05 Clutch/Transmission Skip at Speed?
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05fjrBluedevil
Well-known member
Here is an interesting article on a slipper clutch, may offer some insight.
It is no secret that Nicky Hayden has been having clutch issues with his Honda MotoGP machine. Reporters following the MotoGP circuit generally acknowledge it, and Hayden's recent starts (particularly, his rapid fade from pole position to 17th in the opening lap at Phillip Island a few weeks ago) point to it. Hayden was testing new clutch parts following last weekend's Motegi round. While you might think it is simple enough to design an effective clutch, and that HRC could not possibly design an ineffective one; it is a bit more complicated than that.
First, let's talk about the huge demands on a MotoGP clutch. My recent experience with motorcycle drag racing, which included a lesson in the basics by famous racer Ricky Gadson, taught me that gaining maximum acceleration away from a dead stop requires heavy use of the clutch, which is modulated to apply the maximum forward drive, without lifting the front wheel or spinning the rear tire. Letting off the throttle causes the engine to lose its momentum, so to speak, so the throttle is held at a steady, fairly heavy application, and power delivery is modulated by slipping the clutch
Slipping the clutch means that the clutch plates are not entirely locked together, but neither are they completely separated - they are lightly dragging against each other, transmitting some of the power while the rest is turned into friction as the clutch plates slide across each other. Of course, friction generates heat, and slipping the clutch generates massive amounts of heat in the discs as well as in any peripheral components. The more powerful the bike, the more heat is generated, and it doesn't get much more powerful than a MotoGP bike! Overheating the clutch can cause the plates to 'glaze', at which point they will no longer grip each other with much force - meaning that, when force is next applied to the clutch (as it is even during in-gear acceleration), it may slip.
Typically, a "slipper clutch", which is intended to let the clutch slip slightly under hard deceleration (preventing rear wheel lockup on corner entry), will actually make it more difficult to smoothly slip the clutch when launching hard from a dead stop. This problem is exacerbated by the setup of a MotoGP bike; Hayden's RC211V almost certainly runs an extremely tall first gear (to allow him to change down to first for slow corners), which will of course require a huge amount of clutch slip for a hard launch. Not only that, but a MotoGP bike's relatively short wheelbase, tall center of gravity and light weight, compared to a purpose-built drag bike make it incredibly wheelie-prone when accelerating hard at low speeds - again, a problem that is usually controlled by slipping the clutch. All this creates massive heat build-up, which can damage the clutch plates to such an extent that they can no longer hold full power without slipping.
One solution would be to switch to a larger diameter clutch, which would have more area to effectively dissipate heat. The problem with this solution is that a larger clutch carries more inertia, slowing down the engine's rate of RPM gain and thus its acceleration. Another solution would be to add more spring pressure, but this would (usually) make the clutch harder to pull, increasing rider fatigue. It might also change the way in which the slipper clutch operates, possibly requiring that system to be redesigned (if the RC211V does in fact have a slipper clutch - with so much of MotoGP developement shrouded in secrecy, Honda might currently be using a completely different system to do the job usually done by a slipper clutch). Of course, we're sure that HRC engineers have been through all these solutions, and probably a few more I haven't thought of!
Now that you have a basic idea of the technical challenges of designing a clutch to handle both the rigors of a standing start, and the entirely different demands of the rest of the race, let's talk about what happens when it doesn't. As I mentioned earlier, once the clutch plates have been glazed due to extreme heat, or otherwise damaged, they may not be able to hold the engine's full power, and can start slipping under hard acceleration. This leads to that horrible feeling when you twist the throttle all the way to the stop, only to see the needle spin quickly across the tach while the bike continues to accelerate as if you're only giving it 60% throttle.
For most riders, this is nothing more than a minor irritant - oh, gee, I'm only able to use 60% of my liter bike's horsepower during the morning commute to work! But for a rider like Nicky Hayden, battling against the world's most talented motorcycle racers in contention for a championship that Honda has spent untold millions of dollars trying to win, it's a much more serious issue. If Hayden exits a corner just behind Valentino Rossi, only to apply his throttle and find less than 100% of his Honda's horsepower being transmitted to the ground, how is he supposed to beat 'The Doctor'? That's a hard enough task aboard an equally powered machine.
Whatever happens between Rossi and Hayden in the final two rounds of the series, I'm sure most fans are hoping that both of these riders have any mechanical issues behind them.
It is no secret that Nicky Hayden has been having clutch issues with his Honda MotoGP machine. Reporters following the MotoGP circuit generally acknowledge it, and Hayden's recent starts (particularly, his rapid fade from pole position to 17th in the opening lap at Phillip Island a few weeks ago) point to it. Hayden was testing new clutch parts following last weekend's Motegi round. While you might think it is simple enough to design an effective clutch, and that HRC could not possibly design an ineffective one; it is a bit more complicated than that.
