PDA

View Full Version : The saffas know how to be safe



haydes55
22nd December 2015, 17:24
318097 120km/h>0 in 30m. The south African government said so. Sounds pretty safe speed to me if you can stop in 30 meters. Doesn't the nz government claim we need like 50m to stop at 60km/h?

sidecar bob
22nd December 2015, 17:36
Our figures are based on a retard with a gn250 that has been riding for 6 months, not Andrew Stroud on a superbike.

haydes55
22nd December 2015, 17:39
Our figures are based on a retard with a gn250 that has been riding for 6 months, not Andrew Stroud on a superbike.
Andrew stroud has nothing on me! (When it comes to the ins and outs of ventilation systems).

In south Africa their brakes must be better.

haydes55
22nd December 2015, 17:41
318104 here's NZs answer

F5 Dave
22nd December 2015, 18:16
You can stop in much shorter distance.


It might just hurt a bit.

rastuscat
22nd December 2015, 18:27
You can stop in much shorter distance.


It might just hurt a bit.

Another rule: the hurt is proportional to the speed of the stop.

Ya wanna stop quickly, but not instantly. Normally only a large fixed object stops one instantly.

FJRider
22nd December 2015, 18:48
Another rule: the hurt is proportional to the speed of the stop.

Ya wanna stop quickly, but not instantly. Normally only a large fixed object stops one instantly.

The bike may stop quickly ... but usually the rider continues on for a bit ... Been there .. done that. It does hurt.

Ulsterkiwi
24th December 2015, 07:14
318104 here's NZs answer

I know that was for illustrative purposes but reaction time is a significant contributor to braking distance.

Rastus comment makes sense if you think about braking effectively. If tyres were to stop instantly they would lose stickiness, its called lock up isn't it? :wacko:

Grashopper
24th December 2015, 12:35
I know that was for illustrative purposes but reaction time is a significant contributor to braking distance.



Very true


I find it very worrying that this "Motorcycle safety institute" published that. At 120 km/h a reaction time of 1 sec would already result in having travelled 33 m before you even go into the brakes :shit:. The reaction time of an alert "driver", who is expecting something, is supposedly 0.7 s; "unexpected" response time is about 1.25 sec; and "surprised" anything up from 1.5 sec... (http://www.visualexpert.com/Resources/reactiontime.html)

rastuscat
24th December 2015, 14:10
I know that was for illustrative purposes but reaction time is a significant contributor to braking distance.

Rastus comment makes sense if you think about braking effectively. If tyres were to stop instantly they would lose stickiness, its called lock up isn't it? :wacko:

Braking effectiveness relates to growing your contact patch prior to applying the maximum braking. Load the weight forward, grow the front contact patch, and you'll have far less chance of a frontal lockup.

It's called progressive braking, and leads to more effective braking and less motorcycle breaking.

george formby
24th December 2015, 14:37
Braking effectiveness relates to growing your contact patch prior to applying the maximum braking. Load the weight forward, grow the front contact patch, and you'll have far less chance of a frontal lockup.

It's called progressive braking, and leads to more effective braking and less motorcycle breaking.

I was lucky enough to be shown exactly this due to someone being a bit "look at me" on a training course. The guy locked up his front on gravelly tar seal just prior to stopping. The instructor took the time to show us the size of the contact patch / scuff on the front tire. It was far bigger than I would have thought, not the palm of one hand, but three. Then he got the bloke to do the same with the back brake. Much smaller contact patch.

Puts into context the braking at the end of the main straight at Paeroa. I love watching the front tire flatten out when they hit the anchors. Epic.

F5 Dave
24th December 2015, 18:53
Been a long time since instructing but the vast improvement of the students after practicing a few runs was astounding.

Racing always kept me sharp. But I'll have to redo those practice runs from now on.

dipshit
25th December 2015, 17:53
Note they give a shorter stopping distance when using both front and rear brakes as opposed to just using the front by itself.

I once got pounced on by several members here after sharing my experience that using both is a quicker way to stop than just the front, as a track day instructor was trying to teach.

www.kiwibiker.co.nz/forums/showthread.php/105129-Emergency-Braking?p=1129349696#post1129349696

F5 Dave
25th December 2015, 18:25
Most people are incapable of braking to the limit (see my post before) therefore the rear brake will make a difference, but it might not to a racer.