revtothelimit - motorbike forum

Horse wrote: Thu Jun 29, 2023 9:16 pm

slowhare wrote: Thu Jun 29, 2023 8:46 pm I thought it was continued application of the rear ... while keeping the throttle engaged.

Balancing throttle, clutch and rear brake is useful for slow control

Trinity765 wrote: Thu Jun 29, 2023 9:38 pm I thought the "trail" in trail braking is because you trail off of the brakes. You brake hard using the front going into a corner but rather than letting go suddenly and the front springing back up you let go gently - trailing off of the brakes.

The above is what I do if I am "having fun" and I feel much more in control when I do it. I also use a tiny bit if back brake as it seems to keep the whole bike a little more settled.

slowhare wrote: Thu Jun 29, 2023 9:22 pm when i do stoppies it’s almost over the handlebars, and that’s front only, obviously, you couldn’t do a stoppie using the rear. When i use rear only the weight transfer always appears to move backwards, i must be missing something here.

trail-braking as i understood it: using rear only through the apex and into the curve while the throttle is still engaged.

Yorick wrote: Thu Jun 29, 2023 9:54 pm

slowhare wrote: Thu Jun 29, 2023 9:22 pm when i do stoppies it’s almost over the handlebars, and that’s front only, obviously, you couldn’t do a stoppie using the rear. When i use rear only the weight transfer always appears to move backwards, i must be missing something here.

trail-braking as i understood it: using rear only through the apex and into the curve while the throttle is still engaged.

No. That's backing it in

KungFooBob wrote: Thu Jun 29, 2023 10:01 pm I tried backing my DR250 into a 90 degree corner on my commute to work.

I needed a new indicator lens and put a hole in my HG over trous.

KungFooBob wrote: Thu Jun 29, 2023 10:01 pm I tried backing my DR250 into a 90 degree corner on my commute to work.

I needed a new indicator lens and put a hole in my HG over trous.

slowhare wrote: Thu Jun 29, 2023 9:22 pm obviously, you couldn’t do a stoppie using the rear. When i use rear only the weight transfer always appears to move backwards, i must be missing something here.

Le_Fromage_Grande wrote: Thu Jun 29, 2023 9:48 pm
Correct, the releasing the brakes gently is the trail bit, I think just letting go of the lever while braking lent over would cause you to crash as the front end would suddenly unload and spring up, though I suppose a huge amount of rebound damping could prevent this.

Horse wrote: Thu Jun 29, 2023 10:19 pm
You could be feeling the rear 'squat'.

Screwdriver wrote: Thu Jun 29, 2023 9:45 pm

KungFooBob wrote: Thu Jun 29, 2023 8:51 pm I always assumed 'trail' braking was done with the front.

Apparently a dab of the rear on entry can help settle the bike, but I've never done it deliberately, however I have had bikes with linked brakes that do feel a bit more 'stable' on the brakes tipping in.

At some stage you're going to have to stop braking and you don't just release the front brake or the sudden release will upset the stability of the bike as the forks decompress and pop up like a pogo stick. So you have to feather off the front brake and if you're going to do that, you either do it before you tip in to the bend (and just let everyone fly past you) or you feather off the front as you enter the bend. Yorick is correct regarding the effect on the steering geometry and it's not a subtle effect either, the steeper rake angle as the forks compress, really quickens up the steering.

Clearly the latter is the preferred method, brake deep into the corner and feather off the brakes until you get beck on the power. Smoothest is fastest but it is also arguably safest, even on the road. On the road, you won't be using all of the ultimate performance so trail braking will leave you some wiggle room if something unexpected occurs and you need to either tighten your line (brake a little harder) or widen your line (release the brake sooner). Also if you need to stand the bike up mid bend in an emergency, the forks are still slightly compressed (because you're still trail braking) and once stood up you can get on them harder without excessive dive being an issue.

