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General => Roadcraft => Topic started by: klaviator on March 09, 2023, 01:28:47 AM
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I'm just curious. Who understands what trail braking is and who here uses it?
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I know what it is but don't do it. I figure it is a band aid approach to coming into a sharp turn too fast. I learned long ago how to go into a turn at the right speed to avoid using any brake unless some obstacle was around the curve that wasn't expected. I prefer to use engine drag if possible. If I use any braking I try to get my bike as upright as possible and still stay safe.
I do know many ST1300 and BMW riders who do trail braking. And it is regularly done in motorcycle racing to get around curves faster. But those riders are REALLY skilled in braking technique.
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My simple understanding is that it is cornering combined with braking at the same time.
Braking is decreased...then gone completely when nearing the apex, after which power is applied.
What bike was it that I first saw the electronics prevent the bike from trying to "right" itself (stand up vertical) while braking in s corner......and leading to a runoff. KTM I think it was?
I have one tight steeply downhill turn which I approach cautiously in my frequent rainy dark rides after big winds.
Do my braking before I encounter the possible road debris ahead....never in the corner 🫣
Stig
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My understanding was that trail braking is used to shift weight to the front suspension by braking as necessary before a turn, reducing the need to brake during the turn, but also the effect of the weight shift basically changes your suspension geometry by lowering front ride height by compressing your forks (just a little does it) decreasing the front suspension's amount of trail, which gives better handling and more front wheel grip through the turn.
Trail is the horizontal distance from where the front wheel touches the ground to where the steering axis intersects the ground.
Other ways of reducing trail are by using a larger diameter rear tire or a smaller diameter front tire, or by slipping fork tubes up a tiny bit in the triple clamp.
Lots of sport bikes in the 80s had a 16" front wheel and an 18" rear to reduce trail.
I cut throttle back at the last minute before a turn to accomplish this weight shift to the front end, usually this is enough to effectively reduce trail at low speeds. It's even enough on my motorcycles, I guess I don't ride that hard even if I'm pushing the speed limits, this is more of an open road or track technique that doesn't play well in traffic.
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(https://i.postimg.cc/s28gvyWL/TRAIL.jpg)
Stig
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I see there are a lot of misconceptions about trail braking out there. That's not surprising considering that not that long ago a lot of "experts" were teaching that riders should get all their braking done before entering a curve. Those "experts" included the MSF and Keith Code who wrote "A Twist of the Wrist" and founded the California Superbike School. I thought it was crap when the MSF taught it when I took their courses back in the 80s and 90s. I also took California Superbike School back in 91. Common sense finally prevailed and neither the MSF or Keith Code teach that anymore. There are a few MSF instructors out there who never got the word and still teach that outdated technique but they shouldn't be doing that. Go to any advanced riding school and they will most likely be teaching trail braking.
This video is over 13 minutes long but its worth watching and sets the stage for what I'll be posting later. https://youtu.be/5ibJuFNwOXk (https://youtu.be/5ibJuFNwOXk)
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Interesting vid Klav, thanks for posting.
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So what exactly is trail braking?
Trail braking is when a rider starts braking before entering a curve and continues braking into the curve. Done correctly the rider will be decreasing brake pressure as he increases lean angle and will be off the brakes before the apex. Normally trail braking is done with the front brake only, especially on the track and when done by sportbikes or other high performance bikes.
If the rider releases his brakes before entering the curve then it is NOT trail braking.
If the rider is already in the curve and applies his brakes, that is NOT trail braking.
Many riders, probably due to the BS the MSF used to teach, consider using the brakes while leaned over to be a dangerous technique that should only be used by experts. This is simply not true and is a potentially dangerous attitude. Trail braking as well as braking while in a curve are techniques that every rider who has gotten past the beginner stage should be able to do. It's not rocket science but before attempting these techniques a rider should be comfortable with countersteering and riding curves as well as using his bikes brakes. Understanding the dynamics of braking is important but far too many riders simply don't understand braking dynamics beyond which lever(s) to pull to slow their bike down.
It is also important to understand tire traction, not only for trailbraking but for riding in general.
I'll cover all these topics in future posts.
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A “bagger”? Never come across this nickname before, but it describes the hard case-equipped HDs well. Seeing racers hustling them around a race track is a hoot.
As an aside, are those machines modded for improved ground clearance? I well recall the Electra Glide I rode around Colorado decked out at very modest lean angles!
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A “bagger”? Never come across this nickname before, but it describes the hard case-equipped HDs well. Seeing racers hustling them around a race track is a hoot.
