Slipery clutch keep me away from my own record on the 1/8 mile

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I’ve got a standard box, with dry belt drive, and no pushrods seal, with no apparent leakage.

Anyone know why some seem to leak and others not?

@ Yves, I’m surprised to hear you’re carrying all that extra weight around in the primary case!

The alloy clutch basket, belt, and alloy Barnet plates I’m using are a tremendous weight saving (rotating weight too).

The Barnet plates are really good too. Yes, like some complain about, there’s a mild squeal sometimes when pulling away, but it’s kinda hard to hear over the rest of the noise being emitted, and moreover, it has good ‘feel’ to the clutch and has been slip free.

Well, actually, it did start slipping once, and I started looking at how to upgrade everything, but all that at happened was the plates had worn down a bit and taken up the slack in the adjuster, thus it slipped. A quick adjustment restored normal service and it’s been good ever since.
 
yves norton seeley said:
What is tranny F oil?
Thanks
Yves
Click to expand...
Type F specifically excludes the addition of friction modifiers and requires fluids which provide improved shear resistance and oxidation protection, better low-temperature fluidity, better EP (extreme pressure) properties and additional seal tests...

In other words, it doesnt slip as much as 20w-50.

https://en.wikipedia.org/wiki/Automatic_transmission_fluid

And I like the Barnett plates too, and run a mixed stack of them with the bronze plates.
 
yves norton seeley said:
Hi Worntorn,
The question is: do I need a pushroad seal with a TTI gearbox?
Yves
Click to expand...

1. Next time you have the clutch diaphragm off the clutch, pull the rod out and wipe off with a paper towel/rag. If it is dry then no gearbox oil can foul the clutch. If you do have oil then a clutch rod seal may be a good thing. Especially if you use a side stand that would cause it to drain out into the clutch.

2. I would never recommend sand blasting of steel clutch plates. I only jitterbug/orbital sand with 240 grit or usually finer grit to remove glaze.

3 curious to know if the release mechanism is stock AMC style, i.e. fixed roller, lever and traveling 1/2" ball?
 
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dynodave said:
1. Next time you have the clutch diaphragm off the clutch, pull the rod out and wipe off with a paper towel/rag. If it is dry then no gearbox oil can foul the clutch. If you do have oil then a clutch rod seal may be a good thing. Especially if you use a side stand that would cause it to drain out into the clutch.

2. I would never recommend sand blasting of steel clutch plates. I only jitterbug/orbital sand with 240 grit or usually finer grit to remove glaze.

3 curious to know if the release mechanism is stock AMC style, i.e. fixed roller, lever and traveling 1/2" ball?
Click to expand...


TTi release mechanism is actially stock Triumph 3 ball part!
 
Fast Eddie said:
Pardon my ignorance here, but, why do you do that?
Click to expand...
That is the way I got the bike, and according to Windy that was a common stacking method from back in the day to help with easier pull and making the Barnetts not so grabby.
 
Fast Eddie said:
I’ve got a standard box, with dry belt drive, and no pushrods seal, with no apparent leakage.

Anyone know why some seem to leak and others not?

@ Yves, I’m surprised to hear you’re carrying all that extra weight around in the primary case!

The alloy clutch basket, belt, and alloy Barnet plates I’m using are a tremendous weight saving (rotating weight too).

The Barnet plates are really good too. Yes, like some complain about, there’s a mild squeal sometimes when pulling away, but it’s kinda hard to hear over the rest of the noise being emitted, and moreover, it has good ‘feel’ to the clutch and has been slip free.

Well, actually, it did start slipping once, and I started looking at how to upgrade everything, but all that at happened was the plates had worn down a bit and taken up the slack in the adjuster, thus it slipped. A quick adjustment restored normal service and it’s been good ever since.
Click to expand...

