Emergency braking with and without DCT

[mission]

Hi,

I'm new to the forum and motorcycling in general. I'll be buying NC next year but I haven't decided yet between DCT and manual version.

I'm wondering how DCT would affect emergency braking, for example in situation similar to this one:
www.youtube.com/watch?v=0ms010d1umI

On a bike with manual transmission I'd just immediately push the clutch down together with brakes. What would happen on a bike with DCT? Would it reduce the gear fast enough?

Thanks,

 

[670cc]

In an emergency stop like that, the DCT may have an advantage over a manual because it will shift down automatically while you concentrate on your braking. The DCT certainly would not make it worse because it has no clutch to grab. Of course, with either bike you should have closed the throttle in the process of braking. The only difference might be the chance you have a stalled engine when you come to a stop, which really doesn't matter in this case. The situation in your video is mostly all about maximum controlled braking, and almost nothing to do with operating a clutch or transmission.

Of course, the rider in this video brought the bad situation on themselves by following close, not noticing the stopped traffic up ahead, not reacting quickly enough, and probably being unskilled at braking. Following a van or truck is a bad choice since it limits forward vision.

 

[DirtFlier]

If the throttle is OFF at the end of an emergency stop, it really doesn't matter what gear is selected since it won't engage without the throttle being opened. I've made some minor emergency stops and never had a problem.

 

[wildeone]

Hi,

On a bike with manual transmission I'd just immediately push the clutch down together with brakes. What would happen on a bike with DCT? Would it reduce the gear fast enough?

Thanks,

and that would be wrong, you would forgive all engine braking. On this video it's not emergency braking, it's stupidity braking
On real emergency either you or DCT will not have enough time to reduce gears BTW. Brakes are all you have.

 

[Deckyon]

I have had a couple "oh shit" moments in traffic of people pulling in front of me. Grabbing a handful of front break and stomping the rear have been enough to keep me from hitting anyone. The DCT, did fine, and while there was not a whole lot of engine breaking at the speeds I was going (less than 30) the breaks combined with ABS did a wonderful job.

As to the video - if you follow that close, expect to rear end the car or drop the bike. That video was a whole lot of "don't ever do this."

 

[Ed Up]

I don't feel the DCT or Manual wouldn't be any different in an emergency brake situation. If you are using your brakes properly the engine braking is a mute point. If you attempt engine braking in an emergency situation you will likely need more distance to stop. Once your using both brakes together without skidding either tire, the engine brake will just push you more forward. If that don't make sense, go try it. At 20 mph you should be able to stop in less than 20 feet. 15 feet would be good, but that takes practice, or your a good seasoned rider. I recommend we all practice emergency braking in a parking lot and get good at it. It's nice to know how your bike will react when there's not a car parked ahead of you.

 

[johnakay]

it seems to me he was had the right gap but not paying attention to whats in front.
he looking at the rear but mind was else where.
that is very common issue with most drivers and riders.(that is why I wont have earphones while riding)
hence why do they pull out out of side roads even though they seem to be looking at you!
drivers going into back of cars/bikes in front at lights.
abs brakes more than once saved us.

 

[Old Can Ride]

Howdy from Texas, welcome to the forum.

 

[kpinvt]

Last year I was riding my DCT bike in manual mode, in fifth gear at 50 MPH. I had to stomp on the brakes because as I rounded a corner I came upon a line of cars stopped for road construction. The ABS worked great in helping to bring the bike to a halt without skidding and the DCT transmission automatically down shifted to first gear.

 

[DirtFlier]

[On a bike with manual transmission I'd just immediately push the clutch down together with brakes. What would happen on a bike with DCT? Would it reduce the gear fast enough?]


If you're using the downshift button, the DCT computer will not let you downshift into a gear that will overspeed the engine. Without using that button, I don't think it'll go all the way to 1st until you're almost stopped.

I was an instructor for 16 years and the key point in such situations is to STOP and not worry so much about what gear you're in. I much prefer to slow drastically then swerve around whatever you're trying to miss but sometimes you won't have that option. Swerving will avoid being hit from behind by a driver who is not paying attention!

In an emergency stop driving a car, few people downshift as they slow because the main concern is to avoid an accident. The brakes are already slowing the rear wheels so a downshift may actually cause a loss of traction from those two wheels. I think you may be worrying about something that isn't a real problem.

 

[Papamike]

with the DCT, you have just to concentrate to your emergency braking,the good influence is that you don't need to act on the clutch lever and at the end of the braking, the gearbox is naturally at the first gear if you are stopped or at the right gear if you avoided the obstacle and continue to ride

 

[walawn]

You guys seem to have the right idea. I can only speak from my experience and technical knowledge. In emergency braking, the engine and downshifting are irrelevant. You don't downshift when you emergency brake. On a manual bike, you would either pull the clutch in or not (possibly stalling if you don't depending on what gear you're in and the speed you slow down to). On the DCT version, the computer would downshift for you in any mode (even push-button manual) if the speed drops enough without rider input. I see the advantage going to the DCT version for two reasons: 1. The bike would stay running since the DCT wouldn't allow it to stall. Not so on a manual bike during an emergency braking situation with a rider who fails to pull in the clutch. 2. The North American version of the DCT comes packaged with ABS. A possible advantage depending on the the situation and various factors. It could have possibly prevented the situation in the video where the front tire washes out and the rider and bike go down.

