Seamless Shift Conspiracy

[Tommy Cookers]

(Backlash .... No gear will be disengaged by normal gear change forces under acceleration/power unless said power is removed/interrupted)

But the latest seamless shift gearboxes, were no gear/dog sliding action is used anymore, will be a different story, eliminates all said above.

perhaps this remarkable statement could be justified by some explanation or evidence ?


seamless shift means only that torque delivery does not stop during the shift
torque delivery IS discontinuous in the scientific sense - the torque step-changes from the step-change in ratio
this step change is alleviated in various ways ie by treatment pre or post step

the 2026 cars will have the much larger K machine potentially affecting the shifting issue
(though remember the 8 speed transmission is of course hugely helpful to the electric propulsion)

[nmoleiro]

"If you dont go for a lower gear that exists, then you are no longer a racing driver"... /s

[NL_Fer]

Afaik teams are using a ratchet system for seamless shift and it isn’t a conspiracy either.

[Juzh]

Down shifting while accelerating. - ''I do it all the time. Press the throttle and realize I need more thrust''. Silly me - Yes of course your type of driving can. But in your type/standard of driving you will actually stop the accelerating you have started in order to shift down which is a totally stupid example to come up against the subject at hand

Nonsense.
If I was driving a car with a seamless gearshift, accelerating after a corner, realise the revs are too low - I would simply press the downshift paddle while keeping the throttle fully depressed. The engine revs and my rate of acceleration will increase. At high speeds in an F1 car you could do the same thing without loss of traction.

I don't know what stivala's problem is, but what you're describing is entirely feasible scenario to found yourself in while in an unexpected situation
case in point that I remember off the top of my head:
hamilton downshifting at full throttle after being pushed off by schumacher:
starts at 7:49


Yes, it happens almost never, especially not with hybrid engines, but tripling down on insisting it's completely implausible is dumb.

[etusch]

I know 4 different type of seamless shift gearbox. One what Honda use, one what Ducati use, one is efigear or pinion gear (maybe I should say 5 ) which are used at bicyles and one is xtrac version of this system. There are videos on the internet. The last one looks not good to me. So I didn't interested with it much.

At Honda version, there is a rachet like system, there are struts sitting on the shaft. A ring keeps the strut in its place, and when ring give it a space it goes up by centrifigul force and locks gear to shaft. When this happened a small ball be pushed under the strut to keep it it's place to keep it locked with the gear when it gets reverse torque. Otherwise revers torque push strut back in it's place on the shaft and gear will be disangaged. In the same time active gear's strut's ball removed from under it. So this strut can be returned its place when it gets a revers torque. When you rev the engine higher and higher gear gets higher rev from lower gear activated shaft, it can automatically drive higher gear's strut it's place on the shaft, so it will be disangaged in the same way of upshifting. Even if this is not worked, they can push the strut back its place by using the ring I talked about. So this gearbox is able to shift both side with no problem.

Ducati made very clever engineering, It is something like a seamless converted dual clutch. I think Ducati version of this system can be used at road cars and motorbikes too. It is cheaper too compared to others. It is completely same with a ducal clutch gearbox. Just use roller bearing clucth instead of clutch. This roller bearing allow it to engage upper gear before disangeging lower so it works like seamless shift.
These systems don't need clutch for shifting but need rev matching. It is only power cut you got during acceleration if you have these gearboxes and it also can be eliminated at hybrid systems.