CG125 Clutch Judder

[Merlin_531]

Hi guys and gals,

I've got a Cg125 (1992) that has the following problem, if revved up in first, and the cluch slowly released, the clutch judders, making the whole bike shake - but just on that initial catch of the clutch. It's not an issue in general daily riding, but is more apparent when doing slow speed riding (medium revs, on the back brake, just letting the clutch slip). The problem is more apparent when the bike is warm.

The main issue, is that I've replaced the following - Steel Plates, friction plates, springs, and the two pressure plates that push the clutch pack together. Also filed down any notches on the clutch basket. I'm out of ideas as to what the problem could be, as the clutch has essentially been replaced, but the problem persists. I was wondering if anybody else had come across anything similar? I'd apprecaite any help/ideas!

[Teflon-Mike]

Why on earth are you attempting slip'n'drag.. higher revs, sliping clutch and holding back on the back brake, on a chuffin 125!!!!

The technique, is firstly deplorable; its a 'trick' born of DAS to get students doing slow speed manouvers more readily... it is NOT repeat NOT 'good practice'.

It's the motorcycling equivalent of p[ratting your head and rubbing your tummy, a display of fine dexterity using three controls, clutch, throttle and brake, when just one.. the throttle should be enough.. basically defeating the gearbox, and getting the bike to go slower than its geared to, in the abscence of a lower cog.

On a ONE-TWO-FIVE fer fuggs sake.... the thing probably tops out at about 10K rpm and 15mph in 1st gear.. how fugging slow do you want the dang thing to go! It is just NOT necessary or even particularly helpful!

It most surely isn't a demonstration of good machine control.... in sports where machine control is all... observed trials, moto-gym-khana, etc.. IF they need the bike to go slower than its gearedto... they fit a bigger back sprocket and gear the fuggiun thing down so they can do it clutch out under drive and in 'full control'.. clutcg on or clutch sluipping, not under drive is NOT in control, so it CANNOT be a demo of 'good' control...

Its like I said it's motorcycles patting head and rubbing tummy.... and doing bog all for you, especially on a CG125, where any judder could be coming from anywhere between the engine and brake... so just don't do it... go ride it 'properly'... THEN tell us if this 'problem' still persists.
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[Merlin_531]

[Easy-X]

Well as Tef says: the problem could be anywhere along the chain:

Engine > Gearbox > Clutch > Front Sprocket > Chain > Rear Sprocket > Cush Drive > Wheel

I'd start with a visual exam of the chain, chain slack, sprockets and so on. A mate eyeballing it all as you set off might shed some insight. It's an old bike so it could also be the cush drive (rubbers behind the rear sprocket.)

<edit: spelling>
____________________
Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Merlin_531]

[The Shaggy D.A.]

If it's more noticeable when warm, could be the oil. Changed it recently?
____________________
Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[blurredman]

If you're using the back brake whilst slipping the clutch, could the shoes be worn, or possibly the wheel oval?

Does the bike shudder when you don't use the brakes?
____________________
CBT: 12/06/10, Theory: 22/09/10, Module 1: 09/11/10, Module 2: 19/01/11
Past: 1991 Honda CG125BR-J, 1992 (1980) Honda XL125S, 1996 Kawasaki GPZ500S.
Current: 1981 Honda CX500B - 91k, 1987 MZ ETZ250 (bored to 295cc) - 38k, 1990 MZ ETZ251 - 49k, 1979 Suzuki TS185ER - 9k, 1973 MZ ES250/2 - 17k.

[Teflon-Mike]

Oh-Kay... its an almost thirty year old learner bike, that has likely sufferered over two decades of the idea 'low-maintenance' means 'no-maintenence', that you have restored... and are assessing by criteria that yolu believe it 'should' do drag'n'slip, liuke a nbig bike... well.. lets be blunt... it aint no big-bike, and neither you nor any learner you sell it on to should be doing drag'n'slip[ on it either.... ie this is NOT a problem, with the bike, thatr it does something 'strange'; when the ridr does something 'strange' with it, theat it was never designed to do, that it domnt need to be able to do, and that is not really helpful to any-one.

