cornering

[ccf]

I went down on a 90-degree right-hand turn yesterday. I'm still trying to figure out what went wrong, and I'm hoping to get some input from the Tribe. It was a right-hand turn, the road has an old chip-seal surface with no loose gravel, the curve is -4.6% entering, it was sunny and dry, and according to my bike computer I entered it at 24 mph. I was sitting up/forward to get a better view and coasting through the turn (no pedaling and no braking). So ...

1. Is it a bad idea to sit up/forward when cornering downhill? I've taken corners like this countless times before without any issue, but I lost rear-wheel traction, so maybe not enough weight on the rear wheel?

2. My other favorite way to take turns like this is laying back on the seat and pedaling through the turn. The pedaling allows me to use foot-steer to make corrections to my line if need be. If the turn is steep, I drag the front brake a bit so that I have some resistance to my pedaling. What are the thoughts on this cornering technique, particularly using the front brake to create resistance for pedal steer?

 

[super slim]

I never sit up in a corner unless I am doing < 5 kph and its a 90 degree bend, as I feel unstable.
I do your nos 2 option if I want max speed through a corner!

I wonder what method Jason uses, as he would be the fastest Cruzbike descender!

 

[ed72]

Sorry to hear of your crash.

Jason being a motorcycle and mountain bike racer would have a more definitive answer.

A few general ideas about cornering.

1. Pick your line and commit to it.

2. Do not brake in corners

3. Keep your center of gravity low and inside

4. When changing tire brand or size, test them on known roads (the corners).

I suspect the forward weight distribution, high center of gravity, and the downhill gradient in combination with a rough bumpy surface caused it, especially if using some certain narrow tires at high pressure. A lot of front tire bias under those conditions. ...?? For me...how a tire corners is very important and tire reviews rarely go there.

Crashing isn't fun, hope you are ok.

 

[Ross Jantz]

I agree with Ed. I generally pedal through most corners, at least from the apex out. These are front wheel drive vehicles, adding power when the rear wheel starts to slip in a corner can (if you're lucky and catch it soon enough) help pull the bike straight. Did that with a bit of a drift through a gravel patch a couple weeks ago. If the front goes airborne and comes down off kilter or loses traction and slides you're pretty much guaranteed to go down. The 'snowmobile' lean also works on fast, sharp corners as it helps keep your CG closer to the center of the bike. I stay off the brake as much as possible. As an added bonus, pedaling through the corners freaks out upright riders and amazes them with our cornering ability.

Hope neither you nor your bike sustained any serious damage. Crashing at 20+ is never fun under the best of circumstances.

 

[hurri47]

Wait. A downhill 90 degree turn on chip seal AT 24 MPH?

I used to be brave once.

-Dan

 

[Robert Holler]

Cornering on a Cruzbike = counter steer like riding a motorcycle. keep the power rolling on smooth. If you are overrunning your fastest gear - know what speed and at what cadence you can re-engage the drivetrain. No sudden movements. Forward pressure on the handlebars. Awareness of what your leg and arm muscles are doing at all times...

Even at near 50 the Cruzbike handles like a dream - but if you are going to go fast (on anything) practice practice at slower speeds. Also tires/tire pressure/road surface quality....

https://www.facebook.com/RoseCityRecumbentCycles/videos/1056806751082576/

 

[Pollock]

@Robert Holler - I just read up a bit on counter steering. I watched a lot of the movie Cars as my daughter loved it for a few years; turn right to go left! I understand the principle, but not something I mentally want to practice Is this in the list of skills to master riding your CruzBike?

 

[benphyr]

When I was learning to ride a motorcycle I think I recall mention of counter steer being effective at higher speeds (speeds of 30km/h or more). Maybe it was just most noticeable at higher speeds. I don't know the physics or accuracy of that teaching. After a certain while steering becomes so natural on motorcycle or bicycle that it is hard to tell reflex action from a learned behaviour. Any good resources on learning to counter steer?

