Locking rear tire: in gear vs. neutral?

[robertwyu]

Hey everyone!

I've been trying to be more mindful of actually downshifting and rev matching all the way down when coming to a stop instead of just pulling in the clutch lever and coasting, and that led me to thinking.

Would it be easier to lockup your rear tire when in neutral compared to when in gear? My rationale is that if you're in neutral there's nothing trying to rotate the wheel other than your existing momentum, and thus there's less that the brake has to fight with, whereas if you're in gear the engine is still providing some rotational power to the rear wheel and thus the brake has more more force to stop.

 

[Slow Goat]

With the bike in gear, there’ll be engine-braking to aid your deceleration but the brake can still lock the wheel.

Bad things happen when the rear locks up from braking, use the front.

 

[Darkness!]

Technically you are correct about the lack of rotational force with the bike in neutral. Of course, a large part of that theory depends on what throttle opening you are talking about.

What I'm curious about is why you are trying to rev match to a stop on the street? That can (and will) annoy or confuse drivers around you and is unnecessary. Just use the clutch as it is intended and designed to be used. Why do you feel that it is even necessary or are you doing it as an experiment?

 

[motomania2007]

Engine braking to a stop is somewhat controversial topic. Some advocate it as good practice for being able to rev match and have an opportunity to accelerate again at any time while slowing.
Some advocate it as smoother stopping.
IMO both of the above have many more negatives than positives.
I see cycling through the clutch and downshifting to a stop as a really bad habit as studies show that when threatened you tyically do what your habits are. So when faced with an SUV cutting you off, if your habit is to use engine braking to stop, then you will very likely attempt to do a quick stop with engine braking, and very likely fail miserably.

Those that advocate engine braking to a stop tend to say they can choose to do a quick stop with just brakes, when the need arises, and I am sure someone, somewhere can, but in my experience with teaching intermediate and advanced riding clinics, I haven't seen very many students that can do a very good quick stop in a class, let alone in a real emergency situation.

I like things as simple as they can be.

 

[onto1wheel]

...Would it be easier to lockup your rear tire when in neutral compared to when in gear? .

I'm not totally understanding why you are asking this question, but the bottom line is this:

If you are moving, you're bike should be in gear.

You need to always be ready to apply power, as you never know exactly how a situation will unfold.

 

[Ocho]

Technically you are correct about the lack of rotational force with the bike in neutral. Of course, a large part of that theory depends on what throttle opening you are talking about.

What I'm curious about is why you are trying to rev match to a stop on the street? That can (and will) annoy or confuse drivers around you and is unnecessary. Just use the clutch as it is intended and designed to be used. Why do you feel that it is even necessary or are you doing it as an experiment?

I rev match to a stop. Are you saying rev matching should only be before turns or non stops?

 

[GAJ]

I usually rev match only down to second as I only use first to get to second or in very very low speed maneuvering.

 

[Darkness!]

I rev match to a stop. Are you saying rev matching should only be before turns or non stops?

No. I meant that at normal street speeds (and normal engine speeds depending on the bike while riding on the street) in stop and go traffic situations it just isn't necessary to rev match to a stop from what I've been taught as a former motorcycle mechanic. May be I'm wrong. Maybe I was taught wrong.



The other reason I stated is because when you rev match to a stop, it can (to non-riders), sound like you're accelerating or revving your engine to try and make cagers to move out of your way. As I said, that can annoy and confuse people who already don't like that bikes can lane-split and filter up to the front of a two lane road. We, as riders, are the minority on the road.

 

[tzrider]

Hey everyone!

I've been trying to be more mindful of actually downshifting and rev matching all the way down when coming to a stop instead of just pulling in the clutch lever and coasting, and that led me to thinking.

Would it be easier to lockup your rear tire when in neutral compared to when in gear? My rationale is that if you're in neutral there's nothing trying to rotate the wheel other than your existing momentum, and thus there's less that the brake has to fight with, whereas if you're in gear the engine is still providing some rotational power to the rear wheel and thus the brake has more more force to stop.

If you are braking with the bike in gear, the throttle should be closed. If matching revs, you’ll blip the throttle to smooth the gear changes, but the throttle is largely closed. Considering that, the statement that “the engine is still providing some rotational power to the rear wheel” is not true. The engine is helping to slow the bike, not working in opposition to the brake.

 

[Bassem]

If you are braking with the bike in gear, the throttle should be closed. If matching revs, you’ll blip the throttle to smooth the gear changes, but the throttle is largely closed. Considering that, the statement that “the engine is still providing some rotational power to the rear wheel” is not true. The engine is helping to slow the bike, not working in opposition to the brake.

idle is still not zero rpm. You can take off from a standstill by gently releasing the clutch (on a big enough engine), no?

