Clutch problem

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Its a routine for many to stick in an extra steel plate. Just heard from a buddy in NY today telling me he had just done this for easier clutch action than his 2 smoke 100 cc. Might slip but bet it don't. I put my extra steel at back of clutch basket to get the nice early lever break over so easier grip to hold full open. Yes there are force distance spring graph available but I don't know where to locate again. Pressure plate don't wear like the friction and steel plates and is one size fits all from factory, like the clutch basket depth, so common not to include that in stack height measure. When ya get it right it will just allow spring install to seat on pressure plate and spring clip to slip in groove w/o pushing on the stack.

Robb's teeth look fine and as reported even notched work ok when stack height is right.
 
hobot said:
When ya get it right it will just allow spring install to seat on pressure plate and spring clip to slip in groove w/o pushing on the stack.
Click to expand...
If I'm reading DynoDave right, that's the whole issue. It's not the distance from the diaphragm to the circlip groove that should be used as the measurement (although it probably could), it's the height of the clutch parts that set up the diaphragm's springs deflection, although they are both related. And if the diaphragm's springs are to flat (the stack height being too much), the correct amount of pressure is not there to keep the clutch from slipping.

That being said, it appears that lots of people set up their clutch with more stack height than is recommended to get a lighter clutch feel and don't report slipping. I don't know what the specification is as to the amount of pressure needed for the clutch not to slip given the HP/torque of the engine, maybe that's on one of DynoDaves pages. I'm sure some engineer figured that out a long time ago, but it's not in the normal literature as far as I know. Then one needs to know what pressure is being produced with the amount of deflection of the springs. There was a thread a long time ago about some fella that even cut half of his springs off the diaphragm and didn't report any slipping, or maybe I just read it somewhere.

I'm sure DynoDave has worked all this out, and correctly, it's just hard to find the information all in one place. His page on stack height is assuming we know something we may not. It's a bit like a geometry teacher I had once, we would ask 'Why' and he would say 'Because God made it that way.' I'm not trying to run down DynoDave's information, it's all good, it's just he may be assuming we know something that we don't. At least that's the way I'm feeling, I don't see all the pertinent information in one place.

Rob,
Yes, I just didn't want to hijack your thread to go off on a clutch tangent that you may not want to. But maybe we are getting somewhere.

Dave
69S
 
Robb2013 said:
Feeling much much better today. Here's the pics:

the culprit?

Clutch problem
Click to expand...

Finally. I go out for a ride yesterday and someone adds 2 more pages to this post.

Robb, do you see how the clutch stack is below the top of the splines? This is what I have been trying to get you to do.
They have to be flush with them. Mine pulled so hard for years because it was just like yours.
If you measure from the top of the splines down to the stack you will probably get a difference of .080", the thickness of 1 steel plate.
Insert a steel plate in the middle of the stack so that you have 2 steel plates sitting next to each other.
And no, your clutch won't slip do to the decreased plate pressure.
 
Remember to toss the soft lock tab and replace with hard steel washer/spacer and use blue loctite on the main nut. I said try a paper plate, but maybe better if 3 coins.
 
DogT said:
hobot said:
When ya get it right it will just allow spring install to seat on pressure plate and spring clip to slip in groove w/o pushing on the stack.
Click to expand...
If I'm reading DynoDave right, that's the whole issue. It's not the distance from the diaphragm to the circlip groove that should be used as the measurement (although it probably could), it's the height of the clutch parts that set up the diaphragm's springs deflection, although they are both related. And if the diaphragm's springs are to flat (the stack height being too much), the correct amount of pressure is not there to keep the clutch from slipping.

That being said, it appears that lots of people set up their clutch with more stack height than is recommended to get a lighter clutch feel and don't report slipping. I don't know what the specification is as to the amount of pressure needed for the clutch not to slip given the HP/torque of the engine, maybe that's on one of DynoDaves pages. I'm sure some engineer figured that out a long time ago, but it's not in the normal literature as far as I know. Then one needs to know what pressure is being produced with the amount of deflection of the springs. There was a thread a long time ago about some fella that even cut half of his springs off the diaphragm and didn't report any slipping, or maybe I just read it somewhere.

