Michael Press said:I tried the "ride around the neighborhood in a single gear" trick and
settled on a 39-21t - far too big for downhills
Your use of "big", I presume, means low -- big rear sprocket.
Quoted message said:but big enough to get
me up hills and comfortable on flats. The 19 seemed a bit harder than
I'm used to; I prefer high-cadence, low gears on hills. I ride 53-39
with 12-27 on my double road bike.
I think that gear is way too low for a fixed gear bike. If you really do
not want to climb in a lower cadence, out of the saddle, then maybe this
is not a good idea.
I ride a 42/17 at the moment, and have stayed around that, or a bit
higher, most of the time for many years. This allows me to get up most
hills, though a long one will be a challenge, and also allows me to get
down hills with minimal slowing due to the cadence alone. But, I have
been doing this for a long time, and can allow the bike to descend at
about a 200rpm cadence if conditions allow. That takes some getting used
to, but at least until then you can take descents more slowly.
We used to do all our winter training on fixed gears. The idea was to
develop something called "suppless" (suppleness, but it seemed more
significant in French). I don't know about that, but it did develop your
ability to tough out a climb in whatever gear you happened to have. This
was important in the days before modern derailleurs, when you literally
could not downshift while in the midst of a climb.
It's also fun to ride a fixed gear. But you need to get a ratio that is
more suitable, especially for flat-to-downhill sections. With your 39x21
gear, a 48.5" ratio, at 100rpm you are only going 14mph. Even a gentle
downhill will get you up to 200rpm, which you will not be comfortable
with. The result is that you will slow down, and your max speed will be
15mph.
Quoted message said:
My test was on a road bike with my commuting rack and bag, so not
necessarily a good fixie comparison, but it's what I've got. I wasn't
trying to hammer at all, just kind of touring speed, since much of my
intent for the fixie will be riding around the neighborhood with kids.
Even for that, get a bigger gear. You will not be challenged in any event
riding with kids, and a bigger gear will let you go beyond rides with kids
on your fixed gear.
Quoted message said:Fixie cogs seem expensive at $25-35 each (gee, you can get a whole 9
speed cassette for that), so I'm looking for opinions from the
experienced before I take the plunge.
You can do better than that kind of price. Look for a swap meet in your
area, where you can get cogs for $5 or less. Even new, you should be able
to get cogs for less than $15. It is good to have a selection. I have
everything from 12 to 21 teeth.
--
David L. Johnson
__o | What is objectionable, and what is dangerous about extremists is
_`\(,_ | not that they are extreme, but that they are intolerant. --Robert
(_)/ (_) | F. Kennedy