How often do you shift without using the clutch?
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pommie john said:
You can see some light scoring on this first gear.
If anyone bothered to look at that animation I linked you can see with the constant mesh that only gear set that isn't moving at the same speed is the first gear. Otherwise the gears are moving at the same speed when they engage. As long as you back off a bit (to reduce the torque and allow the dogs to engage) it shouldn't cause any problems.
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The only gearboxes that are at risk to proper clutch-less shifts are those with synchronizer cones which does not apply to the vast majority of antique to super modern motorcycles. Done properly clutch-less shifts can be easier on gearbox and clutch gizmo's. Done in anger it can lower acceleration times is that ever matters.
I have had times in tractors, trucks, cars and Commando's and my SV650 where
clutch gizmos failed and only chooses were wait for a pick up or just ride home
snicking shifts up and down clutch-less matching rpm and loads as normal and to find N before rolling stopped. Search web on this reveals countless similar tales
and not one single event of geabox damage but the alert don't do it on syncho egquiped gearboxes.
Swooh, please point me to your animation here or in private please.
hobot - hope for torque enough in Peel to eliminate most shifting needs.
I have had times in tractors, trucks, cars and Commando's and my SV650 where
clutch gizmos failed and only chooses were wait for a pick up or just ride home
snicking shifts up and down clutch-less matching rpm and loads as normal and to find N before rolling stopped. Search web on this reveals countless similar tales
and not one single event of geabox damage but the alert don't do it on syncho egquiped gearboxes.
Swooh, please point me to your animation here or in private please.
hobot - hope for torque enough in Peel to eliminate most shifting needs.
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maylar said:
Same thing happened to my old '79 Bonnie. Got home just fine but hardest part was coasting before gently "slamming" it into second.
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hobot said:
I'm sure you've seen worse and probably done worse.
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Ok i found the 6 speed display link with this comforting piece of news for us clutch-less shifters.
3 gear boxes, 4 rear drums, a pair of shafts, couple sets of wiped off cog teeth, trashed bushes globally -, yeah I've an idea of what I can and can't get away with. Clutch-less shifting is not dangerous, a handy skill and delicous normal way to shift. Purely a style or opportunity choice, either for fun or forced into it.
hobot - not so confident a mechanic I've decided to build rock wall this wkend and delay a bit more my risking another engine and gear box assembly fumble.
3 gear boxes, 4 rear drums, a pair of shafts, couple sets of wiped off cog teeth, trashed bushes globally -, yeah I've an idea of what I can and can't get away with. Clutch-less shifting is not dangerous, a handy skill and delicous normal way to shift. Purely a style or opportunity choice, either for fun or forced into it.
hobot - not so confident a mechanic I've decided to build rock wall this wkend and delay a bit more my risking another engine and gear box assembly fumble.
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hobot said:
Yeah, um, you didn't read the part about backing off on the throttle first before clutchless shifting. :mrgreen:
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First may be the only only one that's not running in sync, but it's also the only one where you consistantly use the clutch to engage, 'cos generally, you're staionary.
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Once the fear of clutch-less Commando shifting is dissolved by understanding, its natural to clutch or not clutch to provide the most sure slick stress-less easy shifting for the conditions and your own mood. If I'm injured or very tired or hurting I'll clutch most the time to avoid mistakes or poor operation of wrist or throttle linkage, unless of course the clutch lever is missing in action.
Alas much as I like hooligan image, i've no claim to breaking AMC shells by hard power usage. First one was DOUBLE mistake not revealed under low power 'break in' period. 1. rear drum teeth machined too wide for 520 chain.
2. 520 O-ring chain was too stiff to lay in valleys when good throttle applied so ran on top of teeth, which put insane drive train jerk loads, which I detected by a sharp kick in the butt as the shocked fully compressed and bottomed out from chain tension. This bent shafts and skewed bearing in bores and may have initiated the axle failure some 4000 wild and wooly hooligan miles later, after new trimmed drum down to .240".
BTW Weakest AMC cog is 3rd gear set and the O in O-ring stands for Obolete!
hobot
Alas much as I like hooligan image, i've no claim to breaking AMC shells by hard power usage. First one was DOUBLE mistake not revealed under low power 'break in' period. 1. rear drum teeth machined too wide for 520 chain.
