Loading The Front

[xfc]

In class we are taught to roll on a little maintenance throttle right after the initial turn in into a corner - as the best way to keep the front tire from washing out. However, I do hear and read a lot about guys who instead load the front tire with more weight (presumably by trail braking) to increase friction and hence keep the front tire from washing out.

 

So which is it? Are we better off unloading the front from too much weight or loading it with a little more weight? Or do different situations call for different techniques?

[hubbard_28]

You can only load the front so much until it gives. When you're in the corner you should start throttling gently. Goosing it in a corner will cause the back end to slide out or, worse yet, highside. You want a 40/60% ratio front/rear tire in the corner. What you're told is "maintenance throttle" will give you the 40/60 ratio. If you have a nice long 180 degree turn or long fast corner, you'll be able to notice it more because you have to throttle to make it through..... gently. Keeping the front loaded through a corner increases your chance of low siding.

[Bullet]

In class we are taught to roll on a little maintenance throttle right after the initial turn in into a corner - as the best way to keep the front tire from washing out. However, I do hear and read a lot about guys who instead load the front tire with more weight (presumably by trail braking) to increase friction and hence keep the front tire from washing out.

 

So which is it? Are we better off unloading the front from too much weight or loading it with a little more weight? Or do different situations call for different techniques?

 

Trail braking and loading the front is what you'd call much more advanced riding tech. It's fair to say that there is a very fine line between being on the bike, and having it tuck when people do trail brake. If you watch bike racing, you'll notice that the vast majority of racers who crash, crash on the way into the corner trail braking.

 

Regardless of whether you enter the first part of the corner trail braking, or on no throttle, you're still loading the front, though to differing degrees. From this point, regardless, you have to apply the throttle rule to get that stability. Racers do it, we all need to do it. You must not confuse the start of a turn to the mid and the end point.

 

Hope that helps clear it up for you?

 

Bullet

(UK Riding coach)

[xfc]

Hmm... understood. Can you actually get on the gas too hard after turn in whereby instead of the rear braking loose first, you unload the front so much that the front starts to tuck first?

 

The reason I bring this up is that while reading this month's Roadracing World, there was an article about the new single spec Bridgestone tires in MotoGP. They talked about how the riders all agreed that the way to ride the Bridgestones was to keep them loaded as much as possible, including on turn-in. The riders spoke of the front tucking when they didnt keep it loaded. It just seems contrary to what we are taught in class.

[hubbard_28]

I would assume not. I'm sure it would affect steering, but when you see them lowside in racing (Simoncelli did it this weekend) it's because they are going in too hot. I've been off track a couple times for this same reason (accelerating too hard IN a corner), but have never lost the front directly by accelerating too hard out of a corner.

I've never heard anyone at the track losing the front by hitting the gas coming out of a corner. You should be getting on the gas at apex, and the pressure on the front tire should be decreasing anyways.

[kawdude636]

40/60 is optimum don't want to over load the front...spells disaster.

[asinn0007]

Trail braking and loading the front is what you'd call much more advanced riding tech. It's fair to say that there is a very fine line between being on the bike, and having it tuck when people do trail brake. If you watch bike racing, you'll notice that the vast majority of racers who crash, crash on the way into the corner trail braking.

 

Regardless of whether you enter the first part of the corner trail braking, or on no throttle, you're still loading the front, though to differing degrees. From this point, regardless, you have to apply the throttle rule to get that stability. Racers do it, we all need to do it. You must not confuse the start of a turn to the mid and the end point.

 

Hope that helps clear it up for you?

 

Bullet

(UK Riding coach)

 

Hi Bullet,

 

I've learned that for street riding, that if the tires aren't biting, that loading the front tire a little will reduce centrifugal forces on the rear tire, while simultaneously giving the front tire enough weight for traction. On the street, I would do that by feathering the rear brake without changing the throttle or anything else about the bike. This also stretches out the fork a bit. And while this will slow down the bike a little, it won't slow it down as much as a high side or low side would. Doesn't California SuperBike School advocate changing the body position to do this?

 

Thanks,

 

Andy

[asinn0007]

Trail braking and loading the front is what you'd call much more advanced riding tech. It's fair to say that there is a very fine line between being on the bike, and having it tuck when people do trail brake. If you watch bike racing, you'll notice that the vast majority of racers who crash, crash on the way into the corner trail braking.

 

Bullet

(UK Riding coach)

 

Have you seen this?

