I confess I know hee-haw about motor bikes. So after seeing one have to stop quite suddenly on motorway today (going down the middle of slow moving traffic and a car decided to switch lanes) I was wondering how their brakes work?
So to start with,
1. I assume one lever is a brake lever, its not like a push bike with front and back levers?
2. Are the brakes balanced in such a way that x% goes to back and y% goes to front or how do they work?
3. What happens when you have to do a full emergency stop, say at 70mph? What prevents lock-up, bum over handlebars etc?
4. Bearing in mind the answer to 3. above, how do some bikers manage to get their standard road bikes up onto front wheel only under braking (seen various clips of this sort of thing in you tube?
Thats all for now!
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Not got any definite knowledge myself, but I believe one hand lever is the front brake (other is the clutch). Back brake is a foot pedal.
I think that answers 1.
For 2, the user balances the brakes themselves through their use of the different controls.
Same again for 3 - always pull the front first to stop from locking the rear and ending up sliding along your side. (I know this is prevailing wisdom, but never quite made sense to me as a cyclist, thinking of the seemingly worse issue of going straight over the handlebars. Think the relative likelihood comes into play.)
And I think 4 is obvious too from previous info.
Last edited by: Bazzabear on Sat 24 Apr 10 at 20:52
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That's basically right - lever for the front brake, foot for the rear. So emergency stops are very much down to skill.
Some bikes have linked brakes (big Hondas mainly), so the lever applies one piston on the rear and vice versa. Quite a few bikes are starting to get ABS.
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Standard bike brakes work as follows:-
Front lever operates front brake, rear pedal works rear brake - you tend to learn the proportion of use with experience, overcook it and the front brake will lock and chuck you off, overcook it on the rear and the back wheel will lock.
The trend these days are for linked brakes i.e. front brake will deliver balanced braking to front an rear. The rear brake remains as described above not linked to anything and is used for hill starts etc. My BMW 1200GS trail/enduro has powered front and rear brakes as well as switchable ABS and will outbrake most things on the road, the rear on this bike is also used for off road stuff (apparantly)
My 1200RT has non-switchable ABS'd brakes but no servo - servos tend to make the brakes a little over sensitive in daily use.
They are very high tech braking systems and have remarkable stopping power....
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As bazzer says, front brake is alever on the handlebar and the rear is a pedal.
Modern bike brakes are good, very good, sometimes too good. Grip the front brake only with all your might in a panic will see the front brake lock (some have ABS) and you will be on your side, or you will be over the top. YOu have to shift your weight back in the bike.
The front brake (like cars) can produce all the stopping power. YOu apply front brake and then rear, increasing the pressure and stopping power if you can.
Some bike have linked brakes, bringing on a % of rear brake with front.
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Traditionally, most bikes use the right hand lever on the bars to operate the front brake.
The rear is operated by a foot pedal, on the right nowadays due to US reauirements in the past.
The left hand bar lever is normally the clutch.
Most bikes have disc brakes, just like a car's. Mostly, the front and back are independent of each other but some have a linked system with delays between the two.
ABS is also common nowadays.
There are variations. My own 600cc Silverwing has no foot pedals. Ideal for my old arthritic legs as I can move them about. The front brake is operated as normal by the right lever, but the left lever also operates the front brake with the addition of the rear brake. There is a slight time delay between them. I also have a handbrake...being automatic, I can't put it in gear when parked on a hill.
Earlier, machines had drums, rim brakes like a bicycle, or even a shoe acting directly on the tyre in some primitive types.
Gearchanges, too, had variations, The first LE Velocettes had a hand lever and a gate on the right side of the tank. My own one has the later right side foot change...one up and three down.
Ted
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Surprised bikes aren't at the point now where brake control can, like a modern car, be handed over to the computer in an emergency stop. Should think that the computer can guarantee perfect brake distribution and maximum stopping power regardless of the rider position.
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Spotty youth on a ying ting 2 stroke trailie thing sporting an L plate used my back bumper to aid his emergency stop the other day. He'd been trying to get into my boot for a while and eventually had a proper go at it when a kid's football came bowling out between two parked cars into my path and I decided to let discretion be the better part.
Fortunately we were both already going quite slowly and he stayed upright and my bumper was undamaged. I stopped though to have a look just in case and mentioned that he might want to consider driving a little further back from other vehicles in future. He grunted something in reply before speeding off in a cloud of unburnt lawnmower juice.
