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Old 01-20-07, 02:31 AM
  #4  
NoReg
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Wind resistance is always a bigger threat cycling than rolling resistance, assuming reasonable tires. I'm not clear on the terms here, but I beleive RR is just the energy lost in deforming the tire as it forms a contact patch over the gorund, as the wheel turns. Does it also include bearings, and the resistance of the wheel (small) lifting itself over roughnesses in the road. There is also the resistance of accelerating the rotating parts of the wheel and so forth. Not sure what all that is called.

In addition there are a bunch of vibrations when pulling a trailer deformations in the trailer structure itself, though the BOB looks very resistant in this regard. Suspension activation.

On the other side, paniers can be large or small and a lot could be done to smooth them, make them aerodynamic, or even fairing like. In the old days, when Zipper fairings were popular on touring bikes, I can also remember reading copy about how low riders and the right paniers could reduce the drag on a touring cyclist, operating as fairings. This may have been balderdash, though it might be possible if it was actually studied and pushed forward. What is certainly possible is to increase the air risistance of bags from behind to allow them to contribute to sailing the bike downwind if the wind should ever change from dead on the nose.

Just because the bob is about the same width as the rider, does not mean that it is drafting the rider, afterall it is low to the ground. If the rider does not rear bags, as in this example, I am not sure the bob is escaping drag though it is low in any headwind that may be present. Any wind that is off the nose a little will pick up the bob, and whatever else the BOB may be it is not very streamlined. Directly aft the wind will find less of the BOB to push. Again, it's low to the road, sloping upward, and narrow. What is more drafting is not as effective at low speeds around roughly shaped objects where vortices form...I am not suggesting that the BOB is as wind resistant as the largest paniers. It might be as wind resistant as some of the smaller ones.

In the real world there can be a number of alternative systems like front paniers and BOB before rear paniers are mounted; Front paniers and a box mounted only on the top of the rear rack, Machka style; Paniers and BOB. etc... These all have their benefits and different drag profiles.

I prefer, where a light to medium load is concerned, to drive a mini van rather than a small sports car towing a trailer. It's mostly the feel of the ride. But I would use a BOB if I needed to carry more supplies.

Last edited by NoReg; 01-20-07 at 02:36 AM.
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