 

[ratz]

1. Is it a bad idea to sit up/forward when cornering downhill? I've taken corners like this countless times before without any issue, but I lost rear-wheel traction, so maybe not enough weight on the rear wh

Don't sit up and don't use the front brake once you are in the turn.

The Front brake will de-weight the rear wheel and at those speed you are going to wash out. As for sitting up; bad idea. The reason you have to lean into a turn is to lower your center of gravity which is what keeps the leverage and traction. If you sit up, you raise the center of gravity; and break your cornering traction as it throw the bike back upright, if anything you want to settle all your weight into the small of you back pushing down on both wheels.

Motorcycles whole different animal; just say no to your front brake in a turn.

 

[RojoRacing]

First problem with answering such a question while not seeing someone ride in person is I must rely on what the rider perceives they are doing which is rarely accurate or conveyed in comparable terms to how the person helping would describe it. When cornering hard I keep my shoulder planted firm against the seat always, the only time I sit up is when navigating something very slowly. If I'm confident my speed and what the corner looks like all the way through I'll keep my head back especially if I'm looking for maximum speed. If I want to gain a little confidence I'll tip my head forward while still keeping my shoulder planted just to get a slightly better view of the corner.

There are dozens of tiny movements and ways you could have surged the pressure through your tires and caused them to break traction. Even without gravel on the road there could have been a single instant of something there that your tire rolled over and would no longer be there after the crash. The idea of pedaling while cornering hard "to gain stability" is flawed in my opinion. The art of going fast on asphalt is about being as smooth as possible to avoid shocks of load through the tires, imagine smooth brush strokes as every one of your movements. Pedaling is adding one more variable to the equation of being smooth. It's because this way of logic that we call motorcycle road racing an art but never refer to motorcross as art, there's nothing smooth about dirt bikes. Now I'll pedal through corners just as much as the next rider but it's never at the limit I'd consider hard cornering. Now like I stated above what one person considers going fast or hard through a corners may just be going easy or relaxing for another. What I call going down hill through corners at fun speeds would have most riders standing the bike up strait and riding strait off a cliff.

So a tiny flick of the wrist or shoulder, a twinge of the foot mid corner or someone unseen on the ground, any one could be the culprit of your crash.

I can count on one hand the number of times I corners hard enough on the V20 with enough G-force that it surprised me I didn't loose traction. Each time I just consider myself blessed by my guardian angle because they don't want to be out of a job. Only times I've slid any tire while corner on the V20 where because of crossing paint lines of gravel which rarely surprise me because I going into those situations prepared for the slide. It's much easier to control a gravel slide on the DF bike vs the V20.

 

[RojoRacing]

95% of the time I corner without any brakes but if I choose to scrub speed through a corner because I'm unsure of my speed I'll drag the rear brake ever so slightly. I'm talking less then 5% brake force on the rear brake which is why I don't recommend the practice as something to rely on all the time because again it's another variable most people don't need to be factoring in.

 

[ccf]

OK, no more sitting up in the corners.

I've looked at the corner on Google Street View a bunch of times, and the only potential issue I see in the images is that it has longitudinal cracks that have been patched with asphalt. Maybe my tire bounced a little on one of those.

As far as braking goes, it seems to me that if I'm pedaling and using just the front brake lightly, that they should cancel each other, right? And what about a really steep corner? I'm thinking about a sharp hairpin not far from the house that is -11%. If you don't break through a corner like that you have to "fall" into the turn to hold a line because you will accelerate so rapidly.

 

[RojoRacing]

As far as braking goes, it seems to me that if I'm pedaling and using just the front brake lightly, that they should cancel each other, right? And what about a really steep corner? I'm thinking about a sharp hairpin not far from the house that is -11%. If you don't break through a corner like that you have to "fall" into the turn to hold a line because you will accelerate so rapidly.

If you’re pedaling get off the brakes you’re just fight one input with another for no reason. Also cornering is a balancing act of countersteering so moving the weight of your inside leg up down and around the center of gravity isn’t going to do any favors unless you’re trying to accelerate.

