So this is my second post in this forum. I bought an 05 CBR600rr over a month ago and have been lurking around this site since Feb.

Anyways, I read a thread about drag racing and how some people keep pressure on the the shifter and when the fuel cuts out at redline, the transmission shifts to the next gear. I was thinking about this while riding around, and decided to try a clutchless shift while unloading the engine (I have messed around with this in cars). It shifted easily, which surprised me. I am a car guy and know the workings of the transmission so I know that by not using the clutch, I am putting extra wear on the synchros. Obviously, during normal driving, there is no advantage to not using the clutch, but does anyone know how badly shifting without the clutch wears the transmission?

 

i read or watched a video online somewhere that said shifting UP without a clutch is ok.
search you tube for speed shifting? or clutchless shifting or something like that, i think thats where i saw it.
i did it all the time on my old cr125 with no problems

 

Up shifting cluthless is fine just remember to preload the shifter and let off the throttle just before shifting.

I haven't heard of downshifting (clutchless) casing any kind of problem on the synchros for one reason. I don't think there are synchros in a bikes transmition. Also You can downshift without using the clutch as long as you watch your revs. IMHO i don't like to downshift because it is a jerky feeling.

As far as wear on the transmition, bikes are close ratioed so upshifting clutchless shouldn't be a problem.Also on a car if done properly you can shift without using the clutch but sense it's not a close ratio gearbox, it's a little tricking getting it from gear to gear.

 

I posted on this last year and what I got out of it seemed to be 'you can do it, but it isn't good for the tranny'. Something about dogs/gears/widgets. I think it is a skill you need if you have a clutch failure, but unless you are on the track where evry little tenth matters I wouldn't do it too often. I always use a little clutch whether it needs it of not.

 

Sounds good. I figure there is no reason not to use the clutch, but I was just curious if people make a habit of it.

 

i dont ride any other way to be honest... however i have gone through4 cbr600 gearboxes in 5 years racing. (3 FX/F4 and1 Fsport)

 

i clutchless shift all the time. esp. when the shop messes w/ where my clutch is.

I have on the other hand, never shifted redline style like you talked about, but come to think of it i would assume it would work the same. Sounds freaking crazy. i MIGHT try it, but i'm too n00b to push it that hard. i'll wait for the track.

 

I wouldn't do it on the rev limiter like you suggest. Try 8k first.

To the poster who's burning up tranies on the track: 2nd gear is weak. That's why there's an HRC transmission kit.

 

Ask yourself the one major question: Why to shift without the clutch? If I'd be on the track chasing clock, it's understandable. If I'm on the road, what's the point??? Any dude can up- and downshift with no clutch, there's no cool effect with that The clutch handle is there for a reason...

PPK

 

I've heard argument that it SAVES the clutch. It seems logical considering that during the on/off transition it is slipping a bit.