paul said:Q: If I had the gearing 34T x 17T, what would my cadence be if I
wanted to travel ~25kmh.
Assuming a 26" wheel, the tyre circumference is generally somewhere
between 2.0 and 2.1m, so each pedal stroke will push you around 4m.
That means you'll need to do n/4 crank rotations each second to do n
m/s, or hold a cadence of around 4.2n to do n km/h.
So you'll need to be holding a cadence of around 105 for 25km/h.
Quoted message said:Q: Also I was wondering if required and I could afford one,
could I retro fit a rohlspeed hub on the Kona unit?
Without actually checking the specs I can't be sure, but it shouldn't
be a problem.
Quoted message said:Q: Another question any other internal geared hubs people have
*used* here. I don't think having twenty something gears or
whatever is really a necessity.
True, and the TdF riders originally only had one gear, or if they were
lucky a flip/flop hub. But if you're dealing with fairly large angle
changes (say +20% to -20%) then having a big range is nice and more
efficient. The Rohloff's range is more useful to MTBers than roadies,
for whom the weight will be more of an issue, and MTBers fairly
regularly hit those kind of grades (+20% and above hurts)
It sounds like you're either able to get power down over a very large
cadence range or you're mainly riding fairly constant grades. In either
case, a single speed probably isn't a bad option for you, and you can
tweak the combination up or down a bit to find what works for you - the
standard 2:1 ratio is just a recommended starting point.
Dave - who hasn't actually used an internal geared hub, but has ridden
with a bloke who uses one regularly.
--
Dave Hughes | [email hidden] | [email hidden]
We tend to view 'all publicity is good publicity' as a challenge
we should endeavour to meet - The Register
