gear inch question

[John Foltz]

Tom Sherman <[email protected]> wrote in message news:<[email protected]>...
>
> Typically, combining a triple crank with a 3x7 hub will result in more than 40 near duplicate
> gear ratios.
>
This is true. I have a relatively huge number of duplicate gears on my V-Rex. However, to claim this
as an argument against such a setup is somewhat misleading. The reason for going with a 3x3x7 setup
is for the total range capability. I typically pick one range and ride. Within any one range, the
duplicates are no worse than for a standard three chainring system. I think of it as having 9
chainrings. Assuming a 30/42/52 set, the rings are as follows, rounding to the nearest tooth: low
range: 22/31/38 direct drive: 30/42/52 high range:
41/57/71.

Obviously, if anybody had a real problem with the duplicates they could play games with the external
gears. I've seen a setup proposed that used small jumps between rings and a corncob cassette to
provide almost no duplicates. Less total range, though.
--

 

[John Foltz]

Paul Worden wrote:
>>John wrote: but recumbents are made to be powered down hills.
>
> With my current 60 front and 11 rear (where's that gear inch table?!), speeds of more than 60 kph
> (36 mph) require a higher cadence than I can (want to?) give (down hill.)
>
Which makes my point about hating to run out of high gears. Lets see, assuming a 20" wheel with a
real diameter of 19.5", you'd have a 106" gear. That's a hair less than 120 rpm to reach 36 mph.
That's plenty fast for a lot of riders. I would feel limited, because I regularly do city limit
sprints in the 35 mph range. With a small hill, that would likely be closer to 40 mph. Ya can't
sprint if you're coasting!

> Recumbents (well - some) roll fast downhill and accellerate rapidly, so pedalling downhill doesn't
> add much to the average speed. It's on the cusp at the bottom you can kick it in and keep it going
> for the next rise.
>
Many, recumbents, including my V-Rex in its unfaired state, accelerate faster on a downhill, and
reach higher terminal velocities, than a DF. That also means there's less disincentive to power the
pedals at higher speeds. Compared to the uprights, we get a higher return for our efforts, assuming
we have the gears to do
it. If you want to increase your avg, you gotta take it where you can get it!

Regarding average speed. Recumbents have a different speed profile from DFs. Everyone talks about
how recumbents are faster on downhills and flats, but how many of us use the downhills and flats to
drop the DFers, and how many of us slow to their speed on the flats and then try to hang with them
on climbs? While doing the latter is OK, if you do it you're handicapping yourself. In itself,
powering down hills may not increase your average speed much. But in conjunction with other
strategies, you might surprise yourself.
--

John Foltz --- O _ Baron --- _O _ V-Rex 24/63 --- _\\/\-%)
_________(_)`=()___________________(_)= (_)_____

 

[Jude T. McGloin]

John, There is all kinda music out there. Gospel to Gangster Rap. We all have different likes and
capabilities. For me I would not have anything less than a 60 on a bent with a 20" wheel. Different
goals, riding styles as well as different capabilities require different equipment. I have learned
to say nothing about ones choice of gearing unless they ask me to comment about it. I often see
recumbents with tiny gearing. So what? If it suits you, it suits you. If I use bigger gearing and it
suits me, so what? Thanks John for the very informative post about why you have high gearing and how
you use it. I'm envious 36 mph sprints.

Jude....///Bacchetta AERO St. Michaels and Tilghman Island.. Maryland Wheel Doctor Cycle and Sports,
Inc 1-800-586-6645 "John Foltz" <[email protected]> wrote in message news:[email protected]...
> Paul Worden wrote:
> >>John wrote: but recumbents are made to be powered down hills.
> >
> > With my current 60 front and 11 rear (where's that gear inch table?!), speeds of more than 60
> > kph (36 mph) require a higher cadence than I can (want to?) give (down hill.)
> >
> Which makes my point about hating to run out of high gears. Lets see, assuming a 20" wheel with a
> real diameter of 19.5", you'd have a 106" gear. That's a hair less than 120 rpm to reach 36 mph.
> That's plenty fast for a lot of riders. I would feel limited, because I regularly do city limit
> sprints in the 35 mph range. With a small hill, that would likely be closer to 40 mph. Ya can't
> sprint if you're coasting!
>
> > Recumbents (well - some) roll fast downhill and accellerate rapidly, so pedalling downhill
> > doesn't add much to the average speed. It's on the
cusp
> > at the bottom you can kick it in and keep it going for the next rise.
> >
> Many, recumbents, including my V-Rex in its unfaired state, accelerate faster on a downhill, and
> reach higher terminal velocities, than a DF. That also means there's less disincentive to power
> the pedals at higher speeds. Compared to the uprights, we get a higher return for our efforts,
> assuming we have the gears to do
> it. If you want to increase your avg, you gotta take it where you can get it!
>
> Regarding average speed. Recumbents have a different speed profile from DFs. Everyone talks about
> how recumbents are faster on downhills and flats, but how many of us use the downhills and flats
> to drop the DFers, and how many of us slow to their speed on the flats and then try to hang with
> them on climbs? While doing the latter is OK, if you do it you're handicapping yourself. In
> itself, powering down hills may not increase your average speed much. But in conjunction with
> other strategies, you might surprise yourself.
> --
>
> John Foltz --- O _ Baron --- _O _ V-Rex 24/63 --- _\\/\-%)
> _________(_)`=()___________________(_)= (_)_____