They trail brake so hard that they seem on the verge of losing control on every turn, IMHO. Any comments?

 

Andy

[avih]

Hmm... understood. Can you actually get on the gas too hard after turn in whereby instead of the rear braking loose first, you unload the front so much that the front starts to tuck first?

 

The reason I bring this up is that while reading this month's Roadracing World, there was an article about the new single spec Bridgestone tires in MotoGP. They talked about how the riders all agreed that the way to ride the Bridgestones was to keep them loaded as much as possible, including on turn-in. The riders spoke of the front tucking when they didnt keep it loaded. It just seems contrary to what we are taught in class.

In mid turn, the tire that lose traction 1st is the one which has more centrifugal force to hold than traction available by load+CP size (that's not a direct algebraic sum but rather a combination of both parameters) . The theory is that the optimal balance is about 60% on the rear and about 40% on the front such that lean angle and (momentary) cornering speed is maximized. To achieve this balance you usually have to apply a little throttle while turning.

 

If you apply some more throttle then more weight goes backwards, let's say to a balance of 25-75, at which case your optimal cornering speed is compromised. If you try to stick to optimal cornering speed though, the rear will lose traction because it'll have to provide more traction than it can (75% of the bike's weight instead of it's maximum 60% for maximum overall centrifugal force), while the front will hold less than what it can, so the front will not wash out. Imagine a wheelie while exiting a turn. The bike is still somewhat turning, 0% weight is on the front yet the front doesn't wash out (and the rear also doesn't wash out because the centrifugal force is lower than in mid corner and so it can hold).

 

Generally speaking, while at maximum lean/cornering speed, the tire that will lose traction is the one which you request to hold more than it can (40% weight for the front, 60 for the rear). If you apply more throttle then it's the rear (usually high side), if you close the throttle or apply some brake, it's the front (low side).

 

The reason people trail brake is not to keep the weight on the front during maximum lean, but rather to brake later than otherwise and to keep the weight on the front while applying the turning command (which requires much traction from the front). As long as the turning has not started, optimally 100% of the weight is on the front while braking. While during the turn, the front holds only 40%, which leaves the rider to handle the transition from 100-0 in a straight line to 40-60 balance at the apex. Optimally, and taking the turning command into account, this is achieved using trail braking.

[Bullet]

Trail braking and loading the front is what you'd call much more advanced riding tech. It's fair to say that there is a very fine line between being on the bike, and having it tuck when people do trail brake. If you watch bike racing, you'll notice that the vast majority of racers who crash, crash on the way into the corner trail braking.

 

Bullet

(UK Riding coach)

 

Have you seen this?

They trail brake so hard that they seem on the verge of losing control on every turn, IMHO. Any comments?

 

Andy

 

Yeah, Big MotoGP fan for sure. You must remember here though that these guys are riding on the best bikes, with the best forks, and tyres and grip you and I can only dream of. There is an enormous amount of difference in the grip these guys have over what you and I could ever get hold of. You shouldn't think you can get away with anything like the same, because I can assure you, you won't (personal experience on slicks has told me so, as has the resulting repair bill, though I felt like a MotoGP god for those few seconds before the crash ).

 

Additionally they have years of experience and their sense of speed, their attention they have on the feel of the bike and the feedback they have will be way above our levels. I think probably the last most important point is they're not paying for their bikes when/if they lob it, which of course even the best do on occasion. :-)

 

If I think about my own riding I don't trail brake for the majority of my riding, though If i'm really at 90-100% of my speed, then I definitely do. Its' worth doing, where it benefits you, and in reality it's really of benefit in my opinion in gaining laptimes little else.

 

Bullet

[Bullet]

Trail braking and loading the front is what you'd call much more advanced riding tech. It's fair to say that there is a very fine line between being on the bike, and having it tuck when people do trail brake. If you watch bike racing, you'll notice that the vast majority of racers who crash, crash on the way into the corner trail braking.

 

Regardless of whether you enter the first part of the corner trail braking, or on no throttle, you're still loading the front, though to differing degrees. From this point, regardless, you have to apply the throttle rule to get that stability. Racers do it, we all need to do it. You must not confuse the start of a turn to the mid and the end point.

 

Hope that helps clear it up for you?

