Bicycle riders cornering techniques

S

SteveBorland

VIP MEMBER
Joined
Nov 15, 2010
Messages
977
Country flag
Watching those loonys yesterday on the downhill bits, and I was wondering why some of the world's best bicycle riders don't seem to understand the physics of cornering.
This bloke for example is keeping his body weight quite central while pushing the bike way over, reducing the grip (which, with those skinny tyres, is not very much to start with!!).
Considering the consequences of falling off, I wonder why he does not try leaning off and keeping the bike more vertical?

Bicycle riders cornering techniques
 
It's hard to change the CG too much whilst sitting on the saddle. He's doing as much as is reasonable by putting his outside foot down and putting a lot of force down through the outside pedal. Getting your weight low can really only be achieved by going forward or back off the saddle. Sliding your weight forward or back changes the bike's weight bias so much as to make the bike difficult to control. Also, they are often times sprinting between corners at 50+ mph, so any cornering advantage gained by slipping off the saddle is lost when the rider in front of you pedals away while you're not able to do so.

"Dropper seat posts" (telescoping tube holding the saddle up, usually operated by an air spring with a lever on the handlebars) are very popular on mountain bikes, allowing you to drop your weight by getting the saddle down and out of the way. There's a very steep descent toward the finish of the Milan San Remo road race that was won by someone a few years ago, because he added a dropper post to his road bike and was able to out-descend the handful of competitors that were capable of keeping up with him on the flat run-in to the line. There hasn't been any other circumstances in road racing that I'm aware of that has used a dropper post to any useful affect.

The UCI (the riders' union) is pretty strict about how you ride your bike in sanctioned races, and the bike you're allowed to ride. There was a short term where riders were sliding forward off their saddles and sitting on the top tube to minimize their aerodynamic profile while going down high speed descents. They made that riding style illegal (during racing) due to the rider safety concerns of also minimizing control while in that position.

There is, of course, a vast spread of skill in the pro peloton. Some riders are very timid, while others easily drop the motorcycles covering and supporting the race on the twistier descents.

This is a remarkable performance:

Road cycling is an excellent form of cross training for many, many other sports, from MotoGP riders to F1 drivers. Aleix Espargaró, particularly, has almost completely switched to bicycle road racing. I'd guess you wouldn't say he doesn't understand the physics of cornering.
 
t ingermanson said:
It's hard to change the CG too much whilst sitting on the saddle. He's doing as much as is reasonable by putting his outside foot down and putting a lot of force down through the outside pedal. Getting your weight low can really only be achieved by going forward or back off the saddle. Sliding your weight forward or back changes the bike's weight bias so much as to make the bike difficult to control. Also, they are often times sprinting between corners at 50+ mph, so any cornering advantage gained by slipping off the saddle is lost when the rider in front of you pedals away while you're not able to do so.

"Dropper seat posts" (telescoping tube holding the saddle up, usually operated by an air spring with a lever on the handlebars) are very popular on mountain bikes, allowing you to drop your weight by getting the saddle down and out of the way. There's a very steep descent toward the finish of the Milan San Remo road race that was won by someone a few years ago, because he added a dropper post to his road bike and was able to out-descend the handful of competitors that were capable of keeping up with him on the flat run-in to the line. There hasn't been any other circumstances in road racing that I'm aware of that has used a dropper post to any useful affect.

The UCI (the riders' union) is pretty strict about how you ride your bike in sanctioned races, and the bike you're allowed to ride. There was a short term where riders were sliding forward off their saddles and sitting on the top tube to minimize their aerodynamic profile while going down high speed descents. They made that riding style illegal (during racing) due to the rider safety concerns of also minimizing control while in that position.

There is, of course, a vast spread of skill in the pro peloton. Some riders are very timid, while others easily drop the motorcycles covering and supporting the race on the twistier descents.

This is a remarkable performance:

Road cycling is an excellent form of cross training for many, many other sports, from MotoGP riders to F1 drivers. Aleix Espargaró, particularly, has almost completely switched to bicycle road racing. I'd guess you wouldn't say he doesn't understand the physics of cornering.
Click to expand...
Good points, and I fully agree with most of your post, but if this bloke simply remained central on his saddle ( Hailwood style), he would be using less lean angle. As it is, he seems to be pushing the bike down and away from his body.
 
SteveBorland said:
Good points, and I fully agree with most of your post, but if this bloke simply remained central on his saddle ( Hailwood style), he would be using less lean angle. As it is, he seems to be pushing the bike down and away from his body.
Click to expand...
Hard to tell from a still screenshot, and he could, for sure, be inept, but he might be reacting to the rider in front, or an unseen (to us) pavement anomaly. Looks to me like he's putting extra weight on that outside pedal with his inside knee out, the best way to get the tires to stick in the apex by pushing down on the contact patches and moving your CG to the inside with the knee.

Tom Pidcock's descent in the posted video shows the same technique. Early on in the video, when he passes the other rider on the outside of the corner, notice how he maintains his weight over the outside pedal, suddenly drops his body, and sticks his knee even further down and to the inside, to drop the CG and sharpen his line. It might look clumsy as hell, but it gets the job done, particularly if the road has a camber to the inside of the corner (as we all hope they do).

