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ghost shifting.

8K views 40 replies 15 participants last post by  JbAtRaCeR 
#1 ·
Hey everyone. Anyone ever be riding and accelerating from a light and go up a gear and a few seconds in to the gear, it will drop down in to the previous gear. Mine randomly does this, and not more in one gear or another. Im thinking of getting the factory pro star, arm, and spring kit to see if it helps. None of my bikes have ever done this. Im just hoping that its not broken dog teeth or something.
 
#2 · (Edited)
I'm not sure that the Factory Pro Shift improver kit will help the bike stay in gear. It's more about making for a more positive shift lever function kind of action. I've found over the years that my footwear can contribute to lack luster shifting. I find I need a stiff upper shoe surface to ensure things go well.
Are you the first owner of the machine? The shifter dogs can get worn on any machine and this can lead to the tranny popping out of gear. Drag racers "back cut" the gear set to ensure they stay engaged during high output riding. How many miles on the bike?

Tony "gittin' shifty wit it" Bagley
 
#4 ·
Might want to check the shifter and make sure it's tight on the splines. Then I would center stand it and try shifting it just setting there. Pay attention to the feel and your normal foot placement. If the BB is new to you or you ride other bikes as well you may be missing the transition differences between them. It may not be so apparent when riding down the road so try it setting in the driveway or garage then you can concentrate on how it feels and not things trying to take you out. Get it feeling right there and you should be set. sounds like your just not pulling it up the last smidge it needs.
 
#5 ·
One other comment is on the shift lever set up. I know that some of the older Honda machines have indexing marks in the shifter linkage that enables for one to install the set up (or re-install) to the factory stock conditions. These often show as a dimple on the shifter shaft end and second indexing dimple on the shift lever and related linkage parts. You line up the "dots" and there you are, done. Of course the XX is only a single lever install, but perhaps it's been changed for some reason? If nothing else this allows for the assembly line install to be correct. I've got a vague memory that there are marks on the XX shifter lever, but at the moment can not confirm that info. The FSM may give more info on this. ( I'll check as time permits) This will at least give you some info on "where" the lever should be in relation to the shifter shaft as per Honda. If this location/set up has been changed in any way you may have some shifting issues perhaps. If you've installed the peg lowering kit I'd think this may effect the relation ship between foot and shift lever in some fashion also. I have the stock set up on my XX so can not comment on how the lowered pegs effect the shifter function or feel.

One of the other members described the Factory Pro Shift Improver kit as a stiffer spring which makes one use a more positive (forceful?) foot action to engage the next gear. I guess the stronger spring would like wise put more pressure on the #7 and thus the #5 (see attachment) to hold things correctly, but I'm still not sure that is the intent of the assembly? I have had the kit in the parts bin for years now but have not installed it as you need to go in behind the clutch basket ( I as I remember) to access the spring and the star-wheel and such. I've just not wanted to go that deep into the clutch area as all else seems to be work fine as is. I guess the reason I purchase the kit was I also thought the shift function might be improved upon. Over time this has been less of a problem for me I guess. But for sure I do not have the tranny popping out of gear into the lower gear. Attached is a parts fiche shot of the gear selector drum. The F-pro kit replace #5, #7 and #8 I believe. Note that the picture is of a right side view so those parts are behind the clutch basket. The shift lever selector shaft is at the top of the picture (gearshift spindle, in Honda parts speak). The shifter foot lever attaches at the end of the "spindle" where you see the numbers 15,17,10.

One more question: Is the gear change to the lower gear a violent event? I ask this because normal down shifting makes for one to want to bring rpm up to make a smooth controlled down shift (you try and balance engine rpm to the bikes forward speed in the new lower gear, right?). What does the bike do when it drops to the lower gear? Does it feel like the brakes are coming on due to engine braking?

Tony
 

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#6 ·
One other thing: Chain tension...is there the correct slack in the drive chain? You profile says "99XX slammed". I take that to mean "lowered". Sometimes a lack of proper chanin slack can effect the easy of gear changes. The slack needs to be correct so that there is some slack when the machine is loaded and the suspension is at normal ride height.

