The rear brake. Who uses it?

[Dreama]

But did you have it up and running though?

Yeah, it works really well. I'm able to use either foot or thumb but mostly I found that when I needed it for hard braking I was a tad 'busy', never mind trying to downshift at the same time.. I did use it when coming into sweepers like Jennian at puke because I had time to think about it.

[Robert Taylor]

You've ridden bikes with the swingarm pivot too far above the axle height, no? They light up the tyre something fierce on corner exit. Took a long time to figure out that's what was causing me to lose speed and drive on my superbike.

'Anti squat' is what some people call it. It means that the front doesn't rake out as much when you load up the rear, and can hold a tighter line...untill of course the power of your bike overcomes the available traction of the tyre. Then the line tightens up MIGHTY quick.

The rear brake isn't used to reduce power, it's to sort the geometry of the swingarm in this application.

Be careful of making over generalisations that something may not work on one particular bike. Where it may work on another bike with a different combination of components.

Take the humble two stroke expansion chamber. We fitted a brand new aftermarket one back a few decades ago to one of Shayne Kings racebikes. (about the same time that you were graduating to sitting on the toilet). The bike was still stock and it dyno'd as having less power and delivery than with the stock pipe. We then ported the cylinder and then repeated the back to back tests of stock against aftermarket pipe. The aftermarket pipe LOVED the ported cylinder. COMBINATIONS. That is no less true of pivot height, etc

Id really like to get hold of some of that really good shit you are smoking!

[Drew]

Be careful of making over generalisations that something may not work on one particular bike. Where it may work on another bike with a different combination of components.

Take the humble two stroke expansion chamber. We fitted a brand new aftermarket one back a few decades ago to one of Shayne Kings racebikes. (about the same time that you were graduating to sitting on the toilet). The bike was still stock and it dyno'd as having less power and delivery than with the stock pipe. We then ported the cylinder and then repeated the back to back tests of stock against aftermarket pipe. The aftermarket pipe LOVED the ported cylinder. COMBINATIONS. That is no less true of pivot height, etc

Id really like to get hold of some of that really good shit you are smoking!

Soooo. If you (in essence) put the swing arm pivot so high that the chain is always shortening the distance between sprockets by extending the shock when under accelerating load, with the right combination of shock and linkage it will still squat? I don't think so.

If the torque is enough to overcome the weight transfer and hold the sprockets closer together, (as in not letting the rear shock compress), then applying the back brake before the gas can assist. After all, the forces from applying the rear brake all add up to the swingarm compressing the rear shock unless you are riding something antiquated with a torque arm. Once the swingarm passes the point of the three points being in a straight line, the torque is then trying to continue that same motion of the swingarm.

I cannot help but wonder if this is the reason manufacturers have gone away from using a torque arm to the rear caliper....or just a happy coincidence from dropping a bit of weight.

[Grumph]

I cannot help but wonder if this is the reason manufacturers have gone away from using a torque arm to the rear caliper....or just a happy coincidence from dropping a bit of weight.

Nah. tyres have got wider but in the main, swingarm pivot widths have stayed the same - so less room for a torque arm. Simplify - and it's probably cheaper too.

[Robert Taylor]

Soooo. If you (in essence) put the swing arm pivot so high that the chain is always shortening the distance between sprockets by extending the shock when under accelerating load, with the right combination of shock and linkage it will still squat? I don't think so.

If the torque is enough to overcome the weight transfer and hold the sprockets closer together, (as in not letting the rear shock compress), then applying the back brake before the gas can assist. After all, the forces from applying the rear brake all add up to the swingarm compressing the rear shock unless you are riding something antiquated with a torque arm. Once the swingarm passes the point of the three points being in a straight line, the torque is then trying to continue that same motion of the swingarm.

I cannot help but wonder if this is the reason manufacturers have gone away from using a torque arm to the rear caliper....or just a happy coincidence from dropping a bit of weight.

Everything in moderation Drew

Having some rear end compression just before applying the front brakes is a good thing as it lower the biggest weight ( the motor ) a tad and gives more rear end extension capacity

[suzuki21]

Everything in moderation Drew

Having some rear end compression just before applying the front brakes is a good thing as it lower the biggest weight ( the motor ) a tad and gives more rear end extension capacity

This would be true, and is exactly what top riders do. Without proper datalogging and people at a level that can decipher the results they are probably better off just riding the damned thing and getting more practice. For example it is common on coaching days people do quicker laptimes when they brake EARLIER as they have time to set up for the corner. Generally people out of the top 5 in SBK or 600 in NZ would be better served by not worrying about swingarm angle or rear brake use, and concentrating on losing bad/incorrect riding habits.

[quickbuck]

Generally people out of the top 5 in SBK or 600 in NZ would be better served by not worrying about swingarm angle or rear brake use, and concentrating on losing bad/incorrect riding habits.

Actually, after witnessing what I did at the final round of the NZSBK Nationals, I would say "Top 10".... But, yes fair point.








Sent from my Nokia using Tapa talk.