Bicycle riders cornering techniques


They're not riding like Mike Hailwood anymore...
 
also, some corners may have high banked verges which may get in the way….

This applies at the Shelsley Walsh hill climb in England, where high-mounted supermono riders have an advantage , as they can see round the corners better.
 
All physics might be the same, but you need to take into account the dynamics of the application.
The motor and the balancer is the same item on a bicycle.
The motor is commanded by the balancer in motorsport.
Sliding off the seat reduces the effect of one stroke of the motor in bicycle races.
And the rider weight significance in the combination of man and machine.
 
t ingermanson said:
Homophobia is tired. Give it a rest. 😘
Click to expand...
Just in case you want to ride something other than your bicycle, I could hook you up with my best friends cousin. Danillo Petrucci, maybe he could give you a few tips in regards to keeping the seat out of your arse and not wearing pantyhose.:)
 
NORTSTER1974 said:
Just in case you want to ride something other than your bicycle, I could hook you up with my best friends cousin. Danillo Petrucci, maybe he could give you a few tips in regards to keeping the seat out of your arse and not wearing pantyhose.:)
Click to expand...

Of course it goes Ad Hominem... 🤣
 
NORTSTER1974 said:
https://www.msn.com/en-us/news/us/m...1&cvid=fb6d170c5dcf46f8e7df977e7b0f1948&ei=34 I guess we'll call you the "Truth" because you can't handle the Truth?😡
Click to expand...
Your message to me doesn't quite make sense with the context of your link (or any context outside of a Jack Nicholson line), but I'll assume you're thinking that anyone on a bicycle is a risk to anyone on a motorcycle, and with your vehemence, I'm guessing you think that it will always be the bicyclist at fault, and they do their damnedest to clog your (and other motorists') inherent right of way. Please correct me if I'm wrong.

Here we are, talking about a bicyclist at the Tour de France, on a closed course, and you've wrung the alarm bells about fearing "men in women's panty hose", with no more context than that. Weird, but I'll go with it, given the new context.

There are currently about 350 million people in the US, with about 6-6.7 million car accidents annually (according to the Googles). Making a jump here, but if you cut the stats deeply enough, I'm sure somewhere there's a baby in a stroller, or an old lady with a walker, or maybe even a Commando Mk3 owner (gasp, the horror!) that was the mitigating factor in a motorcycle fatality. Are you going to raise the alarm of babies, old ladies, and Commando owners? A bit of a non sequitur, but probably not. Please correct me if I'm wrong.

Yes. Accidents happen. Obviously, we should all ride within our limits and expect all kinds of crazy shit around the next blind corner, whether on a motorcycle, or a bicycle, or a car. Personally, I rarely ride motorcycles or bicycles in groups bigger than two or three because the risks are too high, and you can get sucked into situations you wouldn't otherwise. Motorcyclists are the fastest user group on the road, so naturally can come up on hazards much faster than other user groups can react. Other road users can of course be annoyed by large groups of any other road user (but somehow groups of belligerent car drivers are immune). Not riding with all this in mind is just dumb, and you get what you get...

Are some bicyclists dangerous, self righteous road hogs? Oh yes, they are. Are some motorcyclists dangerous, self righteous road hogs? You bet. It seems weird to have to point out that it naturally runs the gamut, and not to kid yourself that all members of a group all fall into the same set of behavioral characteristics. I get that you might be champing at the bit to create an easy target for "us-against-them" forum fodder, but there's plenty of folks here who, like me, enjoy both bicycles and motorcycles. It can be a hard truth that it's possible.

If your cousin's brother's, daughter's boyfriend's uncle's niece wants to come give me motorcycle riding lessons, sounds great. I'm all for learning something new. If an ex-pro motorcyclist finds it worthwhile to provide a backstop for your internet forum interaction/threat (somehow lending gravitas by proxy?), by coming out for a skills clinic, I'll pay for both your and his track day at Laguna Seca, my hometown track. You can even stay at my place and I'll show you around the roads here. We've got some nice roads for motorbikes, and our orchard is just coming on. If you can hurry, you'll come home with more plums and peaches than you know what to do with. If you wait, you'll have to settle for apples.
 
Last edited:
With any cornering on two wheels - steering geometry is a key issue. It determines how the bike can be ridden. In one of the training videos on motorcycles, it says that if you tend to run wide in a corner, more lean is the answer. I do the exact opposite. I stand the bike up and get on the inside of it, and trail brake to wash-off speed until I judge I have grip, then I accelerate. When the back goes down, the bike turns in the direction I need to go. There is never any need to panic. If I ride at Winton, when I am fast enough, there is one particular corner where I always run wide - it tells me when I am up to speed. It turns more than 90 degrees. Most road bikes have neutral steering - when you accelerate mid-corner, they usually turn in the correct direction instead of running wide faster. The trouble is that if you are not used to the speeds, you usually will not accelerate in the middle of a corner. It then takes a leap of faith.
 
Back
Top