Strange Braking Technique...

huskie69

Hi all

I seem to have developed an odd braking technique when I need to "emergency stop". I think I've been doing it for a few years without thinking anything of it but I wanted to run it past some other people to see if it's "acceptable behaviour"!

I'm quite a heavy rider (>17st) and carry quite a lot of forward momentum when I'm rolling at a decent pace. This makes it difficult to stop suddenly without either skidding insanely or just failing to stop altogether.

To counteract that momentum, I've noticed I subconsciously bounce the rear wheel whilst feathering both brakes - rolling up on the front momentarily, to bounce the rear tyre to avoid skidding then releasing front brake and repeating. All happens in a fraction of a second, pracitaclly beyond my control - maybe a primitive human ABS system?!

It certainly feels like it helps me slow down quickly while retaining control over the bike. Whether or not it actually is working is up for debate!

Just wondering if this is anything anyone else does (especially the heavier riders)?

roger_merriman

No I modulate each brake independently, with most bikes you can feel the rear lighten the aim under hard braking is to hold it at that point, ie getting the maximum, even if it means locking/loosening off the rear. Very few bikes can brake hard with the rear.

dork_knight

Have you ever ridden fixed as it sounds similar to a skip stop?

huskie69

Dork Knight wrote:

Have you ever ridden fixed as it sounds similar to a skip stop?

That's exactly it!

Never heard of a skip stop before but after finding an example on YT, https://www.youtube.com/watch?v=ewhWYqqIXb0 this is what I'm doing.

Having never ridden a fixie before, why would it be a "fixie" thing?

DeVlaeminck

I doubt anyone can press and release the front brake fast enough to act like a human ABS. Emergency braking at speed it's not unknown for the rear wheel to lift even without stopping - a high speed rolling endo - but I'd like to see someone repeat that multiple times in one stop.

huskie69

DeVlaeminck wrote:

I doubt anyone can press and release the front brake fast enough to act like a human ABS. Emergency braking at speed it's not unknown for the rear wheel to lift even without stopping - a high speed rolling endo - but I'd like to see someone repeat that multiple times in one stop.

Nah, I was just using ABS as a very basic comparison in attempt to convey the fact that's it's quite a complicated way of braking - as opposed to "normal" braking.

See the video, that's what I've been doing. And it is deliberate, it doesn't just happen. I effectively slam down the rear wheel multiple times (when the rear brake is clamped shut) to assist in a quick slowdown.

I'm glad I'm not the only one who does it (skip stop) and there must be something to it if other cyclists use the technique.

debeli

huskie69 wrote:

Nah, I was just using ABS as a very basic comparison in attempt to convey the fact that's it's quite a complicated way of braking - as opposed to "normal" braking.

See the video, that's what I've been doing. And it is deliberate, it doesn't just happen. I effectively slam down the rear wheel multiple times (when the rear brake is clamped shut) to assist in a quick slowdown.

I'm glad I'm not the only one who does it (skip stop) and there must be something to it if other cyclists use the technique.

Other folk do indeed do this, but it is to compensate for the absence of a rear brake. They lock the rear wheel of a fixie (or similar) by hopping it off the ground and stopping the pedals.

What you describe seems unnecessary on a bicycle fitted with a working brake on each wheel. However, it seems to work and you seem to be alive, so it must (at least up to a point) be doing what you need it to do.

There is something, however, to be said for smoothness and for not causing alarm among other road users.

The trick to generating retardation through the rear tyre is generally to keep it in contact with the tarmac. This may best be done by moving the mass of the rider (you quote 17 stone) to the rear. If you straighten your arms and shove your posterior rearward, you may find that you can apply more rear brake without causing rotation about the front axle.

Any well maintained bicycle is quite capable of throwing its rider over the bars in dry conditions on tarmac when the front brake is applied with vigour and abandon. The trick is to modulate the use of the front and rear brakes to arrive at the desired velocity in full control of the bicycle and looking as cool as is possible.

Cadence braking on the rear while hauling full-beans on the front brake sounds entertaining but potentially inefficient and alarming. But if it helps you and hurts no-one else, go at it.