As an aside, are those machines modded for improved ground clearance? I well recall the Electra Glide I rode around Colorado decked out at very modest lean angles!
A Bagger Racing league was started a couple of years ago for racing between Harley and Indian Baggers. These are race bikes with bags on them. In real life a bagger refers so a cruiser type motorcycle with hard bags but not a tail trunk like an Electra Glide or Tour glide, at least that is my understanding.
As for limited ground clearance, this really varies a lot with stock Harleys. Some start dragging as soon as you start leaning, others do pretty well. A couple of years ago a couple of Harley baggers passed my on the dragon, the first time a Harley has ever passed me on a twisty road. It's an interesting story:
I was taking a break at the overlook near the bottom of the dragon and getting ready to ride back up to Deal's Gap. There was a Concours 14 also getting ready to go. I wanted to let the Concours go first because I was on my Like 150i. He was so slow getting ready to go I finally went first but I was expecting him to catch me. After a few miles I did see some headlights behind me. I also started hearing the distinct Potato.potato sound of a Harley.....Hmmm. After a mile or so they caught up to my so I used a pull off to let them by. It was two harley baggers followed by the Concours 14. I pulled in behind them and tried keeping up. Eventually the two baggers pulled away but I kept up with the Concours 14. OK, I was on a 150cc scooter but I am still faster than most motorcycles on a twisty road. These Harley riders knew how to ride and their bikes had decent cornering clearance. It goes to show its more about the rider than the bike.
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Before going back to trail braking I'm going to discuss some real basics. There is nothing more basic to riding a motorcycle or scooter than tire traction. Without tire traction you couldn't accelerate, brake or turn. Tire traction is a function of three things, Your tire, the road surface and the weight on the tire. Tires varies from sticky race tires to very hard tires. Once you go riding you are stuck with whatever tires you have on your scooter. Road Surface. This varies from clean dry pavement to wet to oily or gravel or debris covered. You do have some control over this as you can choose to avoid patches of gravel or other slippery stuff. Of high importance is recognizing stuff on the road that will affect traction.
Last is weight on the tire. The more weight that is on a tire the more traction it will have. The weight on your tires is not static. It changes as you ride. As you accelerate weight transfers from your front tire to your rear. As you decelerate or brake the opposite happens. This all sounds pretty simple right? However, I don't think most riders really understand tire traction all that well.
Here's a video by Nich Ienatsch that hopefully explains things better than I do.
https://youtu.be/Fy1AIAc76Qo (https://youtu.be/Fy1AIAc76Qo)
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Your last sentence Klav? "It goes to show its more about the rider than the bike."
Absolutely. When riding in groups (I don’t anymore), I always felt any fool with a litre plus sportsbike could blast past me on the straight, but take me in the twisties? Then I’d be impressed.
These days I much prefer solo riding or with one other. Safer and more enjoyable.
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I'm going to re post a diagram that stig posted because it is a good one.
(https://i.postimg.cc/s28gvyWL/TRAIL.jpg)
The numbers in this diagram are just an example. The actual used in trail braking can vary a lot. This diagram shows a fairly aggressive street rider using trail braking. How do I know that? Two reasons. A racer would be probably be braking harder than 70% approaching the curve. A racer would not normally used a delayed apex line as shown. A delayed apex is not the fastest way around the track but it is considered the safest line on the street.
So what exactly is happening in the diagram.
The rider is braking pretty hard approaching the curve. Before starting to turn the riders lightens up on the brakes from 70% to 50%. Then as he goes more into the curve he lightens up on the brake as he leans more until he is off the brake by the apex and then accelerates after passing the apex, increasing acceleration as he starts to straighten the bike up. He used a delayed apex to stay outside and increase his sightline longer. By the time he hit the apex he could probably see the corner exit before starting to accelerate. If he was racing he would have apexed midway through that curve.
What is important, although the diagram doesn't show it, is that the rider never exceeded 100% traction on his tires. That is the the reason so many people are afraid to brake and lean at the same time. They think they will lose traction and crash. They think it takes an expert rider to balance braking and turning and not crash.
It does take an expert to do it if you are trying to use close to 100% of your tires traction as a racer does. However, on the street even experienced riders try to leave a margin for error. In the diagram the rider was only using 50% of his traction when he started turning. He had 50% left. I'll bet the average street rider rarely uses more than 50% of his available traction when turning.