The engine is helping slow the bike until the wheel rotation speed is less than the idle rpm x gear x sprocket ratio. when you dip below (by using the rear brake), the engine is accelerating the rear.

What am I missing?

 

[tzrider]

idle is still not zero rpm. You can take off from a standstill by gently releasing the clutch (on a big enough engine), no?

The engine is helping slow the bike until the wheel rotation speed is less than the idle rpm x gear x sprocket ratio. when you dip below (by using the rear brake), the engine is accelerating the rear.

What am I missing?

Probably the fact that for most of a normal braking cycle the engine is above idle.

 

[Bassem]

Probably the fact that for most of a normal braking cycle the engine is above idle.

OP said "coming to a stop", so towards the end of braking, you're going slower than you would be if idle only.

Obviously, you pull the clutch in when going that slowly, but assuming you don't the rear brake and engine are acting in opposition for the last bit.
If you're in a high enough gear, you can (and I have) stall while rear braking hard (definitely if you just jam the lever and lock up)

 

[Enchanter]

Tangent: I’ve always been able to stop in shorter distances when disengaging (squeezing) the clutch.

I’m sure some of this is that it allows me to completely focus on braking and not the clutch/throttle interface.

I also think that when the clutch is engaged (lever NOT squeezed) that the rear brake is not only slowing the rear wheel, it is also slowing the engine and transmission.

I’ve played with this while riding (clutch engaged, using only the rear brake), and on a dyno. I can slow the bike (and dyno roller) more quickly when squeezing the clutch while braking.

 

[tzrider]

OP said "coming to a stop", so towards the end of braking, you're going slower than you would be if idle only.

Obviously, you pull the clutch in when going that slowly, but assuming you don't the rear brake and engine are acting in opposition for the last bit.
If you're in a high enough gear, you can (and I have) stall while rear braking hard (definitely if you just jam the lever and lock up)

OK, you got me.

If you come to a stop with the bike in gear and the clutch engaged, you'll kill the engine. Do we really think the OP is doing that? He's pulling the clutch at some point. After downshifting to first, but the time the engine falls to idle, you're going about 10 MPH. Is that the area of concern in this whole thing?

 

[Bassem]

OK, you got me.

If you come to a stop with the bike in gear and the clutch engaged, you'll kill the engine. Do we really think the OP is doing that? He's pulling the clutch at some point. After downshifting to first, but the time the engine falls to idle, you're going about 10 MPH. Is that the area of concern in this whole thing?

I'm not trying to 'get you' dude. Thanks for engaging me in this convo.

 

[tzrider]

Maybe it's time to ask the OP what part of the braking cycle he's concerned about.

 

[Gary856]

I think the OP was asking: which way can you stop faster – in gear, or in neutral?

My answers:

- if a) you want to come to a full stop, AND b) you need to slow faster than engine braking, then pulling in the clutch allows you to stop faster.

- If you’re in transition but not want to come to a full stop, it may be better to stay in gear (until you need to shift) for more bike control and stability.

- In practice, I brake in gear until I need to shift, or until just before coming to a stop.

 

[Holeshot]

Maybe it's time to ask the OP what part of the braking cycle he's concerned about.

Or the application?

OP, on an emergency stop, I wouldn't change anything about how you ride (as George said) and simply dynamite the brakes. Max braking force, don't worry about downshifting/ rev matching, rear end locking up due to engine braking, etc. Just reduce speed as much as possible, especially if you're going to hit something. Reduce speed/ reduce speed/ reduce speed. 20 mph can make a significant difference.

If you're talking about quicker stops in a controlled situation, learn to slip the clutch. Slipping the clutch is a half measure to the rear locking up and pulling the clutch all the way in. You'll be able to control how much engine braking by slipping the clutch.

Rev matching: if you don't know how to do it WELL, there's a signifgant chance it'll not allow you brake with the front lever as hard as could if you did not rev match. Also, if you rev match with too high an RPM, you'll be putting energy into the rear wheel and when you're trying to stop quickly, that simply adds stopping distance. If your bike has a slipper clutch; use it.

One thing on pulling in the clutch when panic stopping; leaving the bike in gear/ using the rear brake aids in keeping the weight transfer more controlled to the front forks. Linked braking systems have the net effect of lowering the whole bike towards the tarmac, not just compressing the front forks. I'm 100% against pulling the clutch in when trying to get maximum braking. I'll rebuild my engine a bit sooner, given the option...and use engine braking where needed. Too much going on to not use the free braking of the engine.

Don't forget that clutch slipping too...