I expect he'll have to hurt himself before he gets the idea.
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I agree modern bike brakes, set up and maintained properly, are superb. Even my 15 year old ZZR600 has a pair of 300mm front discs gripped by fairly hefty four pot calipers, and they are primitive compared to the proper modern stuff.
Rear brake use in an emergency is fairly pointless on a non-ABS machine, as the forward weight transfer means the rear brake can do very little before locking the wheel. For planned braking, the rear brake can contribute quite a lot to the effort, and for low speed manouevring it is really useful. I was taught to balance engine power / clutch slip against rear brake when performing slow speed turns or squeezing through tight gaps. The drive helps balance the bike and keep it upright, and the brake controls the speed. When braking from very slow speeds (< 10 mph) or from higher speeds just before the bike comes to a complete stop, I tend to use rear brake only. It doesn't compress the forks as much and keeps the bike better balanced. Plus a rear end slide/lock-up on a bike is far less scary than the same thing on the front.
The front brakes on their own can do amazing things, as long as you don't snatch at the lever. If you apply them progressively, you can almost stand the bike on its nose, and the stunt boys do just that.
Typical modern bike controls:
- left lever = clutch
- right lever = front brakes
- left pedal = rear brakes
- right foot operated up/down lever = sequential gear change. Starting at the bottom, and kicking up in order you get 1st, Neutral, 2nd, 3rd, 4th, 5th etc.
Typically on the bars you will also have switches for lights, indicators, starter (always on a button rather than the key) horn, plus a "kill switch" to stop the engine in an emergency (although turning the key to off is used on a day to day basis, much as with a car.
Last edited by: DP on Sat 24 Apr 10 at 22:00
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Absolutely no chance of doing a crash stop on the Vulgar Velo. To do any braking you have to make advance arrangements !
Weedy little cable operated drums. 1st gear is a much better brake but you've got to be pretty nippy with old right foot to get it down the box in time. Best option is to look ahead and keep well behind !
Ted
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Shocking how much chassis tech has progressed in bikes - I used the 83 CB650 I had for a couple of days - the brakes were like balsa wood with handful of front brake needed to have any retardation effect - they were up to spec with refurbished calipers last year and new fluids - frighteningly poor retardation.
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>>Best option is to look ahead and keep well behind !
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>> Ted
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Ted, there has to be a joke there somewhere. Still working on it though. Bantam or Tiger Cub??
M
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That's just reminded me O Devonian one....I've got a D reg, 175 bantam in bits in the garage. I've got no wheels but everything else is there including a V5C
Must put it together some time ! Better start checking EBay.
Ted
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>> Must put it together some time ! Better start checking EBay.
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>> Ted
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Nought like the whiff of 2-stroke.
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>> Typical modern bike controls:
>>
>> - left lever = clutch
>> - right lever = front brakes
>> - left pedal = rear brakes
>> - right foot operated up/down lever = sequential gear change. Starting at the bottom and
>> kicking up in order you get 1st Neutral 2nd 3rd 4th 5th etc.
>>
Left pedal on all the bikes (Japanese 97, 02, 07, 08 & 09) I've ridden has been the gearlever, the right is the rear brake.
I use sintered pads on the front, much better than the standard items though never found them any better on the rear.
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Kawasaki brakes were the business in the 80s sintered pads and drilled discs banished sluggish when wet disc brakes. Motto Guzzi ran their bikes on linked front/rear brakes in the 70s and 80s long before Germans and the Japanese got into it. Disc pad technology has come on in leaps and bounds over the years with pad makers like EBC being at the cutting edge of the industry both in bike and car terms.
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>> Left pedal on all the bikes (Japanese 97 02 07 08 & 09) I've ridden
>> has been the gearlever the right is the rear brake.
Glad someone is awake! :-)
You are of course spot on. Never did know my lefts from my rights. doh!
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No one seems to have tackled 4.
Like hanging the back end out in a RWD car it takes practice to do a stoppie without landing in a heap. Load the front forks to absorb the spring compression then lift the rear but keep in mind the front wheel has to keep rotating then release the front before coming to a standstill to drop the backend back to earth gently.
You don't want to do this too often has it shortens the life of the headstock.
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....and the rider, possibly.
Ted
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My brother-in-law does that outside our house on his "Fireplace". Wish he'd stop it. He's 45 and bald for goodness sake !
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Motorbikes - emergency stops - Bazzabear