[Boo]

OK I've kept up with the post and all the feed back, I use a rear hand brake because
1.When I do wheelies my ass slips down the seat and I can't keep my foot on the rear brake lever because my guts is too fat.
2. When I trail brake into a corner my guts is not trying to fly over the bars it just pushes up against the tank.
3. If you slip off the back and try to run alongside the bike, if your in anything higher than 1st your fucked.
4. If you break that good shit up into tinnys ill take two.

[Robert Taylor]

This would be true, and is exactly what top riders do. Without proper datalogging and people at a level that can decipher the results they are probably better off just riding the damned thing and getting more practice. For example it is common on coaching days people do quicker laptimes when they brake EARLIER as they have time to set up for the corner. Generally people out of the top 5 in SBK or 600 in NZ would be better served by not worrying about swingarm angle or rear brake use, and concentrating on losing bad/incorrect riding habits.

For once you are largely talking some sense Steve. Even though you have many bad habits and attitudes! For me Jaden Hassans steady progress was a standout, all without any rider ''aids'' such as traction control or data logging. A winner in his rookie season and 4th overall. But for an unfortunate gear linkage fracture in the final race ( whilst leading ) he would have finished second overall in the championship.
Im not against data logging by any stretch of the imagination but its clear that you can become so overly preoccupied with it that it takes a hell of a lot longer to establish a setting direction and theres not always the luxury of that amount of time. Sometimes instinct is a lot faster.

Indeed one of the very top Ohlins technicians in Moto 2 ( looking after the very top guys ) does not look at data logging and relies most on his own setting instincts. This class is full of young guys with relatively very little setup knowledge and as is fairly suggested they are best to concentrate on riding skills. Given of course that they are given bikes that are on the money

[Shaun Harris]

This would be true, and is exactly what top riders do. Without proper datalogging and people at a level that can decipher the results they are probably better off just riding the damned thing and getting more practice. For example it is common on coaching days people do quicker laptimes when they brake EARLIER as they have time to set up for the corner. Generally people out of the top 5 in SBK or 600 in NZ would be better served by not worrying about swingarm angle or rear brake use, and concentrating on losing bad/incorrect riding habits.

The problem with the last part of your comment mate is people spend to much time reading shit on the net about tech issues when they should be spending time on what you have said, ( Or is some cases just getting what they have going so they can test themself out) just learning to ride smoothly and evalluating where there weaknesses are and what they need to concentrate on to eradicate bad and introduce new habits.

[roogazza]

The problem with the last part of your comment mate is people spend to much time reading shit on the net about tech issues when they should be spending time on what you have said, ( Or is some cases just getting what they have going so they can test themself out) just learning to ride smoothly and evalluating where there weaknesses are and what they need to concentrate on to eradicate bad and introduce new habits.

I like the way this thread is heading. Ride smooth and practice !
I drag the shit out of the rear always have (like 50 yrs !) Never really thought of it much. Just tried to be as smooth as. Different era I know,but I can remember mates coming up at Street races saying how they notice me dragging the rear into corners!
(Old drum brakes would turn gold.)
It was all instinct,not taught. Too old to bother changing now.

[Tony.OK]

With the advent of slipper clutches, is rear braking so important coming into corners now?
I can see the benefits on mid corner and exit for wheelspin control and settling/tightening line mid corner.
I remember years ago they had a camera looking at Edwards (I think) foot in WSBK, was surprised how much he was using the rear mid and late corner.

[Shaun Harris]

With the advent of slipper clutches, is rear braking so important coming into corners now?
I can see the benefits on mid corner and exit for wheelspin control and settling/tightening line mid corner.
I remember years ago they had a camera looking at Edwards (I think) foot in WSBK, was surprised how much he was using the rear mid and late corner.

yes Tony I think is is. it actually does help reduce speed which is what it was intended for, so based on that alone, it most deff has a place still for racers and road raiders as a safety control. A smidgeon of time gained on each corner entry adds up after 6 or so breaking turns compounding on lap after lap till end of race.

[Mental Trousers]

With the advent of slipper clutches, is rear braking so important coming into corners now?

There's still plenty of cases where a slipper clutch isn't the entire answer. For instance, Taupo heading to the sweeper before the main straight I don't change up to fifth I just keep it in the same gear. But that means I get to the braking area with 14,000rpm on board and when I close the throttle and brake the engine momentarily locks the rear wheel, which causes the wheel to leave the ground for a split second because the shock is able to react a lot quicker than the slipper clutch. It repeats this a couple of times so it's the classic engine braking lock up problem until the slipper clutch reacts and cancels it out.

In that case the rear brake helps.

Either that or I fiddle the computer and take 3 degrees of ignition advance out over 12,500rpm @ 0% throttle, which is what I've done cos it's easier than learning to use the rear brake again

[YellowDog]

Great thread guys.

My rear brake lasts just over half as long as my front one, so I guess I must be using it quite a bit.

You need it for low speed control and 14,500 rpm is not something I have experienced