Thank you for the detailed explanation. It makes perfect sense. A LBS is trying to locate one of
these Campy 50-40-30s for me (with some trouble), and the owner of the shop was trying to convince
me that I might spin-out if I only get a 50 big ring. I wish I was that fast and strong. A 50-12 @90
rpm cadence equates to 29.6 mph while a 52-12 @90 rpm gives you 30.8 mph. I could live with the 50
just fine, and if I ever need that extra speed, I'll just pedal faster.
"Matt O'Toole" <
[email protected]> wrote in message
news:[email protected]...
>
> "rosco" <reverse-the-following"ocsor_g"@hotmail.com> wrote in message
>
news:[email protected]...
>
> > What do you mean by a optimized triple rather than a double + granny? I
ask
> > because I've only used doubles on road bikes, and as I age I'm
considering
> > going with a triple on my next road setup. My natural inclination is to think about a triple as
> > a double with a bail-out granny addition. With
an
> > optimized triple do you think about your gearing in a different way?
>
> First, as Peter suggested, chainline is better overall. The 42T ring is
more
> universal than a 39, and since it's in the middle you get a good chainline across the whole
> cassette. For lower or higher gears, the inner and outer
rings
> are better aligned with their corresponding cogs.
>
> As I just mentioned, the gaps in the front shifts are smaller, so you can
use
> them more freely -- an upshift won't stall your cadence. You can use the
rear
> for little shifts, and the front for bigger ones. Having a smaller gap
between
> the middle and big rings seems more useful than between the small and
middle.
>
> > The other triple I thought was interesting is the more difficult to find (but apparently
> > available) Campy 50-40-30.
>
> That would be a good choice, if it has the range you need. A 50/12 is
plenty
> tall for me, and a 30/25 low enough. YMMV.
>
> > To Sheldon's point, a third party chainring could always be substituted for the 30 to make a
> > more effective granny and still stay close to the 23 tooth max differential
for
> > the front.
>
> Most people would probably benefit from that. My stock Ultegra is fine
for me,
> but for an extra long ride or carrying some baggage I'd probably go a
little
> lower. Again, YMMV.
>
> Sheldon seems to think stock triples are overgeared, and he's probably
right.
> Most higher-end bikes probably *are* overgeared for most people. Bike
makers
> sell us racer image and racer gearing, whether it's suitable for us or
not.
>
> Matt O.