By "accident" I was getting ready to downshift my bike comming to a stop, when I downshifted before pulling the clutch. It didn't sound any different than usual, but I was afraid that doing this could f**k up the bike after a while.

I always figured that you need to shift with the clutch engaged whether it's upshifting or downshifting. As with a car or truck, it's possible to shift without using the clutch because of the synchronizers that control the spinning gears. But as anyone that drives a stickshift car or truck knows it's transmission "doesn't like doing that too much!"



So with a motorcycle's tranny, It can't be that much different can it? I only assume that with a motorcycle, the tranny's internal spinning mass is so little that shifting without the clutch doesn't affect it much. motorcycles do use synchros right? if so, wouldn't it start wearing down the synchro after a while?

After trying to find out if it is normal to shift w/out a clutch, all I could find was one person on a forum saying yes, and the next guy saying no.

I just want to know the technical reasoning people have for either saying it's OK to downshift without the clutch, or it's ok to upshift but not downshift without the clutch. I keep hearing two sides to this debate. I figure it's safest to just use the clutch all the time, but maybe I'll change my ways if somebody out there can make a compelling argument for, or for not using the clutch.

 

I used to run a wrecker for my buddy and only used the clutch for first gear. Its not bad on the tranny or the clutch...in fact that trucks tranny lasted longer than the rest. I have 2 bikes that I do the same in....with the exception that I use the clutch to downshift. I have put over 8k miles on one bike with no problems and 1800 on my new bike with no problems. Im not gonna say your gonna have the same results...but I dont care what someone says....im still gonna do it the way I do now.

 

Downshifting without the clutch can be tough on a motorcycle tranny, but it won't kill it either. I only "Speed Shift" when racing and only on upshifts. I just keep my foot right on the shifter and just blip the throttle while shifting up. This will not harm the tranny or clutch at all due to motorcycles having a constant snycro-mesh type wet clutch that allows slippage until under load, which is why I blip (slightly let off) the throttle. While downshifting the rpms are going up with every lower gear putting more load on the motor and not allowing slippage.

 

Yeah, like the other guys said... The tranny in your motorcycle is VERY different than the one in your car. Most motorcycles have a "Constant-Mesh Sequential Transmission". There are no synchro's in a motorcycle tranny like there are in a car. I'm a visual person, so I found this to be extremely helpful in showing me how a typical motorcycle tranny works... http://home.cfl.rr.com/genecash/tran...on_applet.html

Some racers use both clutchless upshifting and downshifting all the time... though it does take a lot of practice. I've gotten clutchless upshifts down, but downshifts are a bit trickier, and as far as I've read, many racers still use the clutch for downshifting, so I always use the clutch for downshifts... I know I'm not good enough to do it w/o excessive wear, and don't really have a need to work on it at this point. The biggest change in gear ratios is between 1st and 2nd, so that's where you'll have the hardest time doing anything clutchless, simply because the loads are going to be greater.

Can you mess up the tranny by doing this all the time?

Well, yes and no... If you know what you're doing, you might actually cause less wear than someone that uses the clutch but still makes clunky shifts. If you don't know what you're doing, you're more likely to clunk it around and cause more wear. If you're shifting smoothly, and not putting pressure on the shift lever when it's not moving, then you're not causing excessive wear... At least that's my two cents worth.

 

i too ocationally find my self shifting without the clutch..both up and down...the only thing i do diff. when i am not using the clutch is that i just eas the lever up or down and the gear shifts really smoothly most of the time smoother than when i use the clutch

 

I can not give oyu any tech info....but, I rarely use the clutch. I usually downshift without it, and up shift almost all the time without it.. Actually makes my shifting much smoother and quicker....Old habit tho, cause you do not use a clutch in a big truck!! lol...