Passenger sliding around
#61
09-07-2018, 01:03 PM
Road Warrior
Join Date: Jul 2012
Location: Cranbourne, VIC Australia
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So let's look at this whole "braking while turning" thing.
First off, your corner entry speed should be pretty much set by the time you reach your turn-in point. If you want to trail-brake the front brake into the corner, that's fine, as long as you realize that you only have 100% of the traction available- if you're using 60% of your front tire traction for turning, and you also try to use 60% of the front tire's traction for braking, you're gonna slide the front tire at the very least, and if you don't let off the front brake, you're gonna fold the front and low-side.
So why do people suddenly feel the need to brake mid-corner anyway? Usually it's because of panic. They get lost in the corner. They THINK that they're going too fast to make the corner, which makes them fear that they're going to exceed the available traction, slide, and fall down. This is a vision problem. Before they even get to the corner, they should be looking at their turn-in point. Once they reach their turn-in point, they should switch to looking in the direction of their apex. And once they hit their apex, they should be looking at the exit of the corner. It is VERY rare that someone crashes because they were actually going too fast to make the corner. And even if they were at the limit of traction, any braking at that point at all, would CAUSE the tire(s) to lose traction.
So let's look at what you have to gain, and what you have to lose, from using the rear brake in a corner. As you brake, regardless of which brake(s) you use, weight is shifted forward, to the front tire. At some point, you will have transferred enough weight off of the rear tire's contact patch, that ANY braking will cause the rear tire to skid. And this is where things get really bad- the rear tire steps out, your brain's subconscious instantly diagnoses the problem causing your foot to come off the rear brake, and the rear tire then suddenly regains traction, while the motorcycle is still sideways, snapping bolt upright, and flinging you (and your passenger if you have one) UP and over the high side of the bike at roughly TWICE the speed you were traveling. To add insult to injury, the motorcycle will then follow you (and your passenger if you have one) into whatever you hit, just like the anvil follows Wile E. Coyote off the cliff. If it's a right-hand corner, your riding error could fling you (and your passenger if you have one) under the front bumper of an oncoming car.
By contrast, let's look at what could go wrong with using the front brake while cornering and the consequences of that. If you do not overwhelm the front tire's traction from using the front brake during a corner, the motorcycle will slow down to the point that you are no longer in panic mode. If you do overwhelm the front tire's traction from using the front brake during a corner, the front tire will slide, which scrubs off speed, which is what you wanted anyways. It will also reduce your ground clearance, so you will need to let off the front brake before hard parts start touching the ground. When you let off the front brake, the front tire will regain traction and the front tire will snap back in line. The bars will wag a little bit, but you'll be fine. If you DON'T let off the front brake before hard parts start touching the ground, you'll fold the front and fall down. You'll fall down at less than half of the speed as you would have if you had high-sided yourself off of the rear brake. You'll only fall a couple of inches, because if you've run out of ground clearance, you're already pretty darned close to the pavement. And you'll follow your motorcycle as you slide, which is a lot better than the other way around.
First off, your corner entry speed should be pretty much set by the time you reach your turn-in point. If you want to trail-brake the front brake into the corner, that's fine, as long as you realize that you only have 100% of the traction available- if you're using 60% of your front tire traction for turning, and you also try to use 60% of the front tire's traction for braking, you're gonna slide the front tire at the very least, and if you don't let off the front brake, you're gonna fold the front and low-side.
So why do people suddenly feel the need to brake mid-corner anyway? Usually it's because of panic. They get lost in the corner. They THINK that they're going too fast to make the corner, which makes them fear that they're going to exceed the available traction, slide, and fall down. This is a vision problem. Before they even get to the corner, they should be looking at their turn-in point. Once they reach their turn-in point, they should switch to looking in the direction of their apex. And once they hit their apex, they should be looking at the exit of the corner. It is VERY rare that someone crashes because they were actually going too fast to make the corner. And even if they were at the limit of traction, any braking at that point at all, would CAUSE the tire(s) to lose traction.
So let's look at what you have to gain, and what you have to lose, from using the rear brake in a corner. As you brake, regardless of which brake(s) you use, weight is shifted forward, to the front tire. At some point, you will have transferred enough weight off of the rear tire's contact patch, that ANY braking will cause the rear tire to skid. And this is where things get really bad- the rear tire steps out, your brain's subconscious instantly diagnoses the problem causing your foot to come off the rear brake, and the rear tire then suddenly regains traction, while the motorcycle is still sideways, snapping bolt upright, and flinging you (and your passenger if you have one) UP and over the high side of the bike at roughly TWICE the speed you were traveling. To add insult to injury, the motorcycle will then follow you (and your passenger if you have one) into whatever you hit, just like the anvil follows Wile E. Coyote off the cliff. If it's a right-hand corner, your riding error could fling you (and your passenger if you have one) under the front bumper of an oncoming car.
