Brown Lines (Don’t Do It): Cyclocross Line Choice

Delish

Well-Known Member
Team MTBNJ Halter's
Ticket to ride, brown line highway
Tell all your friends, they can go my way
Pay your toll, sell your soul
Pound-for-pound costs more than gold
Freeze! Rock! Freeze! Rock!


Was Grandmaster Flash talking about Cyclocross?

@jShort asked the following question about line choice:

“How do I determine the optimal line ? How do I know I am taking it? I feel like I am, but what if I am just lying to myself and overestimating my skill?”

In my opinion it’s THE question because if you 1) pick fast lines and 2) have good cornering technique, free watts be raining down on you. Today we will cover picking fast lines. Cornering deserves a thread or two on its own.

Simple Answer: The simplest answer is that the best line is the one that gets you through the turn with the least amount of energy and the highest exit speed. That is to say, there isn’t typically one optimal line. The optimal line may be different for each situation, each person, each lap, etc...

The Racing Line: In auto racing, there is an optimal line (i.e. “the racing line”) that maximizes overall speed through a corner. It typically involves maximizing the turn radius through the corner by setting up wide, hitting the apex and exiting wide. Depending on the type of corner, whether single apex, double apex, the line will change. As @gtluke likes to point out, if you want to learn racing lines, play Gran Turismo.

racing-line.jpg


But there are lots of reasons you might not want to ride the racing line in a cross race.

The Cyclocross line Part 1: We are Not Cars. Cars do not get tired. While it is true that the optimal racing line is often the one that yields the highest exit speed, unlike cars we do not have unlimited ability to accelerate out of every corner. Exit speed should be your #1 consideration. Higher exit speed means fewer watts you have to put out and you save matches to burn when you need them.

Corrolary: If you crash, your exit speed is zero. Hence, the best Cyclocross line is the one that keeps the rubber side down

The Cyclocross line Part 2: Find the traction. Cross courses are not auto tracks. We ride on mixed surfaces, there are bumps and roots and small undulations in the corners. Conditions change throughout the day—grass becomes dirt, ruts form, hardpack gets loose, etc… Cyclocross line choice means taking these factors into account and adapting the line choice to fit the situation. You will often see riders riding at the edge of the brown stripe where the a bit of green grass provides a little more traction.

4: The Cyclocross Line Part 3: Races are dynamic. Be Smart. Your line choice should depend on the race situation. There will be situations where the smart line is not the racing line. Some examples:

First lap, heavy traffic, you’ll want the line that gets you through the inevitable pile-up that you already knew was going to happen (right?).

The Fighting-for-position-laps: Chopers gonna chop. Sometimes you may not want to take a Wide-Apex-Wide racing line because it invites other racers to slide up on the inside of the turn and chop you. Setting up less wide can close the door on choppers.

Setting up for the pass. A great way to pass people in traffic is to be faster on the gas coming out of a corner and make the pass on the inside. Instead of hitting the racing line, set up Wide, apex late and duck inside after the apex as the person in front of you goes wide to finish her/his turn. Some people call this "squaring off" the turn
455b7f5a4c7c42d22c3c3d40dd6b88e1.jpg



The Cyclocross Line Part 4: Go off script.
Get creative.Picking the optimal racing line isn’t hard but so many lower level racers just don’t do it well. The brown line that gets burned into a course by Cat 4 & 5 races early in the day is incriminating evidence. Don’t be a sheep. Pick your own lines. Remember: Brown Lines (Don’t Do It)--don't count on the brown line being the best line.

Sometimes the best line is the one that nobody else sees. Start seeing those. Listen to the CXHairs interview wih Sven Nys. It's really really really good. If you are short on time just watch the video companion to the inverview (link below). If you are really short on time, FFW to 12:54. Sven demonstrates how a completely different line allows him to exit a turn with higher speed, find better traction and make passing easier at the World Championship race in Zolder last year.

Conclusion: Find your inner Sven. Start trying to see different lines and test them out. Use your course inspection time (don't call it pre-riding) to look critically at the lines. Get off your bike, look at the surface, duck the tape & try re-riding he same corner with a different line. Keep trying different lines until you unlock the free watts. Warmup on your trainer--use course inspection time to be a detective. Keep experimenting until you get it right.