Tony
 
#7 ·
This happens to me if I get lazy or tired. It also seems to predicate more often with certain oils. I found the Motul 5100 to be the least offensive in that respect, the Rotella I'm currently running seems to cause it to happen a bit more frequently, but again, only when I'm not paying attention.

As for Tony's remarks:
Tony Tolstoy said:
I've got a vague memory that there are marks on the XX shifter lever, but at the moment can not confirm that info.
I can confirm that there is a small indexing dot on the shaft that lines up with the slot in the shift lever.
 
#8 ·
rayaamx69 said:
it will drop down in to the previous gear
wordmeister said:
Is the gear change to the lower gear a violent event?
This sounds strange to me, dropping out of gear and getting a false neutral I can understand but dropping back into a lower gear just doesn't sound right since it requires more than one 'fault' to occur. With the gearbox design why would it 'choose' to drop down just one gear (ignoring the big bang that could occur if it dropped two at high revs) .. drum fault?

Educate me please I must be missing something obvious.
 
#10 ·
The false neutralling (almost) always occurs for me on the 1-2 shift, usually in front of a crowd of onlookers...

The sudden "lower gear transition", when it does happen, happens in the rest of the range and always after a sloppy up shift under light load. I can't explain the physics of it though, as I've not had the gearbox open to inspect the bits properly.
My guess is that, after only lightly selecting the next gear, it has engaged only on the very edges of the teeth and there is still a slight back pressure on the star as the lever was not run through the full range of motion during the shift process. When the gear interface receives enough torque to break what little contact there is, the residual pressure on the star wheel pulls the box down into the lower gear.
Again, pure conjecture on my part, but based on my own observations of the event and the odd feedback given by the lever at the moment of occurrence.
 
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#9 ·
Tony
Your right in the prostar having a stronger spring as well as a roller bearing follower. The concept is that he stronger spring snaps or rolls the shifter drum quicker. The roller follower compliments that effect by reducing the drag it follows the indexing ramp. The roller mitigates some of the springs increased tension making the shift effort less. The result is a faster advancing drum because of the cam effect and the increase in spring force. I believe the shape of the lobes on the new star wheel are more aggressive as well.
 
#11 ·
That may be coupled with the fact in how easy it is to up and down shift the BB without the clutch. I for one am thankful it will do this the other alternative isn't to pretty.
 
#12 ·
So after some beating on it today it seems that it mostly does it from 4th to 5th. Itll drop back to fourth once i get a good load on it. Chain is properly tensioned and it isnt lowered anymore. It does it randomly. Its not a consistent issue. This isnt my first xx, and Im sure it isnt me being lazy on the shift because ill make sure it goes in, then hit the throttle and it will drop. Im thinking that it may have a bad shift fork. Im going to pull the clutch this week and look at the star and lever to see if theres any visible issue there. I may just get a whole trans, forks, drum, everything off ebay and put it in. On a good note, One of my runs today was against my old 05 ZX10r. Bike and rider weighs the same as the xx without me on it. I pulled him pretty bad.
 
#13 ·
I used to happen on my K1000 after a mate hit it in gear whilst I was sitting at a set of light. From that day on it down shifted automatically. It was actually pretty good because it down shifted when I was getting into it and the revs were only half of redline, So the extra gear/revs boosted me down the road faster. And the change was SUPER FAST. Faster than I could ever do it.

I never did find out why it did it but obviously there was something damaged or out of alignment after the friends hit into gear whilst idling in neutral.

I sold it with the "issue"
 
#15 ·
Yeah i know. I actually went to your neck of the woods on monday Bees. The whole trip there and back, not a single fault. It could just be me but it just doesnt seem like it. I did finally notice that sometimes the gear lever will hang in the up position for a fraction of a second o_O
 
#17 ·
You know going back and reviewing your original symptoms thinking you may have a weak detent spring. Yhr spring and roller are what hold the selected gear in place. The shift drum is actaully a barrel with canm tracks cut into it. there are lands for the respective selects but the retention is partly the load friction of the gear dogs and the star wheels and the spring and roller that keep it engaged. You may have a stressed spring or very possibly broken. The only way to be sure would to open it up. If you check the Proshifter site they also offer just the lever and the spring at a lower price. If it's constantly kicking out i would park it if you can till you can get it open. The last thing you want to do is start rounding the leading edges of the gear dogs.
 