Let's suppose instead of 50% braking the rider only used 20% when starting the curve and then tapered it off. That's still trail braking and certainly not dangerous. Like any technique, trail braking should be learned by starting real easy and then increasing the level you are doing it at.
But why not just just doing all your braking before starting the curve? What is the advantage of trail braking?
I'll discuss that next but first another video:
https://youtu.be/MJOteNDthWc (https://youtu.be/MJOteNDthWc)
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What bike was it that I first saw the electronics prevent the bike from trying to "right" itself (stand up vertical) while braking in s corner......and leading to a runoff. KTM I think it was?
I think it was KTM that first introduced cornering ABS. It had absolutely nothing to do with a bike trying to stand up and running off in a corner. Cornering ABS is designed to prevent your tires from loosing traction if you use your brakes to hard in a curve or you are braking in a curve and hit something slippery. If you are leaned way over in a curve and grab a handful of brakes you will most likely crash. Cornering ABS MIGHT prevent that from happening but it can't change the laws of physics. It is still a good idea to use your brakes properly while in a curve even if you have cornering ABS.
But that is not what trail braking is all about. Trail braking is already having your brakes on when entering the curve and smoothly decreasing the brake pressure. Can you still loose traction even if trail braking correctly? Sure you can if you hit something slippery. It can also happen if you are just leaned over in the curve with no braking involved. You still have to pay attention to the road surface as well as your speed.
Even if you prefer the old technique of completing your braking before entering the curve, trail braking is a useful tool to have at your disposal if you need it. I know there are some riders out there who will claim they have been riding for many years without trail braking and they don't need it and they aren't going to start now. I have met some of those riders who have been riding forever and know it all. They are safe because they ride slow and safely. I'll bet the two Harley riders in the next video fell into that category:
https://youtu.be/pUB2darr5mU (https://youtu.be/pUB2darr5mU)
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I know that some of you are still unconvinced. You learned that brakes should only be used when upright because braking and leaning at the same time are dangerous. Let's look as some scenarios.
Here is an example stig posted:
I have one tight steeply downhill turn which I approach cautiously in my frequent rainy dark rides after big winds.
Do my braking before I encounter the possible road debris ahead....never in the corner 🫣
Stig
For this scenario I think what stig posted makes sense. Steep downhill, wet, debris. Yeah, I'd go slow too.
Now lets change the situation a bit. A steep downhill curve but it is a dry and sunny day. So how steep is it? I know some roads that are so steep and curvy that you will be braking in the curves whether you want to or not, especially on a scooter. Scooters don't have nearly as much engine braking as motorcycles so if it is steep enough engine breaking won't be enough. Another issue with scooters is that if you go too slow the clutch will disengage and now you have no engine braking. If you live in Kansas or Florida you may never have ridden a road like this but they are out there. I have ridden a bunch of super steep and curvy roads where you pretty much have to brake in the curves. It makes more sense to trail brake than to wait until you feel uncomfortable with your speed and then have to apply your brakes mid turn.
Let's look at another scenario. Downhill curve but not that steep. Again, sunny and dry day. So approaching the curve you brake to what you feel is a comfortable speed and then release your brakes before entering the curve. After entering the curve you see a bunch of gravel all over the road. The speed you thought was slow enough suddenly isn't. So you don't believe in braking while leaned over. Now what do you do?
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Bends (curves)? I tend to subscribe to the late Mike "The Bike" Hailwood's maxim, slow in, fast out. Worked for him and (mostly) works for me.
Can I trail brake? Yes. Do I? Not that often road riding as I prefer to get my braking out of the way on the approach to the bend so I can concentrate on getting leaned over without the drama of upsetting the geometry by hard braking. Then any minor adjustments (e.g. unsighted gravel beyond the apex) are dealt with by gentle use of the rear brake.
Track day riding I no longer do, but when I did then yes, trail braking lets you carry a much higher corner speed and that matters on the track. On the road my days of riding 10/10ths are long behind me. As I've got older, that safety margin is more and more important to me.
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Can I trail brake? Yes. Do I? Not that often road riding as I prefer to get my braking out of the way on the approach to the bend so I can concentrate on getting leaned over without the drama of upsetting the geometry by hard braking. Then any minor adjustments (e.g. unsighted gravel beyond the apex) are dealt with by gentle use of the rear brake.
Track day riding I no longer do, but when I did then yes, trail braking lets you carry a much higher corner speed and that matters on the track. On the road my days of riding 10/10ths are long behind me. As I've got older, that safety margin is more and more important to me.
I don't understand. What does trail braking have to do with upsetting the geometry????
