Wheelies

[rchase]

No no. It's not what you think! I won't be asking how to "clutch it up" or asking for advice on how to wheelie here! Quite the opposite actually.

 

I bought a "slightly" more powerful BMW that loves to lift the front. I discovered it's tendency to do this in rain mode being a complete gentleman on the throttle. In the interest of not becoming best friends with someone holding a black flag I have a few questions on how to minimize wheelies.

 

1. How can I use throttle control to minimize wheelies?

 

2. Is there a gear, RPM combination more prone for the front end to lift?

 

3. What's a good technique to "quickly and safely" put down the front end when approaching a corner or braking zone?

 

4. How can I use my body weight to weight the front and possibly keep the wheel on the ground?

 

5. I have read Keith's "steer from the rear" part of one of the twist books. I have also seen people in corners turning with only one wheel on the ground. Any extra info here on the dynamics of how that works might be helpful.

 

Ironically after being thrown in the deep end of the pool by the bike when I was not expecting it wheelies no longer bother me. I just would like to remain as polite as possible and not get in trouble for having too much fun when it's not appropriate.

[Hotfoot]

^{OK, I don't claim to be expert in this area, but I do have some thoughts:}

^{First of all, any good corner worker should be able to tell the difference between a power wheelie and a "look at me" stunt wheelie - if the front is lifting a bit under power and you are not standing it straight up or making obvious efforts to wheelie it, they shouldn't be giving you too much grief about it.}

 

^{1) Ease up, lead foot! OK, kidding aside, GRADUAL throttle application is important, especially in low gear at high rpm. You may have to slow the rate of your roll-on, either in general or as you approach the RPMs where the bike starts accelerating exponentially. Use your data logger to see how the acceleration rate jumps up at certain RPMs and be aware that you may need to slow your roll-on as you get up there.}

^{2) Lower gears are more prone to wheelie, and higher RPMs will give you harder acceleration, so one relatively easy solution is to short-shift the bike (meaning, upshift sooner than you normally would; hopefully around 7-8K rpm will handle it, if not you may have to shift at even lower rpm). You will still get good acceleration but without the rocket power of the 10K and up RPMs. Or, you can use a higher gear to begin with, to reduce the power - if you were taking a sharp turn onto a straight in second, consider trying it in third, for example.}

^{3) Refer to the throttle control section of Twist of the Wrist II - you generally want to let off the throttle smoothly (not chopping it) and the deceleration will set the front down. Some riders use the rear brake to set down a wheelie - you should ask around on this, I don't have enough data to help much with that.}

^{4) The more forward and low you can get your upper body, the better for keeping the front down - get your body mass forward and down. If you sit UP you great increase your chances of wheelies. Make sure your arms are relaxed and your lower body is well locked on - if the bike's acceleration is sliding you back in the seat and causing you to pull on the bars, you are contributing to the wheelie tendency.}

 

^{Be cautious not to use the spring-back of the forks to bounce you up into a wheelie when exiting a corner; example if your forks are compressed by cornering forces then you suddenly straighten the bike and hammer the gas, the sudden spring release of the forks can contribute to lofting the front wheel. Making sure your rebound damping is set correctly (no rebound damping at all would be the worst case for contributing to wheelies) can help with that. Some riders use this technique to get huge wheelies (for showing-off purposes), they do a quick twist of the bars (to load the front) then release and gas it, and the bike fairly leaps into the air.}

[csmith12]

We move shift points (markers) and short shift all the time on the track to keep rider's front wheel planted firmly. It is also one of "my" clues that gearing might be off or could be better for a given track. Other times (most of the time), it's purely the rider... greedy throttle hand right in the peak gear/rpm range for laying down serious power to the tarmac.

 

Doing a search of throttle control and crests here should shed additional light.

[rchase]

Hotfoot and csmith12. VERY helpful comments. Thank you for the homework. I'll be looking up those references here shortly and doing a lot of reading.

 

I have to admit that I have formed some bad habits with throttle control that I am working on correcting. I tend to run my stock bike in sport and rain for more TC protection but then end up fighting against the preemptive part of TC system that cuts power way before traction is lost. I should probably just use Race from now on when I ride that bike. It's a TC system rather than a corner exit launch control system.