Sush drive rubbers have been mentioned... on the CG they aught to be simple metalastic-bushed pressed into the back wheel hub, four pins bolted to the sprocket sit in, the sprocket held on with a large C-Clip..... rather notoriouse, folk undo the peg drive nuts to change the sprocket, loose the C-~Clip and mumble about the sprocket wobbling...

IF riding the dang thing 'clean' not trying to drag'n'slip like it was a big-bike... the problem persists.. THAT is where I would look first... at the state of the Chain and speockets, sprocket retension by way of the drive pes and C-Clip, alignment of rear wheel and adjusters that are so oft chewed to bludgeyry, wtc et etc...

B-U-T, any 'judder' could be in any [part of the drive line from the motor to the back wheel, and simply here and now you are looking presuming a fault that simply ISN'T with the mechanics... but on the RIDING... trying toii Drag'n'Slip, which is NOT a good practice on ANY size bike, but may be more apropriate on a big-bike, for Mod1 cone excersises, and little more.

REALLY this is NOT good practice and far FAR from a displaty of 'fine conmtrol' its actually an abdication of control and admission you dont have much, but hey! You can pat your head and rub your tummy...

As said... report back what its like when toy 'just' ride the dang thing properly.
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[Teflon-Mike]

Oh-Kay... its an almost thirty year old learner bike, that has likely sufferered over two decades of the idea 'low-maintenance' means 'no-maintenence', that you have restored... and are assessing by criteria that yolu believe it 'should' do drag'n'slip, liuke a nbig bike... well.. lets be blunt... it aint no big-bike, and neither you nor any learner you sell it on to should be doing drag'n'slip[ on it either.... ie this is NOT a problem, with the bike, thatr it does something 'strange'; when the ridr does something 'strange' with it, theat it was never designed to do, that it domnt need to be able to do, and that is not really helpful to any-one.

Sush drive rubbers have been mentioned... on the CG they aught to be simple metalastic-bushed pressed into the back wheel hub, four pins bolted to the sprocket sit in, the sprocket held on with a large C-Clip..... rather notoriouse, folk undo the peg drive nuts to change the sprocket, loose the C-~Clip and mumble about the sprocket wobbling...

IF riding the dang thing 'clean' not trying to drag'n'slip like it was a big-bike... the problem persists.. THAT is where I would look first... at the state of the Chain and speockets, sprocket retension by way of the drive pes and C-Clip, alignment of rear wheel and adjusters that are so oft chewed to bludgeyry, wtc et etc...

B-U-T, any 'judder' could be in any [part of the drive line from the motor to the back wheel, and simply here and now you are looking presuming a fault that simply ISN'T with the mechanics... but on the RIDING... trying toii Drag'n'Slip, which is NOT a good practice on ANY size bike, but may be more apropriate on a big-bike, for Mod1 cone excersises, and little more.

REALLY this is NOT good practice and far FAR from a displaty of 'fine conmtrol' its actually an abdication of control and admission you dont have much, but hey! You can pat your head and rub your tummy...

As said... report back what its like when toy 'just' ride the dang thing properly.
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[stinkwheel]

A CG125 is a LEARNER bike. So it's FOR practicing for your test. Slow riding in first while slipping the clutch is part of the test.

It shouldn't be juddering.

First thing I'd check is the clutch push rod. Get it out, make sure it isn't rusty and roll it on a sheet of glass to make sure it's straight.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Merlin_531]

[Merlin_531]

[T6Clement]

[martin734]

This may sound a bit silly, but try lubing or even replacing the clutch cable. Sometimes corrosion on the clutch cable can cause it to jam slightly in the sleeve and make slipping the clutch quite tricky, especially when letting the clutch out slowly.
____________________
Current bike: ST1100 "Big Red"