Poll - Torque limiter failures on 449/511

And in parts, very helpful.
Granted in other parts, no so much, but there is some very useful information there for us all.

We were able to measure up to 280ftlbs of torque on our TLs. However, everyone I know who has actually added shims to the TL stack, SpeedBrain included, has either broken a transmission or spun their TL apart. I'm sure you could do it if you were easy on it, but if you ride hard/race it will fail. I'm pretty sure has something to do with beveled spring washer not having room to flex.

I managed to get the TL to 280Nm and installed it . I hope not to break the Transmission with the 280nm. The Tl will bed in and come down in its Nm reading and hopefully stay for a while in the 200-240nm.

i might pull it out after a couple rides.. just want to know how it goes.

i am awaiting some TL from Speedbrain... who would have thought ... used ones. They never waited actually until they failed. TL have been replaced on a Service Schedule .
After every single race and / or by the end of the Race day. TL was part of daily Maintenance .
Just have to wait until the Guys are back from Marokko .

Cant wait for it and the extra goodies .....

Love parcels in the post....

The Speedbrain guys are pretty helpfull actually. I am also waiting on reply regards breather.. Just interested to see how they do it.

This might also be said of the other raceteam in that regard.
All the porting, the big torque increases & flat-out desert racing isn't what most guys do to their bikes.
For sure, we can all learn from their heavy duty treatment, but for the little guy the failure rates will be a lot less.
Good to know how they got more life from them, or how deal with it.

We got the info on the Belleville washer once already from Tinken, Good info though, Thanks.

I wonder why this particular Husqvarna used the Cable/wire rope activated clutch? I've seen this on many of the Rallye bikes just like this example shown? Then again I have seen the earlier BMW G450 based Speedbrain and Touratech rallye bikes using the Husqvarna hydraulic actuator cover as well? I also wonder if they use the deeper BMW Clutch basket as well with the mechanical activated clutch for some reason? Maybe because the BMW had thicker clutch plates than the Husky's did stock by about .015 to .020 or so each. The BMW clutch basket uses the same amount of plates, they are a just a bit thicker? Could this just be for the individual riders preference? It took me some time to get used to the Hydraulic clutch actuation mechanism on my TC engine after running the cable set up.

Just to be clear to all, my comment wasn't a swipe at anyone. What I tried to say is that raceteams like ZT & SpBr put big loads on race bikes & this will accelerate wear on parts like limiters.
We can learn from that, but the wear on an un-modified private bike will obviously be at a slower pace.
Sorry for any confusion. DM

Did they ever say that the TL was the Reason for DNF... i never saw any message about that.

OK. We have established then that shimming the torque limiter is relative to an increase in breakaway NM numbers and doing this will cause these numbers to clearly be increased.

Shimming or re-shimming to the point of staying within tolerance also seems clear and the safe thing to do to avoid them from coming apart and causing a catastrophic event.

Once reassembled and ready for reinstallation after testing. If a TL has been "too tightly" re-shimmed to an out of tolerance specification (excessive) it can cause the Belleville washer to not have enough room to do its thing which could lead to it coming apart and cause a possible catastrophic failure. As mentioned above. Excessive shimming = no room for the Belleville spring washer.

Then I would suspect that at least a few of these (or maybe more) Torque Limiters mentioned and tested, one at 280ft lbs. that was sold that way or possibly others with similar excessively high readings upwards of 320 to 380 NMs would be at a release breakaway point that wouldn't allow that same Belleville Washer to have room to do its thing either?

Which is to say these would likely be the first to let go or fail first. Or at least be the ones considered to fail first during hard use and service. These should be used an example for this discussion, as this would happen first to the ones with excessively high or beyond normal tolerance if we all follow what's being said here through all this. Even much more so than ones re-assembled within breakaway tolerance and specifications which we are being told we shouldn't exceed.

If this is not the case or in fact these high rated breakaway TLs are the exception to what's being said here. Than could we get an explanation why this phenomenon as being discussed here doesn't apply to these high rated over tolerance TLs. Both of which apparently haven't yet failed or don't fall into this rule of thumb and neither has caused any transmission failures at this point as well.

I'm not really confused but some may be.

Just a thought. Its all relative. Thanks

I have a total grasp of what a Belleville washer is. Thanks for the explanation for the rest of us though because some probably don't. I probably wouldn't have been referring to it as such if I didn't know what it was. The newer 2000 and up Harley clutches use a Belleville washer spring or as they call it a diaphragm spring and have some heavy duty ones available. Stock if I remember is like .075 thick and the Screaming Eagle heavy duty one is like .085 thick or something like that. It increases the lever pull quite a bit. I've installed them myself when the bike is new to keep the clutch from going south on my Baggers.

What if a heavier and thicker Belleville washer could be sourced, BMW/Kymco had to have sourced the one that's in there now.

I am sure the coefficient of friction amongst the mating surfaces is going to bed itself upon the first few good rides and become worn in pretty quickly as the rough plates appear to have a sintered metallic rough coating. My Old Maico's have clutch plates like this, with no fiber, just sintered metallic.

Like it or not the TL would also wear in the direction of deceleration against one another too whether or not it ever establishes or reaches a point of this slippage under excessive power application going forward or being abused. It could happen either way.

Still would like to know why the tested super high numbers on the TLs aren't going to be doing this themselves to the Belleville spring though. 380 NMs is a hell of a lot.

9880sts test destroyed one and it completely shelled itself at approximately 350NM. No doubt about it. May have been a one time thing on the bench but its just as possible to do this in the engine too or it would shell the transmission gears first then under load. Makes sense to me.

What say you?

Sorry for interrupting the flow, but I can't stop thinking about why we are in this position in the first place. By adding a clutch or "TL" to the transfer gear, the impact on the transmission was softened to keep it from breaking on jumps, in the whoops and whatever else. So why was the transmission breaking anyway? Thin gears? Forces from a transfer gear on a backwards spinning engine too great? Am I missing something here or is there a design flaw in the transmission itself, and the TL is just a band aid for a bigger problem that nobody wanted to deal with? I know obviously the only thing we can do now is keep the stock TL from heating up, or create a better one. But has anybody thought about stronger transmission gears or is that impossible?

I don't know how far down the road with the gearbox design BMW/Husky were, I wasn't there,
but it does seem pretty clear from what Tinken has said that they started breaking gearboxes.

The limiter seems to me to be a patch repair instead of a having to redo the gears (gearbox v2.0)
However, it isn't too expensive to do & as a fuse it works pretty well & they are currently available.
My own concern is getting one in a few years time if it fails then.....it will be a real PITA.

You could build bigger gears, but the cost would be crazy. Better to buy a new bike