Another newbie shifting question...

pacfit said:

As I have searched through the older threads here relating to this
topic I have learned a little bit more about shifting and gears. I
also consulted a friend of mine who races road bikes. About a year
ago, I purchased a Specialized Sirrus hybrid. On the left side of the
handle bar, the numbers are 1, 2, 3. On the right side the numbers are
1-8. I am assuming that means 24 speeds total. All of the riding I
have done is in 2 on the left. All the talk of cogs and grannys is
confusing to me. I did once shift into 1 or 3 (can't remember) and
threw the chain. Haven't done that since. I guess I am just looking
for some clarification. I ride about 30 miles a day with some pretty
good hills and would like to make sure I am using my bike to it's
fullest potential. Thanks for any help.

Yes, you have "24 speeds" but some of the possible front/rear
combinations should be avoided as they force the chain into an extreme
angle.

The largest front chainring sould be used with the four smallest "cogs"
in the back. These are your "big gears" and should be used when going
fast (with a tailwind or downhill). The smallest front chainring should
be used with the four largest cogs in the rear. These are your "low
gears" used for climbing hills. The middle front chainring should be
used with the middle cogs in the rear. These are the gears you will
usually use for cruising on level ground.

The fact that the chain dropped when shifting in the front indicates
that the front derailleur may need to be adjusted or re-positioned. If
you're only using the middle chainring, you're not getting the full
potential of the bike. Take it to a good bike shop and have it fixed.
Then ask them to put the bike on a trainer and have you shift through
the gears to see how it's supposed to work.

See:
http://sheldonbrown.com/gears.html

and

http://sheldonbrown.com/derailer-adjustment.html#front

Art Harris

pacfit said:

As I have searched through the older threads here relating to this
topic I have learned a little bit more about shifting and gears. I
also consulted a friend of mine who races road bikes. About a year
ago, I purchased a Specialized Sirrus hybrid. On the left side of the
handle bar, the numbers are 1, 2, 3. On the right side the numbers are
1-8. I am assuming that means 24 speeds total. All of the riding I
have done is in 2 on the left. All the talk of cogs and grannys is
confusing to me. I did once shift into 1 or 3 (can't remember) and
threw the chain. Haven't done that since. I guess I am just looking
for some clarification. I ride about 30 miles a day with some pretty
good hills and would like to make sure I am using my bike to it's
fullest potential. Thanks for any help.

Art's given you the full answer. I'll only add that my daughter used to
have a bike which was like yours. She never fully understood the need to
keep the front and rear shifted correctly and in fact, viewed it as an
impediment to her riding enjoyment.

When her bike was stolen, she chose to replace it with an REI 'Buzz'
model bike which has one shifting area - the rear. She's much happier
just having 8 speeds and doesn't seem to be hurt in speed or power by
the lack of more gears.

-paul

"pacfit" <[email hidden]> schreef in bericht
news:[email hidden]...

Quoted message said:

As I have searched through the older threads here relating to this
topic I have learned a little bit more about shifting and gears. I
also consulted a friend of mine who races road bikes. About a year
ago, I purchased a Specialized Sirrus hybrid. On the left side of the
handle bar, the numbers are 1, 2, 3. On the right side the numbers are
1-8. I am assuming that means 24 speeds total. All of the riding I
have done is in 2 on the left. All the talk of cogs and grannys is
confusing to me. I did once shift into 1 or 3 (can't remember) and
threw the chain. Haven't done that since. I guess I am just looking
for some clarification. I ride about 30 miles a day with some pretty
good hills and would like to make sure I am using my bike to it's
fullest potential. Thanks for any help.

Do you move the pedals forward during shifting ? Maybe this is a stupid
question ?

"Art Harris" <[email hidden]> wrote in news:1148920969.727886.299580
@i40g2000cwc.googlegroups.com:

....

Quoted message said:

Yes, you have "24 speeds" but some of the possible front/rear
combinations should be avoided as they force the chain into an extreme
angle.

The largest front chainring sould be used with the four smallest "cogs"
in the back. These are your "big gears" and should be used when going
fast (with a tailwind or downhill). The smallest front chainring should
be used with the four largest cogs in the rear. These are your "low
gears" used for climbing hills. The middle front chainring should be
used with the middle cogs in the rear. These are the gears you will
usually use for cruising on level ground.

The fact that the chain dropped when shifting in the front indicates
that the front derailleur may need to be adjusted or re-positioned. If
you're only using the middle chainring, you're not getting the full
potential of the bike. Take it to a good bike shop and have it fixed.
Then ask them to put the bike on a trainer and have you shift through
the gears to see how it's supposed to work.

See:
http://sheldonbrown.com/gears.html

and

http://sheldonbrown.com/derailer-adjustment.html#front

Art Harris

What I'd add is the remaining part of the drivetrain, that is YOU.

Depending on the expert you consult, there are a number of theories about
what most cyclists should aim at for an optimum foot RPM. Some say
higher is better (usually 90+) while others have lower figures.

You have to figure out what makes the most sense for you and then shift
the gears to keep your pedaling RPM near that optimum rate.

Because I'm taller than average, I think I've got a little more inertia
tied up in the masses involved in pedaling, so I feel most comfortable at
about 85 to 90 RPM. I'm sure people with less mass and shorter strokes
can comfortably do much higher.

However, just like the best evil car drivers, especially the
professionals, have been trained to keep their engines in the optimum RPM
range (listen to the in-car F1 microphones if you get a channel that airs
the races) I believe the same goes for your cycling effort. I've gotten
to the point that I shift more now through the magic of indexed shifting
and integrated brake/shifter levers in one standard lap than I used to
for half my normal 8 to 10 lap circuit.

I'm sure I'll get copiously corrected on this, but that will expose you
to even more theories you can use for deciding actually when to shift all
those gears as Mr. Harris intelligently notes above.

Hans said:

Do you move the pedals forward during shifting ? Maybe this is a stupid
question ?

Yes, you do. Moving the shift lever tightens or loosens the shift cable,
allowing the derailleur to deflect the chain towards the desired gear.
As you pedal with the chain deflected towards said gear, the teeth of
that gear engage the chain, and the chain is moved completely onto the
selected gear.

mark