[hpv] Steering head bearing loads in front-drive bike

[Ben Brown]

I'm working on a front-drive bike, similar to Tom Traylor's design 
(http://traylor_fwd.home.mindspring.com/) or Cruzbike 
(http://cruzbike.com/). I was considering the loads on the headset 
bearings, since the pedaling loads will be transmitted to the front fork 
assembly through these, along with the usual load from the weight on the 
fork. With strong pedaling thrust (I assumed 200# to be possible), I 
estimate the side load on the lower headset bearing to be around 
400#-500#, depending on the headset bearing separation. This seems like 
a lot for typical steering bearings, certainly more than would be 
encountered in a conventional diamond-frame bike. Has anyone else 
considered or had experience with this?

I'm attaching a copy of my analysis, in case anyone is interested in the 
details.

	Thanks, Ben

_____________________________________________

H. Ben Brown
Carnegie Mellon University
Pittsburgh, PA
hbb at cs.cmu.edu