something something MOTORCYCLE CLUTCH!

okay [Music] [Music] um this is the bike we rebuilt the top end on not too long ago or sort of half rebuilt it it didn't have great compression and you may recall a new piston and piston rings solved that problem a new piston and piston rings solved that problem it's been doing a lot better the engine is happier but all that raw power those unbridled two and a half horsepower the engine is putting out are getting lost somewhere along the way i think there's something up with the clutch and if my calculations are correct it should be in here i don't actually have new clutch parts if i do end up finding a problem but this exercise is more of an exploration an expedition maybe let's see what we find and what we can do with what we got if anything at all i know some of you don't like motorbike videos and some of you love them i hope you see the pickle that puts me in let me take this pack out we'll have a close look at it on the bench geez how many discs does this thing have six it's got six discs well six friction discs the reason the bike's leaning over on its side is so all the oil doesn't come pouring out all right i'm going to need just a minute to make some bench space next video if all goes well will be a maho update i'm slowly putting the mill back together cleaning things up as i go along waiting for one or two other parts though sneak peek maybe i already said this the drives came in and the motors are turning under mock control is that awesome or what these things are so nice i may have just peed a little bit multi-plate clutches don't let that name intimidate you multi-plate is simply short for multiple plates let's talk about them just a minute now i heard all those eye rolls those of you out there that already know what's going on here take a moment to think of the kids would you you recall this electro mechanical clutch we saw a couple of videos ago it had a splined input side and a splined output side and power couldn't move through this until the cute little toothed face gear thing was engaged you might have a motor on one side spinning this all the time like crazy and whatever you want connected to the other side just sitting there not moving one side spins the other side doesn't until you give it the green light the toothed wheel slides over connects the two and now you have power from your motor to your blender or whatever is attached to the driven end this is the same thing only smooshed really really flat these are the input splines these little lugs on the outside just like this other clutch and here are the output splines or lugs again just like the other side of this clutch the outside ones can turn freely without moving the inside ones unless the clutch is doing its thing then they all spin together you could consider this an axial clutch transferring torque along its axis and this one may be a radial clutch transferring torque from the outside to the inside radically i mean radially instead of that toothed face gear on the electromechanical clutch the bike clutch works on friction again there are friction plates with all these little brake pad looking things and then there are smooth steel sometimes aluminum plates like a smooth disc brake and the brake pads work against the brake disc and there's quite a few of them six pairs it looked like so if you were to quote unquote stomp on the brakes push this whole pack together torque on the outer splines the outer lugs is transferred to torque on the inner splines the inner lugs and where does that torque come from i have no idea the clutch basket basket may just be the outside bit i'm not totally sure but there are two parts an outer housing and an inner housing this might be the hub maybe they're not connected the clutch plates are what bridge those two parts although i left them over at the back the steel plates with the internal lugs the internal spline key up to the clutch hub so they're connected to the middle the friction discs have no lugs on the inside only the outside and they interface with the clutch hub the outer bit again the basket i think is connected to the engine hit the kickstarter it spins along with the engine it's turning any time the engine is running and the clutch hub in the middle is currently connected to nothing because the bike isn't in gear but if you put it in gear the transmission connects it to the rear wheel and no power is transmitted unless all the clutch plates are smashed together when you let go the clutch lever up on the handlebars and the clutch pack is closed all those little brake pads are pushing on the brake disc power flows from the engine through the clutch to the rear wheel driving you face first right into a tree or a rock maybe notice how i said when you pull the lever in this clutch is arranged backwards to the electromechanical clutch this engine is always connected to the wheel until you pull the lever to disengage them in this little clutch the load was never connected to the motor unless you push the button or something sent power to the ring gear so how on earth do you get a clutch to work only when you're not doing something well we'll talk about that later when we put this back together for now let's go have a very close look at just like brake pads or a box of donuts these