Super steep downhill corners put more weight on the front so no need to add any more with the front brake. It’s better to drag the rear like I said before while going through the corner but get your initial hard braking done before you lean in with the front brake.

 

[bladderhead]

When I was 7 years old I crashed my bike and hurt my hand really badly. I started thinking about how it hapenned. I was going downhill and turning. I remembered the front wheel going sideways. Then I remembered that I had been braking. I had locked the front wheel. This is what happens if you brake hard in a turn. Since then I never have. Sometimes I brake a bit, but not much. See the turn coming. Brake hard. Then get off the brakes. If you are going through the turn faster than feels comfortable, you should have been braking before.

 

[ed72]

OK, no more sitting up in the corners.

I've looked at the corner on Google Street View a bunch of times, and the only potential issue I see in the images is that it has longitudinal cracks that have been patched with asphalt. Maybe my tire bounced a little on one of those.

As far as braking goes, it seems to me that if I'm pedaling and using just the front brake lightly, that they should cancel each other, right? And what about a really steep corner? I'm thinking about a sharp hairpin not far from the house that is -11%. If you don't break through a corner like that you have to "fall" into the turn to hold a line because you will accelerate so rapidly.

That would do it.

I was just leaning my Gen 1 C-Record Vitus Carbonne 9 into a corner at 45+ mph coming down from Big Bear and Lake Arrowhead and hit such a crack in concrete. I never saw it. One of the few times I went down on an upright, fortunately, it was a left turn.

I agree 100% with everything Jason wrote.

I corner a little slower (relatively) on a recumbent compared to an upright simply because I don't have as many tools as my disposal on a bent as on an upright to deal with surprises.

Some real numbers on my test corner. On an upright with 35 mm wide Compass extra legere tires at 60 psi, I can corner at 30 mph but with 25 mm Conti GP4000 at 95 psi, it is more around 26 mph and with the small Conti tires on my bent, it is 21-22 mph. The road bumpy, country chip seal. Big tires with lower pressure laugh at the surface irregularities. Personally, I would not take a 5% downhill, 90 degree corner at 24 mph unless I had a number pinned and the corner was marshalled.

 

[Robert Holler]

Ill echo the no sitting up unless you are navigating very slow - like walking speed. As soon as you sit up you are now pulling on the bars and have lost all of your ability to leverage your steering (or counter-steering depending on your speed and the corner) Also upon sitting up you pit your legs and arms in a battle for control over the movement of the front end - not good especially at speed. Like has been mentioned - the back of the seat and using it as leverage/weight distribution is your friend.


As far as counter steer goes, there are a lot of youtube about it and I have always found it useful riding bikes as well - particularly a Cruzbike with its "heavier" front end. I will say it is not nearly as noticeable on a bicycle as it is on a 500lb motorcycle, but (IMHO) the principles are similar and keeping them in mind will prevent you from getting what I call a "loose front end" in a corner. Also where you are looking will play a huge role. If you are cornering and you look down at the road right next to you, you probably will wind up there.

"Back in the day" when I had motorcycles I would practice this sometimes for fun.

Ill also echo Jasons comments about being smooth as possible - which takes total concentration. In the video I linked above of the partial footage of my fast downhill on an S30 I was mentally and physically exhausted at the end of that run - high speed and high speed cornering is not for the rider who wishes to tune out and relax.

 

[paco1961]

One reason I am slower on twisty descents on the CB is simply limited sight capacity. The lower head height means it’s much harder to see many of those little road surface imperfections compated to DF position. And twisting down a hill at 30mph or so is not a time to make quick little steering corrections. Whatever speed you can maintain at max smoothness is a good target. Sort of like driving a car at night. Never want your lighted sight distance to exceed your required braking distance.

 

[ccf]

I took this same corner again yesterday on a club ride. I entered it a little slower this time (20 mph) and stayed back on the seat. And voila, no problems!