The double switchback off-camber turn at Zolder (World Cup & World Champ venue) is the best cyclocross feature in the world. It almost always plays a huge role in the outcome of the race. Last year it was the turn in which Mathieu Van der Poel put his foot through Wout Van Aert's front wheel. In this Svennes video, he tries 5 or 6 different lines through the section until he finally get it dialed and delivers the final blow to Niels Albert.
 

gtluke

The Moped
Yes!
Take your turn to set up the next turn (if there is one close after). You don't want do wind up in the tape on the inside of the 2nd turn(which was the outside of the 1st turn)

Can you brake and turn simultaneously effectively? With suspension it's generally not a great idea as it dives the front end and cause brake jacking on some bikes.
But cross bikes are rigid. Hmm.
 

ChrisG

Unapologetic Lifer for Rock and Roll
Can you brake and turn simultaneously effectively? With suspension it's generally not a great idea as it dives the front end and cause brake jacking on some bikes.
But cross bikes are rigid. Hmm.
If you put on the brakes in the midst of a higher-speed corner, slowing the gyroscopic effect of the spinning wheel destabilizes things and makes the bike want to go upright.

I think that's the explanation. I barely passed HS Physics, though. I'm sure @Delish knows the answer.

On the other hand, I often pedal against the brake while turning in really slow hairpins on cross courses.
 

axcxnj

Hipster Keys
Simply put, picking the right line which will give you the most exit speed is about maximizing the radius of the turn, in the first picture that Eric posted, thats all that is happening. Increasing the radius of the turn will decrease the lateral forces acting on the body in motion, which will allow for an increase in average velocity through the turn, the limiting factor being grip.

CX get a bit more complicated due to cambered surfaces and changing from grass to dirt to pavement or whatever, But thats the general goal from a kinematic perspective. Often a racecar will use a late apex technique as seen in the second picture posted by eric, but like eric said, cyclists dont have unlmited power on tap to accelerate out of corners, so it can be less effective. of course a lot of these things go out the window when youre bumping muddy elbows and just trying to stay upright
 

The Squirrel

Well-Known Member
The double-switchback video is very insightful. My only question is what is the advantage to dismounting on the downhill side of your bike? A, I would think it makes for a riskier landing on the slope with a farther drop and B, it puts you on the outside of the turn while running through. I'll look again, but he didn't shoulder the bike, so the whole dirty side think doesn't really come into play (does it?). I'm a little wet behind the ears, but an uphill side dismount seems to me to be more of an advantage. Thoughts?
 

gtluke

The Moped
If you put on the brakes in the midst of a higher-speed corner, slowing the gyroscopic effect of the spinning wheel destabilizes things and makes the bike want to go upright.

I think that's the explanation. I barely passed HS Physics, though. I'm sure @Delish knows the answer.

On the other hand, I often pedal against the brake while turning in really slow hairpins on cross courses.

I do the same thing in technical mountain biking. Pedal against the brakes. But that might be bad habit picked up from owning a turbocharged car with annoying turbo lag ;)
 

ChrisG

Unapologetic Lifer for Rock and Roll
I do the same thing in technical mountain biking. Pedal against the brakes. But that might be bad habit picked up from owning a turbocharged car with annoying turbo lag ;)
Yep, it's the cycling equivalent of left-foot braking.

There were 2 or 3 corners on this year's Hippo course where I did that every lap.
 

Mountain Bike Mike

Well-Known Member
What about braking... Isn't that HUGE in the game of efficiency and flow while cornering and maintaining exit speed?

@Delish - would you consider brakes, if not applied optimally, as watt pay outs or watt killers? Every time you "over break", you lose your opportunity for free watts and possibly give some of those watts back and end up working harder to get back up to speed?
 

gtluke

The Moped
What about braking... Isn't that HUGE in the game of efficiency and flow while cornering and maintaining exit speed?

@Delish - would you consider brakes, if not applied optimally, as watt pay outs or watt killers? Every time you "over break", you lose your opportunity for free watts and possibly give some of those watts back and end up working harder to get back up to speed?

Every time you apply the brakes NOT at full pressure you are wasting inches of grass which you could be covering at a faster rate. If you aren't slamming on the brakes, you're wasting speed. Just don't lose control, or blow your corner.
 

