My loaded touring bike is a standard Rivendell Atlantis (high trail). When load I put the light stuff (sleeping bag etc...) in the back and the heavy stuff (tools, food, etc...) in the front. I do not get the front wheel flopping all over the place; not even at low speed going up a hill. It is a very pleasant bike to ride loaded.
When a load is farther away from the steering axis it has a longer moment arm through which to act, when a load is closer to the steering axis (low riders, shoved all the way back) it has a shorter moment arm through which to act. Thus 10 lbs in a high, far forward handlebar bag can have a larger effect than 10 lbs in a handlebar bag mounted low and close the the fork crown. Angus On Dec 30, 11:11 am, Doug Shaker <[email protected]> wrote: > At 05:54 AM 12/30/2008, you wrote: > > >I am interested in what design > >considerations go into making a frame more rear-weight than front- > >weight friendly. > > Wheel flop/trail are the main considerations that I know of. > > As I understand it, trail (the distance between the tire-ground > contact patch and where the headset turning axis would hit the > ground) effects handling in that the larger the trail, the more > the front wheel wants to go straight. High trail is, in that > sense, stabilizing. > > However, the more trail you have, the more wheel flop you have. > Wheel flop comes from the way that the wheel lowers itself slightly > when you turn it any direction from straight. Gravity pulls the bike > into wheel flops, so wheel flop tends to de-stabilize bikes. > > At high speed, the stabilizing effects of high trail dominate. At low > speeds and high front loads (more weight, more flop) the de-stabilizing > effects of wheel flop dominate. Since high trail and wheel flop go > together, a bike that tracks beautifully at high speed may be very > difficult to control at low speed. > > I have one bike with high trail that is perfectly fine 99% of the time, > and pleasant 95% of the time. But with a front load and going up hill, > it just wheel flops all over the place - I have to get off and walk it > rather than risk driving into traffic. > > At least this is my understanding. This understanding might be completely > wrong. If so, I would love to be corrected. > > - Doug "Anonymous" Shaker --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Bicycle Lifestyle" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/bicyclelifestyle?hl=en -~----------~----~----~----~------~----~------~--~---