I'm sure DynoDave has worked all this out, and correctly, it's just hard to find the information all in one place. His page on stack height is assuming we know something we may not. It's a bit like a geometry teacher I had once, we would ask 'Why' and he would say 'Because God made it that way.' I'm not trying to run down DynoDave's information, it's all good, it's just he may be assuming we know something that we don't. At least that's the way I'm feeling, I don't see all the pertinent information in one place.

Rob,
Yes, I just didn't want to hijack your thread to go off on a clutch tangent that you may not want to. But maybe we are getting somewhere.

Dave
69S
Click to expand...

No Dave, it's all related and definitely going somewhere. Good post.
 
hobot said:
Remember to toss the soft lock tab and replace with hard steel washer/spacer and use blue loctite on the main nut. I said try a paper plate, but maybe better if 3 coins.
Click to expand...

I'm sure this doesn't make any difference, but there's a hard steel washer AND a lock tab on there. That's the way PO left it. Will toss the lock tab next time it comes off. It's too bad I got the heavies the other day or I think we'd have this all ironed out by now. Felt OK yesterday but was still recovering. I have to do some family things today but when I get back this afternoon I'll put something in there to take up the gap, will put on the freshly and properly lubed cable and will report back. I appreciate all the help you guys have been giving me.
 
I don't know if you have the early or late clutch, Rob. At any rate, Old Britts sells machined plain plates in different thicknesses, they are rather expensive, like $30 ea. You can buy the whole kit for about $150 and send back the ones you don't want. They are all thinner than the standard plain plate which is .080 and that one is about $18 at OB. DomiRacer has the plain plates for about $10, they may be inferior, I don't know. Other thing is to keep an eye out on ebay for a set of used plates, but don't spend too much for them given what they cost.

I had the OB kit and at the time couldn't figure out that I could put 2 plain plates together and Fred didn't suggest that. Some put it on last by the pressure plate, it looks like Guido puts his in the middle and I think hobot said he put his in first. I was thinking at the time it wouldn't be a good idea to put plain plates together, but I guess it doesn't hurt anything. I was thinking I had to replace one of the plain plates with one in the kit, but since they are all thinner than the standard plate it didn't do me any good. I know differently now, but I still don't have any plate to put in extra since I sent the kit back.

Dave
69S
 
Believe me or not but past Ms Peel with accidental expedient combo, was dangerous to nail on surfaces with traction w/o first locking on bars and down in seat like a dragster. Her gearing was 21T zone. Her stack required two steel plates together to get spring set right then worked easy and never slipped while upsetting famous brand '04-'05's 600's to over the ton. ATF helped too. I did have to temper throttle on 1st to 2nd snicks as tire spin would hesitate acceleration joy and took a while to discern noise was tire squeal not clutch plates.
 
Robb2013 said:
I haven't done much with this problem today, due to my energy still not being up to speed, but mostly just wanting to give it a rest for a while. There's a lot of little things going on: crud on the inner gears, stack low, plate seems not to bow in enough when relaxed, half ass lube job done on clutch cable. The inner gears crud really shouldn't make a rats ass of a difference as far as a hard pull goes because the pressure is being exerted outside of all the plates, on the pressure plate, and the crud is only on the inner portion of the gears. As far as stack height goes, that's a new one. I forget who made the suggestion of sticking some paper or something in there to raise the height and see if that changes anything... which sounds like an easy and possibly productive experiment. I have to admit, the clutch cable was a little bit stiff... I'd seen worse with no effect on other bikes, but I did give it a good soaking in silicone lube so when I hook it up again I can eliminate that as a possible problem.