Why do you need to be braking hard to be trail braking???
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I don't understand. What does trail braking have to do with upsetting the geometry????
Why do you need to be braking hard to be trail braking???
Perhaps you misunderstand me or I didn't explain myself clearly enough Klav. I know trail braking (done correctly) will not upset the steering geometry or involve hard braking. I was merely pointing out that on the road, I far prefer to separate braking and cornering as much as possible. OK that may not be the case 100% of the time, but where I can, that's my preferred MO.
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Perhaps you misunderstand me or I didn't explain myself clearly enough Klav. I know trail braking (done correctly) will not upset the steering geometry or involve hard braking. I was merely pointing out that on the road, I far prefer to separate braking and cornering as much as possible. OK that may not be the case 100% of the time, but where I can, that's my preferred MO.
OK. I understand the appeal of "slow in and fast out". I do it myself a lot of the time. I also trail brake some of the time, not because I need to but because I think it is a valuable skill and practicing it on a regular basis keeps that skill sharp.
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OK. I understand the appeal of "slow in and fast out". I do it myself a lot of the time. I also trail brake some of the time, not because I need to but because I think it is a valuable skill and practicing it on a regular basis keeps that skill sharp.
Sounds like we're on much the same page there Klav. It IS a useful skill that is well worth practicing. Use it or lose it.
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I think it was KTM that first introduced cornering ABS. It had absolutely nothing to do with a bike trying to stand up and running off in a corner.
I guess I was remembering this video from years ago from Bosch, "MSC"
See 2:20
https://www.youtube.com/watch?v=-gu1W2DR-vU
Stig
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I guess I was remembering this video from years ago from Bosch, "MSC"
See 2:20
https://www.youtube.com/watch?v=-gu1W2DR-vU
Stig
Interesting video. Bosch has been a leader in motorcycle electronic aids like ABS. My Like150i has 2 channel Bosch ABS and it works well.
In this video Bosch talks about ABS, MSC, traction control and wheelie control. I didn't hear anything about cornering ABS.
Lets talk real world. ABS has become very common and is available on even low priced bikes. Traction control is also becoming common on mid to high priced bikes. Vespa for example has traction control on their 300cc scooters. Cornering ABS is available on some high end bikes. I don't know about MSC but probably only on some high end, high priced bikes.
They do mention controlling the tendency of bikes to stand up and run wide when braking in a curve. There are two thing that cause a bike to stand up under braking, maybe more, but tow I know of. The first is the tires. Some tires have a tendency to make a bike stand up if the brakes are on when leaned over. Its probably the tires profile. This is something I experienced myself. My Yamaha FJ1100 had a strong tendency to stand up under braking. I replaced the FJ with an EX500 which was perfectly neutral under braking and didn't stand up. At least not when I bought it. When the OEM tires wore out I replaced them with Dunlop 591's, the same tire I used on the FJ. Now the EX would stand up under braking. Eventually I went to different tires and that tendency went away. Since then whenever I got a new bike I would check to see how they behaved when braking in a curve. None of my current bikes stand up under braking.
The other reason is what the video showed. If you jam on the brakes in a curve you will upset the chassis which can cause the bike to stand up and run wide. I have never experienced this but i have read about it. Jamming on the brakes in a curve is just plain stupid. I refer you back to the 100 points of traction video I posted earlier where Nick Ienetsch talkes about being smooth when applying the brakes.
So back to the Bosch systems. Who here has all of that stuff on their bikes? ABS, sure. Traction control? Maybe. Cornering ABS or MSC?? Anyone? I have 5 bikes. Two have ABS and that's it. None of these other systems.
So if you don't have all these electronic rider aids on your bike it would probably be a good idea to know how to ride without it. That's why I brought up trail braking. Trail braking is a technique that racers use to go faster on the track. It is also a technique that WILL make you a safer rider on the street if you know how to do it properly. It is a useful technique even if you have no desire to go faster.
So how do you learn trail braking on the street safely? That's coming up.
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So back to the Bosch systems. Who here has all of that stuff on their bikes? ABS, sure. Traction control? Maybe. Cornering ABS or MSC?? Anyone? I have 5 bikes. Two have ABS and that's it. None of these other systems.
Well Klav up until last month only ABS. Then I bought the DTX and guess what, it has ABS & TCS! So 2 out of 4 now. I've only ever had the ABS kick in twice where I wasn't actively trying to use it and on one of those occasions I am sure it prevented a sub-20mph spill with all the costly plastic damage that would entail. Paid for itself, right there. TCS? Occasionally kicks in when in the car, but I'll have to get back to you regarding the DTX. On a 300cc scooter I'm wondering if it's overkill? (But then I thought that with ABS and I'm now a convert.)
