Clunking Trans

[Kevin Daly]

I guess I agree with this to some extent. Afterall, I've got 19k on it now with no more than some thought into a resolution. And on the way home tonight, I couldn't easily reproduce it without riding like a total nit.
The fact of it still keeps me thinking about what it would take to resolve it at the design level. It's more of a conversation topic now than anything else.

well, needless to say, the dude that solves this (the only) weakness of the shaft drave concept (IMO) will become a rich man. And well deserved too I might add. Huck, when you figure it out I will buy one

 

[alan sh]

I guess I agree with this to some extent. Afterall, I've got 19k on it now with no more than some thought into a resolution. And on the way home tonight, I couldn't easily reproduce it without riding like a total nit.
The fact of it still keeps me thinking about what it would take to resolve it at the design level. It's more of a conversation topic now than anything else.

well, needless to say, the dude that solves this (the only) weakness of the shaft drave concept (IMO) will become a rich man. And well deserved too I might add. Huck, when you figure it out I will buy one

Is this conversation primarily about the AE? I have the "Normal" '07 and I don't see any of this. it "snicks" into first gear (no clunk) and all changes up and down are silky smooth.

Alan

 

[Huck Fonda]

I guess I agree with this to some extent. Afterall, I've got 19k on it now with no more than some thought into a resolution. And on the way home tonight, I couldn't easily reproduce it without riding like a total nit.
The fact of it still keeps me thinking about what it would take to resolve it at the design level. It's more of a conversation topic now than anything else.

well, needless to say, the dude that solves this (the only) weakness of the shaft drave concept (IMO) will become a rich man. And well deserved too I might add. Huck, when you figure it out I will buy one

Is this conversation primarily about the AE? I have the "Normal" '07 and I don't see any of this. it "snicks" into first gear (no clunk) and all changes up and down are silky smooth.

Alan

Pretty much, yes. When you have control over the clutch, you know when it's engaged / disengaged, and if only partially engaged, how much. The AE system has some kind of variable rate engagement. The genie in the box can only remember so many algorithms.

 

[jestal]

From my observations there is about the same amount of lash in most motorcycle drives but the lash is much more evident with a shaft compared to a chain. There is a reason. The shaft is rigid and lash is positively transmitted thru the driveline. Period. With a chain, the chain droops slightly between the slack side of the sprockets and when the force is reversed the slack side is snapped tight and the tight side droops....but....the slack chain must by pulled tight which adds some inherent dampening as the slack chain is acclerated "sideways" to the taught position. You can ride a bike with a fairly loose chain and sense the slack and freeplay but the hard "lash" feel is dramatically reduced compared to a shaft under those conditions.

Certainly the intake and induction type make a lot of difference. As has been mentioned before, the great-grandfather of the FJR1300, the 1978 XS1100 Yamaha, was shaft drive and carbureted. And it had much WORSE driveline snatch or lash than the FJR does. Trust me. I put 118,000 miles on one and it is still sitting in my basement. The CV carbs on that engine were even more sensitive than big bore throttle bodies and the shaft drive had the same freeplay (even more in second gear) as the FJR does. To make it smoother you could have smaller throttle bodies or a slower opening throttle....but then you would loose power or hear the complaints of how far the throttle must be opened. Just a compromise.

I think the driveline snatch on the FJR is just a characteristic of a powerful engine with rapidly opening throttle bodies combined with a shaft that has little to no forgiveness. Since the FJR is more of a sport bike than some others with shafts the engagement windows for the transmission dogs are a bit wider (to enhance the ability to pull off a power shift) which , out of necessity, adds more lash to cause driveline snatch compared to some lesser or non-sporting bikes.

Learn to drag the rear brake lightly in slow going and keep the throttle cracked to lightly load the driveline and the snatch disappears. Control creeping speed with the rear brake (while holding the throttle constant) to keep tension in the driveline so prevent the driveline jerk from interrupting a parking maneuver or u-turn.

I think the whole thing is just the nature of the beast and something to be put up with if you want a shaft drive and the kind of performance the FJR offers.

 

[Huck Fonda]

Yeah, but if it could be worked around, wouldn't there be value to that? I've had other shafties, and ridden many, and realize that TDDT (that driveline does that), but if it did't, I'd have nothing left to complain about (except the rear shock, but that's easy).

I guess accepting it as normal without keeping an eye to resolution or future design suggestions (who's listening out there?) just doesn't sit well with me.

Sure it's folly, but then again...

 

[jestal]

I don't mean to insinuate that it wouldn't be better if it didn't have the lash. just offered more input as to why it might be the way it is.

Part of the discussion involves understanding the hows and whys of the lash and clunk so as to establish root cause. I'm not sure all of the whys and hows have even been brought up yet.

Only by understanding the root cause can the "problem" be fixed. Bandaids can be effective and are often applied to eliminate "problems" like this but root cause analysis is what kills it at the end of the day.

Every engineering situation is always a variety of compromises. The lash and clunk might be lessened and/or eliminated via tighter dog/window clearance, slower opening throttle blades, softer cush drive, etc.... But then the bike might not be as quick or fast or powershift as well.... That is the compromise as it stands. Just understanding it helps avoid problems with it sometimes.

 

[ELP_JC]

Everything is a compromise on a motorcycle. The tranny itself is a compromise: packaging constraints, simplicity, and weight/cost savings means no synchros and sequential shifting. And that in turn means enough 'slop' to allow reliable shifting, or we'd be b*tching about missed shifts. And don't forget to add final drive lash (chain and/or gear slack). If you want to minimize driveline lash, you'd need belt final drive with a belt tensioner, such as Buell's, which practically eliminates the driveline component of it, but the tranny component will always be there; nature of the beasts (motorcycles). Again, driveline lash on any bike can be imperceptible with appropriate riding technique. And yes, you can always be smoother; that's why motorcycling will always be exciting to me. Take care.

