The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: alanp on 05.04. 2011 13:50

Title: Belt primary types?
Post by: alanp on 05.04. 2011 13:50
Does anyone run their belt drive primary dry and if so is the drive take up smooth? If so, what type/supplier of drive is it.
I ask this because I took my Hayward belt drive off since run dry the drive take up when warm was jerky and dragged when stationary in gear no matter how I adjusted the cable, the springs or clocked the pressure plate to run true. I'm back to chain and oil in the casing complete with oil drips since what is the point of the expense of belt drives if you need to run with oil? I feel it is just the clutch that the Hayward system uses which is a later Triumph type since I didn't have this trouble with a Bob Newby clutch on my previous Gold Star where the clutch friction plates were one piece Ferodo type friction material and not friction pads on steel plates.
Thanks
Alan
Title: Re: Belt primary types?
Post by: beezalex on 05.04. 2011 16:02
Hmmm, when you say the takeup is jerky, do you mean it grabs?  Now, I haven't had one on a pre-unit, but the Hayward drives I've used on the unit twins worked really well and I know several people running Haywards on goldies and they work great.  My guess is that there's something else going on.  One guess is basket bearing or maybe a bad cush drive?  I wouldn't give up on this...and maybe you should just call Tony Hayward (no, not the BP one).
Title: Re: Belt primary types?
Post by: alanp on 05.04. 2011 19:30
Hmmm, when you say the takeup is jerky, do you mean it grabs?  Now, I haven't had one on a pre-unit, but the Hayward drives I've used on the unit twins worked really well and I know several people running Haywards on goldies and they work great.  My guess is that there's something else going on.  One guess is basket bearing or maybe a bad cush drive?  I wouldn't give up on this...and maybe you should just call Tony Hayward (no, not the BP one).

Jerky in my case means that whereas the oiled chain drive feeds power smoothly while slipping to take up the drive in a predictable way, the dry clutch doesn't take up the drive in a progressive predictable way.
There aren't any changes in the rest of the clutch operating system i.e. cable/push rod, and the oiled chain drive is back to normal smoothness.
Did yours run dry or in oil?
All parts are new and in top condition as supplied (apart from the oil thrower thread on the clutch centre adaptor being the wrong hand that is, which wouldn't matter if it ran dry).
When I bought the kit Tony was a bit reserved about running it dry but I thought this was just to cover potential problems with clutch centre bearing life.
I'm prepared to put the kit on the shelf and go for another type, provided that I am confident of a good result.

Title: Re: Belt primary types?
Post by: muskrat on 05.04. 2011 21:13
G'day Alan,
               sounds like a warped plate or the plates not sliding in the basket or hub properly. It doesn't take much to make them grabby.
I have a dry belt system with a diaphragm clutch (Norton) from Lytedrive in Melbourne. Not enough O's in SMOOOTH.
Cheers.
Title: Re: Belt primary types?
Post by: beezalex on 05.04. 2011 21:40
All the applications I've ridden were dry.  As you say, running a belt in oil seems pretty pointless since it defeats a major advantage of the belt.  I think this is mainly to soothe the late model triumph and triple owners that would have to make major modifications to their primary to make it run dry.  That said, when you drop the clutch, it stays put on one of these multi-plate deals.  Just out of curiosity, how many plates are you running?  Also, are you running a center-guided pressure plate or a stock steel one?
Title: Re: Belt primary types?
Post by: alanp on 06.04. 2011 12:04
Alex, I've attached a photo of the clutch plates and pressure plate. It's not centre guided. Any idea where I can get one? If I could get one that would fit this clutch I'd give it a try.
Title: Re: Belt primary types?
Post by: beezalex on 06.04. 2011 14:50
SRM, MAP, Lyford classic spares, most alloy pressure plate kits for triumph and BSA unit twins come with a guide pin that goes about 1" into the pushrod tube channel in the mainshaft to makes sure that the pressure plate lifts off square.  I think that any of the belt drive kits should come with one of these (I think the Newby drive does?) as these things are otherwise pretty prone to grabbing.

