Compact v. Triple

I'm thinking of converting a triple to a compact on my son's bike.
The current triple is an old Shimano with an Octalink BB. It started
creaking bad and loosening up on a ride yesterday, and I suspect it
may be toast. He is a good climber and natural spinner and is
currently using a low of 30/26 -- so I'm thinking a 34/28 is going to
get him to about the same place, although he won't have as many gear
choices. Is there any great penalty switching to a compact?

-- Jay Beattie.

Big question to ask is what kind of shifters does the bike have? That pretty much determines whether you run a triple or double crankset. If you have STI/Ergo/click shifters for the front derailleur, then you are talking $200-300 to change from triple to double. Have to buy a pair of shifters, not singles. Crank and bottom bracket will be $100 total. Is the bike worth spending $200-300 to change shifters? If the shifters don't have to be changed then I see no reason not to do the changes you mentioned.


On Sunday, June 2, 2013 5:45:48 PM UTC-5, Jay Beattie wrote:
I'm thinking of converting a triple to a compact on my son's bike.

The current triple is an old Shimano with an Octalink BB. It started

creaking bad and loosening up on a ride yesterday, and I suspect it

may be toast. He is a good climber and natural spinner and is

currently using a low of 30/26 -- so I'm thinking a 34/28 is going to

get him to about the same place, although he won't have as many gear

choices. Is there any great penalty switching to a compact?



-- Jay Beattie.

On Sun, 2 Jun 2013 15:45:48 -0700 (PDT), Jay Beattie
wrote:

I'm thinking of converting a triple to a compact on my son's bike.
The current triple is an old Shimano with an Octalink BB. It started
creaking bad and loosening up on a ride yesterday, and I suspect it
may be toast. He is a good climber and natural spinner and is
currently using a low of 30/26 -- so I'm thinking a 34/28 is going to
get him to about the same place, although he won't have as many gear
choices. Is there any great penalty switching to a compact?

-- Jay Beattie.

I've got two road bikes, one with a triple and one with a double and I
find that I prefer the double. In my case the double (9 speed) has 17
usable gear rations while the triple has 19. the highest (gear inches)
is 108 for the triple and 93 for the double, lowest is 18 for the
triple and 20 for the double. since I can't pedal the highest speed on
either on the flat and the lowest (double) has gotten me up every hill
I've tried I prefer the compact double over the triple.
(although not to the extent that I have plans to convert the triple to
a double :-)

--
Cheers,

John B.

On Jun 2, 4:44*pm, "
wrote:
Big question to ask is what kind of shifters does the bike have? *That pretty much determines whether you run a triple or double crankset. *If you have STI/Ergo/click shifters for the front derailleur, then you are talking $200-300 to change from triple to double. *Have to buy a pair of shifters, not singles. *Crank and bottom bracket will be $100 total. *Is the bike worth spending $200-300 to change shifters? *If the shifters don't have to be changed then I see no reason not to do the changes you mentioned.


This is all contingent on the female splines on the crank being shot
after the crank got loose. If not, I'll leave everything alone, but
I'm going to see if it comes loose again. BTW, they are visually O.K.,
but I had this problem on another bike years ago, and it kept coming
loose -- and I replaced the crank.

Anyway, I can see getting a compact specific front derailleur, but why
would I need to change the shifters (which are 9sp Ultegra)? And I
agree, I would not want to dump the money on a compact crank and a new
cassette if I didn't have to.

Also, while we're at it, is there any reason why a new "10sp" FD would
not work with a 9sp set up. I can't imagine why it wouldn't unless
the cage is super narrow.

-- Jay Beattie.

try a section of coke can or douse with red loctite or both.

using say a coke can over 45 degress of male spline or opposing sections or quadrent sections, each smaller.

for wear check, look at spline's outboard ends. Maybe movement rotate forward at the outboard end.

amazing how 'immeasurable' wear here throws everything out of kilter.

On Jun 3, 2:38*am, Jay Beattie wrote:
On Jun 2, 4:44*pm, "

wrote:
Big question to ask is what kind of shifters does the bike have? *That pretty much determines whether you run a triple or double crankset. *If you have STI/Ergo/click shifters for the front derailleur, then you are talking $200-300 to change from triple to double. *Have to buy a pair of shifters, not singles. *Crank and bottom bracket will be $100 total. *Is the bike worth spending $200-300 to change shifters? *If the shifters don't have to be changed then I see no reason not to do the changes you mentioned.

