Hi Ryan and all, The mystery rider finally comes out of the woodwork. Sorry I've
been
absent for so long but I have been lurking around the dark edges of the
discussions here.
The ride I took with Ryan on his P/R was great. I'm mostly a commuter rider and
was
looking for the next bike to take me to another level. Ryan's offer was too much
to pass up
and we did a 25 miler with little problem or soreness. The only issue I
encountered was
the shimmy.
I weigh about 185 and run a seat height of 77-78cm. This was up a good 8-10 cm
from
Ryan's setup, but we decided it was too much work to also change the bar height.
I was
riding the Trimlines with a Jintesha front bag with a fairly minor load to
it(5-6 lbs?). I was
checking out the bike to see how it fit and handled to help me with my decision,
so I was
doing things with it to see what behaviors ensued. One of those was to give a
shake to the
bars to see what that felt like. The shimmy that it induced was of a bit greater
amplitude
and duration than I expected or was really comfortable with. It was especially
something
that I noticed on downhill runs where I just didn't feel the solidity that I've
known on other
bikes. I feel that the added leverage and higher center of gravity of the
increased seat
height were contributing factors in the shimmy, as well as my inexperience with
the bike. I
always have found it takes many more miles to find the little adjustments of
bike and body
that give the harmony we all seek. I have little doubt that with a bit more work
and
experience things may have worked out that way.
As for my conclusions about the bike, I didn't end up buying one for a variety
of reasons,
most of which didn't involve the bike or the ride. The main reason I didn't buy
a Kogswell
is that the old Frejus that I bought in high school and traded on another bike
in the late
80's came up on Ebay. I bought it back and put together a dandy single speeder.
I also
found a set of NOS Reynolds 531 tubes and a mentor that I'm in the process of
building
my first frame with. (I'm a skilled metalworker and this just got under my skin
a bit.) I'm
working to design a frame that echos the P/R, but seems to more closely match my
odd
body proportions. I'll let you know what happens with it. I still think the P/R
is an amazing
machine and if finances would allow I'd have one now.
When I embarked on this, I bought a 30mm trail 650B P/R fork that I'm now
planning on
selling. Drop me a line if you might be interested and we can work out a price
or trade.
Cheers,
Jamie Hascall
Santa Fe
>
> No shimmy for me either way.
> Jamie, are you still here? If so, when did my bike shimmy for you?
>
> Ryan
>
I think that front-end shimmy is a harmonic. I think that shimmy occurs when some multiple of the resonant frequency of the bicycle is induced. I think the...
I'm all over that. I have been planning a test ride (maybe as soon as this afternoon) where I would ride a several mile loop that includes varied terrain,...
On Sun, Jun 29, 2008 at 8:19 AM, Kogswell Cycles ... That is how I understand it as well. My cargo bike generates a shimmy when loaded, and my experience has ...
... James, I hear what you're saying, but as a counter point my P/R also shimmies with a light load in a Candy Bar bag strapped to the handlebars. That bag...
... Hi Jim: That is unfortunate to hear, but I guess I'm not too surprised. With my Nishiki (73 deg. HA, 40mm trail), I had no shimmy at all before I installed...
... I may be interested, but I've got my bike set up just the way I like it, so I don't want to modify much. A bit of data: I lent my P/R to a list member for...
... Interesting. Any ideas what would account for the bike shimmying with one rider, but unwilling to shimmy with another? Is the other rider of similar body...
... On my bike, the frequency of the shimmy seems to be somewhat in sync with my pedal cadence. And if I stop pedaling and touch a knee against the top tube,...
... You reminded me that I did notice on my cargo bike that pedalling really slowly, less than 60 rpm, seemed to lessen the shimmy when I had a huge front...
... James & Ryan, just to clarify -- do your bikes shimmy even with hands on the handlebars? To be clear, mine doesn't: the only shimmy I'm experiencing is...
... My road bikes typically don't shimmy with hands on the handlebars, the shimmy usually gets going shortly after I start with the no-hands. My cargo bike...
Hi Ryan and all, The mystery rider finally comes out of the woodwork. Sorry I've been absent for so long but I have been lurking around the dark edges of the...
... No idea. He's pretty much my size. About the same height overall, but longer legs, I guess, since I had to raise the seat. Maybe something in riding style...
... I remember now that we couldn't get the bars as high as he would like. Maybe not being quite comfortable had an effect on riding style and led to shimmy? ...
... sideways ... How much do you weigh, and what pressure do you run your tires at? Also, please refresh my memory: how wide are those Trimline tires? Thx, ...
... About 180 lbs when I got the bike last fall, about 170 now. I lost 10 pounds on the Kogswell diet plan! ;-) Trimlines are about 36mm actual width I think...
You all are coming up with the same factors that I have collected/observed over time. The list of things that I have directly observed as affecting shimmy...
I agree - both my low trail bikes (P/R Mk I and G with low trail fork) have been prone to shimmy if the headset gets loose. Otherwise, they are very stable...
To add my two cents the only shimmy I've ever noticed on my G2 was at very low speed - say 5 MPH. And this loaded a bit oddly with a front bag (5 to 10 lbs) on...