 

[wildeone]

BTW, now when I think about it there is absolutely no use of engine braking during emergency stopping so even DCT could drop a gear or two (although I doubt) it will actually make braking less effective.
The reason is the engine braking is far weaker then brakes so it actually slowing down the brakes in their job. That's why when in emergency braking on manual bike pull the clutch, you will stop faster then on DCT.

 

[L.B.S.]

BTW, now when I think about it there is absolutely no use of engine braking during emergency stopping so even DCT could drop a gear or two (although I doubt) it will actually make braking less effective.
The reason is the engine braking is far weaker then brakes so it actually slowing down the brakes in their job. That's why when in emergency braking on manual bike pull the clutch, you will stop faster then on DCT.

Yup, when I'm truly emergency braking, the rear tire is up off the ground, or in such slight contact with the ground, that compression braking will be of no avail.

Man, I think it would take me a really long time to adjust to a DCT bike. I always only thought about the acceleration part and the slow speed maneuvering, but not so much any kind of emergency braking. My left hand and foot would be phantom pulling and tapping down frantically, lol.

 

[Ed Up]

I do like the fact the DCT is downshifting. The MSF course teaches, and I agree, that when doing an emergency stop you should be downshifting. Not letting the clutch out, but be in a gear that you could take off in, in the event the person behind is not stopping quick enough. Last thing I want to do is get stopped and notice a car coming at me and I'm in 6th gear. No time to shift at this point, just jump and run.

 

[wildeone]

and here is the confirmation why pull the clutch and not use engine braking.
Many other useful tips there BTW.

Tips for braking on a motorcycle

Why pull the clutch?
You would think that it is not wise to pull the clutch, because you would profit from the engine brake.

The engine is capable of braking the motorcycle a bit when you stay off the throttle, but it also resists more deceleration. And because you should brake much harder than the engine brake, you pull the clutch.

p.s.
some here I see don't distinguish emergency braking with stopping, it's milliseconds...you don't have time even to think.

 

[Russell733]

Have had a few emergency braking situations with the non DCT where when the crash doesn't happen the biggest problem is that when you go to accelerate again you realize your doing 15 or 20 MPH but still in 5th gear and have to do an awkward multiple downshift. I imagine the DCT would handle that better but not sure since I never rode one.
In normal riding and braking using downshifting to save some break wear is good, although not nearly as much on the NC as on my old XL500 thumper. But in an emergency there isn't time for downshifting, its just all about stopping

 

[TigerDude]

and that would be wrong, you would forgive all engine braking. On this video it's not emergency braking, it's stupidity braking
On real emergency either you or DCT will not have enough time to reduce gears BTW. Brakes are all you have.

That's contrary to how MSF teaches it. Downshift to first with clutch in in case you have to make a getaway. Your rear brake should be close to lockup anyway just with brakes.

I would think with DCT you just don't even worry about it.

 

[Deckyon]

That's contrary to how MSF teaches it. Downshift to first with clutch in in case you have to make a getaway. Your rear brake should be close to lockup anyway just with brakes.

I would think with DCT you just don't even worry about it.

You don't worry about the shifting, no. Still have to perform the breaking correctly (front and rear) no matter what the transmission. And with the DCT, you don't have to worry about locking up either wheel. The DCT does a great job of quickly changing gears to match speed - I have gone and worked with it a bit to see, after this thread got started, and I was quite impressed. I have only really tested up to 30 mph right now, but I have fully applied the breaks to a standstill and then twisted the throttle and drove off without needing to hot the Downshift button.

The only times I have had to come close to emergency breaking have been in the city at speeds of less than 30 mph. The DCT has been bullet proof so far, and for a newer (first year on a bike, but over 9k miles now) rider, it has made the experience so much fun and much more relaxing. One less thing to worry about.

 

[Beemerphile]

Back when I was coming up (long ago when sex was dirty and the air was clean), the drill for emergency braking was "In with both levers, down with both feet." This was at a time before control locations were standardized and was largely taught to prevent confusion. There were left and right shift models around. Engine braking is out the window during an emergency stop. Kenny Roberts used to say that there would be fewer motorcycle wrecks if they didn't have rear brakes. Keith Code used to talk about the $10 that represented 100% of your thinking ability. How much of it do you want to spend trying to modulate a rear brake to keep it from sliding when it isn't doing much anyway. The more you brake on the front the less effective the rear brake is AND the more likely it is to lock up. When it locks you lose directional control. Basic Inescapable Fact: Motorcycles are gyro-stable. When the wheels quit turning, they are most stable on their sides. It seems better to spend the limited concentration modulating the front brake to maximum deceleration and thinking about when and whether to transition from braking to avoidance maneuvers (or planning an elegant dismount).

Of course, ABS makes a lot of that cognitive overload go away. (But I have never owned a bike with ABS, so that doesn't help me.)