JC

 

[clutchless1]

After riding the FJR for about a year now I personally don't see where any adjustments we could make or come up with is going to make this problem go away which is unfortunate. I think if there was a way to do this Yamaha would have already done it (I did say I "THINK" they would have), and don't think there is a fix for this setup and the way it was designed. I like a few others ride the AE Model, if you ride the A Model and think the clunking gets on your last nerve, try riding one of these; you at least have a clutch to counteract some of this. On the A Model I have found very early If you don't come off of the throttle at exactly the right moment when shifting, you can really hear and feel the abuse the whole driveline takes, and from that noise you know it won't be too long in the future before something takes a major ****. About the only fix I could personally come up with was all in how I used the throttle and the shift paddle at the same time, I found if I was nice and smooth the whole driveline was nice and quiet.

One thing that bothers me is the way some of these problems are coming forward at a rapid pace concerning the AE Model. When we speak of driveline slop some say we have already delt with that issue and it should be put to bed, or we have already done and gone through all of this so we don't want to re-hash this anymore. But this is a new and completely differnt bike to an extent starting with the introduction of the 06AE Model. The driveline issue we talk about is now (it seems) starting to take it's toll on gear dogs. More and more I'm seeing and reading about someone else who has a problem with their transmission either not going into gear or slipping out once it was in. We start to notice once a teardown of the transmission has been done it clearely shows the dogs and the related gear these dogs mate with are worn to the extent they can no longer do what they're supposed and designed to do. Call this what you may, but the bigger issue here is this driveline slop seems to be directly linked to these premature transmission failures especially on the AE Models because of what I was speaking about earlier, the way the softer (so to speak) shifting should or needs to be done to keep this models transmission from really banging each time a gear is changed.

This may be the very beginning of an underlying problem, or just plain ole abuse. Personally I'd like to know if these failures are happening at a certain rate related to mileage, or does mileage have nothing to do with it. Are all or some of these failures due to the fact some riders are riding and shifting these bikes like they're at the racetrack running these things for all that they are worth? I don't know the answer. But I think this driveline issue is starting to show it's ugly side, and all who ride and know about these bikes inside and out should really try to help one another out so if this is indeed a underlying problem, it may be able to get resolved with enough help and rider information. Isn't that what this Forum is all about?

 

[Fred W]

After riding the FJR for about a year now I personally don't see where any adjustments we could make or come up with is going to make this problem go away which is unfortunate. I think if there was a way to do this Yamaha would have already done it (I did say I "THINK" they would have), and don't think there is a fix for this setup and the way it was designed. I like a few others ride the AE Model, if you ride the A Model and think the clunking gets on your last nerve, try riding one of these; you at least have a clutch to counteract some of this. On the A Model I have found very early If you don't come off of the throttle at exactly the right moment when shifting, you can really hear and feel the abuse the whole driveline takes, and from that noise you know it won't be too long in the future before something takes a major ****. About the only fix I could personally come up with was all in how I used the throttle and the shift paddle at the same time, I found if I was nice and smooth the whole driveline was nice and quiet.
One thing that bothers me is the way some of these problems are coming forward at a rapid pace concerning the AE Model. When we speak of driveline slop some say we have already delt with that issue and it should be put to bed, or we have already done and gone through all of this so we don't want to re-hash this anymore. But this is a new and completely differnt bike to an extent starting with the introduction of the 06AE Model. The driveline issue we talk about is now (it seems) starting to take it's toll on gear dogs. More and more I'm seeing and reading about someone else who has a problem with their transmission either not going into gear or slipping out once it was in. We start to notice once a teardown of the transmission has been done it clearely shows the dogs and the related gear these dogs mate with are worn to the extent they can no longer do what they're supposed and designed to do. Call this what you may, but the bigger issue here is this driveline slop seems to be directly linked to these premature transmission failures especially on the AE Models because of what I was speaking about earlier, the way the softer (so to speak) shifting should or needs to be done to keep this models transmission from really banging each time a gear is changed.

This may be the very beginning of an underlying problem, or just plain ole abuse. Personally I'd like to know if these failures are happening at a certain rate related to mileage, or does mileage have nothing to do with it. Are all or some of these failures due to the fact some riders are riding and shifting these bikes like they're at the racetrack running these things for all that they are worth? I don't know the answer. But I think this driveline issue is starting to show it's ugly side, and all who ride and know about these bikes inside and out should really try to help one another out so if this is indeed a underlying problem, it may be able to get resolved with enough help and rider information. Isn't that what this Forum is all about?

I dunno. Maybe it's just me. But this whole thing about how an "auto" trans works on a motorcycle... I guess that's just why I wouldn't buy one. I mean, you guys that jumped and bought the AE's, if it works for you that's great. But if it doesn't... well it's not like anyone made you go out and buy one.

To me, it's a solution looking for a problem.

I have never... and I mean NEVER! had any kind of an issue with having to use the clutch on a motorcycle.

But hey, that's just me. And your mileage may vary, etc., etc.

 

[ELP_JC]

Just wanted to point out driveline lash and dog design are 2 different animals; not much can be done on the former, but the latter can be fixed. In fact, seems like Yamaha added an extra dog on some gears in '08, confirming the problems reported above. Plus some changes in the clutch as well (maybe somebody has the precise scoop on this). The above was only mentioned in the AE changes on Yamaha's dealer news, but should have been incorporated to both models. Later.

JC