Leaning help..

[Moonlight]

In my lastest topic in a series of amaturish and most likely annoying questions , I ask about leaning on my road bike.

I work monday and tuesday so don't have time for a decent cycle, instead I go 'strength training', which is essentially cycling up steep hills in a high gear and trying to increace my muscle strength.

Anyway, as I was desending one of my hills today I came across a sharp curve! and breaked to navigate it safetly...however, I thought back to the Tour and knew that they did such turns a lot faster! So the next time I went down the hill I did so at 30km (18mph) and increaced my speed again to 34km (20mph).

To end my ranting, at what angle and speed can I take a corner without loosing my wheel grip?

Note: my back tire is a £17 Kevlar jobby, my front is a stock Kenda. My tire width is 25.

Thanks!

 

[ASC1951]

To end my ranting, at what angle and speed can I take a corner without loosing my wheel grip?

Too many variables, Moonlight - the state of your tyres, tyre pressure, road surface, moisture, degree of corner, road camber, speed, your weight, skill level....

Thinking back to my days with an 850 Norton Commando, the real heroes could get the foot pegs to strike on the inside of a corner. You can't get that far over on a pushbike because you can't generate the same acceleration in the corner.

The steeper you want to bank, the faster you have to go; but it's not about the angle, because that is automatically generated by the other variables, principally the camber and your speed. In reality the limiting factor is your nerve - that sets the speed and everything else falls into place. Depending on frame layout, whether you pedal on the corner etc, I reckon you could get over to about 30deg from vertical before you risk pedal strike. Any sensible person backs off well before the sliding-angle.

The secret of fast descending isn't cornering angle. It's choosing the right line, smoothness, small weight adjustments with your knees and keeping up the appropriate pedalling cadence. Oh, and knowing what is round the corner - the pros do ride the route first.

 

[fossyant]

A lot down to guts etc. Us older fellas/ladies usually back off a bit more these days as we don't bounce as well as we did in out 20's.

I wouldn't push it on Kenda's - get some Mich. Pro Race 2 or 3's

 

[Joe24]

Wang it over and find out.
I often go around a courner doing about 27mph that cars do at 20mph. I really lean the bike over for that.
If you really wonted to find out how far you could go, then find some courners you can go around fast, that are tight and sighted(or not if you have confidence) and just go for them. Being able to see around them for if a car is going to be also coming around then you can brake and try again. Be better if its clear so that if you need to go onto the other side because you took it fast then you can. Oh and know if there is a drain cover on the courner aswell.
But, remember to relax when yor doing it, and that noice you hear from your tyres is good(i think) and just shows that the are gripping But mine have stopped making that
ASC1951, what is the sliding angle, is that the 30' like you say before you get pedal strike? I know i often go around courners where if i were still pedaling my pedal will strike the floor.
Sorry, not a techinical reply, but learn by doing Whats the worst that can happen?

 

[Halloway]

You might want to check out counter-steering as well. I've found that understanding it helps with control in corners (I also ride a motorbike and consciously being able to use counter-steering can be a life-saver).
http://en.wikipedia.org/wiki/Countersteering

 

[Renard]

Go with the flow and look around the corner. Don't think about it too much.

 

[Moonlight]

Hmm...ok, thank you for your informative replys. I must experiment!

 

[Joe24]

To find out how to go before pedal strike, put one pedal close to the floor and tip the bike ove and see how far it will go over. Do it on both sides just in case the courner is really tight.

 

[ASC1951]

I often go around a courner doing about 27mph that cars do at 20mph. .....

ASC1951, what is the sliding angle, is that the 30' like you say before you get pedal strike?

You can certainly outrun a car on a twisty descent, but that is a lot to do with the small mass of a bike, which can accelerate and brake faster than a car over short distances.

By sliding angle I meant the amount of lean where the centrifugal and cornering forces* balance and beyond which the tyres lose grip and you stop cornering. On a bike that is usually the end of your control, because you can't put any more power in. I remember the tyres for my motorbike (TT something or others) had a smooth strip part way round the section of the tread, which gave you a gentle slide at that point to alert you that if you leant it over any more you were soon going to smear yourself across the road. I never dared test it.

*Someone more technical will have the right terms.

 

[Tynan]

general rule of thumb is that you'll bottle way before the bike does

gravel and stuff aside, natch

 

[Fab Foodie]

You might want to check out counter-steering as well. I've found that understanding it helps with control in corners (I also ride a motorbike and consciously being able to use counter-steering can be a life-saver).
http://en.wikipedia.org/wiki/Countersteering

You countersteer to get the bicycle to fall into the corner, but from there on in you can't countersteer like a motorcycle because you cannot power-up the rear wheel. You can try, but have a nurse standing by and a lot of bandages.
IIRC 45 degrees is about the max for a bicycle. Some of this was covered in the previous thread about cornering.

Read all about it...

http://www.sheldonbrown.com/brandt/descending.html

http://www.sheldonbrown.com/brakturn.html

 

[monnet]

general rule of thumb is that you'll bottle way before the bike does

gravel and stuff aside, natch

Agreed

 

[Muddyfox]

Wang it over and find out.

Quality

Simon

 

[asterix]

.... Oh, and knowing what is round the corner - the pros do ride the route first.

..what's more on the TdF they know there's no oncoming traffic so can use the whole road to make their line.

On the mountain descents even without the road cleared, a bike can get round the hairpins a lot faster than a car. Some drivers in France actually pull over to let you past!

 

[Paulus]

It helps on fast descents when corning to hang your knee out in the direction you are turning, something to do with moving the centre of gravity so you can go around the bend quicker.