By contrast, let's look at what could go wrong with using the front brake while cornering and the consequences of that. If you do not overwhelm the front tire's traction from using the front brake during a corner, the motorcycle will slow down to the point that you are no longer in panic mode. If you do overwhelm the front tire's traction from using the front brake during a corner, the front tire will slide, which scrubs off speed, which is what you wanted anyways. It will also reduce your ground clearance, so you will need to let off the front brake before hard parts start touching the ground. When you let off the front brake, the front tire will regain traction and the front tire will snap back in line. The bars will wag a little bit, but you'll be fine. If you DON'T let off the front brake before hard parts start touching the ground, you'll fold the front and fall down. You'll fall down at less than half of the speed as you would have if you had high-sided yourself off of the rear brake. You'll only fall a couple of inches, because if you've run out of ground clearance, you're already pretty darned close to the pavement. And you'll follow your motorcycle as you slide, which is a lot better than the other way around.
#62
09-07-2018, 01:11 PM
Seasoned HDF Member
"...stock seat with a HD backrest" Sorry, either I missed it or misunderstood. I was talking about a driver's backrest. If your wife is sliding back & forth with both driver's and passenger backrests, I've got nothing left to offer. It may all boil down to what's already been suggested - technique and familiarity.
#64
09-07-2018, 01:26 PM
Seasoned HDF Member
You should have your OL sign up and head off to the QOTR and chat with the ladies. I'm sure at least some of them spent some time on the back seat at some point.
#65
09-07-2018, 01:50 PM
Road Captain
[QUOTE=nevada72;17662022]Because the squishy front end on a HD touring bike dives...[quote]
Then fix the suspension by installing the correct fork springs for the combined weight of the motorcycle and everything on it.
Then fix the ergonomics of the motorcycle so that you're not making unintended steering inputs that stand the bike up on the brakes.
Too hot for what? Too hot for the available traction, too hot for the available ground clearance? Braking reduces both.
Then fix the suspension by installing the correct fork springs for the combined weight of the motorcycle and everything on it.
...and the bike wants to straighten up out of a lean, throwing your line off. That's why.
As to why brake in a turn? Many reasons come into play out on the road as have been mentioned. One common pucker moment for many riders is riding in an unknown area and hitting a descending radius curve too hot.
#66
09-07-2018, 01:57 PM
Supporter
Then fix the suspension by installing the correct fork springs for the combined weight of the motorcycle and everything on it.
Then fix the ergonomics of the motorcycle so that you're not making unintended steering inputs that stand the bike up on the brakes.
Too hot for what? Too hot for the available traction, too hot for the available ground clearance? Braking reduces both.
Then fix the ergonomics of the motorcycle so that you're not making unintended steering inputs that stand the bike up on the brakes.
Too hot for what? Too hot for the available traction, too hot for the available ground clearance? Braking reduces both.
Last edited by QNman; 09-07-2018 at 02:51 PM.
#67
09-07-2018, 02:08 PM
Road Captain
Unfortunately, many motorcycles are built with rider and passenger accommodations designed to accommodate a wide range of rider and passenger sizes, including people who are most politely described as "gravitationally-impaired" or "circumferentially-challenged". This is especially true with cruisers- I've never seen a cruiser with a pillion pad that actually works. This often places normal-sized passengers too far away from the rider, and tiny riders can almost share the rider's saddle with the rider on many motorcycles.
For this reason, it is not unusual to have to build an extension off the front of the pillion pad, out over the rider's saddle, for the passenger to get up on the rider. To get the shape right, you can build a temporary one out of adhesive-backed superbike seat pads- just cut out the shapes you want, stack them together, shave them into shape with an electric carving knife, and cover them in duct tape for now. Try it out up and down the street (and around at least one corner, if you can) until you get the shape right. If the OEM pillion pad has contours that make it difficult for her to get further forward onto the extension you're building, you can pull the pillion pad cover off, and shave the foam with an electric carving knife to remove the contour. Once you get the shape right, then you can build a permanent one, and take it to an automotive upholstery shop to have it upholstered permanently. This also gives the rider a butt pad so that on acceleration he's not pulling on the handlebars on acceleration trying to keep himself from sliding back on his saddle.
The laws of physics apply regardless of the brand of motorcycle. You don't get to make up your own. Try stepping off a loading dock and arguing with the law of gravity and see how far that gets you.
Last edited by ChickinOnaChain; 09-10-2018 at 08:43 AM. Reason: Multiple posts
#68
09-07-2018, 02:15 PM
Outstanding HDF Member
build an extension off the front of the pillion pad..... To get the shape right, you can build a temporary one out of adhesive-backed superbike seat pads- just cut out the shapes you want, stack them together, shave them into shape with an electric carving knife, and cover them in duct tape for now..
#70
09-07-2018, 02:31 PM
Seasoned HDF Member