2. 520 O-ring chain was too stiff to lay in valleys when good throttle applied so ran on top of teeth, which put insane drive train jerk loads, which I detected by a sharp kick in the butt as the shocked fully compressed and bottomed out from chain tension. This bent shafts and skewed bearing in bores and may have initiated the axle failure some 4000 wild and wooly hooligan miles later, after new trimmed drum down to .240".
BTW Weakest AMC cog is 3rd gear set and the O in O-ring stands for Obolete!
hobot
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hobot said:
The day mine blew up I had been clutching up wheelies. On the ride home, the throttle no longer gave forward thrust . Coasted to side of road. Called old lady with instructions to bring me my tools. Removed primary and clutch fell out with the end of the mainshaft attached. Trucked home to find the box and most of the interior scrapped.
Will
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never unless my clutch cable snaps
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Sorry I had to resurect this one: Yeah a constant mesh gearbox is just what it says it is, the teeth in all the gear pairs are always engaged and turning at the correct relative speed. But as it says above
Try it, if you get smoother shifts then it works, if you don't: then forget it .
I very much doubt that clutchless shifts work between all gears and at any engine speed on any bike.
Cheers! ~ Gary
When not transmitting power the free spinning gear and its shaft are travelling at different speeds and they have to be brought to something like the same speed before one of the
Any error and the shaft and whatever else it is connected to will have to under go an almost instant speed adjustment which it, and you, will feel as a jolt. If you are not using the clutch the engine is connected to the shaft and you will experience a large jolt. If you are using the clutch the engine is disconnected and you will only feel a small jolt, if any at all. Clutchless shifts work fine if the time needed for the speeds of the engaging parts to become synchronized just happens to equal the time it takes the shift mechanism to shift gears (this is determined by the shift mechanism, not you!) but it can only work well in a limited range of engine speed and when shifting between certain gears. I've tried it on a Yamaha R6 when racing and I can get better shifts, clutchless between the top 2 or 3 gears at red-line revs where engine speed changes very rapidly and the "gap" between gears is small. I also race a Suzuki GT750 (believe it or not) and it's engine speed changes too slowly for clutchless to work.
Try it, if you get smoother shifts then it works, if you don't: then forget it .
I very much doubt that clutchless shifts work between all gears and at any engine speed on any bike.
Cheers! ~ Gary
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I've been able to clutchless shift every cycle I've been on plus dual ratio rear end tractors and dump trucks with like 8 gears to work through. Its sorta like torque values, either you get a sense for it or must depend on interface to function.
Its pretty easy to get a sense of when rpm and loads conditions are ripe to let it just slide into next gear w/o snatch, jerk or any strain, like magic easy. But the other side of this sense is knowing when best to clutch and not take time to match rpm/loads. In public its a personal style choice only, it racing it can make a slight difference where slight differences make all the difference.
Hardest one was big red Indian Chief with hand lever next to tank and dead man foot clutch above the front porch foot rests. Kind a tractor like took some pause for everything to synchronize then level slipped easy no effort for next throttling up to cruise or above.
If you are not careful to keep any toe pressure off shifter while riding it can happen all by itself so beware not to be caught clutchless shifting.
Its pretty easy to get a sense of when rpm and loads conditions are ripe to let it just slide into next gear w/o snatch, jerk or any strain, like magic easy. But the other side of this sense is knowing when best to clutch and not take time to match rpm/loads. In public its a personal style choice only, it racing it can make a slight difference where slight differences make all the difference.
Hardest one was big red Indian Chief with hand lever next to tank and dead man foot clutch above the front porch foot rests. Kind a tractor like took some pause for everything to synchronize then level slipped easy no effort for next throttling up to cruise or above.
If you are not careful to keep any toe pressure off shifter while riding it can happen all by itself so beware not to be caught clutchless shifting.
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I'm with Ken and Gary on this one.
You have to match the speed of the gears before they will engage really smoothly. Because it's very difficult to match the teeth on gears with 30 or so teeth when spinning incredibly fast we match the 3 or 4 dogs on the sides of the gears into holes or slots on the adjacent gears we shift to. It's these dogs that take the pounding. Have a good look at them next time you take your box apart. They usually show evidence of some of those bad shifts. If you get in the practice of matching your rpm's between gears you can save wear on your clutch too.
Like you Hobot, I too learned to shift on some different vehicles. Here's a shot of my 54 Dodge Power Wagon that I really learned clutch-less shifting on.