Pearl

THIS CHANGES EVERYTHING
Team MTBNJ Halter's
did you gank these illustrations or make them yourself?

Every time you apply the brakes NOT at full pressure you are wasting inches of grass which you could be covering at a faster rate. If you aren't slamming on the brakes, you're wasting speed. Just don't lose control, or blow your corner.

trying to word this right, give me a second...

in a vaccum this is correct, just like if you aren't sprinting to max speed at any given moment, you are wasting speed.

last weekend would actually coast on a downhill straight into a corner and use little/no brake instead of sprinting 1000% into it, slamming on them, and getting back to the speed i was coasting at. not sure if this is the definition of free watts or free recovery, but this is more efficient to your body over the race.
 

Delish

Well-Known Member
Team MTBNJ Halter's
Braking goes under the topic of cornering. Next week perhaps...?

Can you brake and turn simultaneously effectively? With suspension it's generally not a great idea as it dives the front end and cause brake jacking on some bikes.
But cross bikes are rigid. Hmm.

Cross bikes do have suspension....well sort of. you have 33mm of front suspension in the form of a 22psi tire and you have your arms & legs. Trail braking on a moto helps tighten up he turning because you effectively changing the front end geometry when the fork is compressed. Trail braking on a cross bike doesn't change the geo but does keep weight on the front wheel and you need to drive the front tire into the ground if you want it to have any traction.

would you consider brakes, if not applied optimally, as watt pay outs or watt killers? Every time you "over break", you lose your opportunity for free watts and possibly give some of those watts back and end up working harder to get back up to speed?

In short, yes, brakes just slow people down and mostly in a bad way. As you describe, people "over break" and lose momentum. Brakes are also bad because it's impossible to corner hard and brake at the same time. 33c tires only have so much traction and you can use it for good or for evil.

Every time you apply the brakes NOT at full pressure you are wasting inches of grass which you could be covering at a faster rate. If you aren't slamming on the brakes, you're wasting speed. Just don't lose control, or blow your corner.

This is another difference between people and cars. Threshold braking is great but is high consequence on a cross bike if you get it wrong.
 

gtluke

The Moped
Braking goes under the topic of cornering. Next week perhaps...?



Cross bikes do have suspension....well sort of. you have 33mm of front suspension in the form of a 22psi tire and you have your arms & legs. Trail braking on a moto helps tighten up he turning because you effectively changing the front end geometry when the fork is compressed. Trail braking on a cross bike doesn't change the geo but does keep weight on the front wheel and you need to drive the front tire into the ground if you want it to have any traction.



In short, yes, brakes just slow people down and mostly in a bad way. As you describe, people "over break" and lose momentum. Brakes are also bad because it's impossible to corner hard and brake at the same time. 33c tires only have so much traction and you can use it for good or for evil.



This is another difference between people and cars. Threshold braking is great but is high consequence on a cross bike if you get it wrong.

as a casual observer I just see a lot of the mortal class of people riding their brakes like crazy anticipating the next turn. Or maybe they are just catching their breath for a moment. I have no idea what I'm actually looking at.
 

MixMastaMM

Team Bulldog Rider
In short, yes, brakes just slow people down and mostly in a bad way. As you describe, people "over break" and lose momentum. Brakes are also bad because it's impossible to corner hard and brake at the same time. 33c tires only have so much traction and you can use it for good or for evil.

Here is a graphic that is a great visual
tractioncircle.jpg
 

The Heckler

You bring new meaning to the term SUCK
OK, now that I've shaken my worst CX hangover to date let's join this conversation!

@Delish, as always excellent information and presentation.

Cornering is something that you can spend time improving upon forever with very little effort. The work required for power hurts like hell and takes more time than breaking down your corners and thinking about every line. You pay to race and should take full advantage of that reg fee. Not only can you pre-ride course inspect, but you can post ride too.

Post ride? Yeah. Seriously, ride the course before your race, race, ride the course after you race. Sure, you show up to your WW and race a course every week, but is that really the same as a full taped course? NO. Get your moneys worth between races if your sticking around anyway. I'm not talking about going hard but go back to parts of the course you found unique, challenging or interesting, watch how other ride it and try different ways.