Hope that helps.

Oh, one more thing...your belt tension is set correctly, right?
Title: Re: Belt primary types?
Post by: alanp on 06.04. 2011 16:02
Thanks Alex. Yep, I checked it a number of times as well as varying it a little and also varying the amount of clutch spring pressure.
I'll track down an updated pressure plate.
Title: Re: Belt primary types?
Post by: chaterlea25 on 06.04. 2011 21:20
HI Alan,
That clutch setup is a new one on me!!!!, It looks as if the centre is just the standard Triumph/ BSA, 3 spring with a basket that takes "Japanese style" plates,
I dont know if these are suited to rumming dry????
I have a couple of friends who have "modern" clutches in their Vincents, these can be wet or dry, depending if the seal behind the clutch is fitted or not
wet they slip and dry they grab *eek* *eek*
The cure is to rub the friction plates with some ATF every so often with a dry setup  *idea*

If the belt you have is suitable to run in oil, its not too big a deal to sort out the sliding plate to make it seal
I turned up a new centre for the sliding plate with a groove in it for a quad ring
the ring runs on the part of the shaft adaptor inside the scroll.
I remember you saying your adaptor is one of the ones with the scroll the wrong direction??
These are not that hard and the scrolled bit can be machined off, then make the sliding plate centre to suit
You could even fit a proper lip seal??
I replacd the felt on the sliding plate with a cork gasket, which I glued to the case and used non setting gasket goo on the plate side
The upshot of this was that I had to fit a breather tube to the primary filler plug as pressure built up inside as the bike heated up  *ex*

This has worked fine for me for over 10,000 miles *smile*

HTH
John O R


Title: Re: Belt primary types?
Post by: alanp on 07.04. 2011 12:58
Thanks John.
Re the scroll thread, I've had it machined off and replaced with a sleeve with the correct LH thread. It's just that I didn't want oil in the primary casing at all or I would have not spent the money on a belt drive.
I have a new pressure plate on the way from SRM to replace the pressed steel version with the kit, to perhaps help the plate to remain running true, which I will try dry. If that fails I'll oil the blighter!
Wish me luck, I think I'm going to need it!
Title: Re: Belt primary types?
Post by: a101960 on 07.04. 2011 15:20
I have the SRM clutch plate and radial bearing. It works very well. You will have to shorten the operating rod, and harden it though.

John
Title: Re: Belt primary types?
Post by: bsa-bill on 07.04. 2011 19:42
Hi Alanp - you'll love the alloy pressure plate, great bit of kit
Title: Re: Belt primary types?
Post by: beezalex on 07.04. 2011 20:21
Oh lordy...oil the plates on a dry clutch?  Isn't that kinda like oiling your brake shoes?  Loosening up your SRM oil pump to reduce the pressure?

If it's just applying to hard, perhaps reducing the spring pressure is in order...
Title: Re: Belt primary types?
Post by: alanp on 08.04. 2011 11:49
Oh lordy...oil the plates on a dry clutch?  Isn't that kinda like oiling your brake shoes?  Loosening up your SRM oil pump to reduce the pressure?

If it's just applying to hard, perhaps reducing the spring pressure is in order...
Alex, I've tried variations in spring pressure - no luck.
The SRM pressure plate has arrived now and looks nicely made. Here's hoping.
The next job on the bike though is to replace the knackered 10mm wide dynamo belt drive with a 15mm version from Dynamo Regulators Ltd and replace the V Reg 11 with a DVR3.
Title: Re: Belt primary types?
Post by: chaterlea25 on 08.04. 2011 22:00
Hi Alan/Alex,
Alex,
""Oh lordy...oil the plates on a dry clutch?  Isn't that kinda like oiling your brake shoes?  Loosening up your SRM oil pump to reduce the pressure?""

