Clutchless/Semi-auto gearbox

[Linksep]

Anyone know how these work? I've tried searching the internets and no luck. I'm talking about the 3-5 spd manual (foot shifted) gearboxes that don't even have clutch levers. (Honda ATVs have had this for 15+ years, just found a few Lifans out there with the same.)

I'm just kinda thinking about building a kart and thinking about different powertrain options (HF Blue 6.5 with CVT, Lifan 110-140cc maybe used semi-auto 3 or 4-wheeler drivetrain, motorcycle drivetrain).

I think a clutchless shifter would be the ticket. It would be fast and fun for me, but easy to drive for those with clutch-a-phobia.

 

[motor_head]

i think they just use a centrifugal type clutch, that why you have to let off to shift so the clutch disengages

 

[TurtleMann14]

i think they might have two clutches to tell you the truth
one roller bearing one direction clutch and a centrifugal clutch

i don't see how just a centrifugal would work engine couldn't drop in rpm to disengaged because its engaged to the trans

mike would be able to tell you i bet, he says he has worked on a some kawasaki bayous

 

[mike75925]

they have a cent w/ a oneway bearing and a normal bike clutch. you rev shift the whole time riding.

 

[motor_head]

can't have a oneway bearing on my 4 wheelers i can engine brake, my newer recon 250 feels like it clutches when you start to move the shift pedal and you don't have to let off, it might have a second clutch, but my fourtrax 250 you have to let off or it won't shift and if you rev it high in first it won't come out of gear untill the rpm's drop way down

 

[TurtleMann14]

he said it has a normal bike clutch, so i would say that when you lift the pedal it disengages the clutch

 

[mike75925]

the one way is not on all, but it is used on the drum body of the cent. when it spins up high enough, the shoes deploy. on some i have seen an arm that actuates the regular manual clutch. on the semis i have ridden rincon, recon, rancher, bayou, etc etc, the revs only have to drop a few rpm to shift up, if shifting down, it has to drop a lot or you will blow a gear. same as a manual.
http://www.bikebandit.com/houseofmo...motorcycle-trx250te-fourtrax-recon-es/o/m2575

#27 in the fiche labeled clutch.

 

[Carlman]

I have a ct110 engine in a chinese 70cc quad frame, the clutch disengages when you press the shifter and when you release the lever it engages. I can gear brake.

When you start off from a stop it builds up rpm and engages like a cent clutch but is really solid (no slip).

I can hold the shifter down from neutral rev then let go to do a med range rpm clutch drop.

Hope any of this helps ya.

 

[mike75925]

when i was little, we would rev the engine and shift for wheelies, this was on a 125 atv.