180 ver 160 brake discs up front ?

[Steven Knoetze (sk27)]

You should hear what the trail builders say!!!

 

Anyway, how's the chain/derailleur setup working now?

 

Don't let me get started.

Will PM you.

[Tromp]

Sooo many people wrecking our trails because they believe locking up the rear is the quickest way to stop.

Feel like samcking them against the head!!!

'Skies my Kroon ,maar dit wassie ekkie. Decades of motorcycle riding has taught me that applying the back brakes until it locks , is a sure way of ruining yourself and the bike , let alone the " trails "

[RichieT]

Locking and drifting the rear around corners on a dirt motorbike often is the way to go.. like car rallying, but on a push bike, very seldom. For slowing & stopping, do it in a straight line with, as Flowta says 70% front. For most apps a 160mm rotor on the rear is enough, but if you do a lot of steep and long downhills, then a 180mm on the front minimises fade.

Drifting, locking up the rear just wastes energy and wears out your tyres! .. as well as messing up the trail.

Edited March 18, 2014 by RichieT

[Paul Ruinaard]

Sooo many people wrecking our trails because they believe locking up the rear is the quickest way to stop.

Feel like smacking them against the head!!!

 

However how do you "back" a bike in to a corner (aka superbikes), unless you lock the rear up and get it to slide?

 

FWIW: Tires can brake or turn - but try and get them to brake and turn at the same time and you will end up having a face plant. Unless you are very experienced.

 

FWIW 2: I am a fat boy and have gone to 180mm ice rotors front and back with Shimano XT brakes. I have so much modulation and control it is like i have depth in the brakes. Never had this before.

 

I think the fitting of larger rotors is the greatest brakes upgrade available, plus one of the best and cheapest hacks. No one tells you to fit bigger rotors - there are however tons of strings on brakes and Hope vs Shimano etc.

 

You always have more power up front and are more likely to lock up the back owing to weight shifting so a 180/160mm front/.rear combo works very well for the average weight guys.

 

203mm tended to throw me over the bars as it was just too much.

[Dicky DQ]

Why do they normally fit the larger diameter brake discs on the front wheel ? The rear brakes are used more often ( with my riding style anyway ).

 

so you are one of those people that need to be banned from single tracks. GRRRRRR!!!!!

[Steven Knoetze (sk27)]

However how do you "back" a bike in to a corner (aka superbikes), unless you lock the rear up and get it to slide?

 

FWIW: Tires can brake or turn - but try and get them to brake and turn at the same time and you will end up having a face plant. Unless you are very experienced.

 

FWIW 2: I am a fat boy and have gone to 180mm ice rotors front and back with Shimano XT brakes. I have so much modulation and control it is like i have depth in the brakes. Never had this before.

 

I think the fitting of larger rotors is the greatest brakes upgrade available, plus one of the best and cheapest hacks. No one tells you to fit bigger rotors - there are however tons of strings on brakes and Hope vs Shimano etc.

 

You always have more power up front and are more likely to lock up the back owing to weight shifting so a 180/160mm front/.rear combo works very well for the average weight guys.

 

203mm tended to throw me over the bars as it was just too much.

 

If you have watched any motorcycle racing of late you will see that only supermotards back into corners now. The new thing is to spin up the rear causing it to slide thereby giving you oversteer to help get around the turn.

On a bicycle, unless you can produce 1000W instanly I think this is impossible to do.

 

All I was trying to say is that the majority of these trail wreckers who lock their rear going into corners are merely slowing themselves down.

[Tromp]

so you are one of those people that need to be banned from single tracks. GRRRRRR!!!!!

Your name says it all. Refer to my comment on post #18. And it is not even Friday yet ??? Edited March 19, 2014 by Tromp

[Flowta]

Your name says it all. Refer to my comment on post #18. And it is not even Friday yet ???

 

There may have been a slight tongue in cheek there.

[BogusOne]

There may have been a slight tongue in cheek there.

 

 

 

http://img1.wikia.nocookie.net/__cb20100720134301/uncyclopedia/images/5/51/Cassilas.gif

[ThePubSA]

Front wheel is your 1st line of rolling... thats why it will stop you faster... 180+ upfront for me

 

Front vs. Rear Brake

On dry pavement, the front brake alone halts the bike over the shortest distance.

Many riders think they need both brakes to stop effectively, if only because most bikes are outfitted with 2 brakes and that implies that one should use both. Here’s the way to think about it: the momentum of your body continues to move forward as your bike is slowing down, so your weight shifts forward. That’s why your rear wheel can come off the ground when braking hard. When your weight comes forward during hard braking, your rear wheel has close to zero traction. If you apply the rear brake under these conditions, the rear wheel will lock up without contributing significantly to the braking effort.

If you can apply the rear brake without locking up the rear wheel, then your weight isn’t shifting forward – a clear sign that you aren’t braking as hard as you should!

We tried braking with both brakes and with the front brake alone, and consistently found that if we focused all our attention on the front brake, we achieved much shorter stopping distances.

