# Commuting - In a strong crosswind, is it better to ride faster or slower?

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Roody
12-03-06, 11:36 AM
In a strong crosswind, is it better to ride faster or slower?

(I vote slower, provided you maintain enough momentum to steer. But I really don't know what the "right" answer is.)

threephi
12-03-06, 02:08 PM
Depends how gusty it is. But in a strong steady wind you're spending a lot of energy counteracting the sideways forces anyway, so there's only so fast you can go.

tsl
12-03-06, 07:16 PM
It seemed to go better the other day for me with about 40 pounds of groceries in the panniers. Then again, maybe there was just as much pushing, but less tipping.

notfred
12-03-06, 08:58 PM
the lateral force doesn't change based on your forward velocity. There's no reason it should make any difference, the wind is pushing you equally from the side regardless of your speed.

chipcom
12-03-06, 09:10 PM
In a cross wind I try to apply some sailing logic - I'll angle into it for a bit to position myself to where I can reverse my angle and get a little tailwind action, repeating as necessary. In the end, it probably doesn't make much difference in effort, but the 'game' makes the time go faster. Obviously, don't try this in traffic. ;)

buzzman
12-03-06, 09:37 PM
the lateral force doesn't change based on your forward velocity. There's no reason it should make any difference, the wind is pushing you equally from the side regardless of your speed.

I'm not a physicist so my reply is not dependable but, while I agree with notfred about the forward velocity not changing the lateral force, I think there might be a formula that would show that the forward momentum of a mass traveling at a greater velocity as opposed to a lesser velocity would somewhat maintain the initial direction of the mass.

In other words, let's say I'm pitching in a softball game and a sudden wind kicks up from my right side. Would throwing the ball underhanded and lobbing it towards the plate cause it to drift more to the left than if I threw the ball harder (more force and velocity)? I think the greater force would keep the ball more on target.

As far as biking: when I've encountered a strong side wind I tuck way down close to the bars and lean slightly into the wind and aim the bike ever so slightly into the wind. Sometimes it's fun dealing with these kinds of winds- gusty ones are particularly challenging- but on busy roads or bridges where I feel a real danger of being blown into traffic I'm not too proud to get off and walk or wait a while.

edit: someone who knows something about long range target shooting, hunting or sniper rifles would probably have the correct formulas that would somewhat correspond to any object moving forward with lateral forces working on it.

nomoore
12-04-06, 07:29 AM
I vote faster is better. I know in moutain biking you are less likely to get thrown sideways off of your bike when going faster because your wheels are spinning faster. The extra centrifigul force of the wheel spinning faster makes the wheel harder to tilt sideways (or harder for the bike to fall over). To demonstrate (some of you may have done this as a kid), take a wheel off of your bike and hold it in the air by the axle. Tilt the wheel. It tilts easily. Now have someone spin the wheel. If you try tilting it now it will be much harder to tilt. The faster you spin it the harder it is to tilt.

CBBaron
12-04-06, 08:06 AM
Heres my thoughts:
With a side gust, the wind is deflecting off the center line on his wheels. The amount of deflection is probably not speed dependent. However the cyclist then has to correct by moving the wheels under the center of gravity again. At higher speeds this correction can be faster. However how much you move off of your centerline maybe greater.
I donno. I'm thinking you will wobble much more at slower speeds but the biggest difference you move may be smaller. My vote is for a fast as possible to minimize the total distance.
Craig

PaulH
12-04-06, 08:19 AM
I encounter winds of 40 mph (70 kph) and above fairly often in the winter. I'd say that slower is better, as it goves more time to react to off course excursions. However, it's all pretty much academic; unless there is a big tailwind component, these winds will slow you down regardless of how fast you would like to ride. I agree with threephi.

Paul

flipped4bikes
12-04-06, 08:47 AM
It seemed to go better the other day for me with about 40 pounds of groceries in the panniers. Then again, maybe there was just as much pushing, but less tipping.

I was bike touring with a similarly heavy load. I had to cross a causeway with nasty crosswinds. I was able to stay on my line without too much trouble. My average speed was 5-8 mph. So I would say, that it is bike stability (design and geometry), cyclist skill, then bike speed.

CastIron
12-04-06, 04:18 PM
With two wheeled vehicles, speed=stability.

Severian
12-04-06, 04:28 PM
Referencing "Bicycling Science" 3rd Edition by David Gordon Wilson on the secion on Bicycle aerodynamics we have the following information:

"There is little remarkable about the behavior of unfaired bicycles in cross-winds, except for the extraordinary stability they normally display."

