Shifting without the clutch?

[eMTea]

Hi!
This might be the dumbest question, but what do you guys do?

I have an RM125 engine I a gokart, and I only use the clutch at start/stop. Will it wear out the gearbox over time, or is the sequential gearboxes made for that rough treatment?

I considering replacing the 2 stroke with a newer type 4 stroke with electrical start, so I wanna know if I'm doing it wrong

 

[josmoloco]

Clutch is only for start/stop, and to prevent stalling in the slow stuff.

 

[SRAD97750]

NO. If you utilize the engine properly while shifting, there is NO need for the clutch and absolutely no "extra" wear.

Because....
A clutch only releases the load between gears to allow shifting between gears.
If you relieve the engine load on the transmission with the "neutral" throttle YOU ARE DOING THE SAME THING.

I have not found a manual transmission (truck, car, bike) that you couldn't shift seamlessly without the clutch.

 

[530ktm]

Hmmm. There have been many times in the past where I have shifted with no clutch but I always try to use it. As SRAD says, you can do it if the rpm and speed is just right, but that is not always the case when I am riding. The same goes for my Jeep, it is just easier to shift using the clutch therefore eliminating any gear clunking, etc. If I were racing, that is another story as you can sure shift those gears quicker with no clutch action.

 

[eMTea]

Good to hear! I just go completely off throttle when shifting.

 

[PALMER84ONE]

Autos and bikes are different transmissions.
Autos have syncros that help mate the gears when shifting and protecting them from grinding. It makes it so the engine speed and trans speed have to be almost perfect to shift smooth.
Motorcycles do not have the synco system and therefore can be shifted much easier, even with engine and trans speed not matching. You create damage to autos if the clutch is not used especially the new model autos than any bike.

 

[cleonard]

Well not quite.

Auto transmissions are more or less the same as your bike. In the gears are always meshed. The synchros help the gears come to the same speed before the dogs engage. There are no synchros in a motorcycle because they would never survive and the dogs are way stronger in a motorcycle transmission.

In general on a dirt bike you can shift with no clutch. I shift with no clutch when the conditions require it. However, I mostly use the clutch. It's a bit easier on the dogs to clutch it. It all depends on how long you will ride your bike. I've put at least 50,000 miles on mine so I try and give the trans a break. Most people will never ride long enough to wear out the transmission.

Riding on the dirt as opposed to the street is also a factor. The dirt can give, the street not so much. I (almost) always use the clutch on my street bike.

 

[SRAD97750]

Sorry eMtea,
These threads* always end up more confusing then a woman... Let the games begin.

*Examples:
Engine break in
2T vs. 4T
"powerbands"
Engine Oils
o-ring vs. non o-ring.

 

[Andrewaust]

If you want to stuff a car/suv/truck manual synchromesh gearbox, shift without a clutch, even truck drivers found after going from road ranger crash boxes to synchromesh transmissions, they had expensive bills shifting without the clutch. Once the synchro's go it is nearly impossible to shift gears properly.

Motorcycles "well most" have constant mesh transmissions which allows shifts without the clutch, its an interesting subject if you have some time to browse the net.

So my advice, synchro boxes, use the clutch, crash boxes and motorcycle constant mesh boxes, not using the clutch is OK, but can cause the dog "some say dog clutches" to wear sometimes in motorcycle constant mesh boxes causing the gearbox to jump out of gear or bend gear selector fork.

Some info here and more on constant mesh transmissions here


A

 

[PALMER84ONE]

If you want to stuff a car/suv/truck manual synchromesh gearbox, shift without a clutch, even truck drivers found after going from road ranger crash boxes to synchromesh transmissions, they had expensive bills shifting without the clutch. Once the synchro's go it is nearly impossible to shift gears properly.

Motorcycles "well most" have constant mesh transmissions which allows shifts without the clutch, its an interesting subject if you have some time to browse the net.

So my advice, synchro boxes, use the clutch, crash boxes and motorcycle constant mesh boxes, not using the clutch is OK, but can cause the dog "some say dog clutches" to wear sometimes in motorcycle constant mesh boxes causing the gearbox to jump out of gear or bend gear selector fork.

Some info here and more on constant mesh transmissions here


A

Well said, I was trying to be articulate but fell short. That's what I was trying to get across.

 

[TIRE]

iv been riding for 2 and a half years now and to this day, i have only shifted gears without using the clutch one time (it was an acitedent) and after the accident, i thought i caused alot of damage to the tranny and i got scared haha. so i gues i have been doing it wrong this whole time! so i guese i will start not using it now. im realy surprised that you dont hear that much talk about this topic. your post was not a stupid question at all in my opinion

 

[Andrewaust]

iv been riding for 2 and a half years now and to this day, i have only shifted gears without using the clutch one time (it was an acitedent) and after the accident, i thought i caused alot of damage to the tranny and i got scared haha. so i gues i have been doing it wrong this whole time! so i guese i will start not using it now. im realy surprised that you dont hear that much talk about this topic. your post was not a stupid question at all in my opinion

Preston, keep using the clutch, it's not the best to ride without using the clutch. My start technique was to start off feathering the clutch and hold it full open if possible "depended on track" shifting with the clutch real quick, to shift without the clutch you have to back off a tad and it doesn't do the box a lot of good. Just say I've seen the results of shifting without using the clutch. One thing you don't want is the problems associated with forced shifting.

I guess my clutch techneque could have been contributed to my solo speedway days, one gear and the clutch takes all the punishment , get it wrong and your either left behind or on your ass.

Like you said it isn't a silly question, it's rather a very sensible one. To replace gearbox components isn't cheap.

Even bush/trail riding, I still use the clutch.


A

 

[snowflake]

Stupid questions make more sense than stupid mistakes. But this isn't a stupid question.

I occassionally shift without the clutch, especially when I'm racing

 

[Kyle]

iv been riding for 2 and a half years now and to this day, i have only shifted gears without using the clutch one time (it was an acitedent) and after the accident, i thought i caused alot of damage to the tranny and i got scared haha. so i gues i have been doing it wrong this whole time! so i guese i will start not using it now. im realy surprised that you dont hear that much talk about this topic. your post was not a stupid question at all in my opinion

Yeah it's best for your tranny to shift useing the clutch because it was made to protect your tranny. But, I've heard that if you rev the piss out of the bike and keep on the gas while you shift it doesn't do much damage. But, I'm to cheap to try it besides it really doesn't improve your lap times by very much either

 

[josmoloco]

Yeah it's best for your tranny to shift useing the clutch because it was made to protect your tranny. But, I've heard that if you rev the piss out of the bike and keep on the gas while you shift it doesn't do much damage. But, I'm to cheap to try it besides it really doesn't improve your lap times by very much either

Come on dude. please research before you post. The clutch in a sequentially meshed wet clutch transmission if for getting in to 1st gear from neutral, although clutching when shifting does not have adverse effect except wearing your clutch out. revving and shifting is a really bad idea too....