Hi all -
I’ve created a photo gallery of my prototype frames at unicyclist.com. The
direct link is
I’ve been riding the new frame as much as possible which hasn’t been much.
The weather has be very cold and snowy so I’m mostly riding little circles
in my garage and practicing hopping and idling. I did take a long ride a
couple of days ago though.
I’ve had trouble with the seat post twisting in the seat tube. Originally
I brazed on the clamping parts but ended up cutting that off and making a
double bolt clamp. It helped but the seat still twists. I’m using a gnarly
old Sem XL seat post that I could never keep from twisting in that frame
either. Maybe it’s the seat post or maybe that’s the nature of all
22.2mm seat posts. The first prototype I made has a 27.2mm seat post and
it’s never twisted.
I rode up a steep paved road with a practically flat Nokian tire (let most
of the air out to help in the snow) the other day. It was a lot of effort
and I noticed the frame flexing quit a bit side to side - an 1/8" or more.
After reading John Foss’s comments about frame twist I looked at that as
well … and it does twist.
The question is: how much flex and twist is too much? The whole idea of
this frame is to come up with something inexpensive to build but a noodle,
even a cheap one, probably isn’t worth having.
I’m going to build yet another frame using 1/2" thick fork blades instead
of the current 3/8" thick material. This should make the frame twice as
stiff in theory … and a little heavier. My target weight is 2 pounds
but with this design it might have to be heavier to be stiff enough.
We’ll see …