 

Bullet

(UK Riding coach)

 

Hi Bullet,

 

I've learned that for street riding, that if the tires aren't biting, that loading the front tire a little will reduce centrifugal forces on the rear tire, while simultaneously giving the front tire enough weight for traction. On the street, I would do that by feathering the rear brake without changing the throttle or anything else about the bike. This also stretches out the fork a bit. And while this will slow down the bike a little, it won't slow it down as much as a high side or low side would. Doesn't California SuperBike School advocate changing the body position to do this?

 

Thanks,

 

Andy

 

Hi Andy,

 

Could you define for me, "not biting" and what it means to you? What does that feel like? Trying to understand and for you to define it so everyone understand it from your perspective.

 

Most of the centrifugal force in the turns comes from rotational forces of the wheels, and this provides the bike with stability. I'm assuming your talking about the sideways force from being in the turn when leaned over?

 

Using the rear brake does help the bike turn a little I understand, though its quite difficult for many to use when the bike is leaned over. I understand from colleagues who are excellent off road riders that it's used for this purpose though it's application on a track is much less.

 

I personally never use the rear brake apart from some slow speed maneouvering, as I can't easily move my feet from optimal footpeg positioning to get to the brake lever to be honest. I think if you really needed to slow the bike down, certainly any brakes is better than a lowside and a crash. I think it's important to define that you only get a highside from braking rear traction, and then it quickly re-gaining this and the subsequent re-loading of the rear suspension spring which throws the rider over the top of the bike. This is typically a problem on the exit of turns rather than into turns when riders apply throttle.

 

Bullet

[Cobie Fair]

For sure covering a lot of ground in this thread.

 

Let's take a look at one thing discussed earlier--what is the reason for the 40 front, 60 rear, what on the motorcycle dictates that this is approximately the correct number(s)?

 

CF

[acebobby]

For sure covering a lot of ground in this thread.

 

Let's take a look at one thing discussed earlier--what is the reason for the 40 front, 60 rear, what on the motorcycle dictates that this is approximately the correct number(s)?

 

CF

 

 

I believe the reason for the 40 front, 60 rear is to achieve the best contact patch for both tyres and that it would be done by opening the throttle! It's once you have initially cracked open the throttle, the book states that once the throttle is cracked on, it is rolled on evenly, smoothly, and constantly throughout the remainder of the turn! So while cracking open the throttle sets the tyres contact patches how do you know how hard or not you can roll on the throttle? And while rolling on throughout the turn are you not moving more weight to the rear effectively unloading the front?

[Bullet]

For sure covering a lot of ground in this thread.

 

Let's take a look at one thing discussed earlier--what is the reason for the 40 front, 60 rear, what on the motorcycle dictates that this is approximately the correct number(s)?

 

CF

 

 

I believe the reason for the 40 front, 60 rear is to achieve the best contact patch for both tyres and that it would be done by opening the throttle! It's once you have initially cracked open the throttle, the book states that once the throttle is cracked on, it is rolled on evenly, smoothly, and constantly throughout the remainder of the turn! So while cracking open the throttle sets the tyres contact patches how do you know how hard or not you can roll on the throttle? And while rolling on throughout the turn are you not moving more weight to the rear effectively unloading the front?

 

Hey bobby,

 

If you look at TW2 page 7, section on "light touch", it describes the definition of how much and what happens if you put on too much too soon.

 

Have a read, see if that covers it of for you mate.

 

Bullet

[acebobby]

For sure covering a lot of ground in this thread.

 

Let's take a look at one thing discussed earlier--what is the reason for the 40 front, 60 rear, what on the motorcycle dictates that this is approximately the correct number(s)?

 

CF

 

 

I believe the reason for the 40 front, 60 rear is to achieve the best contact patch for both tyres and that it would be done by opening the throttle! It's once you have initially cracked open the throttle, the book states that once the throttle is cracked on, it is rolled on evenly, smoothly, and constantly throughout the remainder of the turn! So while cracking open the throttle sets the tyres contact patches how do you know how hard or not you can roll on the throttle? And while rolling on throughout the turn are you not moving more weight to the rear effectively unloading the front?

 

Hey bobby,

 

If you look at TW2 page 7, section on "light touch", it describes the definition of how much and what happens if you put on too much too soon.

 

Have a read, see if that covers it of for you mate.

 

Bullet

 

Got it, cheers! Its like everyone says, it doesn't matter how many times you read the books you always pick up on something else!

I think I might be one of the people making the error of being to greedy with the throttle, it hasn't caused me any real issues yet fortunately but I will be working on correcting this!

 

Thanks Bullet!