Be considerate to other racers who have not yet raced but I say you have a right to be on that course.

I spent over an hour on the Town Hall course before the race and it payed HUGE dividends come race time. I wasn't pedaling hard before the race but I gradually ramped speed through corners and pushed lines. You will carry that experience to the next weekend.

Of course you need to consider conditions. KMC was WETWETWET on Saturday. I only rode a couple technical features and mostly walked or slow rolled the rest of the course in the interest of keeping my gear running smooth.
 

Norm

Mayor McCheese
Team MTBNJ Halter's
I will add a few things based on me being on my 2nd espresso of the morning.

1. Vacuums and cross do not exist. So it is almost always the case where communism works in theory, but not in practice.

2. In regards to the brown lines, just remember that the least skilled classes make those lines.

3. Sprinting into a turn and slamming your brakes means you will be tired when you turn and lead to mistakes. Slow is smooth and smooth is fast, or something. This is sort of like that Michaux camp where things make sense then you get home and realize it all breaks down when you are tired.

4. w/r/t the conversation about passing in corners. If you are just barely faster than someone I highly recommend the fake-corner-pass a few times before you actually try it. Set up for the pass repeatedly and make the (potential) passee hammer to keep you at bay. Do not give max effort but make them burn a match and after a few of these, make the real pass. This requires some experience but for sure it works, especially at a place like Nittany.

5. At some point it doesn't hurt to go to a field and corner until you fall. It's not a terrible idea to know how and when your tires are going to fail. Having said that, conditions dictate a lot of that.

6. If you take nothing else from this whole thread, just always approach wide. Road, cross, mountain - approach wide. That's a start.
 

MadisonDan

Well-Known Member
Team MTBNJ Halter's
5. At some point it doesn't hurt to go to a field and corner until you fall. It's not a terrible idea to know how and when your tires are going to fail. Having said that, conditions dictate a lot of that.
This is one of things we tried to work a few times at the Thursday Madison sessions... Both short, tight, figure eights, and longer, faster 90 degree turns using the penalty box of a soccer field as a guide. I felt the difference at Nittany for sure. After the first few turns I could feel where the tires had that tiny bit of give right before they bit into the ground. Definitely helped. Obviously much easier in dry conditions like we had before the rain.

Also.... the drills in the field let you play with tire pressure a bit, which helps on race day...
 

Mountain Bike Mike

Well-Known Member
To add to @Norm #5 espresso point - I find this to be very helpful. Knowing your bike's breaking point in the corners is very important. If you've practiced pushing the corner until your tires lose complete traction and you fall, now you know. You can then work on minor tweaks to form, speed, braking, lines, tire pressures from there.

This is something I love to do when riding (not racing). I enjoy pushing to the breaking point in corners, forcing a little slide here, another there, trying to slide just enough to keep the speed but not completely wash out. This helps build experience, knowledge and confidence.

Last night was out tooling around on my new bike which has fat road tires on it and I was pushing corners in the grass... One corner, was going in a little hot, the back end hung out on me and I saved it. I let out a WHOOOAAA SHIT and after I saved it, was laughing hysterically - So fun. At that point, I had an idea on what that tire would do in a corner at that speed. As the ride went on, I kept messing with it to see if I could do it again.

When I went to a couple Ottos nights this year, I would do the same thing.. I was dicing it out with a few guys towards the end of a session, I pushed a corner a little harder and a little more inside and both front and rear tires power slid, I put a foot out and saved it, didn't fall, but lost momentum and lost a couple bike lengths on the other guys but I knew I couldn't push that corner any harder or tighter. After that, I switched my line a little wider / further outside going in to it, set the apex a little further out and went into the turn a little easier by breaking earlier and coasting through the apex and then worked on the correct gearing exiting the corner each lap.

Shit, @MadisonDan - Remember Bubblecross last year on the first lap when I overcooked the Gazebo off camber turn and went tiltawhirling on my back off the course. I rode that line three times before the race and couldn't get it right. In the race, it was a whole different story... After that, I went into the corner super easy and them hammered out instead of high speed in and through the corner. Lesson learned

Thankfully, with Cross, sliding out in grass is comical and doesn't hurt too much.
 
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