Wiping the plates with a little ATF just knocks the harshness off the drive take up, its not oiling as such
Anyway it works on the Vinnies *smile*
I know that usually there are "different" type plates for wet and dry clutches, so I wonder if the ones in Alans belt drive clutch are suitable for dry running???
You will need some high temp grease for the radial thrust bearing also the chainwheel bearing if running the case dry

Regards
John O R
Title: Re: Belt primary types?
Post by: alanp on 19.05. 2011 19:26
Alex, I've tried variations in spring pressure - no luck.
The SRM pressure plate has arrived now and looks nicely made. Here's hoping.
I've fitted the SRM pressure plate and the difference is......nil. That grip/slip/grip affect is still there as I'm pulling away and after a half dozen take offs neutral doesn't want to be found.
I know it's not the levers/cable etc since the chain drive works as sweet as a nut.
Had a thought that maybe the frictions need to bed in to get a smoother surface on them so I've been running the engine in the garage on the centre stand in gear and have been releasing the clutch lever a tad to bed them in, driving against the back brake locking the back wheel. I'll road test her over the next few days to see what happens.
Happy days!
Title: Re: Belt primary types?
Post by: Big Nick on 21.05. 2011 08:58
tony haywood and srm pressure plate is the way to go, well that what i use
Title: Re: Belt primary types?
Post by: alanp on 21.05. 2011 14:08
tony haywood and srm pressure plate is the way to go, well that what i use
Nick, do you run the primary dry?
If so I can't understand how mine judders on take off yet with the chain kit it's smooth. I haven't tried the Hayward with oil and am reluctant to do so since I bought the belt system to avoid using oil in the primary case.
The clutch assembly sequence I used is as follows, anyone see anything wrong with this:
Mount adaptor onto the gearbox main shaft using a key and having ensured the tapers are a good fit.
Insert the thin spacer ring onto the adaptor, up against its back face with the plain steel surface of the spacer ring facing outwards and the copper coloured face towards the gearbox.
Load 20 rollers onto the adaptor with grease to keep them in position.
Slide the clutch basket over the rollers.
Mount the clutch centre (3 spring one with the integral shock absorber) onto the adaptor splines and fix with the washer and nut.
Load the friction plates and plain plates into the clutch with a friction in first and a plain one ending up last.
Mount the SRM pressure plate and springs having inserted a correct length push rod to suit the SRM plate.
Ensure the SRM plate is running true.
Set clutch cable clearance.
Title: Re: Belt primary types?
Post by: muskrat on 21.05. 2011 15:04
G'day Alan,
               sounds good to me but I've never seen a Hayward set up. The only problem I can see is that the only time the rollers see lube is when you service the clutch (not often).
Try it without the spacer ring. It still sounds like it's dragging.
Cheers
Title: Re: Belt primary types?
Post by: chaterlea25 on 21.05. 2011 22:03
Hi Alan,
A question on the thrust washer fitment??
I have only used these on A65's,
on these there are tabs which locate into holes on the shaft adaptor
this prevents the thrust washer turning relative to the adaptor,
SO the copper face is fitted towards the revolving chainwheel?????

The  reason the thrust washer is fitted  on later clutches is because there is no lip on the clutch centre to hold the innermost  plain plate
The extra (first) friction plate moves the spring pressure onto the chain wheel, which is why theres a thrust washer fitted behind it
The thrust washer requires lubrication,
I wonder if this is why you have problems with running the primary dry ????

HTH
John O R

Title: Re: Belt primary types?
Post by: alanp on 22.05. 2011 09:39
Hi Alan,
A question on the thrust washer fitment??
I have only used these on A65's,
on these there are tabs which locate into holes on the shaft adaptor
this prevents the thrust washer turning relative to the adaptor,
SO the copper face is fitted towards the revolving chainwheel?????