Anyway... got my master cylinder rebuild kit in the mail today. The beagle chewed up one of the rubber bushings while I was out of the room for 5 minutes. Luckily it was only one of the 2 dollar parts so next time I order something from OB I'll throw it in the mix. I really didn't pay much attention to the master cylinder when I pulled it all apart. Today when sorting it all out to see what the extent of the beagle damage was, I noticed that the piston was pretty badly scored on the sides. I had stuck my finger down in the cylinder back when I pulled it apart and it felt nice and smooth in there. But with this scored piston I thought, how can that be? So I stuck my little finger way down in there until I felt roughness on the cylinder walls. Sooooooo I guess that means my master cylinder is toast. Here's a pic of the piston:

Clutch problem
Click to expand...

Rob great thread you have going here, I just installed my gear box and will be setting up the primary and clutch shortly as well. So have been following along with the lessons, knowledge and passion that the forum has been putting forth. ( so if anyone would like me to measure any parts or take a picture of something while I have my primary apart let me know).

A little off topic, but... My master cylinder was a little rough as well, so I sent it out to Walridge motors and had it sleeved down to 13mm, for a claimed 33% more breaking power, ( along with a braided steel line ). While maintaining the original look, with exception of braided stainless brake line.

Great discussion guys... Cheers 8)
 
Piston ain't a brake power issue as only a spacer to hold the sealing o-rings but the pitted bore sure is for braking. What happens with the rough piston is don't seal at the low pressure boot at the level contact. My Trixie still has rough piston and hold fluid in till recently over 100' F in garage has squirted fluid out on the floor in a long puddle. ugh. Hylomar only works up to a point. If this happens on road, blowing away unknown, brake works perfect til next instant nothing at all.

Might call a vendor with a bone yard like Baxters and get used stack cheap if not better deal on ebay.
 
Robb2013 ,yes it is time to send the brake MC assembly to Mike at Walridge for the upgrade. Get the braided cable brakeline for it too. This will cost i'm afraid but you do need it to be safe on the road. Mother Peter. Still wondering how to get my rotor off in primary as the belt pully is right up to it so no leverage tools can get behind it.
 
Phil at Fair Spares also has the sleeved master cylinders.Good guy to deal with also.
YING
 
Following this post, Am i right in thinking if the stack hight is high and the spring is almost flat then the clutch action would be very light?
The guy who posted this thread states his spring is almost flat.and the clutch pull is heavy ..is that in keeping with the "high" stack hight?
 
[/quote]Rob great thread you have going here, I just installed my gear box and will be setting up the primary and clutch shortly as well. So have been following along with the lessons, knowledge and passion that the forum has been putting forth. ( so if anyone would like me to measure any parts or take a picture of something while I have my primary apart let me know).

A little off topic, but... My master cylinder was a little rough as well, so I sent it out to Walridge motors and had it sleeved down to 13mm, for a claimed 33% more breaking power, ( along with a braided steel line ). While maintaining the original look, with exception of braided stainless brake line.

Great discussion guys... Cheers 8)[/quote]

How much did that sleeve job from Waldridge set you back SM? I guess I need to figure out what to do with the master cyllinder. Was hoping that was just going to take a rebuild kit but they tell you not to even stick a fluffy cotton rag down in that cylinder to clean it... any roughness on the walls has to make it worthless except for a sleeve job.
 
The cost was about 250 ,an exchange situation. You send the old pitted MC and they mail back a remanufactured one off the shelf pronto, no waiting. One look at that sad piston and I know the bore is hopeless.
 
Rob great thread you have going here, I just installed my gear box and will be setting up the primary and clutch shortly as well. So have been following along with the lessons, knowledge and passion that the forum has been putting forth. ( so if anyone would like me to measure any parts or take a picture of something while I have my primary apart let me know).

A little off topic, but... My master cylinder was a little rough as well, so I sent it out to Walridge motors and had it sleeved down to 13mm, for a claimed 33% more breaking power, ( along with a braided steel line ). While maintaining the original look, with exception of braided stainless brake line.