#16 ·
Hey Ray, Feel free to take and post pics while tearing down your trans. I'm in a similar boat with you.
My trans needs to be rebuilt after I bent a shift fork or shaft? Not sure yet till I tear into it.
 
#18 ·
When I was metaphorically scratching my head in my previous post, the only 'logical' reason I could think of why the previous gear was selected (and not a false neutral) was the drum mechanism either not turning fully (so the higher gear is never fully selected) or being free to 'turn back'. If you manually play with these parts with the box in bits you would be surprised how strong that spring is.
 
#19 ·
Yeah i know theyre strong. I had a hell of a time putting the factory pro one in my vtr1000. It doesnt do it constantly, and its my daily vehicle 40 miles each way to work. it isnt constant enough for me to freak out about. When i get a chance, i have a spare stock spring and lever that ill put in it. Thanks for the input guys
 
#21 ·
I do not know if this would apply in your situation but it is a common mod in the drag racing world. The stock gear dogs on most/many transmissions are "straight cut" units from the factory. The "dogs" are the parts of the gears that connect and notch/mesh into one another to transfer the power to the next gear set as you up shift. The straight cut design, over time tend to wear and begin to round off to a degree, which in the end reduces the ability of the gears to stay locked into each other. If high horse power is in use (as in drag race applications) and/or speed shifting/power shifting/clutchless shifting is the order of the day, the gear dogs or shifter dogs can become worn as they are banged together during the shifting process. The end result of this can be at first, missed shifts, and then the transmission jumping out of gear when under load.

A common mod in drag racing is to "under cut" or "back cut" the gear dogs in such a fashion so as to produce a taper into the dogs. The taper will actually increase the holding force between the gear sets as power is applied, due to the ramped shape of the gear dogs. See the attachment.

If you suffer from not being able to get the machine into the next gear, then perhaps that would indicate a shifter fork issue. The jumping out of gear might more closely mimic a gear dog issue. Back cutting the shifter dogs would help to cure this problem, if the gear sets are not damaged beyond repair. The attachment will help explain my words to a better degree.

T.

Gear Auto part Metal Steel Automotive engine part
 
#23 ·
Been thinking some more on this one and have a question to ask. What type of footwear do you wear when riding the bike? Boots, soft toed sneakers? etc?

The reason for asking: I found with my older CB-F's (when getting them back on the road after a ten year lay-off from riding) that if I did not have a good shoe with a stiff "upper" (toe and instep) that shifting and getting full engagement of the gears was somewhat problematic. I up graded my footwear to riding boots (use to use work boots back in the day) and hey presto the missed shifts and popping out of gear seem to go away. Note: I knew that the transmissions had not been abused as I was the orginal owner of the machines and knew the historys.

You might also check the indexing on the shifter foot lever to ensure that it is in the correct position. I think (testing the memory here) that there are indexing dots on the shaft and on the lever that should line up and give you the OEM set up for the lever. (I know this is the case for the older CB-F machines,..perhaps I might be confusing the two model types info?). It might be that you are not getting the full mechanical advantage available from the shift foot lever? Worth a look see anyway.

And again, back to footwear: Depending on what you wear you might also need to slightly adjust the shift foot lever to give maxium advantage to your shifting efforts. Do you have footpeg lowering blocks in service? This would most likely alter your foot shift action to some degree I believe. I do not have lowering blocks on my machine, so this idea is a guess on my part.

All this to say: Check all your normal items before you think you need to tear into a transmission overhaul. Take note of how you shift in a detailed sense....is it the machine or is it you perhaps which is causing the issue. Somewhat interesting to me that it's the 5-6 up shift that you relate as the problem.

Also, what is the history on the bike as you know it? Mileage etc. This may help indicate what the trouble is. I'd hope it's not a shifter dog issue. Partsguy drag races his XX and I think he's been doing with a stock "non-back cut" transmission set up. I've also thought the XX transmission to be rather robust given the h.p. that is placed on it in a stock OEM sense.

