Countershaft loctite fix - comment

I was wondering if it might be a good thing to, after applying the loctite, to reassemble the sprocket and other parts while pulling the chain backwards as tightly as possible with engaged gear. This would be to limit the 'unglueing shear' to the decel mode only. It can be imagined that said shear forces would be much greater on acceleration that on deceleration, so if the sprocket is assembled while resting firmly clockwise on the shaft splines, there is a much smaller chance that the loctite bind might eventually fail. I thought this up because I still find it rather hard to believe that the loctite can stand up to the tremendous force coming from the engine shaft.

1: NO I don’t think it is a needed step.

2: I think you under estimate the torque applied from tire contact, though drive chain to that sprocket on deceleration

Michaelks, I actually did just that for the same reason you had this concern. I don't think it's about underestimating the deceleration force, it's just that if it's sitting snug, metal to metal on at least one rotational direction, you might minimise the fatigue on the loctite. I also had that doubt about the loctite withstanding the forces, so did a rep for loctite (I recall a thread about a rep or someone disputing the validity of the loctite fix) yet it has proven itself worthy on both my drzs. I had play on my dirt jumping mountain bike crank and applied a version of the loctite fix, and miraculously, it's still holding up with no play to speak of.

Forget the Loc-tite, torque to spec. bend lock tab, forget about it till next sprocket change.

Well, I believe there will be more stress during accel than during decel. When you accelerate, it's the motor against inner friction,

tires, etc. A rocket only has gravity to work against. When you take your hand off the throttle, the engine is still running,

you still have some thrust, but although the same 400 cc volume of air/gas mixture per rotation is still being admitted to the engine,

the mixture is much leaner because the throttle is closed (hence the popping) and you would have only idle speed for that much gas, if

the transmission were not engaged. But engaged it is and the same old friction forces are at work against your wish to move on.

But...there still is a piston working, explosions are taking place inside the cylinder, and there is a forward force, however

now it is not enough to keep the bike moving at this speed, so the net result is a deceleration tugging at the sprocket counterclockwise, but there still is the motor working against that. This needs more elaboration than i am capable of now, but  the key idea is the motor cancels out some of the stress on the chain during decel, which is why it's easier on the loctite.

 

Think of it this way : to accelerate, you need to work against friction and to change the speed of the vehicle plus its passenger(s) Chain very tight. When you have reached a speed that pleases you, then you set the throttle to just keep working against friction and maintain constant speed. Chain still tight but less. Now you decide to take it slower so you twist the throttle a little less (not full decel). This will now tighten the chain but from below, pulling on the sprocket conterclockwise, but less strongly than on a full sudden decel, because the motor is still faster than idle. I hope you get the idea.

Edited by michaelks

However, It might be just  logical to have it in the middle so there is an even amount of loctite front and back.

On my DRZs I loctite the sprockets by using an impact wrench but I'm begining to wonder if they really need it. As I had previously mentioned I do have an "S" with 135,000 miles on it. It had never been loctited and the output shaft shows no sign of wear.

None of my 2 stroke bikes were ever loctited also none of them use a nut to hold the sprocket in place. My GasGas's are 450s and they also use circlips instead of nuts on the output shaft. None show any sign of wear.

 

Again, However, all my friends with Honda 650L's have suffered from worn output shaft splines.  Having seen the problems that they have had, I just figured better to be safe than sorry but I am stingy with the amount of loctite I use and I go through the extra step of red on the splines... blue on the threads and always let it set overnight.

 

Tony

The purpose of Loctite on the splines is not to reduce spline wear, although that may be a side affect.

Forget the Loc-tite, torque to spec. bend lock tab, forget about it till next sprocket change.

Really? Can you detail you position and recommendation for your suggestion? 

It's reassuring to know the loctite works so well, and also that it can even be done without. I'll play it safe and do it anyway. But still I'd reaffirm that the tension on the chain upon decel (counterclockwise unglue on the sprocket) is way less than that upon acceleration. For the good reason that on decel the tension on the chain is only due to inertia spinning the engine at a higher rotation than it has gas for, and this the starter (or your leg) does every morning (and without ignition to boot). That has to be much less than what is needed to bring 200 kg of bike and rider up to speed.

Or, take the bike from zero to 100 in ten seconds, then see if it will come to a stop in the same ten seconds with only the unthrottled engine to stop it.

 

Really? Can you detail you position and recommendation for your suggestion? 

Just my personal experience from having owned 50 + bikes in the last 45 years, I've never had a countershaft/sprocket problem using the oem hardware and the specified tightening torque.

Edited by Kioti

Just my personal experience from having owned 50 + bikes in the last 45 years, I've never had a countershaft/sprocket problem using the oem hardware and the specified tightening torque.

That’s great background. And with your breadth of experience you might have excellent insight and support for your position.. Please share.

 

So specific to the DRZ... why do you recommend not addressing the issue found commonly on this bike, all years, all models of DRZ?

