Mort
19th June 2008, 21:36
Looks like Honda have a new take on their linked braking system
This from Superbike Magazine...
Honda's new ECBS anti-lock brakes in-depth
Bob's back from Germany, and here's what he learned about the new Honda electronic brake system ... Scroll down for the full story
Bob's been looking at Honda's new electronic combined braking system. here's what he reckons to it.
"I'm just back from Baden Baden in Germany, where Honda has just demonstrated a working prototype of its new electronically controlled combined anti-lock brake system for Supersport machines (or ECCBSABS for short?). The system, which should be available as an optional extra on models such as the Fireblade and CBR600RR from 2010, is a completely revised version of their existing combined braking system (CBS), that links the front and rear brake systems, applying pressure to both circuits regardless which lever the rider operates. But the main aim of the system is not to improve lap-times. Instead, it should increase stability under braking and reduce braking distances for less confident riders especially in an emergency situation.
"Unlike current CBS, which works mechanically, the new system is completely electronic and has been referred to as brake-by-wire technology, meaning there's no need for caliper mounting mechanisms to mechanically operate the other pistons. The calipers on the prototype CBR600RR we rode were identical to the standard production bike, but that's where the similarities end.
"Here's how it works. At speeds below 3.5mph the brakes work normally — so fluid pumped by your hand or foot reaches only the caliper you actuate. Above 3.5mph a valve in the brake line operates and diverts brake fluid towards pressure sensors. Now when you pull the front brake lever you're not working the caliper. Instead the sensor sends a signal to the brake control unit (BCU) telling it what you're doing. The BCU then sends a signal to a pump which generates the pressure at the front caliper, not you. At the same time the BCU also sends a signal to the rear brake pump, which is how the combined system works electronically. If you use the rear brake the system works in reverse.
"In itself that's quite clever, but it's not the whole story, because there's also ABS to consider. Unlike conventional ABS systems that generate a pulsating feel when triggered, Honda's system is completely smooth through the chassis and brake lever. Of course it works in the same way as other systems, monitoring the rate of deceleration and comparing this to threshold value, and reducing brake pressure as the threshold is approached and exceeded. But because the pressure at the calipers is being generated by the pump, they're able to vary the brake pressure like a dimmer rather than a light switch.
"In the short time I got to try the system I was impressed. It's clear something out of the ordinary is happening, but it doesn't feel intrusive. For starters, it was impossible to tell that pumps were operating the calipers and not me, and I wasn't aware of the ABS cutting in or out at any point. We didn't get lots of laps of the test track but braking into corners didn't really feel any different when using the front brake, although going in using the rear brake did. To me, it felt a bit like the rear end had been lifted slightly, but I doubt it had.
"So is it a good idea? Yes, I would say. First of all it's important to remember that while you won't officially be able to disable the system if fitted, it will be optional. So if you don't like the idea of linked brakes, don't choose them. But for the majority of people, including myself and a nearly everyone I know, I can't logically see how the downsides of weight and price (neither of which Honda could tell us), can be outweighed by the benefits."
Pros
Increased braking stability for non-expert riders, reduced stopping distance for non-expert riders, greater and greater chance of stopping safely for all riders in a panic situation.
Cons
Increased weight (possibly 10kg), increased costs, may not be able to feather rear brake going in and out of corners*. Unable to tell if the system would upset expert riders on track.
It was suggested that as well as exceeding 3.5mph you also had to exceed a certain brake pressure before the system took over from you. I heard both 0.05kPa and 0.05MPa given as this threshold but couldn't get a definitive answer. However, if 0.05MPa (0.5 bar) was the threshold then this may well be possible.
This from Superbike Magazine...
Honda's new ECBS anti-lock brakes in-depth
Bob's back from Germany, and here's what he learned about the new Honda electronic brake system ... Scroll down for the full story
Bob's been looking at Honda's new electronic combined braking system. here's what he reckons to it.
"I'm just back from Baden Baden in Germany, where Honda has just demonstrated a working prototype of its new electronically controlled combined anti-lock brake system for Supersport machines (or ECCBSABS for short?). The system, which should be available as an optional extra on models such as the Fireblade and CBR600RR from 2010, is a completely revised version of their existing combined braking system (CBS), that links the front and rear brake systems, applying pressure to both circuits regardless which lever the rider operates. But the main aim of the system is not to improve lap-times. Instead, it should increase stability under braking and reduce braking distances for less confident riders especially in an emergency situation.
"Unlike current CBS, which works mechanically, the new system is completely electronic and has been referred to as brake-by-wire technology, meaning there's no need for caliper mounting mechanisms to mechanically operate the other pistons. The calipers on the prototype CBR600RR we rode were identical to the standard production bike, but that's where the similarities end.
"Here's how it works. At speeds below 3.5mph the brakes work normally — so fluid pumped by your hand or foot reaches only the caliper you actuate. Above 3.5mph a valve in the brake line operates and diverts brake fluid towards pressure sensors. Now when you pull the front brake lever you're not working the caliper. Instead the sensor sends a signal to the brake control unit (BCU) telling it what you're doing. The BCU then sends a signal to a pump which generates the pressure at the front caliper, not you. At the same time the BCU also sends a signal to the rear brake pump, which is how the combined system works electronically. If you use the rear brake the system works in reverse.
"In itself that's quite clever, but it's not the whole story, because there's also ABS to consider. Unlike conventional ABS systems that generate a pulsating feel when triggered, Honda's system is completely smooth through the chassis and brake lever. Of course it works in the same way as other systems, monitoring the rate of deceleration and comparing this to threshold value, and reducing brake pressure as the threshold is approached and exceeded. But because the pressure at the calipers is being generated by the pump, they're able to vary the brake pressure like a dimmer rather than a light switch.
"In the short time I got to try the system I was impressed. It's clear something out of the ordinary is happening, but it doesn't feel intrusive. For starters, it was impossible to tell that pumps were operating the calipers and not me, and I wasn't aware of the ABS cutting in or out at any point. We didn't get lots of laps of the test track but braking into corners didn't really feel any different when using the front brake, although going in using the rear brake did. To me, it felt a bit like the rear end had been lifted slightly, but I doubt it had.
"So is it a good idea? Yes, I would say. First of all it's important to remember that while you won't officially be able to disable the system if fitted, it will be optional. So if you don't like the idea of linked brakes, don't choose them. But for the majority of people, including myself and a nearly everyone I know, I can't logically see how the downsides of weight and price (neither of which Honda could tell us), can be outweighed by the benefits."
Pros
Increased braking stability for non-expert riders, reduced stopping distance for non-expert riders, greater and greater chance of stopping safely for all riders in a panic situation.
Cons
Increased weight (possibly 10kg), increased costs, may not be able to feather rear brake going in and out of corners*. Unable to tell if the system would upset expert riders on track.
It was suggested that as well as exceeding 3.5mph you also had to exceed a certain brake pressure before the system took over from you. I heard both 0.05kPa and 0.05MPa given as this threshold but couldn't get a definitive answer. However, if 0.05MPa (0.5 bar) was the threshold then this may well be possible.