Hi Nigel,
Like I say before, I try different belt systems and not one did it more as 1000 miles and I don't wish to stay along the road anymore
 
dynodave said:
1. Next time you have the clutch diaphragm off the clutch, pull the rod out and wipe off with a paper towel/rag. If it is dry then no gearbox oil can foul the clutch. If you do have oil then a clutch rod seal may be a good thing. Especially if you use a side stand that would cause it to drain out into the clutch.

2. I would never recommend sand blasting of steel clutch plates. I only jitterbug/orbital sand with 240 grit or usually finer grit to remove glaze.

3 curious to know if the release mechanism is stock AMC style, i.e. fixed roller, lever and traveling 1/2" ball?
Click to expand...
Hi Dynodave,
I strip the clutch at least once a year, and never found oil on the pushrod, I think the problem is coming that I go to 5.000 RPM on the drag strip before I release the clutch and also I dont find time to strip the and clean the clutch before the race, my stupidity.
This week I am very busy with my 70 birtday party, in fact I will be 68 but my wife says always: if you stay smoking you will never ritch 70, thats why I do the party two year earlier!
We will be more as 100 persons at the party, from motorcycle racing and jet-ski racing, with some big legends and a band that play only hits from th sixties,
Take the plane and joint us
Yves
 
it was common back in the day. one reason was the old style barnett clutch was way to aggressive but with the new type friction materials they are using it is not necessary to mix old and new. i do sometimes mix 850 and 750 friction plates to adjust stackup for an easier pull. another mod i do is to increase the id on the steel plates to increase the holding capacity. it is along the same lines as the RGM high torque clutch but done obn the steel plates rather than the frictions. just as a side note the steels are very hard to machine.

gortnipper said:
That is the way I got the bike, and according to Windy that was a common stacking method from back in the day to help with easier pull and making the Barnetts not so grabby.
Click to expand...
 
yves norton seeley said:
Hi Nigel,
Like I say before, I try different belt systems and not one did it more as 1000 miles and I don't wish to stay along the road anymore
Click to expand...
Yves,
How tight do you run the belt drive system? Belts need to be set on the loose side to not cause problems. The Aluminum Clutch drum expands quite a bit when in operation which cause belt failures if set too tight.
Belts are safer too as opposed to triplex letting go when you put the coal to your sled and easier on the gearbox. Is the problem with the belt system at the TTI gearbox main shaft end?
Cheers,
Thomas
 
I have changed to Barnett clutch plates earlier this year as the "teeth" on my surflex plates were becoming very pointy and needed replacing.

I never had clutch slip with the surflex plates and RGM thin pressure plates, except when I accidentally rested my hand on the clutch lever and give it full power and the clutch would slip, so it suggested to me that my clutch was marginal. Incidentally that is running a Dyno dave clutch seal, triplex chain, 20/50 engine oil and 920cc with a Steve Maney st2 head.

In the blurb on Holland Norton Motor Works site, it says about the Barnett clutch plates; "High quality friction material, much lighter, no clutch slip guaranteed."

I had to put an extra plain plate in to get the clutch light, but it is working well without a hint of slip. The plates do look like they are well made i.e. flat, and they are light as well. Whether or not they would stand by their guarantee, I don't know, but maybe they are worth a try?
 
CanukNortonNut said:
Yves,
How tight do you run the belt drive system? Belts need to be set on the loose side to not cause problems. The Aluminum Clutch drum expands quite a bit when in operation which cause belt failures if set too tight.
Belts are safer too as opposed to triplex letting go when you put the coal to your sled and easier on the gearbox. Is the problem with the belt system at the TTI gearbox main shaft end?
Cheers,
Thomas
Click to expand...
Hi Thomas,
Yes a set the belts on the loose side, the problem with the Seeley frame is that the gearbox is higer and farder away from the crank, so I must use longer belts, and it was difficult to find the good lenght in the quality I wish to find.
No problem with the belt system at the TTI gearbox main shaft end
Thanks
Yves
 
Dyno*Dave wrote:
"2. I would never recommend sand blasting of steel clutch plates. I only jitterbug/orbital sand with 240 grit or usually finer grit to remove glaze."

