And if you shift between neutral and first while coming to a stop, no clunk! But my Aprilia Futura made the same clunk when shifting from neutral to first at a stop as BMW 2014 GS! Strangely my 1974 Norton just snicks in no mater what gear or stopped. I give, why the clunk?

 

Motorcycles use a constant mesh transmission for various reasons. Is there such a thing as synchros for a constant mesh transmission? I don't know. Manual transmissions are often classed as one of constant mesh, sliding mesh, or synchro mesh.

 

simple really

See if this helps

 

This is great. So a constant mesh gearbox looks much simpler than the others and possibly more robust but I'm just guessing.
Its downside is that without a sense of when to change gears or using a blip of the throttle when down shifting, it may ""clunk". Once again I'm just guessing.

With all of the fancy electronics, Shift Assist Pro etc. it just seems like the "clunkyness" of the BMW's box is out of character.

Back to the other part of my original question. What about the clutch side of things?
Is my clutch also, so tough that there is no need to disengage when stopped at lights, and no need to fear slipping it when riding slow or off-road?

 

Clutch or de-clutch when stopped

Hi Mark,
When you stop with the bike in gear, there is a small amount of friction on the clutch plates so clunking into gear is almost unavoidable. Most of the heat is taken away by the oil so burning the clutch shouldn't be an issue unless you are constantly slipping it under load.
Because the clutch is immersed in oil, there is always going to be some oil drag between the plates. The drag is also present when changing gears and sort of works to your advantage. Each bike has a unique best method of changing gear and you might play around with yours to perfect it. I find that changing from first to second gear, shifting at lower revs is better. On higher gears it's only necessary to pull the clutch only half way if you're changing up. Changing down takes more care and sometimes a blip on the throttle.
A sychromesh transmission in a motorcycle would solve the problems but that adds bulk. A sychromesh mechanism requires friction rings, springs and cones to make it work and with motorcycles, making it compact is a priority. Motorcycle gears are smaller, have less inertia and are closer ratio so gear so non-syncho changing is relatively simple.

 

The fog is clearing a bit now. I guess this all makes sense.

Not too long before we will all be riding electric bikes :wink2: and gearboxes will be a thing of the past.

 

Yeahnah...

 

Yeahnah

Nope nope nope lol

 

The point of being in gear at a stop is to be able to make an emergency departure if someone is about to hit you, usually from the rear. Always watch your six o'clock until you know the car coming from behind is going to stop AND always have an escape route with enough space for you to execute your exit. Worse case, drop the bike and run, seriously, don't just sit there. 4 bikers were killed by a dump truck in AZ a few years ago, he plowed right through them as they sat at a stop.

 

That is a very, very good point.

My wife and I were over in the US this year and were out in the hills of Colorado to the east of Durango. We were heading up the hill and pulled off to the left into an overlook parking area to get photos.
Less than a minute later, this came flying down the mountain and jack-knifed. The crash and the sound of metal scraping the blacktop was like an explosion.

We still talk about it and wonder what would have happened if we had arrived two minutes later and been faced with this semi coming straight at us.
Would we have the presence of mind to just open the throttle and race across out of its way, drop the bikes and run for cover, or would we be like a deer in the headlights and get slammed before we could react?

We were OK, the driver was OK and even his dog in the cab escaped without injury - so I guess we will never know the what ifs.