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Pre-Loading and Shifting Questions


Decimation

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the clutch is there for a reason. its not just for starting and stopping it also helps take some of the stress out of the rest of the drivetrain during shifting. in a synchromesh transmission the whole point of the syncros is to eliminate the need to manually match the engine speed to the road speed to allow the gear selection to take place. therefore, all you do when you dont use the clutch is put the added stress of the engines output on the synchros and transfer that stress to the rest of the drivetrain - gears, synchros, dogs, output shaft, bearings, chain, rear hub - as an instantaneous shock . the clutch is the consumable item in the system by design. so, instead of trying to get used to getting the timing right just use the clutch; you're not saving much time anyway. bedsides, you're doing all the time consuming motions of shifting already, just pull the clutch a bit while you're doing them. it just doesnt make sense not to.

a motorcycle's transmission isn't like the one in a standard car/truck. a motorcycle transmission is called a sequential transmission.

which is specifically designed to be able to shift without the clutch.

that's the whole idea of it.

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A sequential manual transmission (or sequential manual gearbox) is a type of manual transmission used on motorcycles and high-performance cars for auto racing, where gears are selected in order, and direct access to specific gears is not possible.

With traditional manual transmissions, the driver can move from any gear, to any gear, by moving the shifter to the appropriate position. This type of transmission is often referred to as a H-pattern because of the path that the shift lever takes as it selects the various gears. A clutch must be disengaged before the new gear is selected, to disengage the running engine from the transmission, thus stopping all torque transfer. In auto racing, this process is slow and prone to human error; hence the development of the sequential transmission is put in hand. A true sequential transmission will very often use dog clutch engagement rather than the more usual syncromesh as fitted to a normal H-pattern road car gearbox. Engagement using dogs only requires a very brief interruption of engine torque to complete a shift into any adjacent gear. This allows shifting between gears without the use of the clutch. The clutch would normally be used only for standing starts.

Benefits

Beyond the ease of use from a driver's standpoint, an additional benefit of sequential manual gearboxes is that use of the clutch via foot pedal or hand control can be minimized or completely obviated, with the clutch only used for starting from a complete stop.

http://en.wikipedia.org/wiki/Sequential_manual_transmission

Edited by serpentracer
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the clutch is there for a reason. its not just for starting and stopping it also helps take some of the stress out of the rest of the drivetrain during shifting. in a synchromesh transmission the whole point of the syncros is to eliminate the need to manually match the engine speed to the road speed to allow the gear selection to take place. therefore, all you do when you dont use the clutch is put the added stress of the engines output on the synchros and transfer that stress to the rest of the drivetrain - gears, synchros, dogs, output shaft, bearings, chain, rear hub - as an instantaneous shock . the clutch is the consumable item in the system by design. so, instead of trying to get used to getting the timing right just use the clutch; you're not saving much time anyway. bedsides, you're doing all the time consuming motions of shifting already, just pull the clutch a bit while you're doing them. it just doesnt make sense not to.

Serpent hit the nail on the head - you were describing more of an automotive designed clutch.

The idea behind clutchless upshifts is time savings. You actually can drop .10 of a second each shift. Count the number of shifts you do a lap at a track day and add .10 to each one. That's a lot of savings...

Point is simple. No wear unless doing it poorly. Bent and wear are results of force.

The guys doing downshifts are going to argue they aren't doing any damage or wear, but I bet a good bit of money they haven't looked at their tranny since they've owned them. It's like saying that a certain oil has never let them down and when the motor is torn down, it is so worn that it isn't funny. Shit still runs so, it's gotta be good, right?:rolleyes:

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If I rev-match/clutch' date=' or blip/dwnshft.. the pressure on the shifter is the same. Now, if I were going from 6th to 2nd I'd prolly use the clutch and rev-match, but I'm just street riding. So, a drop from 4th to 3rd isn't going to hurt anything.

I know, cuz I'm wunna' dem der mekenix.[/quote']

Exactly Pauly. As I was saying, some bikes are fine for downshifting without the clutch, and others aren't. I know that some don't like clutchless upshifting as well, either.

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