What's the objection to sandblasting the steel plates? roughness of the surface or??
I've a set of Ducati plates that have been shot blasted, gives a clean, slightly rough surface, which I am considering using, hence my question.
 
Bernhard

Norton Commando clutch won,t slip if the postage stamp/segment type Barnett plates are used with the O.E. steel plates, can,t understand why people don,t fit them as a matter of course as on older Japanese bikes, many now using full synthetic and with much more torque such as my modified FJ1200.

A heavily modded big bore Commando like Yves should hold no fears if set up correctly with Barnett plates and a good or new diaphram.

Commando Barnett plates will also run trouble free in full synthetic oil as I found out when trying Redline Shockproof Heavy and Redline MTL full synthetics in the primary.
Clutch no problem but synthetics BAD for e start sprag clutch, too slippery so the sprag slips with a horrible screeching sound with failure not far behind.
Back to 200cc of 20w/50 mineral oil as per service manual. Not one finger pull like worntorn but 100% trouble free.
 
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Sandblasting won't remove high spots from the plates. Flat plates = max friction. A piece of sandpaper taped down to a piece of glass (or flat machined surface) will reveal these spots. If they are too difficult to remove with fine sandpaper then maybe look for a different plate.
 
I have tried all the available clutch plates in my bike at one time or another.
I have a dry clutch with a belt drive.
The only plates that have held with my 924 engine have been the RGM high torque plates.
I use them with the heavy diaphragm. I set the plate stack height so the diaphragm is flat when the lever is pulled to the halfway point. Jim
 
Yves, I run Maney belt drives in both my Nortons, a 30 mm wide in my road bike and a 40mm wide in my race bike.
I use the standard bronze plates in my race bike and a standard stack height with a machined pressure plate to give full pressure from the diaphragm . This makes the lever pressure slightly heavy , although not very heavy.
The clutch centre needs to have absolutely no notches in it from plate wear ( I was sent one of the new ones from CNW for testing) other wise your plates will always fall into the notches in the centre and once quite bad create slippage.
I have 75 HP at the rear wheel with this bike and no slippage , even with hard launches off the start line.

With my road bike , I have the same set up except I use an extra steel plate in the clutch pack (this plate goes in first when loading all the plates)to give an easier lever pull, this also doesnt slip although it isn't as powerful as my race bike .
The clutch centre is also one of the new CNW ones that doesnt notch, it is one I purchased from them.
Hope some of this info helps.

My race bike used to slip when racing usually when I was at 6000 rpm + in 3 4 & 5th gears of my TTI gearbox, it is now very good with the changes I made.

Regards Mike
 
KiwiNeill said:
Bernhard Norton Commando clutch won,t slip if the postage stamp/segment type Barnett plates are used with the O.E. steel plates, can,t understand why people don,t fit them as a matter of course as on older Japanese bikes, many now using full synthetic and with much more torque such as my modified FJ1200.
A heavily modded big bore Commando like Yves should hold no fears if set up correctly with Barnett plates and a good or new diaphram.
Commando Barnett plates will also run trouble free in full synthetic oil as I found out when trying Redline Shockproof Heavy and Redline MTL full synthetics in the primary.
Clutch no problem but synthetics BAD for e start sprag clutch, too slippery so the sprag slips with a horrible screeching sound with failure not far behind.
Back to 200cc of 20w/50 mineral oil as per service manual. Not one finger pull like worntorn but 100% trouble free.
Click to expand...

Synthetic oil was designed for car engines which use a dry clutch, which is fine if your bike has this set up, many years ago when someone was production racing a V twin Moto-Guzzi they changed over to synthetic oil and got a few extra MPH on top speed. I have used synthetic oil and even semi synthetic in Jap bikes with wet clutch and always got clutch slip after the change, where there were none before.
 
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