It has no synchro, no constant ratio, not even helical cut gears! just straight cut gears with nothing in between yet it shifts like a dream without clutch. You just pull it into neutral, bring the rpm's up or down to match the gear teeth on the gear you want and "offer" that gear to it and it "pulls it in" if you are close on your rpm's. On a machine like a Norton Commando with constant ratio this equvicates to letting off on the throttle just a bit as you shift or bring the revs up when down shifting, no need to hang out in neutral territory in between gears. Clutch-less shifting can give you instant acceleration which is quite exhilarating but I do think it wears the dogs faster.
So right! When all is properly aligned it will pull itself into gear.
lcrken said:
ggryder said:
You have to match the speed of the gears before they will engage really smoothly. Because it's very difficult to match the teeth on gears with 30 or so teeth when spinning incredibly fast we match the 3 or 4 dogs on the sides of the gears into holes or slots on the adjacent gears we shift to. It's these dogs that take the pounding. Have a good look at them next time you take your box apart. They usually show evidence of some of those bad shifts. If you get in the practice of matching your rpm's between gears you can save wear on your clutch too.
Like you Hobot, I too learned to shift on some different vehicles. Here's a shot of my 54 Dodge Power Wagon that I really learned clutch-less shifting on.
It has no synchro, no constant ratio, not even helical cut gears! just straight cut gears with nothing in between yet it shifts like a dream without clutch. You just pull it into neutral, bring the rpm's up or down to match the gear teeth on the gear you want and "offer" that gear to it and it "pulls it in" if you are close on your rpm's. On a machine like a Norton Commando with constant ratio this equvicates to letting off on the throttle just a bit as you shift or bring the revs up when down shifting, no need to hang out in neutral territory in between gears. Clutch-less shifting can give you instant acceleration which is quite exhilarating but I do think it wears the dogs faster.
hobot said:
So right! When all is properly aligned it will pull itself into gear.
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RennieK. thanks for shifting reality check and impressive flavorful Dodge in colors and setting that just melts me with the heat, bug bites and thorny scratching tasks it takes ya too. This is the hardest thing for me to not grind teeth on clutchless shifts.
'38 JD LA "Popin Jonnny" idle 240 rpm, max 1800 rpm slow but can grind its tires off with kettle drum thumper sounds. Tranny is custom fitted WWII 'Duce' truck.
'38 JD LA "Popin Jonnny" idle 240 rpm, max 1800 rpm slow but can grind its tires off with kettle drum thumper sounds. Tranny is custom fitted WWII 'Duce' truck.
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There's a good explanation of what's involved in clutchless shifting by Paul Dean in the current (OCT 2011) issue of Cycle World (page 66). He doesn't actually say anything that hasn't already been said in this thread, and he supports both sides of the argument, but somehow it seems more authoritative coming from the pages of CW.
Incidentally I accidentally performed a perfect clutchless downshift recently, so I've got to admit it can be done. I got a bit hurried between turns and did everything I would normally do including blipping the throttle, but I didn't touch the clutch lever. I'm not even going to try to do it again, which makes me a little bit concerned that my spirit of adventure is lacking, but no, if you read Paul Dean's explanation of what's going on inside the gear box it should be apparent that ignoring the clutch makes timing much more critical and will increase the frequency of botched shifts.
I have a book on race car driving technique by err?....some famous French driver who's name escapes me, and he recommends to use the clutch because even though it won't provide any benefits in a single race or even a season, it will over the course of your racing career. Well, you might not be racing but you are probably still interested in avoiding destroying a gearbox in your Commando riding career.
Cheers! ~ Gary
Incidentally I accidentally performed a perfect clutchless downshift recently, so I've got to admit it can be done. I got a bit hurried between turns and did everything I would normally do including blipping the throttle, but I didn't touch the clutch lever. I'm not even going to try to do it again, which makes me a little bit concerned that my spirit of adventure is lacking, but no, if you read Paul Dean's explanation of what's going on inside the gear box it should be apparent that ignoring the clutch makes timing much more critical and will increase the frequency of botched shifts.
I have a book on race car driving technique by err?....some famous French driver who's name escapes me, and he recommends to use the clutch because even though it won't provide any benefits in a single race or even a season, it will over the course of your racing career. Well, you might not be racing but you are probably still interested in avoiding destroying a gearbox in your Commando riding career.
Cheers! ~ Gary
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