T.
 
#25 ·
I would reiterate what TigreST has said. Whist I have for many years used the same boots (SIDI B2's) I have gone through a few pairs. As they wear they get loose/more flexible over the toe area ..... I've ben know to change the gear lever by one spline just to cater for new/old boots just so I have the same feel for the lever. I've also found that if I have to change to a standard seat I need to make adjustments.
So far the transmission on Duck shows no issues in site of the high torque/HP ..... there has to be a fair bit of reserve factor built in.
 
#26 ·
Actually I use 2set of riding gear, one for touring and one for tack days, both are Alpinestar but I use only one speed boots, Alpinestar as well.
I did lower the foot rest, but I did adjust the shift lever accordingly.
I ride bikes now for over 30 years and I did enduro racing for 10 years or so, I know the reason/base of your idea but i do pay attention.
My BB has 55000 km on the tacho, i bought it with 18000 km, but I do not know how it was ridden earlier.
To be honest now I can put the whole story together.
I did notice earlier occasionaly dull feeling when shifting to 5 th or 6 th, as it would not be locked properly.
An other thing is that I do at least 3 times in a season track racing, but this is a new track a really fast one I visited on friday. I was logged on the fast sections over 280 km/h and the problem started on the end of session 3 (3x40minutes).
At first I could not shift to5 without feeling the teeth on the gears, that means I had to lift the lever two times to feel that the gears are locked. Than it was okay for a while but than it jumped between 5 and 6 all the time, I could not even hold it in 5th with the lever and later it was just shooting into sixt, all the time.
Beleive me the way home was not that nice.
So yes, i must tear it off and repare it...
But in the future I will pay more attantion how I shift...
 
#27 ·
Boyo73 said:
At first I could not shift to5 without feeling the teeth on the gears, that means I had to lift the lever two times to feel that the gears are locked. Than it was okay for a while but than it jumped between 5 and 6 all the time, I could not even hold it in 5th with the lever and later it was just shooting into sixt, all the time.
That unfortunately does sound like worn dogs to me.
 
#28 ·
I've dropped my shifter a tooth like duck has described for the same reason.

Also agree it sounds like the dog faces have been rounded. The only way to find out is split the cases. If it's not to badly rounded I would back cut like Tony has described.
 
#29 ·
Dogs x 3.My yosh built GS 1000 did it after 75k really hard miles. First time it did it i knew it was done and the second time it did a power downshift from 4th to 3rd i was on the gas @8k laid over on a freeway onramp. Good thing there wasn't any traffic, the bike went 2 lanes left before i had it under control. I too it apart that same day.No obvious damage, the faces of the dogs just get worn.
Like the drag racer mod the dogs a back cut but not near as much, it is what holds it in gear. Try to pull it outa gear under load, it aint gona happen. Chopping throttle, the clutch or an ignition interrupt is used to unload the the dogs enough to get it out of gear and it the dogs are worn it will spit the slider back with enough momentum back into the previous gear. I replaced the 2 gears that had the dogs that engaged for 4th gear and it was fine. It doesn't happen very often, could you imagine the product liability involved with a motorcycle that would downshift without warning? High milage? Driving style? Abuse? I have no idea.The bike made 140 hp, it had HD clutch springs and a spark plug washer under each one so the clutch lever took more effort so i didn't use the clutch to shift a lot of the time.I rode like that all the time and I don't wear boots, shifting is not about needing a stiff toe for positive shifts, it's about timing and finesse. If that were the case shifters would have a heel lever. Try a part throttle power shift sometime..Get rollin in any other gear than 1st at 1/8-to 1/2 throttle, pull up on the shifter as hard as you want, nothing happens, pull up the lever with 5lbs of force, u can do that with your bare foot, pull the clutch lever about half in, just barely into where you can feel it do something and do it as fast as you can and it will shift clean and smooth. The 1-2 shift takes more pressure..just to make sure the gear gets in place...I don't miss gears, ever..part throttle or hammer down. Miss a gear is mostly from not maintaining pressure on the lever until the dogs are completely engaged.
 
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