What's your view on trail braking? | Page 6 | GTAMotorcycle.com

What's your view on trail braking?

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An extra comment thought of after my post ...

All the maths in the world and understanding of physics doesn't mean that the person at the controls knows these things are happening when. And if I understand how to calculate ground trail vs real trail or the anti-dive forces of a telescopic fork vs a Yamaha GTS1000 hub suspension means NOTHING to going fast around a track.

If someone can apply a rear brake into a corner and get a lap time without high-siding all the power to them. Personally I have enough going on with downshifting, front brakes and turn-in that I am not sure I want play with my other foot on the rear brakes.

So there is a physics/academic view to all this. And then there is the doing aspect of it. They don't have to agree with each other and the rider doesn't have to know the physics to ride well or fast. For some it helps. As Dave Moss points out in videos, how the riders brain works often has a lot to do with how much feedback they want out of the bike. Some riders are damn fast and don't care what trail is, if they countersteer or how much rebound they have ... they just ride and are damn fast. I believe I am more analytical about what is doing what ... but I am also slow :)

Jeff
 
ReSTored said:
You're kidding, right? A rider initiates a turn into a corner by pushing on the left grip to turn left and perhaps some riders do this subconsciously. During the corner you can keep your existing line by continuing to apply the same pressure or you can tighten (or loosen) up your line by pushing harder (or lighter) and this, obviously, requires conscious thought and action.

In the context of the thread I'm saying that on most Ontario roads simply using counter steering is more than adequate to navigate roads at a reasonably sane speed. I'm not saying that trail braking is not effective.
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Sorry. NOPE.
A rider initiates a turn by leaning the bike in the direction the rider wants to go.
This lean changes the shape of the contact patch, by virtue of the tire being round and the trail and rake of the bike.
This change in shape of the contact patch, combined with the lean will cause the steering to push in the opposite way of the lean.
Counter steering.
it is not something the rider initiates.

So now that we're here: When you trail brake, by my definition stated earlier, you cause the front suspension to compress. When you compress that front end the wheel base is shortened, rake and trail decreased, tightening up the corner.

If you want to understand this all better I have some home work for you: Get a bicycle and push it around while holding the seat, not the handle bars and push it around corners while watching the handlebars.
You will find with the bike completely vertical to make the bike go right,the bars turn right.
Now hold the bike by the seat and lean it into a right corner, let's say 15 degrees lean. What do the handle bars do? No suspension, no centripedal force, only rake, trail and contact patch. Please notice the radius of the corner.
Now take the same bike, same lean angle (15 degrees) BUT install a smaller front wheel or shorter forks, effectively decreasing rake and contact patch (trail will stay the same) What happens to the radius of the corner?

Jeff: you are only considering the centrifugal forces, you have to take into account the changes in geometry of the rake and trail. If you remove all the centrifugal and centripedal forces from the equation you still get counter steer (Try the bicycle tests)

The Foale/Parker FFE would be cool except I don't think the Yamaha part in the middle is up to the task, PLEASE build the thing and prove me wrong.
I have always wanted to build a Foales "spine" framed TZ, (Yamaha chassis » Motochassis by Tony Foale) but I found out that you can't keep rings in the thing, rings only last one race... if you're lucky.
Do you know Denis Curtis of CMR Racing? If not, you should.


Anyone in the GTAM sphere want to speculate on why a frame would ruin piston rings?
 
@bitzz I think we will have to agree to disagree on counter steering. If the lean alone allowed you to turn the bike at speed you should be able to initiate quick turns without the need of handlebar input.

My definition of trail braking is also cause the front suspension to compress. When you compress that front end the wheel base is shortened, rake and trail decreased though I usually consider trail braking with front brake but I also find modulation of the front brake much easier due to its hand control vs foot.

No Yamaha part needed for a Foale/Parker FFE, its just the term for the upper A-arm over the wheel and lower arm close to centre of wheel. The project is indefinitely on hold as riding a current bike around the track is more fun than building a bike with the want to take it to the track. It might resurface when I get some time as my kids get old enough that I am not helping with their projects as well.

Jeff
 
imho
The fastest way to initiate a lean when you are traveling at speed is to counter-steer but if you don't follow through with your body then it won't be happening,
in fact you can counteract an appreciable amount of counter-steer by leaning your bodyweight the opposite direction lol I know, i went for it one day and tried it, you can ride all crooked like in a straight line like an automobile on 2 wheels.
but if you counter-steer and lean wow now that's motorcycle power steering ?
 
Blacque Jacque Shellacque said:
Been there. Let be honest here, these roads wouldn't even be noticeable in Virginia. Just as one example, check out State route 16 in Virginia between Talisman and Marion. It passes over two mountain ranges and it has more switchbacks and tighter curves than every road in the entire province of Ontario combined!
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True...but $CDN at par here plus if you come off your bike you won’t need to sell your kidney for your hospital visit or tow home.
 
Is mountain ranges vs canadian shield, the frontenac area is known as land'o lakes because there is 1000 lakes within 1000 square miles, hundreds of those lakes have roads around them, many are lightly traveled, but it does help to know where the roads go as well, gas stations are few and far between. Rideau Canal area is not far to the east and more populated, some really nice roads to explore there too.
 
Follow any road on or near the Niagara Escarpment (Bruce Trail/900km) for great roads.A lot of people don't give Ontario a fair chance.
 
Lions Head Trial is on the Bruce Peninsula, the road to Lions Head is fun on a bike
and you can go check out the trial event, all it will cost is whatever meat the black flies eat:
https://www.motorcyclingcanada.ca/wp-content/uploads/2019/01/0525-Ontario-Trials.pdf
Road around the perimeter of the Bruce Peninsula is nice, the road up the middle is too straight to be interesting.

... and that is so far off the topic of trail braking unless you plan to break the speed limit on the way there lol
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