The how-tos of braking and not skidding

So it was that I found myself coming down from Outer Ring Road towards Mysore Road and the busy, dusty Nayandahalli junction. There were two buses in front and beyond that Mysore Road. I probably had some 10 seconds to get past the signal or otherwise it would be another 5 minutes’ wait. There was no need to speed and the bus in front also meant that I couldn’t. The bus took a hurried left, suddenly liberated from the choke-hold of Nayandahalli traffic. The other bus was on the right and like a righteous US-returned desi, I expected it to go straight. Wrong! At the very last minute he started an elaborate left turn.

Thankfully I hadn’t committed to overtaking him from the left or zooming by. I was still in the teens speed-wise and I braked. Once a compulsive back-brake hitter, the bike had taught me over close skiddy experiences to go front-brake first and then rein in the rear after the speed comes down. There was a reason why they put all those fancy disk brakes on the front. So it was the front brake that went first. Wrong again!

Turns out that this being Nayandahalli all rules go to the wind. First of all, you take a shower after passing through this junction. If the dust won’t get you the sweat and the noise will. Sometimes it’s a heady combination of all of them. Cops who monitor this junction routinely go on long medical leave to recover. All this dust also means that the roads are full of mud/sand, the dry kinds. This also means that the front-brake first technique doesn’t hold true either.

The theory is that the front brake locks, because of the fancy brakes, but it won’t come to a stand-still because the ground is not exactly firm when you have loose mud/sand all over it. This means you have a non-rotating but mobile front and a rotating back-wheel both operating at different speeds in the same direction which leads only to one result – skidding. So I felt the bike sliding sideways and I fell. This being Nayandahalli, and with its high density of trucks and buses, I looked back and miraculously (even for Indian roads) was the lone vehicle in a 20 Ft radius. Thankfully, a couple of passers-by turned up, as they always do on Indian roads, helped me up, and most importantly helped the bike up (It’s not easy lifting up the 150Kg behemoth) and took me to the side where I surveyed the damage.

I knew the bike was good. It was just me. There were minor bruises, but the foot had a mild cut. The signal had changed and I stood there talking to the sympathetic cop. I asked him what happened, as all this theory is from hindsight. The male ego refused to believe that it had actually done something WRONG while riding a bike, and wanted to blame it on someone. It was slightly disappointed to note that there were no vehicles which had knocked from the back. Just pure skidding, which although blamable on the road surface, still counts as own fault, as no other human, dog or cow could be blamed!

I blamed the BDA for taking too long to construct the damn flyover and enquired about the cop’s health. Always good to find someone else who has a gripe about your object of agony. He seemed pretty happy to let loose on the health and respiratory problems he had been facing, before he was called over by another cop to the other side. I started the bike and came home once the signal turned green. A TT injection and dressing later, began the analysis.

Which led me to this interesting article that I’ll excerpt from. Three main points:

1. We are always taught to go rear-brake first. Doesn’t hold with bikes. Your centre of gravity will move forward during braking and the rear tyre is the one stalling which means the lighter weight part is trying to hold the heavier front part. Think of it as stopping a moving whale by its tail. It’ll wobble, which is what’ll happen with bikes. Had realized this over time and became a front-braker.

2. Front braking. Always a good idea. Great physics, good control on centre of gravity, and no wonder the better brakes are on the front.

3. …But, the caveat is that with front brakes physics holds with ideal conditions – good roads. Roads with gravel etc don’t qualify. There you don’t even have a proper friction surface to stop the bike. The idea is to slow the vehicle down with the rear brake – not pressing and holding, but taps to bring down the speed and then going for the front or even better both. At lower speeds, vehicles are always much controllable – elementary! But this naturally rules out safe panic stops on loose surfaces. Prepare to fall and get some bruises. Skidding and falling is never dangerous, you just need to have the right gear to cover the body and of course less speed! You can’t skid at 60 Kmph and expect to be alright!

My bike: Suzuki GS-150R

Of course, with my bike, the Suzuki GS-150R, pic above, there are other factors that also come into play.
1. For starters, the suspension is much higher, which means you are sitting higher than most bikes which affects the centre of gravity when the bike skids or is likely to fall. In simple terms, the bike is more likely to fall than an Enfield which has much lower seating.

2. The tyres which are normal 100/90-18 M/C 56P, which is wider than an average 100cc Hero Splendour, but not exactly *wide*, don’t lend well to stability when combined with the point above. You are taller and thinner! More likely to fall in instability as your centre of gravity falls outside the bike more easily.

This means I had a better chance of not falling with a lower seat-base and/or wider tyres. Considering that I’ve bored people enough, if at all you got till this point(!), I guess the plan of action now is to recover completely and then get wider tyres for the bike. Also, need to find out if the suspension can be lowered. I remember reading somewhere that it can be!

Oh well, something to write about. Always love the Physics behind these things. 🙂

Advertisements

5 thoughts on “The how-tos of braking and not skidding

  1. Honestly, you are the only person who’l sit back and write, in retrospect, about an unsavoury incident. The kicker here is that you seem to be describing it with so much love!!! Like, WTF??!! Love the analysis, though. 😀 😀 and honestly, lowering the suspension doesn’t help. Give away the top-heavy bike and get an RE. We could start our own little biking club in the family 😛 😛

  2. i always knew the nayandahalli traffic cops were the routinely sick lot due to occupational hazards.. its just pathetic, that stretch.. sadya.. there was no one coming on to you.. gaadi’s got scratches aa??

    loved this line “If the dust won’t get you the sweat and the noise will.” and this one too…. “You are taller and thinner! More likely to fall in instability as your centre of gravity falls outside the bike more easily.”… lol

    how much physics related research on bikes and skidding and other random things did you do ??? 😛

    1. Hehe…thanks..
      Not much scratches visible actually! Your bro and cousin both now selling Enfield to me. Trying to stay above temptation… 😀

  3. “like a righteous US-returned desi” … yummy line! Quite a level-headed analysis and writeup about an accident that would anger most people.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s