Since I was brought up on two strokes, I use the rear brake a LOT. All the time while braking and a fair bit while accelerating (!). We used to do this on strokers because they're so damned peaky, a slight wheelspin as you power out of a bend can instantly give you a LOT more horsepower as the engine is right at the start of the power band. The upshot is highsides galore since a tiny wheelspin picks up the revs, the engine immediately delivers more power to the rear giving you more wheelspin etc.

Dragging the rear brake can help prevent this runaway effect since the initial onset of wheelspin might just be a slide or a bump and not because you have too much throttle on. If you have power induced wheelspin, it won't help much but the trick with two strokes is to have the engine right the start of that precarious ramp of the power band with just enough throttle to keep it there. It's a real balancing act, immensely satisfying when you get it right, painful when you get it wrong. It's why so many of the best motorcyclists in the world could be seen trowing themselves into the air every weekend. Traction control has levelled that playing field but Rossi was an absolute master of the technique. The rear brake effectively was your traction control.

I still use it to this day on the road where you often need to accelerate while pulling away round a corner for example. Especially at junctions. Even on a plodding old FireBlade (or my trust Fazer), a sharp getaway while turning can lead to a similar "runaway" wheelspin. I drag the rear brake, just in case.

I never did get to the level where I could use the rear brake when wheelieing, I'd always end up trying to change gear with the brake lever! Too late to teach an old dog new tricks but it's easy enough to get on it to stop yourself flipping, just looks a bit dumb if you're half way up Chelsea bridge and you have to bail out.

Another thing about rear brakes is that it does stabilise the bike mid bend since you are effectively adding a little bit of extra damping to the rear suspension. It is way too complex a geometry to try and explain since it is acting via the top and bottom chain run (!) relative to the engine braking or acceleration but this post is way too long and I should stop before this gets out of hand...

Le_Fromage_Grande wrote: Thu Jun 29, 2023 10:11 pm

KungFooBob wrote: Thu Jun 29, 2023 10:01 pm I tried backing my DR250 into a 90 degree corner on my commute to work.

I needed a new indicator lens and put a hole in my HG over trous.

There's a road in Crete that comes down a mountainside through a load of hairpin bends, the tarmac is shite, I backed a hired DR200 into every one of the bends thanks to a gripless Goldenboy rear tyre, there was so little grip the back wheel would lose traction by just slamming the throttle shut and kicking it down a gear, it was so much fun I rode back up the road and did it again.

Trinity765 wrote: Thu Jun 29, 2023 9:38 pm I thought the "trail" in trail braking is because you trail off of the brakes. You brake hard using the front going into a corner but rather than letting go suddenly and the front springing back up you let go gently - trailing off of the brakes.

The above is what I do if I am "having fun" and I feel much more in control when I do it. I also use a tiny bit if back brake as it seems to keep the whole bike a little more settled.

Le_Fromage_Grande wrote: Thu Jun 29, 2023 9:48 pm

Trinity765 wrote: Thu Jun 29, 2023 9:38 pm I thought the "trail" in trail braking is because you trail off of the brakes. You brake hard using the front going into a corner but rather than letting go suddenly and the front springing back up you let go gently - trailing off of the brakes.

The above is what I do if I am "having fun" and I feel much more in control when I do it. I also use a tiny bit if back brake as it seems to keep the whole bike a little more settled.

Correct, the releasing the brakes gently is the trail bit, I think just letting go of the lever while braking lent over would cause you to crash as the front end would suddenly unload and spring up, though I suppose a huge amount of rebound damping could prevent this.

Looking at what I've just typed have I just had a Eureka moment, you could have electronic controlled damping that increased rebound damping when you released the front brake to prevent the forks springing up after braking.

Horse wrote: Thu Jun 29, 2023 6:20 pm

slowhare wrote: Thu Jun 29, 2023 4:45 pm Are new entrants actively taught trail braking?

I doubt it.

@Bigyin to clarify