Road bike fit

On Dec 17, 10:25 pm, OccasionalFlyer wrote:
I'm shopping for a new road
bike, with better components than the twenty-year-old 105 components
on my Trek 2100. The main bikes in the price range I'm aiming for
include a Trek Madone, Cannondale Synapse or Supersix, or Cervelo
(like an R3). I'm having trouble with finding a bike that fits.
Cannondale and Cervelo both seem to have frame sizes of 51 and 54 but
nothing in-between. My current road bike is 52cm and that feels
right. I've tried both the 51' with the seat raised and the 54' with
the seat lowered. The person at the bike store who worked with me
didn't really seem able to say, "You can tell if it's the right frame
size if..."

You can tell if it's the right frame size if it doesn't feel wrong
when you ride it.

Ride. Feel.

On 19/12/11 08:37, Dan O wrote:
On Dec 17, 10:25 pm, wrote:
I'm shopping for a new road
bike, with better components than the twenty-year-old 105 components
on my Trek 2100. The main bikes in the price range I'm aiming for
include a Trek Madone, Cannondale Synapse or Supersix, or Cervelo
(like an R3). I'm having trouble with finding a bike that fits.
Cannondale and Cervelo both seem to have frame sizes of 51 and 54 but
nothing in-between. My current road bike is 52cm and that feels
right. I've tried both the 51' with the seat raised and the 54' with
the seat lowered. The person at the bike store who worked with me
didn't really seem able to say, "You can tell if it's the right frame
size if..."

You can tell if it's the right frame size if it doesn't feel wrong
when you ride it.

Ride. Feel.

Lee: That's it! How did it feel?
[Student thinks; Lee smacks his head]
Lee: Don't think. FEEL. It's like a finger pointing at the moon.
[Looks at student who is looking at the finger; smacks student again]
Lee: Do not concentrate on the finger or you will miss all of the
heavenly glory!
[Student bows; Lee smacks him again]
Lee: Never take your eyes off your opponent... even when you're bowing!
[Student bows again this time keeping his eyes on Lee]
Lee: That's better.
[student walks away; opening credits begin]

Bruce Lee, "Enter the Dragon"

--
JS.

On Dec 18, 6:49*pm, damyth wrote:
On 12/18/2011 09:25 AM, Ron Ruff wrote:



Like others have said, you need to determine the contact points
coordinates of your current bike relative to the bottom bracket, and
make sure you can replicate this on the new bike.

This is assuming that you don't want them to change. If you do (or
might in the future) want them to change, then make sure you can
accommodate that. Stem lengths are readily available from 80-130mm and
have different amounts of rise, handlebars have varying amounts of
reach as well, and seatposts have varying setback. It isn't hard to
make a wide range of sizes fit perfectly.

Based on the frame size, I'm probably around the same height as the OP.
* I don't want to make a mountain of a molehill but I find it's pretty
difficult to fit people when frames sizes are =52cm.

Fitting is one thing. *Getting a great ride is another. *I've pretty
much come to the conclusion with 700c wheels (front and back) too many
compromises must be made for small frames/riders.

Use shorter cranks. 1/5 inside leg or 1/2 femur length at maximum.

On 19/12/11 11:15, thirty-six wrote:
On Dec 18, 6:49 pm, wrote:
On 12/18/2011 09:25 AM, Ron Ruff wrote:



Like others have said, you need to determine the contact points
coordinates of your current bike relative to the bottom bracket, and
make sure you can replicate this on the new bike.

This is assuming that you don't want them to change. If you do (or
might in the future) want them to change, then make sure you can
accommodate that. Stem lengths are readily available from 80-130mm and
have different amounts of rise, handlebars have varying amounts of
reach as well, and seatposts have varying setback. It isn't hard to
make a wide range of sizes fit perfectly.

Based on the frame size, I'm probably around the same height as the OP.
I don't want to make a mountain of a molehill but I find it's pretty
difficult to fit people when frames sizes are=52cm.

Fitting is one thing. Getting a great ride is another. I've pretty
much come to the conclusion with 700c wheels (front and back) too many
compromises must be made for small frames/riders.

Use shorter cranks. 1/5 inside leg or 1/2 femur length at maximum.

I tried to measure my femur. Not sure how accurate, but I got about
45cm. From the lump at the top just out from my hip, to the lump at the
outside of my knee. Wow, that means I could ride a 225mm crank!