 

My "lead throttle hand" does not work out so well with a bike that has more power and less preemptive intervention. The big place that it's a problem is coming onto the straight. Even though I "think" I am being gentle sometimes it does not work out that way. I'm going to try to shift early and get my body forward and lower on the tank to see if that helps keep the wheel on the ground.

 

One other question. What's ultimately faster on a straight away? Fast is the goal here.

 

1. Allowing the bike to do it's thing with the wheelie control eventually coming in?

2. Using a higher gear and a slower roll on and shifting my weight forward?

 

While I don't really want to modify settings (the bike is absolutely brilliant just the way it is) I might pick a mode and turn up the wheelie control a bit to make life easier in case I get a particularly not fun set of corner workers. Rain mode might be a good choice for that as who in their right mind wants to ride on one wheel in the rain? Ok. Don't answer that question! I'm sure some of you guys really enjoy going really fast in the rain.

[csmith12]

1. Allowing the bike to do it's thing with the wheelie control eventually coming in?

2. Using a higher gear and a slower roll on and shifting my weight forward?

 

It's my experience that a smooth throttle roll is the fastest, but let's try to figure it out for you, because both can be plenty fast depending on rider skill/tolerance and bike tech.

 

How does the turn in point and line affect throttle application at the beginning and end of the corner? If there is a line that allows for getting on the gas earlier, would you need to roll as aggressively on exit? Would the bike tend to wheelie as much at higher exit speeds?

 

Now lets compare that to a point and shoot bike/rider combo. Their line tends to square off the corner and then plays to the bike's high power output to drive out the corner with more skillful throttle finesse and a preference to let the tech keep the front from lifting too high.

 

What kind of rider are you currently?

 

Next... Can you use the timing of the exit pickup and continuing the roll to somewhat manage wheelie tendency? Instead of ham fisting the throttle when the bike is straight up, one can continue a smooth throttle roll on exit to increase speed before pinning it, hopefully reducing the tendency to wheelie.

[csmith12]

Another thought...

 

At least on some of the tracks I ride, the turn before the strait is fairly tight. It's easy to charge that turn or over brake for the corner. Which normally leads to wanting to make up the lost exit drive with a more aggressive throttle roll. Yin and yang!

[rchase]

As much as I really hate to admit this (because I know better!) it sounds like I'm "pointing and shooting" my entry onto the straight. The brutal acceleration that the bike has is somewhat intoxicating and sometimes I just can't help myself. By doing this though I'm probably giving up a lot of speed with my lead throttle hand.

 

In my mind I'm also thinking"oh yes here comes the straightaway" and I forget all about the important last corner that dictates the speed onto the straight. Higher exit speed + acceleration = overall higher speed.

 

It sounds like I need to break this problem into two parts.

 

1. Maximize my exit speed on the last corner.

2. Work on smoothing my throttle application on the straight to keep the front wheel down.

 

Sounds like I'll be working on throttle control and the pickup drill. Level 1 and 2 stuff. It's always amazing to me how many of the problems that I run into come back to the basics taught in Level 1 and 2.

 

Thanks again for pointing this stuff out to me.

[csmith12]

Always happy to help when I can.

 

The brutal acceleration that the bike has is somewhat intoxicating and sometimes I just can't help myself.

 

ikr!!! I felt the same way when I was given an rc8 to ride for a session. The bike would want to wheelie on the back straight @100+mph. Soooo much fun, yet not my fastest lap times. Massive adjustment in application of skills vs. my r6.

[rchase]

What I find interesting about the more powerful bikes is how their power can radically change philosophies of riding. When I was riding my FZR400 on track days I found myself irritated with the cat and mouse between the big 1L machines and little machines like mine. Now I'm cackling in my helmet as I blast down the straights myself. It's funny how that works. If you can't beat em. Join em they say.

 

So..... I let the cat out of the bag a bit helping my friend Nate sell his HP4 on the S1000RR forums. Since it's no longer a closely guarded secret I figured I would share why I'm so interested in preventing wheelies. The Motorsport RR in this photo has been mine for a while now. I can't wait to take it to Barber in May.