Does the MBB FWD negate any wind issues for deep rims?

[Rampa]

So I know a few of the speedy folk here are using deep section carbon rims. Does wind effect the steering at all? With the extra strength and damping of the legs, I would think any wind twitchiness would get just get absorbed and not really matter. Is that the case?

 

[Balor]

So I know a few of the speedy folk here are using deep section carbon rims. Does wind effect the steering at all? With the extra strength and damping of the legs, I would think any wind twitchiness would get just get absorbed and not really matter. Is that the case?

In theory, yes, In practice, it depends on your 'leg steering' skills. If your read reports by 'seniour cruizbikers' dual disks are still tricky.
More than than, since legs are connected to the steering, they already *kind 0f* provide 'deep rim effect' even if you don't have any - because they shift lateral CoP away from steering axis. I was once buffeted by a passing truck on my 'more confentional' MBB (I was using very shallow rims, MTB ones in fact) when I was tired after a brevet and it was the scariest experience of my life.

To make youself more or less immune to wind steer even with dual disks you must have a negatively offset front wheel, so CoP will be centered on axis and will not have any steering leverage.

 

[MrSteve]

So I know a few of the speedy folk here are using deep section carbon rims. Does wind effect the steering at all? With the extra strength and damping of the legs, I would think any wind twitchiness would get just get absorbed and not really matter. Is that the case?

"Does wind effect the steering at all? "
Yes.

 

[3WHELZ]

Agree, must notably with wind gusts above 20 mph. It has never felt unsafe, but I do grip the bar more firmly.

Long ago, I ran a full rear disc on a DF. High winds in that configuration was nearly impossible to ride, especially in open field areas.

 

[Balor]

Well, I once went with full disks in 20 mph winds (and open field) just to test how it works:

You do have to lean into the wind, but otherwise only time I've felt *something* approaching 'wind steer' is when I've been hit by an amplified gust of wind channelled between two buildings (Venturi effect), and I can swear than it was *out* of the wind, not into the wind, despite having about 60mm of *negative* offset. It seems that even 60mm of negative offset is not enough to, ehehe, offset the lateral area of your legs, crankset and other bits that in front of steering axis (at least in my case).

What is *worst* with positive offset, however, that it leads to what I call 'negative aerodynamic trail' or 'windvane' effect - steering corrections at speed would generate torque 'into the turn' - which is opposite of what is required for stable steering. So, in theory, at high enough speed, negative aerodynamic trail (quadratic with speed) may overcome positive trail that is based on friction and rises linearly with speed and make the bike behave like one with negative trail. Very, very scary thought.

 

[RojoRacing]

The effects are the same with deep rims on both my DF and Vendetta. The main difference is when a gust hits me on the DF it causes a small correction arc to straiten out. On the V20 that same correction arc becomes much greater due to how the bike responds to small inputs, so I feel less safe descending mountain roads where the gusts can be unpredictable and thus run a shallow rim on the front. I run a full disc in the rear no matter how windy it gets and never feel threatened by the wind at all.