DeVlaeminck

@Huskie - Well that video is on fixed and I'm assuming you aren't riding fixed. They are locking the rear wheel by stopping the pedals and then pulling the rear wheel off the ground by pulling up on the pedals.

If you are doing something similar you are saying you are locking the rear wheel by using the brake and then bouncing it by pulling up on the pedals ? If so I'd quite like to see a video but it sounds quite a skill though I'm not sure what it achieves other than wrecking your rear tyre and extending braking distance ?

Alternatively are you claiming to bounce the rear wheel by applying pressure to the front brake - in which case I'm sceptical that is possible but I admit I've never tried it.

huskie69

Hmm. It's a difficult one to explain (and justify!) and seems to perhaps be a bad habit I've developed.

I've never been confident in applying too much pressure to the rear brake as I've quite often managed to lock up the rear and started skidding - and when you're clipped in, it's no fun! You might say it's pretty difficult to lock up the rear wheel but when you're approaching a "flock of pedestrians" at 25mph who aren't paying any attention to the road, a rear wheel lock up is a pretty easy thing to do.

As a motorcyclist, (despite the fact that the mechanics are somewhat different, and no, I've never done this on a motorbike!!) I know how easy it is to lock up a rear wheel and lose control, and I try not do it on the road bike if I can help it.

I'm no expert in traction/friction dynamics or whatever but I'd assume this method is causing no more harm to my rear tyre than getting into a full on skid would. For example, the contact patch on the rear wouldn't be the same as inbetween "skipping", the rear tyre would be in free rotation so I'm not ripping through the same part of the tyre.

I dunno, maybe I should start learning to throw my weight as far back as I can and slow it down normally. It's a "fat guy" problem!

huskie69

DeVlaeminck wrote:

Alternatively are you claiming to bounce the rear wheel by applying pressure to the front brake - in which case I'm sceptical that is possible but I admit I've never tried it.

No, definitely not, it's more alternating the braking pattern between front and rear rapidly, and while the front isn't clamped on, I'm clamping on the rear brake, and I *think* I'm lifting the rear up by pulling up on the pedals (I don't think this would be easy if I wasn't clipped in).

thomasmorris

huskie69 wrote:

I've never been confident in applying too much pressure to the rear brake as I've quite often managed to lock up the rear and started skidding - and when you're clipped in, it's no fun!

Locking the rear wheel is a lot more fun than locking the front!

The skip stop thing I always thought was where the gear ratio on a fixie was too high for you to initiate or hold a skid by back pedaling (if you have a big gear, the back end has a massive mechanical advantage on you if you try to back pedal). You repetitively lift the rear wheel to allow you to lock it before it hits the ground.

...but with working brakes and no fixed gear, I've no idea why it would be any more efficient that just modulating the brakes. Can't think why being heavy would make a difference either.

DeVlaeminck

On dry roads it's quite hard to accidentally lock the front wheel - so long as you are braking at all progressively your rear wheel will lift and you just need to release some pressure on the front brake to get it down again. As ThomasMorris says above locking the back is no biggy so long as you are in a straight line again just back off the pressure a bit to relieve any skid.

Your pulling up the back wheel is a problem on two counts. Firstly whenever that wheel is in the air you are losing any possible braking force from the rear. Secondly by pulling the back of the bike are you are reducing the amount of braking force you can put through the front before going over the handlebars because you are throwing your mass upwards and forwards yourself.

slowbike

DeVlaeminck wrote:

I doubt anyone can press and release the front brake fast enough to act like a human ABS. Emergency braking at speed it's not unknown for the rear wheel to lift even without stopping - a high speed rolling endo - but I'd like to see someone repeat that multiple times in one stop.

It's called cadence braking - taught in cars in skid pans to control skidding ... done it in a car (hmm .. I'm that old I'm pre ABS!) - but not on the bike ...

All ABS is is a method of applying the brakes and releasing them quickly so the wheel keeps turning allowing the driver to retain control over steering - and a turning wheel trying to be stopped has more friction than a stopped wheel.

Not sure it's of that much use on a bike - unless you're skidding the wheels - a no-no on the front - but not so critical on the back.