First, let's talk about the huge demands on a MotoGP clutch. My recent experience with motorcycle drag racing, which included a lesson in the basics by famous racer Ricky Gadson, taught me that gaining maximum acceleration away from a dead stop requires heavy use of the clutch, which is modulated to apply the maximum forward drive, without lifting the front wheel or spinning the rear tire. Letting off the throttle causes the engine to lose its momentum, so to speak, so the throttle is held at a steady, fairly heavy application, and power delivery is modulated by slipping the clutch
Slipping the clutch means that the clutch plates are not entirely locked together, but neither are they completely separated - they are lightly dragging against each other, transmitting some of the power while the rest is turned into friction as the clutch plates slide across each other. Of course, friction generates heat, and slipping the clutch generates massive amounts of heat in the discs as well as in any peripheral components. The more powerful the bike, the more heat is generated, and it doesn't get much more powerful than a MotoGP bike! Overheating the clutch can cause the plates to 'glaze', at which point they will no longer grip each other with much force - meaning that, when force is next applied to the clutch (as it is even during in-gear acceleration), it may slip.
Typically, a "slipper clutch", which is intended to let the clutch slip slightly under hard deceleration (preventing rear wheel lockup on corner entry), will actually make it more difficult to smoothly slip the clutch when launching hard from a dead stop. This problem is exacerbated by the setup of a MotoGP bike; Hayden's RC211V almost certainly runs an extremely tall first gear (to allow him to change down to first for slow corners), which will of course require a huge amount of clutch slip for a hard launch. Not only that, but a MotoGP bike's relatively short wheelbase, tall center of gravity and light weight, compared to a purpose-built drag bike make it incredibly wheelie-prone when accelerating hard at low speeds - again, a problem that is usually controlled by slipping the clutch. All this creates massive heat build-up, which can damage the clutch plates to such an extent that they can no longer hold full power without slipping.
One solution would be to switch to a larger diameter clutch, which would have more area to effectively dissipate heat. The problem with this solution is that a larger clutch carries more inertia, slowing down the engine's rate of RPM gain and thus its acceleration. Another solution would be to add more spring pressure, but this would (usually) make the clutch harder to pull, increasing rider fatigue. It might also change the way in which the slipper clutch operates, possibly requiring that system to be redesigned (if the RC211V does in fact have a slipper clutch - with so much of MotoGP developement shrouded in secrecy, Honda might currently be using a completely different system to do the job usually done by a slipper clutch). Of course, we're sure that HRC engineers have been through all these solutions, and probably a few more I haven't thought of!
Now that you have a basic idea of the technical challenges of designing a clutch to handle both the rigors of a standing start, and the entirely different demands of the rest of the race, let's talk about what happens when it doesn't. As I mentioned earlier, once the clutch plates have been glazed due to extreme heat, or otherwise damaged, they may not be able to hold the engine's full power, and can start slipping under hard acceleration. This leads to that horrible feeling when you twist the throttle all the way to the stop, only to see the needle spin quickly across the tach while the bike continues to accelerate as if you're only giving it 60% throttle.
For most riders, this is nothing more than a minor irritant - oh, gee, I'm only able to use 60% of my liter bike's horsepower during the morning commute to work! But for a rider like Nicky Hayden, battling against the world's most talented motorcycle racers in contention for a championship that Honda has spent untold millions of dollars trying to win, it's a much more serious issue. If Hayden exits a corner just behind Valentino Rossi, only to apply his throttle and find less than 100% of his Honda's horsepower being transmitted to the ground, how is he supposed to beat 'The Doctor'? That's a hard enough task aboard an equally powered machine.
Whatever happens between Rossi and Hayden in the final two rounds of the series, I'm sure most fans are hoping that both of these riders have any mechanical issues behind them.
Ari Rankum
NAFO Karting Champion, 2012
It's starting to sound to me like a design defect. I had the exact symptoms mentioned at the top of this thread on my 05 at 10,000 miles. I took mine in, got the same BS. I talked about 20 years of riding on everything from dirtbikes to dualsports to sportbikes to a flippin' Goldwing for Pete's sake. I told them every single one of my bikes was taken well over 10,000 miles without a hint of a similar problem. I told them I've never, in my life, on any vehicle, attempted a clutchless upshift, regardless of how many times I've been told it's a perfectly reasonable thing to do. Moreover, at 39 years old, I was extremely unlikely to be thrashing a $14K touring bike. The dealer backed me up with some statements about how clean the bike was and how well-maintained it appeared to be. With that I got the same deal as you - it's not a defect, and we'll fix it this one time as a courtesy, after that, you're going to have to pay for it, because it's you, not the bike. I think that's ******** and a crappy way to treat a customer.
