GSXR wheels for a 1200 with a Corsa swinging arm

My rear brake gets very little use on the road or the track. I've got it set up well enough to pull the bike up from about 10kph. Good enough for steadying and controlling the bike under braking or on dirt descents in conjunction with the front. There's a reason fast motos have 2 x 320mm front rotors and miniscule 1 x 220mm rears.
 
sfcpiet said:
Not of much use if you intend actually USING the brake.  Brakes made for 60kmh, 75kg machines are a bit overwhelmed when asked to slow down 200kg from 200kmh. ::)
piet
Click to expand...

That is maybe the point, he is barely using it, as - according to him - under heavy front braking the rear tends to block anyway quite easily...

BTW: acccording to german law, the rear brake only needs to slow down with 1g. That is almost nothing... Engine braking is 1,2 - 1,5g...
 
Laverdalothar said:
That is maybe the point, he is barely using it, as - according to him - under heavy front braking the rear tends to block anyway quite easily...

BTW: acccording to german law, the rear brake only needs to slow down with 1g. That is almost nothing... Engine braking is 1,2 - 1,5g...
Click to expand...

Always stunned by the number of bicycles I repair/service where the rear brakes are virtually down to base metal and the front are like new. people just don't get it - or they are simply very afraid of the front ... probably because it's so effective! Try explaining even how car brakes work ....
 
Laverdalothar said:
BTW: acccording to german law, the rear brake only needs to slow down with 1g. That is almost nothing... Engine braking is 1,2 - 1,5g...
Click to expand...

Every motorcycle must be non-compliant with German law then. I could believe 0.1G, but not 1.0G. There's no way you'd have enough tyre friction to pull 1G deceleration with the rear wheel alone, whether applying the brake or under engine braking. Especially when you factor in the forward weight transfer under braking.

Most production road vehicles have a maximum braking G-force of around 0.8G, and that's with a skilled driver (or ABS) using all the brakes - front and rear. Apparently a Bugatti Veyron can manage a bit over 1G because of the aerodynamic forces sticking it down onto the road.

A F1 racing car will brake at around 5G but it has wings that force it downwards. That massively increases the friction forces between tyres and road.
 
point before or after the number - not much difference, right?  :D

you are right, 1g is the total braking power under dry conditions (average bike; maximum is at 11m/s= 1,1xg), 10% of it goes to the rear-brake = 0,1g

So - if the rear brake only does 10% of the job (besides stabilizing the bike during corners maybe on a race track), there is no need for a large brake on the rear other than getting maybe rid of heat.

That is one reason maybe the rear brake of my SF(0) always blocked with the slightest tip of a toe..
 
On a modern short wheelbase sports bike, YES, but on our long-wheelbase dinosaurs with a reasonably strong application of the rear brake, you get less front dive. The whole bike tends to sink in a more level state. Both brakes get a solid bit of use especially on big mountain descents with tight bends. Less heat-induced fade on the front brakes as well.Horses for courses. And there is always Backing it in for those braver than me.
 
The man who taught me to ride and get ready for the test was a police motorcyclist and an old school rider.
He was wary of front brakes, and particularly with inexperienced riders so taught me to use nearly only the back brake.
Bike was a 250mk3.

Incidentally, he'd stop in the caf? next to the riding school between lessons for his glass of ros? and his Gauloise.

I therefore use the back a lot. A rear that blocks the wheel if you insist is lovely.

Paul
 
Laverdalothar said:
you are right, 1g is the total braking power under dry conditions (average bike; maximum is at 11m/s= 1,1xg), 10% of it goes to the rear-brake = 0,1g
Click to expand...

G is an acceleration SI unit (= 9,8 metres per second squared = gravity of Earth).
So unit is m/s2 (metre per second squared).
"m/s" is a speed SI unit (metre per second).

S.
 
Paul, so you learned from a drink/drive policeman?
And you are suggesting his riding tips to you are credible?  :-* :D 8)
 
Steph said:
G is an acceleration SI unit (= 9,8 metres per second squared = gravity of Earth).
So unit is m/s2 (metre per second squared).
"m/s" is a speed SI unit (metre per second).

S.
Click to expand...

Air speed is in knots I believe.

Paul
 
Steph said:
G is an acceleration SI unit (= 9,8 metres per second squared = gravity of Earth).
So unit is m/s2 (metre per second squared).
"m/s" is a speed SI unit (metre per second).

S.
Click to expand...

acceleration can be negative, too... G is just another word for 9,8m/s?, not sure what the point is then? It is a bit like saying "Mach 1" or the exact speed that reflects Mach 1... No?

scratching my head trying to understand what you want to tell me to be honest...

The T?V-Guy f.e. that tested my brake setup for getting it into the papers was using a G-sensor with a printer to proof if the brake works within the values needed. And yes, it was well witin... (0,2x g).
 
If so many claim not to use their rear brake, why is it then that I need to replace so many rear brake pads?  And discs? :o

I always try to keep my rear brakes in decent working order, ie, so they are able to actually slow me down and not only generate heat.

Of course I could ride my RGS all day using only my front brake, but in the alps with dozens of downhill hairpin bends in a day, the strain on the wrists and lower arms is getting a bit much.  My nicely-working rear brake affords some relief, but it does get a bit ruffled after a little spirited riding.  I'm looking to upgrade to a 260mm disc from the gixxer 240mm unit so I don't have to work it so hard.

piet
 
Piet,
Your clients are obviously a total load of numpties who know nothing about riding a bike. Or are on the wrong forum.
And since you mentioned the Alps, if you have two drums, it's nice to alternate so as to let the drums cool down a bit.
Paul
 
Have to admit, having spent the first 20 years of my riding career on big trailies I?ve always been attuned to the need for a well adjusted and functioning rear brake: for me the front is merely for pulling up at junctions (bolt)
 
Lots of times when we end up in our tiddler like mountain passes I find it staggering how many car drivers activate their brake light and obviously their brakes and ride them from the top to the bottom constantly on. With the limited engine braking cars have now even the older drivers who should know better do it. I don't know why I am surprised by this, shows just how piss poor the standard of driving really is. Most wouldn't even know why this is so dumb
 
Some pretty surprising reading in this thread. 'Experts' teaching novice riders NOT to use their front brakes because they're dangerous???? I mean really! Everyone is welcome to ride the way they want but don't try and tell me that the last time you had to stop on a freeway or anywhere in an emergency situation that you relied heavily on the rear brake. Sure, trail riding and gravel riding require different braking dynamics and sensitivity of input, but why ride 99% of the time relying on the rear brake and then expect to have the ability to stop in and emergency where ONLY the front brake can save your arse???

I'd love to see the carnage if cars relied only on rear brakes using ABS ... and they have the benefit of much more weight on the rear tyres.

If your brakes overheat and fade on downhills, your moto is unsafe - upgrade your brakes. I don't ride on drum front brakes - my choice. My SF1 was fine in almost all normal riding situations - it's the ones where my life could be on the line that are the reason I tossed the drum front; I don't like leaving my life to chance.
 
I always thought I hardly used the rear brake.  :-[

After riding the right hand gear change Laverda, I'm surprised how many times I dab the gear lever down while riding.
I suppose it's not something we think that much about.
 
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