 

Are you aware there is a systemic issue with wear of the second gear bushing caused by the sprocket moving relative to the countershaft splines?

 

Are you aware no amount of clamp load possible from the countershaft nut before the threads fail will stop this movement?

 

 If you are aware of those well documented issues.. what is your suggestion to address it (note, oem hardware and the specified tightening torque fails to work as required often.)

 

Thanks

I'd like to add to my comment about my 135,000 mile DRZ without the use of Loctite. In all those miles the bike was used 99% as a street bike and probobly never subjected to more than 1/2 throttle. My other 2 DRZs that are subjected to normal conditions and stress have always been loctited.

 

 

Re: acceleration de-acceleration which seems to be a strange paert of this discussion let me say that SMs with their 150 &160 sport  tires may be putting more stress on  de-acceleration as they down shift and hit the rear brake to swing the back end around when cornering than they ever could by acceleration.

 

Tony

Forget the Loc-tite, torque to spec. bend lock tab, forget about it till next sprocket change.

 

 

if you change the sprocket once a week, that may be fine. i need both hands for enough counting fingers, of how many bikes i've found with a barely finger tight countersprocket nut on drz's. the owners are always surprised, as they once thought like you that the torque specs were good enough. 

 

i've seen two that had the sprocket tack welded on as a 'fix'. 

 

i've yet to see a drz with splines worn so bad they were confused as a badly worn sprocket (suspected chain jump) on a drz, but the interwebs will find pictures of things like that. 

 

:) 

I'd like to add to my comment about my 135,000 mile DRZ without the use of Loctite. In all those miles the bike was used 99% as a street bike and probobly never subjected to more than 1/2 throttle. My other 2 DRZs that are subjected to normal conditions and stress have always been loctited.

 

 

Re: acceleration de-acceleration which seems to be a strange paert of this discussion let me say that SMs with their 150 &160 sport  tires may be putting more stress on  de-acceleration as they down shift and hit the rear brake to swing the back end around when cornering than they ever could by acceleration.

 

Tony

 

I'm sorry to have been unclear about this. Bottom line is, what the chain has to do during :

 

acceleration : taking 200 kg of bike plus rider up to cruising speed in say, under 30 seconds

deceleration : only the engine in forced rotation

 

Now compare these two loads on the chain/sprocket.

 

I'm sorry to have been unclear about this. Bottom line is, what the chain has to do during :

 

acceleration : taking 200 kg of bike plus rider up to cruising speed in say, under 30 seconds

deceleration : only the engine in forced rotation

 

Now compare these two loads on the chain/sprocket.

Take it from an engineer's perspective… your right wrt the torque being applied to the sprocket/splines is greater during acceleration than deceleration. However your over thinking it... sometimes things just work and there is no reason to make it more complicated than it needs to be. Put four drops of high-strength loctite around the splines, install sprocket, install locking washer, drop of high-strength loctite on threads, install/torque nut and bend over tabs. I'll let it sit overnight before riding.

Well, that's exactly what I'll have to be doing in a hurry - by pure chance i happened to touch something under the sprocket cover that made exactly the noise that has been bothering me since I bought this bike...and here it is. There's no locking washer, I'm afraid  :( 

 

(Sorry I couldn't find how to include a video link)

 

http://www.youtube.com/watch?v=rVpGpKYH1I8&feature=youtu.be

 

 

That sheet metal washer under the nut is the locking washer.  Part of the washer is bent over a flat on the nut.  Apparently the only thing still holding the nut on.

Well, that's exactly what I'll have to be doing in a hurry - by pure chance i happened to touch something under the sprocket cover that made exactly the noise that has been bothering me since I bought this bike...and here it is. There's no locking washer, I'm afraid  :(

 

(Sorry I couldn't find how to include a video link)

 

http://www.youtube.com/watch?v=rVpGpKYH1I8&feature=youtu.be

Your video shows the countershaft nut has lost clamp load,, the fact it is still in position retained by the locking washer means the nut did not loosen, as some still mistakenly believe is happening. 

 

 So now you remove it, clean, re tighten the nut (with or without having done the lock tite procedure)  and you get to see just how bad you have worn the second gear bushing... Once the nut is tight,, if you have drag, or it catches as you rotate the countershaft (without chain)  then the bushing is damaged beyond use. 

If the countershaft rotates freely .. then your good, ride on. 

Been a while since we had a good "loose countershaft nut" thread.

Hope it proves entertaining :goofy:

 

Well, I removed the sprocket, oiled the thread and torqued it up to 90 N.m, which is about 66 lbf.ft, and didn't notice anything except for a little drag that didn't seem to be anything but normal. There is also a little clicking when i move the sprocket to and fro.

 

http://www.youtube.com/watch?v=3xeAUFxtwIs&feature=youtu.be

 

Wonder if I should put this sprocket back on or get a new one before loctite.

 

yk47.jpg

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