[usernamedoug]

So i've been wondering all season (as this was my first year riding) had a couple times at the track doing clutchless up shifts down the straight (really just from 2-3 as its a small track) where i would mess up the shift and it would seemingly fall into neutral???

Seeing as how i have zero understanding as to how a bike transmission actually works is this destroying the transmission?

basically coming up to redline, roll off and shift, go to roll on and it seem like its in neutral...but between gears.

Whats happening here? All that i had to do was clutch in and click up and it would go into the gear it was supposed to be going to.

 

[R1100S-Rider]

Yea, a false neutral. Happens sometimes. Try pushing (pulling) harder or just use the clutch. Easier on the transmission if you use the clutch.

 

[LDS]

Yep. False neutral.

This is why you NEVER count on a downshift to scrub off speed at the track...

 

[usernamedoug]

Yep. False neutral.

This is why you NEVER count on a downshift to scrub off speed at the track...

i couldn't imagine ever being in a situation at the track where i would need to slow down and not be on the brakes.

thanks was mainly wondering if it hurt the transmission.

 

[R1100S-Rider]

i couldn't imagine ever being in a situation at the track where i would need to slow down and not be on the brakes.

thanks was mainly wondering if it hurt the transmission.

You'll learn that there are situations where you use more engine braking than actually braking.

It doesn't really hurt the transmission. As long as you are not grinding the gears, just shows how crappy the transmission is. Watch out, sometimes it will pop back into gear and lock the rear.

 

[usernamedoug]

You'll learn that there are situations where you use more engine braking than actually braking.

It doesn't really hurt the transmission. As long as you are not grinding the gears, just shows how crappy the transmission is. Watch out, sometimes it will pop back into gear and lock the rear.

If it locked up i think i'd survive, i've done pretty well with scary moments at the track like not rev matching high enough and chattering the back tire going into the 90 degree left hander at the end of the straight.

Theres lots of times that i use engine breaking for a split second to help me slow down, and technically you're using a bit of engine braking when you're trail braking into a corner.

cant imagine too many tracks where you'd be down shifting to use engine braking and not also be on the brakes

 

[kevin_stevens]

The way to avoid the false neutrals is to preload the shift lever with your foot. It won't shift as long as the power is on. Then when you roll back on the throttle the transmission will snap into the next gear.

If you roll off and *then* go to shift, you may or may not be doing it fast/hard enough to get into the next gear - without the power on the bike won't stop you from hitting a false neutral.

KeS

 

[usernamedoug]

The way to avoid the false neutrals is to preload the shift lever with your foot. It won't shift as long as the power is on. Then when you roll back on the throttle the transmission will snap into the next gear.

If you roll off and *then* go to shift, you may or may not be doing it fast/hard enough to get into the next gear - without the power on the bike won't stop you from hitting a false neutral.

KeS

much appreciated, i really should know that already, but thinking about it and being a new rider at the track i'm trying to do too much too fast, i was definitely trying to do it simultaniously, rather then pre-loading the shifter a little.

thanks

 

[Jim Moore]

Practice it on the street. No need to wait for the track to work on it.

 

[usernamedoug]

Practice it on the street. No need to wait for the track to work on it.

i do, most of my practicing i do at a slow pace just getting used to not screwing it up. I;ve never missed it on the street, only at the track in a tuck trying to do a WOT clutchless up shift as its about to ping off the limiter.

as kevin mentioned, its because im trying to shift as i roll off the throttle, as opposed to pre-loading it in a more controlled manner

 

[kevin_stevens]

i do, most of my practicing i do at a slow pace just getting used to not screwing it up. I;ve never missed it on the street, only at the track in a tuck trying to do a WOT clutchless up shift as its about to ping off the limiter.

as kevin mentioned, its because im trying to shift as i roll off the throttle, as opposed to pre-loading it in a more controlled manner

I've been known to preload and just let the bike bang off the limiter when I'm in a hurry. That's generally enough of a power cut to release the transmission and pop the shift. Really, that's how the speed shifters work, they just do the ignition cut based on pressure rather than leaving it up to the rev limiter so you can choose when to do it.

KeS

 

[usernamedoug]

cool to know, thanks

 

[baldheadeddork]

Even if you do clutchless shifts the right way as Kevin explained, it will still greatly increase the wear on the transmission.

These are two gears from an old GSXR transmission. Note that this isn't the set for one gear. These are neighboring gears on one shaft, probably first and second from the input shaft.

The raised areas on the left gear are called dogs. When you shift from one gear to another, the dogs on one gear lock or disengage from the slots on the gear next to it, like you see in the gear on the right in this picture.

All the power your bike makes at any given moment is transmitted through those dogs to the slots, and then from the input gear to the output gear. You get a false neutral when the dogs slip out of the slots.

This can happen if you put more power through the gear than it was designed to take. Turbo bikes have big problems with popping out of gear when they get on the boost unless the faces of the dogs are cut back (undercut) to make sure they lock in. When you do a clutchless shift the dogs can pop out because you are applying power when the dogs are only partially engaged.

The problem is that even when the gear does fully engage, having a load on the dogs when they meet the slots will cause wear at the top of the dog. You can see this in the picture. The shiny, beveled part on the dog at the top of the gear isn't supposed to be there. That has been ground and hammered away because of shifting without the clutch. Whoever had this bike lost the ability to do clutchless shifts some time ago because the gear can't engage, and with half of the surface area on the face now missing I'll also bet it was popping out of gear when he got on the gas hard.

I've seen guys destroy their transmissions like this in just a couple thousand miles. If you do it the right way you can put off problems for ten thousand miles or more, which is a lifetime for a race bike, but you will be causing more wear than if you use your clutch all the time.

Because you have to remove the engine and split the cases to repair this, you can easily expect a four-figure bill to replace a couple of gears with worn dogs. I always told guys to use the clutch even on the track unless they were racing for money or if they had someone to pay their bills. Work on your corner speed instead of trying to save a millisecond by not using the clutch. And in my book you're a straight-up squid if you don't use the clutch on the street.

 

[kevin_stevens]

It's interesting that BMW is offering a quick-shifter on several of their bikes now (the HP2, K1300S, and S1000RR), and is, at least publically, unconcerned about transmission damage. I was asking specifically if there was any restriction on the factory extended warranty when the quick shifter was ordered - no worries was the response.

KeS

 

[Jim Moore]

And in my book you're a straight-up squid if you don't use the clutch on the street.

Lol. Squid it is, then. BTW, 22K miles on my CBR600RR. Clutchless upshifts from day one. 108K miles on my latest BMW. Clutchless since day one. They seem to be holding together OK.