things don't last forever they're a consumable item the friction material or the steel plates wear glaze over and you get less and less power transfer through the clutch if your brakes slip they're not going to stop your car if your clutch slips it's not going to move your bike of course it's not all or nothing you can have a worn clutch that transfers some power just like you might have poopy brakes i've printed a couple of pages from the shop manual for this bike fortunately they just happen to be the ones about the clutch discs these just have some key measurements listed wear limits specifications for the minimum thickness of the friction discs and minimum dimension of like the spline or the lugs coming off the perimeter it says the limit is two and a half millimeters mine all measure 2.7 and change 2.75 and up thickness wise they're still inspect i was really expecting to find worn discs or plates though they don't look particularly glazed or cooked to me so what i think i'm going to do is simply clean these up a bit maybe give them a bit of a razzing on some sandpaper i assume that can only help and then we'll also take a close look at the clutch basket itself yeah i'm just kidding this is 600 grit sandpaper 800 would have probably been better this should be fine but it's important to know i'm doing almost nothing i'm not trying to sand these down i'm not trying to flatten them the goal of this is to just sort of scuff that surface up the next step washing and cleaning arguably is more important than this left to my own devices i'd be doing this on a surface plate instead i've just spray mounted some sandpaper to a piece of thick glass it's come to my attention that not everyone has a surface plate at home but i mean come on can you really consider that a home next i'm just going to give them a good scrubbing with a new stainless steel brush i've got just some water and a little bit of dish detergent in there this break material this friction material is porous it's like a cork or something i don't know what they put on there i'm just trying to knock out any debris that may have become embedded i think this is why they call these wet clutches this would probably be a lot easier in some sort of container big enough to let you scrub the discs under water though frankly you could probably do this dry this is just maybe keep the dust down and perhaps here you can see the difference between one i just scrubbed and one that i haven't granted this isn't a great comparison as this thing is still oily and has stuff on it from the sandpaper while i've got you in here this close some people like to go to the trouble of cleaning out sort of all this glue between the friction material i hear it helps if you have things like a sticky clutch you know when you first start the bike up after it's been sitting for a couple of days i'm not gonna go to all this trouble but maybe you're more into clutches than i am it took me two and a half podcasts but i managed to clean up the whole pack i don't know if i actually did anything positive but i'm happy with how they turned out now for kicks this is how i get my kicks i wire brushed a few of these dry and if i'm being honest that worked perfectly fine definitely less sloppy though it did stink like it smelled these things certainly kick up a lot of dust i've also concluded that the sandpaper was probably a complete waste of time the wire brush with enough elbow grease seems to break up the surface just fine the steel plates i scotch-brited now i haven't done this to a clutch pack in probably 15 years and here's hoping it'll be another 15 before it ever dawns on me again not fun 2 out of 5 stars would not recommend as i'm prone to do i've jumped the gun a little and removed the clutch basket from the bike is that a pretty piece of engineering or what i noticed something while taking the pack out that i'd like to address but first bit of a backstory the clutch pack if i can get this aligned fits in here like so the hub would be on the inside of course and there's a pressure plate that closes this whole thing up the plate with the springs you might remember from earlier in here the clutch pack expands and contracts opens and closes slides in these slots transmitting torque when it's compressed when it's closed or not transmitting torque when it's open and let this be the last time i have to tell you this these lugs are what pick up the engine power coming from these gears and transmit it to the wheel stay with me this is important without any pressure on the clutch pack the steel plates can rotate you know all of them would rotate they're keyed to the hub so the hub rotates they drive the hub until you push this whole pack down and then friction is helping you out nothing can move relative to each other and the whole thing moves as one piece remove the pressure and the inner hub can slip anyway here's what i noticed if i get these clutch pack out take a look inside of these slots where the friction discs interface with this basket where the basket is pushing the discs that then push the steel plates that then pushes the hub you see all those little lumps in there i hope you do because from where i'm sitting i can't little wear spots where each friction plate would make contact there should be six maybe bright