This question is about an ebike but I think the topic is more suited to be answered in this forum because you folks are more likely to be packing weight on your bikes.

How important is the weight distribution between the front and rear of the bike? I am doing research on the best way to convert a bike - front, mid or rear motor - and am concerned about the handling characteristics of the bike with an additional (at least) 20 pounds of weight, ultimately 50 pounds, plus frequently a person on the back.

20 pounds is hardly noticeable, almost an improvement in handling if you ask me, aside from the fact you have to push extra weight. You wouldn't want it for tight manovering, but it shouldn't be a problem for more normal going. Don't forget that motorcycles can have front ends that weight a lot. One of those springers in solid bar must weigh more than a whole touring bike, loaded. Geometry is your friend.

Geometry? Well...I must say I didn't do very well in math beyond algebra I know you are referring to the position of the seat posts relative to other parts of the frame. Which kind of geometry is more well suited for a an upright riding position? I have trouble with my back and cannot slouch or bend over for periods of time.

I believe the recommended weight distribution is approx. 60% of the load in front and 40% of the load in the back.

Physics is also your friend when it comes to these sorts of things.

I hear from others that recumbents handle better than ordinary bicycles...is it because more of the weight of both the bike and rider are pushed towards the front?

The weight on a recumbent is mostly toward the back ... that's where the rider sits. And recumbents are quite "twitchy" until you get used to them.

I'm looking at panniers right now and wondering about weight distribution, specifically; why, if the optimum weight distribution is 60 front/40 rear, are all these panniers sets rigged with the large bags in the rear and often with a rack bag to boot? Is it just a question of practicality or is the idea to load the really dense compact items up front (stove, shoes, etc.) and the bulkier, lighter items (sleeping bag, clothes, etc.) toward the rear?

I'm having a hard time figuring out how one would achieve the optimum weight distribution with these things.

In a word, yes.

Food, cooking gear, liquids (soaps, fuel, etc), books, maps and anything with a fairly high density should go to the front. Bulky low density stuff goes to the back.

One note: if you use liquid fuel, don't put it with food. Ugh!

I normally hear the opposite -- 40 front, 60 back. Which could explain your observation.

Don't forget, though, that different objects have different weights and densities. E.g. you could have small panniers filled with tools, food and water, and it will weigh more than a pannier filled with clothes and a pillow

The main thing is that 100% front or 100% back will throw off your handling. 50/50, 40/60 will balance it out a bit better. Anything else is up to preference.

Thanks.

That third set of water bottle bosses would seem a good place to carry liquid fuel.

Waiting on a LHT to be used mostly for utility cycling, but; there's this friend of mine who is making noises about a cross country (SF to DC) trip in May '08, so; we will see where that goes.

Might be prudent to get a few shorter trips in before then, wot?

Fortune favors the prepared and all that.

Keep the weight as low down as possible also,low center of gravity greatly helps handling.