Great discussion guys... Cheers 8)[/quote]

How much did that sleeve job from Waldridge set you back SM? I guess I need to figure out what to do with the master cyllinder. Was hoping that was just going to take a rebuild kit but they tell you not to even stick a fluffy cotton rag down in that cylinder to clean it... any roughness on the walls has to make it worthless except for a sleeve job.[/quote]

Just looking at their flyer, and the " master cylinder exchange " is $235.10 CAD. Using the exchange program you have no wait time, and get back on the road faster with a freshly rebuilt , sleeved and powder coated norton master cylinder.
So you give them your core and $235.10 CAD and they send you one back.

Cheers 8)
 
john robert bould said:
Following this post, Am i right in thinking if the stack hight is high and the spring is almost flat then the clutch action would be very light?
The guy who posted this thread states his spring is almost flat.and the clutch pull is heavy ..is that in keeping with the "high" stack hight?
Click to expand...
That's what I'm trying to figure out, but I'm being lazy and haven't got my primary cover off yet. My stack height is about right, at least the parts are within spec, but I know if I don't have things set up right, the clutch slips. Early clutch 1.167 stack height.

Dave
69S
 
staticmoves said:
so if anyone would like me to measure any parts or take a picture of something while I have my primary apart let me know).
Click to expand...
Yeah, what is the distance from the bottom of your clutch basket to the circlip groove? Then measure it with the backing plate on. What I'm looking for is the difference between clutch pack height and clutch basket depth to circlip. I'm assuming the backing plates are all the same thickness? I know there's a difference between the early and late ones as far as how the backing plate locks in place, mine has 2 tiny roll pins, I don't know how they hold the clutch from slipping.

Dave
69S
 
DogT said:
staticmoves said:
so if anyone would like me to measure any parts or take a picture of something while I have my primary apart let me know).
Click to expand...
Yeah, what is the distance from the bottom of your clutch basket to the circlip groove? Then measure it with the backing plate on. What I'm looking for is the difference between clutch pack height and clutch basket depth to circlip. I'm assuming the backing plates are all the same thickness? I know there's a difference between the early and late ones as far as how the backing plate locks in place, mine has 2 tiny roll pins, I don't know how they hold the clutch from slipping.

Dave
69S
Click to expand...

Circlip groove to backing plate is 1.258". And 1.312" to bottom of basket.

Cheers 8)
 
Well, here's the latest... I went out and did all the things you all suggested. Made some shims out of newspaper and shimmed the stack so it was perfectly flush with the outside gear. As hard as I tried, I couldn't get the circlip on. I started taking my "shims" out until I finally was able to get the clip on. At this point the stack was still a few thousandths low. I hooked up the clutch cable, adjusted the ball and pulled the lever. It still was hard to pull, like harder than any clutch on any bike I ever rode, but it was MUCH easier than before. I took it all apart again and pulled the newspaper out, then hooked it up again and pulled. Was about as hard to pull as with the shims... maybe a slight bit easier, but more importantly, I felt that compound bow like reaction when I pulled it. I could actually ride the bike with the clutch like it is... not sure if I'd get used to it or not. It might have been the way I adjusted the rod and ball this time. I screwed the screw in until it totally locked up, then backed it off a turn. It's a little ambiguous in the manual, I had the idea you just snugged it up till you felt tension on the rod. What I actually did was locked up the rod then kept my finger on the actuator and backed off till there was play in there and it would jiggle back and forth. Part of it could have been that the cable hadn't been properly lubed before. Not sure. I still don't think it's right... still takes a really hard pull on the lever, but it seems like we're getting somewhere. I also notice the diaphragm has a longer throw than it did before. I know that if I stuck another steel plate in there there'd never be enough room to get the circlip in. And I'd certainly not enjoy riding the bike around town with the clutch the way it is now, although it would be rideable.
 
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