Inlaw1
Well-known member
It's pretty much the same I'm getting from the Yami dealer I bought my 06 from, just on different problems.
I've got grease showing up on the rear wheel (probably too much grease on the drive splines I was told, even though it's documented that Yamaha is very skimpy in this area), I've got a clunking in the front end when the bike is rocked back and forth holding the brake (it's the bushings in the front end, "supposed to do that" the mechanic told me), and the front wheel, which has no wheel weights on it and shakes the front end above 80, isn't out of balance. "I didn't feel anything when I rode it". Well, he can't go above the 65 mph speed limit where the shake is just barely starting to become perceptible.
As for your gear problems, it's been long known Yamaha has a problem with it's transmissions on the big bore bikes. My 84 FJ had the second gear put in twice by the time it hit 33K. The FZ 1000 was also known for loosing second gear. Same thing that happened to you guys, starts to pop out. Many times it was due to some abuse, but it was known it didn't take much. Didn't quite get it engaged and it slipped out once or twice? You were on your way to bending those dogs on the gears and heading towards a tranny repair.
Known Yamaha problem for a long time. When you do your up-shifts, keep pulling the gear lever up with your foot (not a lot of pressure) until the clutch is completely engaged and you know it's gone into the next gear
have any of you had your transmissions replaced by Yamaha that was not under warranty? My 05 has 22k miles on it and I did not purchase YES (figured I would only have it a year or two and that it should hold up fine for 2 years). I think I have the 2nd gear issue and was wondering if anyone that did NOT have YES and had theirs covered under warranty?
I have an '03 with 42,000 miles on it and have been experiencing the exact same symptoms in second gear only. I have never clutch less up shifted. I don't have the YES, but it would have been over by now anyway as I got the bike in Nov '02. I have an appointment next weekend to take it in for diagnosis. Has anyone gotten Yamaha to pay for the $1,800 repair without having the YES? If so, who did you have to talk to?
Thanks for your time,
Comet
Thanks for your time,
Comet
painman
Well-known member
Hate to say it but I never had this kind of problem with HD dealers. When I had issue with the front brake master cylinder on the 06 I had to convience them there was a problem and even after 3 mechanics confirmed there was a problem they were still balking. They still tried to tell me there was no problem. I wanted them to sign a letter to document this and told them I was going to give one copy to my attorney and one to my next of kin. I think the main two reasons they finally decided to fix the problem was of that and I had confirmation from other people that there were other bikes with the same issue and the fact that I called Yamaha myself and got the results needed. The service manager even suggested for me to call Yamaha as the "customer gets better results going that route than dealing with him"! What's wrong with that picture? Good luck. PM. <>< :angry2:
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I just got off the phone with the Yamaha dealer my ’03 FJR is at. It is second gear and the fork that is damaged. $2,000 in labor and $600 in parts. They contacted Yamaha based on the information from this thread and the Yamaha rep said they had never heard of this or ever paid for the repair. So I am on my own. That leads me to think about things like is it worth spending $2,600 on a bike platform which may or may not have an inherent transmission issue. Should I spend a third of the bikes street value to make a repair that may be needed again in a couple of years? Should I just ride it until it detonates and buy the Kawi C14 when it comes out next year? Anyway, any thoughts from the group on this? Anyone know how to contact someone at Yamaha that may have heard of this issue?
Thanks for your time,
Comet
Thanks for your time,
Comet
05fjrBluedevil
Well-known member
I do not know what to say other than they did fix mine, however I did have the warranty and it only had around 16000 on it when it started to occur.
They did have it for almost 3 months waiting on parts
So to me it is just something that they can either fix or try to say you abused it....
I would not fix it unless I could do it myself if it had to be paid for....
But i will say driving this bike, having no second gear kind of defeats everything that makes it a good ride!!!!
I found this out last year at EOM, on the snake and other nice roads, I had to hold my boot under the shifter to keep it from popping out, and it it did because there was a lot of force on the shifter to pop it out of gear, i would just try to shift it in..again and hold it there, now if no load was on the transmission it would not pop out....
The first time it happen to me it scared the &^8--7 out of me because i was in a curve....
I have not rode it much since getting it back in the dead of winter, but am planning to run down to IMS in Atlanta if everything goes as planned... going to try and ride it the next few days, to see if i want to ride over 1000 miles with it....