When we braked with the rear brake only, the stopping distance was more than three times as long. In fact, Hahn overshot the stop sign and went into the road at the bottom of the hill (above). This was despite Hahn modulating his rear brake carefully to keep it below the lockup point as much as possible. Skidding the wheel would have increased the stopping distance further.

[patches]

A simple illustration of a moment...

 

 

http://www.torqueleader.com/default/assets//Image/torque-calculation.gif

 

So in easy to understand terms, think of the following:

• T - your ability to stop. The greater the better.
  
• F - The "power" of your brake caliper.
  
• L - the size of your rotor
  

Some simple calculation will indicate that this means a 180mm rotor is 12.5% more effective than a 160mm. And a 200mm rotor is 25% more effective.

 

And all this is purely from the torque side of things. As mentioned above, the larger surface areas of the increased rotor diameters also dissapate heat better, so again, larger is more effective.

 

As for the Front vs Back (and again, it has been stated above), under braking ones weight moves forward, putting more traction on the front wheel. The rear wheel unweights causing it to lock up and skid easier. Larger rotors on the back are sometimes a hinderance becasue they lock up too easily.

 

@RitchieT

 

As for the dirt bike or rally car drifting the rear wheel(s) into corners. Remember, they do most of their braking in a straight line. They may touch brakes briefly to get the tail out. Then they use the throttle/accelerator to push through the corner. They do not just jump on the brakes until they're through the corner.

 

My bicycle does not yet have a throttle, but it doesn't mean that this technique cannot be used on the trails.

 

Again, do most of your speed modulation in a straight line. unweight the rear and twist your hips to get the tail out (sometimes a dab of the brakes is needed), this is done BRIEFLY then LET GO of the brakes and the bikes will feel like it's accelerating, and you will have more control around the corner as breaking fights the wheels gyroscopic forces and makes the bike want to stand up. This is also more friendly on the trails as one isn't dragging their rear wheel into and out of the corners, causing brakig bumps.

Edited March 19, 2014 by patches

[Tromp]

Front wheel is your 1st line of rolling... thats why it will stop you faster... 180+ upfront for me

 

 

Front vs. Rear Brake

On dry pavement, the front brake alone halts the bike over the shortest distance.

Many riders think they need both brakes to stop effectively, if only because most bikes are outfitted with 2 brakes and that implies that one should use both. Here’s the way to think about it: the momentum of your body continues to move forward as your bike is slowing down, so your weight shifts forward. That’s why your rear wheel can come off the ground when braking hard. When your weight comes forward during hard braking, your rear wheel has close to zero traction. If you apply the rear brake under these conditions, the rear wheel will lock up without contributing significantly to the braking effort.

If you can apply the rear brake without locking up the rear wheel, then your weight isn’t shifting forward – a clear sign that you aren’t braking as hard as you should!

We tried braking with both brakes and with the front brake alone, and consistently found that if we focused all our attention on the front brake, we achieved much shorter stopping distances.

When we braked with the rear brake only, the stopping distance was more than three times as long. In fact, Hahn overshot the stop sign and went into the road at the bottom of the hill (above). This was despite Hahn modulating his rear brake carefully to keep it below the lockup point as much as possible. Skidding the wheel would have increased the stopping distance further.

Game , Set and Match !!

[Toon63]

Brakes? I don't like using them they just cost money.

MTB now for 4 years and only replaced them once

[Steven Knoetze (sk27)]

Brakes? I don't like using them they just cost money.

MTB now for 4 years and only replaced them once

 

Dude, I did an enduro on Sunday and I had to will myself in keeping my fingers off of the lever.

Was super scary but a lot more fun!!!!

[V12man]

Skidding the wheel would have increased the stopping distance further.

 

Don't know who wrote that, but he is wrong - the distance will be shorter, BUT - you will have much less control over steering/direction - possibly none.

 

Works for cars too - ABS does not shorten braking distances (wet or dry) but it does allow you to change direction when braking hard - this is why race cars with configurable race ABS systems allow you to push through the ABS to get it to lock - you just have to REALLY stand on the pedal (although cutover pressure is configurable)

 

Useful feature if needed as a last resort - rather learn to drive AROUND things.

[braailegend]

Don't know who wrote that, but he is wrong - the distance will be shorter, BUT - you will have much less control over steering/direction - possibly none.

 

Works for cars too - ABS does not shorten braking distances (wet or dry) but it does allow you to change direction when braking hard - this is why race cars with configurable race ABS systems allow you to push through the ABS to get it to lock - you just have to REALLY stand on the pedal (although cutover pressure is configurable)

 

Useful feature if needed as a last resort - rather learn to drive AROUND things.

 

Skidding makes your braking distance further, as there is less traction on the tyre (thus less resistance to stop), than when you gradually braking, keeping traction (More resistance on the ground)

 

Edit: As soon as the wheels lock, the resistance coefficient is that of the Tyre to ground, in stead of Brake pad to rotor

Edited March 19, 2014 by braailegend