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Well Klav up until last month only ABS. Then I bought the DTX and guess what, it has ABS & TCS! So 2 out of 4 now. I've only ever had the ABS kick in twice where I wasn't actively trying to use it and on one of those occasions I am sure it prevented a sub-20mph spill with all the costly plastic damage that would entail. Paid for itself, right there. TCS? Occasionally kicks in when in the car, but I'll have to get back to you regarding the DTX. On a 300cc scooter I'm wondering if it's overkill? (But then I thought that with ABS and I'm now a convert.)
Where I see TCS being most likely to kick in is if you are accelerating from a stop or at low speed and you are on something slippery like a wet road with oil on it. Even a 150 can spin its rear tire in that situation.
I have also read where TCS can get you stuck and you have to turn it off to get going.
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two things to remember from about 1.5 million street miles
#1 traction----tires are already working hard bike leaned over, too much braking force added and down you go.
#2 most bikes, lean and steer related---brake hard in turn and bike may come upright and in the bushes you go!
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two things to remember from about 1.5 million street miles
#1 traction----tires are already working hard bike leaned over, too much braking force added and down you go.
#2 most bikes, lean and steer related---brake hard in turn and bike may come upright and in the bushes you go!
With 1.5 million street miles I'm sure you are proficient at trail braking and aren't stupid enough to do to do #1 or #2 above.
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If you aren't proficient at trail braking or don't even know how to do it, it's not hard to learn and it is not a dangerous technique. It could prevent you from crashing in the future.
First. You need to be able to brake smoothly in a straight line and have a good feel for your brakes. If you can't do these two things you need to practice braking in a straight line. This is a basic skill that all but very new riders should have.
Assuming you have reasonably good braking skills then you are ready to try trail braking. Find a curve you are comfortable with and one that you know is clean. Ride towards the curve and start braking to slow before entering the curve. Instead of releasing your brakes before entering the curve keep some brake pressure on as you lean into the curve. It doesn't have to be much pressure. Starting off it should just be light pressure. Then smoothly release brake pressure as you increase lean and be off the brakes by the Apex or roughly half way through the curve. Try this a few times gradually increasing speed as well as brake pressure. No reason to do this any faster or harder than you feel comfortable with. The point here is to get comfortable being leaned over with some brake pressure on. You will see that this is a non issue. It is not difficult. You bike won't do anything funky or fly off the road.
Why do you want to do this? Because someday you will find yourself in a curve going faster than you want. Maybe you just misjudged the curve or maybe you get into the curve then see some grave ahead. If you are already on the brakes and comfortable with the brakes on in a curve it will be easy to adjust brake pressure to slow or even stop. If you do this then it is no longer trail braking but it sure beats being in that curve with no brakes on and suddenly you need to brake. Now you are much more likely to grab your brakes and screw things up, especially if you aren't proficient at using your brakes while leaned over.
Braking after entering a curve is also a usefull skill to have. It can be done smoothly and safely but it is more difficult to do than trail braking. It just makes sense to learn trail braking first. The thing is that if you are used to trail braking it is much easier to properly adjust your speed and makes it less likely you will need to apply brakes mid curve.
A lot if riders will trail brake up to the point where they see the corner exit before releasing their brakes. They may be barely using any brake pressure, maybe just enough to have the brake light on but they are on the brakes.
Trail braking on the track or with a high performance bike is normally done using only the front brake. That's what I do with my Versys but I find scooters just brake better using both brakes so that's what I do.
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This is the best video I have seen so far for explaining how and why every rider should be trail braking. I don't agree with 100% of what he says in the video but it is still a great video. If you want to be a safer rider and you don't regularly use trail braking then you should watch this video unless you live someplace like Kansas that doesn't have any curves.
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This is the best video I have seen so far for explaining how and why every rider should be trail braking. I don't agree with 100% of what he says in the video but it is still a great video. If you want to be a safer rider and you don't regularly use trail braking then you should watch this video unless you live someplace like Kansas that doesn't have any curves.
Should there have been a video attached to this Klav?
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Should there have been a video attached to this Klav?
I lost the plot here, too.
Ya' got your trail braking, and your counter steerin' and your.....
Stig
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Oops. Yes there should have been a video. Let me try again.
https://youtu.be/KHl_7WpCWok