BTW I am going to look at the C14
The black1 looks good
They did have it for almost 3 months waiting on parts
So to me it is just something that they can either fix or try to say you abused it....
I would not fix it unless I could do it myself if it had to be paid for....
But i will say driving this bike, having no second gear kind of defeats everything that makes it a good ride!!!!
I found this out last year at EOM, on the snake and other nice roads, I had to hold my boot under the shifter to keep it from popping out, and it it did because there was a lot of force on the shifter to pop it out of gear, i would just try to shift it in..again and hold it there, now if no load was on the transmission it would not pop out....
The first time it happen to me it scared the &^8--7 out of me because i was in a curve....
I have not rode it much since getting it back in the dead of winter, but am planning to run down to IMS in Atlanta if everything goes as planned... going to try and ride it the next few days, to see if i want to ride over 1000 miles with it....
BTW I am going to look at the C14
The black1 looks good
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Update- I have been speaking with Corporate Yamaha and they have decided that they will pay for the tear down to determine if the problem is manufacturer defect or user error (I am not really sure how). If it is manufacturer defect they will pay for the entire repair. If not then I will be stuck for all but the tear down portion of the repair. So although not perfect I am much happier with this than just being out in the cold.
Comet
Comet
Yamaha has had junk transmissions for years. It's either in the materials
or heat treating. I worked as a bike mechanic for many years in the 70's
and 80's, and still do on occasion. I mostly worked on Kawasaki's, also
owned and throughly abused them. In 85 I had to have a FJ1100, (great
bike by the way), it started jumping out of gear while still under warranty.
I rebuilt it myself, and couldn't believe how bad the "WHOLE" trans looked,
compared to the many Z-1s/KZs i've had apart. It happened a second
time, so I had the gears undercut on this rebuild (yamaha wouldn't pay
for this one). It lasted for many more years, and miles after that. If you
need a trans rebuild talk to your dealer about sending the gears out for
undercutting, (you'll pay for it yourself).
I wish i had found this thread before i bought my 06.
or heat treating. I worked as a bike mechanic for many years in the 70's
and 80's, and still do on occasion. I mostly worked on Kawasaki's, also
owned and throughly abused them. In 85 I had to have a FJ1100, (great
bike by the way), it started jumping out of gear while still under warranty.
I rebuilt it myself, and couldn't believe how bad the "WHOLE" trans looked,
compared to the many Z-1s/KZs i've had apart. It happened a second
time, so I had the gears undercut on this rebuild (yamaha wouldn't pay
for this one). It lasted for many more years, and miles after that. If you
need a trans rebuild talk to your dealer about sending the gears out for
undercutting, (you'll pay for it yourself).
I wish i had found this thread before i bought my 06.
Further update- Corporate Yamaha and their DSM trotted out the service bulletin and said it was my fault for bad shifts. It's not, but because this is my second '03 FJR (first one hit by car @ 15k miles) and it had 8k miles on it when I bought it they are saying original owner likely caused the damage and I was lucky it lasted 35k miles. So it looks like I am stuck paying for the repair. I am waiting for the estimate now but they are likely replacing 100% of the tranny internals and the clutch.
I would like to give a shout out to the Olympia WA Yamaha dealer as they have been on my side and honest with me since day one. They are going to give me a discount on the parts and put it as a priority for reassembly when the new parts arrive. This is the first dealer I have dealt with in quite a few years that I did not feel lied to or cheated when my bike needed work.
Comet
I would like to give a shout out to the Olympia WA Yamaha dealer as they have been on my side and honest with me since day one. They are going to give me a discount on the parts and put it as a priority for reassembly when the new parts arrive. This is the first dealer I have dealt with in quite a few years that I did not feel lied to or cheated when my bike needed work.
Comet
Randy
Well-known member
If there is anyone else that has had this issue that hasn't posted in this thread, could you please do so? I'm having the same problem and I told the dealer that I was aware of others having the same problem. If you had/have the problem, it would be helpful if you could post:
a ) did you have it fixed at a dealership
b ) if done at a dealership, did you have to pay or did Yamaha pay
c ) if Yamaha paid, was it done under Y.E.S. or did they pay for it outside of the warranty period
d ) year of the bike and mileage when problem was encountered
Your input could possibly help others.
Thank you.
a ) did you have it fixed at a dealership
b ) if done at a dealership, did you have to pay or did Yamaha pay
c ) if Yamaha paid, was it done under Y.E.S. or did they pay for it outside of the warranty period
d ) year of the bike and mileage when problem was encountered
Your input could possibly help others.
Thank you.
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Randy
Well-known member
Thanks to those who have replied via PM. Keep 'em coming. Thanks!
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