The  reason the thrust washer is fitted  on later clutches is because there is no lip on the clutch centre to hold the innermost  plain plate
The extra (first) friction plate moves the spring pressure onto the chain wheel, which is why theres a thrust washer fitted behind it
The thrust washer requires lubrication,
I wonder if this is why you have problems with running the primary dry ????
HTH
John O R

Thanks John, but my spacer ring/thrust washer thingy doesn't have tabs on it. I've kind of given up now and ordered a belt drive kit from Bob Newby, the same as I used on my Gold Star. I'd really like to find out why it doesn't work though, for my sanity sake!
Title: Re: Belt primary types?
Post by: alanp on 26.05. 2011 14:45
GREAT NEWS! Well it is for me.
I've just test run the bike with the new Bob Newby belt drive and it's as smooth as silk on take off. No more jerky take up when pulling away.
Phew, what a relief.
Just as a bonus the kit came complete with the correct width spacers for mounting the engine pulley, a crank nut pre-drilled for lock wire AND some lock wire to secure it to the pre-drilled engine pulley. This meant it took no time at all to install. That's what I call service.
Anyone want a Hayward belt drive kit at a big discount, only done 30 miles or so, complete with a lovely new cush drive clutch, correct hand scroll on the clutch adaptor and a custom A10 engine pulley spacer but will need to run with oil in the primary.
Alan
Title: Re: Belt primary types?
Post by: Big Nick on 28.05. 2011 10:58
I use AFT in the primary drive
Title: Re: Belt primary types?
Post by: alanp on 28.05. 2011 12:11
I use AFT in the primary drive
Nick, it's good to know they work fine with oil in the primary. I've got the kit up for sale for 1/2 price at the moment on this forum to see if anyone wants to get rid of their primary chain and its associated wear/noise. My primary chaincase is too distorted to run with oil in there and it drips like mad if I do.
Alan
Title: Re: Belt primary types?
Post by: rocket man on 28.05. 2011 16:21
heres my srm kit very good pickup

dave
Title: Re: Belt primary types?
Post by: muskrat on 28.05. 2011 18:56
 That is good news Alan. *yeah*
Shame you went to all that trouble and expense with the Hayward job. I'm sure that there must have been something wrong with it that you couldn't see, maybe a part not machined square. Did you discuss it with them? I would have thought that they would take it back as it didn't work as intended.
What ratio is the Newby? Std 19/43 is 2.26:1, mine is 1.88:1 which is close to the 23/43 1.87:1.
Cheers
Title: Re: Belt primary types?
Post by: alanp on 28.05. 2011 21:15
That is good news Alan. *yeah*
Shame you went to all that trouble and expense with the Hayward job. I'm sure that there must have been something wrong with it that you couldn't see, maybe a part not machined square. Did you discuss it with them? I would have thought that they would take it back as it didn't work as intended.
What ratio is the Newby? Std 19/43 is 2.26:1, mine is 1.88:1 which is close to the 23/43 1.87:1.
Cheers
When I bought it I said I wanted to run it dry. He was hesitant and said that some parts of it are best with oil lubrication, but I naively ignored this since the Newby on my Goldie ran dry and had no wear problems and I assumed it would be no different. However, the clutch itself is based on a late type 3 spring, cush drive centre BSA/Triumph clutch, with unsealed rollers, which normally runs in oil. It also came with a clutch adaptor with the oil flinger scroll on it (wrong hand scroll which I had to have corrected, but that's another story). Newby's doesn't come with an oil flinger scroll at all. So, I can't honestly get back to them and complain at my own stupidity.
Even Big Nick in a post above runs his Hayward with ATF in the primary. My primary case is an bad 'oil dripper' so I had to draw a line under this type.
I would have bought a Newby in the first place but Steve McFarlane was designing his A10 electric start to suit a chain drive and the Hayward belt drive only, maybe because his gear drive and sprag clutch inside the case also needed oil I don't know. As it happens I don't need the electric start since I seem to be able to kick her over OK.
Yes, it's a shame but no worries. Financially it's of no consequence so It'll either sell at 1/2 price or if not it'll stay on my desk as a reminder to never assume anything.
The Newby is 2 : 1 ratio. The Hayward is 1.833 which is close to the '62 ratio of 1.87
Alai