This seems a little more useful...

http://www.53x12.com/do/show?page=article&id=59

--
JS.

On Dec 18, 7:04*am, Duane Hebert wrote:
On 12/18/2011 1:25 AM, OccasionalFlyer wrote:





I'm shopping for a new road
bike, with better components than the twenty-year-old 105 components
on my Trek 2100. *The main bikes in the price range I'm aiming for
include a Trek Madone, Cannondale Synapse or Supersix, or Cervelo
(like an R3). *I'm having trouble with finding a bike that fits.
Cannondale and Cervelo both seem to have frame sizes of 51 and 54 but
nothing in-between. My current road bike is 52cm and that feels
right. *I've tried both the 51' with the seat raised and the 54' with
the seat lowered. *The person at the bike store who worked with me
didn't really seem able to say, "You can tell if it's the right frame
size if..." *The 54' is too tall, even with the seat lowered, while
the 51' feels a bit too cramped. *I know that comfort (since I'm not
trying to race any more) is important but there are multiple
adjustments that could be made, like stem height, to make the right
sized frame feel more comfortable. *Is there any good technique
beyond
standing over the top tube and assessing how much space there is
between the bike and the rider to determine if I'm choosing the right
frame size? *There are probably bike shops where I could get more help
with this but I haven't found any yet in my area (Pasadena to Pomona
in LA county, southern California). *Any suggestions? Thanks.

Ken

Specialized Tarmac comes in 49, 52 and 54. *Probably similar to the Trek
or Cervelo that you are considering. *May be worth a look.- Hide quoted text -

Madones come in 52 and 54cm, and the Cannondale SuperSix comes in a
52. It's not a whole lot more than the Synapse, depending on
component package. The Synapse jumps from 51 to 54cm. I think in
that frame size, there is not going to be a huge difference in ride
charactertistic.

-- Jay Beattie.

On 12/18/2011 10:19 AM, wrote:
On Dec 17, 11:25 pm, wrote:
I'm shopping for a new road
bike, with better components than the twenty-year-old 105 components
on my Trek 2100. The main bikes in the price range I'm aiming for
include a Trek Madone, Cannondale Synapse or Supersix, or Cervelo
(like an R3). I'm having trouble with finding a bike that fits.
Cannondale and Cervelo both seem to have frame sizes of 51 and 54 but
nothing in-between. My current road bike is 52cm and that feels
right. I've tried both the 51' with the seat raised and the 54' with
the seat lowered. The person at the bike store who worked with me
didn't really seem able to say, "You can tell if it's the right frame
size if..." The 54' is too tall, even with the seat lowered, while
the 51' feels a bit too cramped. I know that comfort (since I'm not
trying to race any more) is important but there are multiple
adjustments that could be made, like stem height, to make the right
sized frame feel more comfortable. Is there any good technique
beyond
standing over the top tube and assessing how much space there is
between the bike and the rider to determine if I'm choosing the right
frame size? There are probably bike shops where I could get more help
with this but I haven't found any yet in my area (Pasadena to Pomona
in LA county, southern California). Any suggestions? Thanks.

Ken
Find a bike shop that:

will put a bike on a trainer. will take measurements of top tube and
seat tube length. look at how you pedal and make sure that you have a
comfortable position. offers to change stem length. let you ride the
bike for at least an hour. Most modern bike, decent bike stores will
do that. is willing an able to change stem and handlebars for a
minimum price after a month of riding.

if you don't have a bike shop that does this, see if you can drive to
a town nearby that does this.


Agreed. I would not spend the kind of money the OP is talking about at
a shop
that couldn't do a proper fit.

On Dec 19, 12:28*am, James wrote:
On 19/12/11 11:15, thirty-six wrote:









On Dec 18, 6:49 pm, *wrote:
On 12/18/2011 09:25 AM, Ron Ruff wrote:

Like others have said, you need to determine the contact points
coordinates of your current bike relative to the bottom bracket, and
make sure you can replicate this on the new bike.

This is assuming that you don't want them to change. If you do (or
might in the future) want them to change, then make sure you can
accommodate that. Stem lengths are readily available from 80-130mm and
have different amounts of rise, handlebars have varying amounts of
reach as well, and seatposts have varying setback. It isn't hard to
make a wide range of sizes fit perfectly.

Based on the frame size, I'm probably around the same height as the OP..
* *I don't want to make a mountain of a molehill but I find it's pretty
difficult to fit people when frames sizes are=52cm.

