Originally Posted by grolby
I've got to agree with Stuart, Daily Commute. Adding weight to the front wheel won't effect the point at which the rear wheel lifts off the ground. Let's think about a bicycle with an applied front brake as a third class lever. A third class lever is one where the force (the braking force trying to lift the rear wheel into the air) comes between the resistance (the weight over the rear wheel, keeping it on the ground) and the fulcrum (the hub of your front wheel).
[snipping a whole bunch of elegant explanation]
What he said. In my defense, I am just a lowly chemist and it's been a long time since I had a physics class. I knew what I needed to say, I just didn't have the proper words.
Originally Posted by grolby
EDIT: Chipcom, the point that I'm making is that weight on the front wheel has little relevance to balance in terms of weight distribution. Balanced weight between front and rear has relevance only terms of handling, and even then, on balance (HA!), more weight on the front is less likely to have a negative influence than more on the back. The critical factor for balancing mass in the front panniers is the right/left distribution of weight, which is indeed very important. For this, among other reasons, I just load up the rear rack, where distribution from side to side isn't critical, but in simple terms of fore/aft weight distribution, you're better off with 15 extra pounds in front than in back.
Also to Chipcom, I will agree with you about the need to balance the load, if you were touring. However we are talking about a rather light load for commuting. Most people would not want to deal with 4 bags on a commute. I've found, through experience, that loading bags on the front wheel has benefits that loading the rear wheel just doesn't have.
To grolby: The right/left distribution isn't that critical. If you were several pounds heavier in one bag over the other, you would notice it but within a few pounds, it really isn't a problem. I notice a weight differential most at high speed on long downhills but otherwise it's not much of a problem. I lost a front bag and didn't see any effect on handling.