spots those aren't good they wouldn't cause the lack of power i think i'm seeing in this bike but they would make for a very poor clutching experience those could cause the plates to not be silky smooth as they expand and contract the result is a jerky clutch you pull the lever the pressure comes off the pack but the plates might be stuck in those little valleys so they don't open quickly or as effortlessly as they should now what you're seeing here isn't too bad but if it were much worse you'd have to replace this clutch basket i'm going to try to lightly draw file those out they're a little deeper on the drive side but there's not very much to do here again luckily here it's very subtle i don't know if this really makes a difference but i want to keep at least my finishing strokes in the direction that the pack moves i'm happy with how that turned out i gave this a quick wash i'm gonna scrub it down a little bit better there's still a bunch of junk in here but i think it's ready to go back together again the point of what we just did was remove any resistance to these clutch discs sliding in and out if you happen to be a real hardcore clutch enthusiast you could probably also polish the mating surfaces on all the lugs on each of the friction discs that or i suppose you could buy good quality clutch plates to begin with on inspection there are bright spots yep there's bright spots on the mating faces of each one of these but i mean come on what are the odds of all of these faces contacting at the same time sooner or later probably within 10 minutes of riding your bike these surfaces will probably move around until they settle into their new home that said i can't tell you how strong the temptation is to walk these over to the filing machine give each one of those lugs a quick lick of course while you have it apart the same goes for the hub again this is where the steel plates interface because of the torque they're pushing these grooves would get the same sort of pitting i don't know if you can see that in the light i can't really feel them under my fingers so i'm just going to leave this one alone but again if it gets too bad you'd have to replace this part too let me give these a good washing and well two things the service manuals don't tell you when you're reinstalling a clutch first try to get as much dog hair out as possible you won't get it all but the more you get out of there the better second do your darndest not to hit the tripod i don't remember a hundred percent how these parts came out there's probably a torque spec for this thing that should be about it and this is the push rod i think when you pull the clutch lever this is the thing you're working on that's the rod you're pushing against if yours has an odd number of plates or an odd number of friction discs make sure you put them in the way they came out if there was a friction disc on the outside make sure there's a friction disc on the outside and not a steel plate and this here is the pressure plate if i pull the clutch now that entire plate translates and what holds that down are these springs these springs keep the clutch pack closed keep the engine always connected to the wheel there's also a length spec for these these are just borderline over time they'll shorten and you should replace them some folks like to install stiffer springs different clutch feel some people only install some percentage of the springs the factory put in there for a lighter clutch pull maybe add some washers that sort of thing the only thing to be careful of you don't want to make the clutch pull so light that when the pack is fully closed there's not enough pressure via this pressure plate to keep that clutch from spinning or slipping there's one more thing i wanted to try out here and that's the end play on this push rod hopefully you can see that it's moving a little bit there's some backlash i guess in there before it engages the pressure plate i'm just teasing the clutch lever if i pull it all the way it'll lift the pressure plate you don't want that end plate to be too much but you need some there yeah it's probably borderline doesn't seem too bad if it were you'd take the pressure plate off again and add another shim between the pressure plate and this push rod either replace the one that's there with a thicker one or add another five tenth out whatever you think you need now comes the absolute worst part of this entire endeavor trying to get this super thin o-ring to stay in place while we get that cover on sounds easy doesn't it this is going to take me the rest of the morning probably means i need a new o-ring i think that does it even though i don't know exactly what it is not sure if we fixed anything to be honest at least not until i take it for a spin but i'm pretty sure we didn't make anything worse and in the end isn't that what really matters i appreciate you sticking around hope that helps someone thanks for watching

Channel: This Old Tony

Views: 541,832

Rating: 4.9599209 out of 5

Keywords: clutch, motorcycle clutch, multiplate clutch, wet clutch, trials motorcycle, beta trials, beta 125, 125cc, replacing a motorcycle clutch, inspecting a motorcycle clutch, some dude that just keeps talking

Id: uhgBqzOE1Fc

Length: 17min 25sec (1045 seconds)

Published: Sat Jul 18 2020