This is all contingent on the female splines on the crank being shot
after the crank got loose. *If not, I'll leave everything alone, but
I'm going to see if it comes loose again. BTW, they are visually O.K.,
but I had this problem on another bike years ago, and it kept coming
loose -- and I replaced the crank.

Anyway, I can see getting a compact specific front derailleur, but why
would I need to change the shifters (which are 9sp Ultegra)? And I
agree, I would not want to dump the money on a compact crank and a new
cassette if I didn't have to.

Also, while we're at it, is there any reason why a new "10sp" FD would
not work with a 9sp set up. *I can't imagine why it wouldn't unless
the cage is super narrow.

-- Jay Beattie.

Make it a superlight bike,remove the garbage for the front shifting,
and tell him to shift the chain with his fingers.

On Jun 3, 2:03*am, John B. wrote:
On Sun, 2 Jun 2013 15:45:48 -0700 (PDT), Jay Beattie

wrote:
I'm thinking of converting a triple to a compact on my son's bike.
The current triple is an old Shimano with an Octalink BB. *It started
creaking bad and loosening up on a ride yesterday, and I suspect it
may be toast. *He is a good climber and natural spinner and is
currently using a low of 30/26 -- so I'm thinking a 34/28 is going to
get him to about the same place, although he won't have as many gear
choices. *Is there any great penalty switching to a compact?

-- Jay Beattie.

I've got two road bikes, one with a triple and one with a double and I
find that I prefer the double. In my case the double (9 speed) has 17
usable gear rations

let's see, on a pared down "racing" bike I have settled on a low gear
ratio of around 36" which will permit me to ride all roads I can ride
to (without a load) and much, much off road stuff. When I have had
trouble with this gear I have also been unable to ride easily on the
flat, I should not be riding. I do have a lower gear and have used
it in emergency. Top gear is 79" which has come into use on rare
days of absolute sparkling ability on the flat or a tail wind. The
low end is satisfactory and the high end mostly so. My next changes
(for bike #1) will likely be looking towards around 90" highest (which
could be 48x14), yet retaining that common low ratio as it is
(currently 39x28). It will be a 1/2-step system and the only
"problem" I have is wondering about locating shorter handsome cranks
(probably around 150mm) with double chainrings which are economically
obtainable. Of course by the time I get around to doing it, the
choices of quality 5 and 6-speed freewheels of 14-3? will be less than
the fingers of one hand and that Mavic derailleur I want.. .

Hmmmm, maybe I should start with the derailleur, even if it is
tatty through use in cyclo-cross.

I know what I want, just being tight because I don't need it. The
question is whether I'll get sufficiently greater pleasure when I
could spend more usefully otherwise.

There's only one way I'll know that derailleur is good and there's
only one way I will know I will benefit from significantly shorter
cranks. Hmmm, any ideas of where to locate a handsome double
chainset with cranks between 140mm to 155mm? In UK please.

while the triple has 19. the highest (gear inches)
is 108 for the triple and 93 for the double, lowest is 18 for the
triple and 20 for the double. since I can't pedal the highest speed on
either on the flat and the lowest (double) has gotten me up every hill
I've tried I prefer the compact double over the triple.
(although not to the extent that I have plans to convert the triple to
a double :-)

--
Cheers,

John B.

On 6/2/2013 3:45 PM, Jay Beattie wrote:
I'm thinking of converting a triple to a compact on my son's bike.
The current triple is an old Shimano with an Octalink BB. It started
creaking bad and loosening up on a ride yesterday, and I suspect it
may be toast. He is a good climber and natural spinner and is
currently using a low of 30/26 -- so I'm thinking a 34/28 is going to
get him to about the same place, although he won't have as many gear
choices. Is there any great penalty switching to a compact?

What's the frame material?

My road bicycle has a triple and I'm glad I got a triple even though
when I purchased the bike I could have bought the model that had only a
double and I was young enough that I could have gotten by with a double.
But 25 years later, I'm glad I got the triple.

If it's a CF bike, or even aluminum, then there's no need to worry about
what's going to happen 25 years down the road. But if it's a classic
steel road bicycle it will have a long life and you might want to put a
new triple on it.