Essentially what he's getting at is there is no net effect on stability for an unfaired bicycle and rider in a crosswind except for a little wobble if you get a gust. I'd say keep trucking and try and turn your tail a little to the wind. As for tacking like a sailboat (as chipcom mentioned) it's a good idea but it would be better if you had something to present to the wind so you get the sail-effect.

Artkansas
12-04-06, 04:33 PM
In a strong crosswind, is it better to ride faster or slower?

(I vote slower, provided you maintain enough momentum to steer. But I really don't know what the "right" answer is.)

I vote for faster. Faster creates a greater intertia forwards. So any given cross gust has to push harder to cancel out this inertia. But it's rare that the crosswind is exactly perpendicular to your travel.

In reality, I don't worry and just go the speed my feet want to pedal. If the wind is somewhat from the front, I slow down, if it is somewhat from behind, I speed up. This happens all by itself.

timmhaan
12-04-06, 04:34 PM
the faster you go, the sooner you'll be out of the cold wind and someplace warm. :)

ragboy
12-04-06, 04:34 PM
In a strong crosswind, is it better to ride faster or slower?

I've found it's best to ride upright

centexwoody
12-04-06, 05:22 PM
If the wind is somewhat from the front, I slow down, if it is somewhat from behind, I speed up. This happens all by itself.

Riding slower in opposing strong winds makes me think about why I bother to commute by bike. Riding faster in opposing strong winds makes me think about why I bother to commute by bike. Either way, in a strong crosswind or headwind, I'm thinking about commuting by bike and reminding myself that tomorrow or the next day or even this afternoon, the winds will probably shift & give me something else to think about...

grolby
12-04-06, 06:26 PM
Riding faster shifts the vector of the apparent wind around so that it appears to be an angled headwind rather than a pure crosswind. Here's a scientific explanation of how wind works when you're on a moving bicycle (includes diagrams): http://sheldonbrown.com/brandt/wind.html
In sum, riding faster isn't going to make it any better, but it probably won't make it any worse, either. There's simply a limit to how much effort you can sustain fighting drag, and that's what determines your speed in any kind of wind.

As to whether it makes a noticeable difference in stability, I don't know. That's probably a variable that depends more upon the individual than anything else.

RomSpaceKnight
12-04-06, 06:47 PM
I vote faster is better. I know in moutain biking you are less likely to get thrown sideways off of your bike when going faster because your wheels are spinning faster. The extra centrifigul force of the wheel spinning faster makes the wheel harder to tilt sideways (or harder for the bike to fall over). To demonstrate (some of you may have done this as a kid), take a wheel off of your bike and hold it in the air by the axle. Tilt the wheel. It tilts easily. Now have someone spin the wheel. If you try tilting it now it will be much harder to tilt. The faster you spin it the harder it is to tilt.

Bingo, bullseye. Beat me to the answer.

squeakywheel
12-04-06, 07:00 PM
I think Physics 101 says it doesn't matter wether you ride fast or slow. A cross wind is not a factor in your forward progress. It just means you need to lean left or right.

Roody
12-04-06, 07:24 PM
Physics 102 says something about vectors that I don't remember very well. But it seems like a cross wind does slow you down--I think because you're sorta going against it just to keep going straight.

squeakywheel
12-04-06, 07:40 PM
Physics 102 says something about vectors that I don't remember very well. But it seems like a cross wind does slow you down--I think because you're sorta going against it just to keep going straight.

You're not going "against it" because you are making zero progress in the direction from which the wind is blowing.

Roody
12-04-06, 07:50 PM
You're not going "against it" because you are making zero progress in the direction from which the wind is blowing.
You're probably correct, but it feels like I'm going against it. Say the wind is blowing left to right. I think I'm always steering to the left, against the wind, just to keep going straight. So it's like I'm going further. I'm not only riding one mile straight ahead--I'm also riding like 1/4 mile to the left.

DC Wheels
12-05-06, 08:43 AM
Roody's question was whether it is better to ride slow or fast in a crosswind not whether forward momentum is affected by wind although there is some relation. The question for me hits on the issue of saftey. A steady cross wind can be managed well at speed, but if I faced very strong gusts in traffic I would think twice about riding that busy stretch without wind cover. And if I just had to ride in those strong gusts in traffic then I would take the lane to give myself more play in keeping a line. On the edge/shoulder I just would not feel safe with an unpredictable line with cars behind me.