems to wear  *good3*

John
Title: Re: Six spring clutch bearing
Post by: KiwiGF on 25.01. 2015 22:03
I have the draganfly bearing and have done 4000 miles no problems so far but the cage part with the holes in it did show signs of wear in the form of a grey paste when I took a look at around the 1500 mile mark (I was replacing the primary case gasket...yet again  *problem* so took the opportunity to inspect it).

My 6 spring clutch works perfectly with no slip and easy neutral finding at standstill, the secret in my case was to have the springs only tight enough to prevent clutch slip but not over tight (found by trial and error) , and to use a dial guage to ensure the pressure plate lifts off evenly.
Title: Re: Six spring clutch bearing
Post by: bikerbob on 26.01. 2015 08:10
Thanks for those replies you have to use a bit of grease to hold the balls in place while you fit the clutch basket I will fit the new bearing and check it after a year as I will probably only do about that mileage on this bike.
Title: Re: Six spring clutch bearing
Post by: Clive54bsa on 26.01. 2015 16:30
Hi Bikerbob, I also purchased the "Draganfly" roller cage for my  '54GF, but, after running it for a couple of hundred miles, felt there was a bit too much slop in the chain wheel, and went back to the conventional bearing, which works well. Although I think the Draganfly unit is easier to fit.
Title: Re: Six spring clutch bearing
Post by: RichardL on 26.01. 2015 23:01
I will fit the new bearing and check it after a year as I will probably only do about that mileage on this bike.

So, this means you are not going to check it the very next time it has to come apart? >:D ;)

Richard L.
Title: Re: Six spring clutch bearing
Post by: bikerbob on 27.01. 2015 14:32
Richard. Obviously if  for some reason I had to take the primary case off in the next year I would look at it but as I do not expect anything to go wrong over the summer months as I do not do a great mileage having also a BSA A65 I am hoping to leave it until next winter when I will look at it again to see how it is standing up along with a modification that I did to the rear of the primary case where I fitted an oil seal that runs on the gearbox mainshaft.
Title: Re: Six spring clutch bearing
Post by: RichardL on 27.01. 2015 15:46
Bob,

That's a much more serious answer than I meant to spawn. I was joking about time between A10 disassemblings. Apparently, it's mostly my A10.

Richard L.
Title: Re: Six spring clutch bearing
Post by: taylor1960 on 22.12. 2015 22:36
Hi Bob im going to fit a 6 spring clutch to my A10 is your bearing still holding up i need a new one and at this stage can get eather new or old type  *conf*
Title: Re: Six spring clutch bearing
Post by: bikerbob on 23.12. 2015 14:39
I have just dismantled the primary side to cure an oil leak from the gearbox and can confirm that the Draganfly bearing is working great  no signs of any problems with the clutch, with the Draganfly bearing fitted there is no wobble on the clutch basket which was there with the old style bearings fitted.
Title: Re: Six spring clutch bearing
Post by: chaterlea25 on 23.12. 2015 18:38
Hi,
A lot of the "pattern" original type bearings are a very loose fit on the shaft adaptor  *warn* *warn* *problem* *problem* *angry* *angry* *angry*
So  I would avoid these !!

John
Title: Re: Six spring clutch bearing
Post by: Tumbleweed on 13.01. 2016 20:21
hi bob, looking at the pics mine don't fit so good ive managed to get a pic ,  a third of the bearing is not being used by the looks of it , and there is still loads of play, have you any ideas please     thanks tw
Title: Re: Six spring clutch bearing
Post by: taylor1960 on 14.01. 2016 08:29
Hii did U fit the plate behind the clutch basket first   *????*
Title: Re: Six spring clutch bearing
Post by: Tumbleweed on 14.01. 2016 09:02
 everthing is in place according to drawings .       thanks   tw
Title: Re: Six spring clutch bearing
Post by: bikerbob on 14.01. 2016 09:23
Your clutch basket looks very close to the inner case I have just measured mine and it is 13mm from the inner case to the center of the teeth on the clutch sprocket. Have you fitted the plate behind the sprocket as the previous  member has asked. You should also check to make sure that your clutch sprocket is in alignment with the engine sprocket.
Title: Re: Six spring clutch bearing
Post by: Tumbleweed on 14.01. 2016 11:15
hi bob , yes I did fit the plate behind the chainwheel and the distance is 13mm same as yours , as I have said on my preveous  enquiry under  "clutch  chainwheel"yesterday ,  the outer ring on the chainwheel width is 10mm the bearing is 15mm , if I bring forward the chainwheel forward level it is out of line with the engine sprocket    thanks  tw
Title: Re: Six spring clutch bearing
Post by: bikerbob on 14.01. 2016 12:04
tumbleweed if you look at the 4 photos that I put up at the beginning you will see that in the first photo which shows the new bearing you can just see the outer balls and if you look at the 4th photo which is the original bearing you can also just see the outer balls. Your clutch basket needs to come out slightly then you can buy a set of  shims to bring out the engine sprocket to bring it into alignment. Have you tried it with the original bearing to see if there is any difference.
Title: Re: Six spring clutch bearing
Post by: Tumbleweed on 14.01. 2016 13:05
hi bob , that is an avenue I will go down for sure , the original bearing was the same width , I fact I can see where the inner ball has been rolling in the CENTRE of the outer ring so only half the bearing seems to have been used .  I think shims will be the answer  .  thanks   tw
Title: Re: Six spring clutch bearing
Post by: BSA_54A10 on 14.01. 2016 15:21
Give the new bearing a gentle tap.
I will be guessing that the old bearing had worn a grove into the race and the balls on the new bearing are getting stuck in the groove.
Title: Re: Six spring clutch bearing
Post by: Tumbleweed on 14.01. 2016 16:10
the groove isn't that deep , it looks as if the chaincase is for a roller bearing  to me,   (not knowing much about beezas )        I am beginning too lose the will to live     am going to have a weekend of R andR and see how things turn out on Monday    ive just eased pass another birthday so that's a plus           cheers  tw
Title: Re: Six spring clutch bearing
Post by: Topdad on 14.01. 2016 16:38
That's what a six spring clutch can do to you , nearly put me of BSA's for good when I was 17 ish always stuck with a 4 spring unit since no way perfect but you do get to ride much more.. When I first saw your post I thought here we go again some poor guy going to waste time and money on a clutch which doesn't warrant it however when I saw the bearing from dragonfly I thought perhaps they had retro found a way to sort the piece of crap but now looks like another way just to torment us poor souls . Sorry to be so negative TW but whilst I admire the skill of the guys who get the 6 springers working whats left of mine is and will remain in the bin . Best of luck with it Bob.
Title: Re: Six spring clutch bearing
Post by: Tumbleweed on 14.01. 2016 18:12
thanks for your sympathy bob, I think I might go in the 4 sprung direction after all  cheers   tw