Fitting is one thing. *Getting a great ride is another. *I've pretty
much come to the conclusion with 700c wheels (front and back) too many
compromises must be made for small frames/riders.

Use shorter cranks. *1/5 inside leg or 1/2 femur length at maximum.

I tried to measure my femur. *Not sure how accurate, but I got about
45cm. *From the lump at the top just out from my hip, to the lump at the
outside of my knee. *Wow, that means I could ride a 225mm crank!

Oh ********. My memory's playing tricks. It's half of something (I
think)

This seems a little more useful...

http://www.53x12.com/do/show?page=article&id=59

--
JS.

On 12/18/2011 1:25 AM, OccasionalFlyer wrote:
I'm shopping for a new road
bike, with better components than the twenty-year-old 105 components
on my Trek 2100. The main bikes in the price range I'm aiming for
include a Trek Madone, Cannondale Synapse or Supersix, or Cervelo
(like an R3). I'm having trouble with finding a bike that fits.
Cannondale and Cervelo both seem to have frame sizes of 51 and 54 but
nothing in-between. My current road bike is 52cm and that feels
right. I've tried both the 51' with the seat raised and the 54' with
the seat lowered. The person at the bike store who worked with me
didn't really seem able to say, "You can tell if it's the right frame
size if..." The 54' is too tall, even with the seat lowered, while
the 51' feels a bit too cramped. I know that comfort (since I'm not
trying to race any more) is important but there are multiple
adjustments that could be made, like stem height, to make the right
sized frame feel more comfortable. Is there any good technique
beyond
standing over the top tube and assessing how much space there is
between the bike and the rider to determine if I'm choosing the right
frame size? There are probably bike shops where I could get more help
with this but I haven't found any yet in my area (Pasadena to Pomona
in LA county, southern California). Any suggestions? Thanks.

Ken




Read, if you haven't, Sheldon Brown's article:
http://sheldonbrown.com/frame-sizing.html

I agree with him that the critical dimension is top tube length. You can
tweak that a little with stem length, but too much can affect handling
and weight distribution.

When we ride less aggressively, we generally want higher bars and a
shallower seat tube angle. The saddle position should be used to tweak
effective seat tube angle, not to adjust cockpit length.

If you have unusual body proportions, like long torso and short legs,
finding the ideal top tube and seat tube proportional lengths may be
difficult in a stock frame.

It's very difficult to decide if a bike is a good fit based on a short
ride, more so if you're very accustomed to a particular geometry.
Anything different is going to feel strange. The thing that's difficult
to know is whether you'll like it better after the initial strangeness
wears off. I find that using a trainer for a relatively long spin allows
you to concentrate just on the bike fit. I typically spend a couple of
hours on a trainer when setting up a new bike, tweaking bar & saddle
height, saddle setback, swapping out stems and even handlebars and even
bar and lever rotational positions, until I get that feeling of perfect
balance on the bike.

Be picky, don't succumb to new bike fever, lest you suffer buyer's
remorse forever. If you're sure you like your current fit and don't want
to change anything, then take measurements and see if you can duplicate
them without compromising with unusual tweaks, otherwise pick a
different bike or go custom. That's the first question to answer,
whether you want a change in geometry.

On 12/18/2011 4:37 PM, Dan O wrote:
On Dec 17, 10:25 pm, wrote:
I'm shopping for a new road
bike, with better components than the twenty-year-old 105 components
on my Trek 2100. The main bikes in the price range I'm aiming for
include a Trek Madone, Cannondale Synapse or Supersix, or Cervelo
(like an R3). I'm having trouble with finding a bike that fits.
Cannondale and Cervelo both seem to have frame sizes of 51 and 54 but
nothing in-between. My current road bike is 52cm and that feels
right. I've tried both the 51' with the seat raised and the 54' with
the seat lowered. The person at the bike store who worked with me
didn't really seem able to say, "You can tell if it's the right frame
size if..."

You can tell if it's the right frame size if it doesn't feel wrong
when you ride it.

Ride. Feel.


I think that you find out if a bike fits you after about the 110th
kilometer. A few kilometers may tell you that the frame size is close
but a setup on a trainer with a good fit guy should be part of the deal.
Especially when you're spending thousands for a bike.

On Dec 19, 6:32*am, Peter Cole wrote:
On 12/18/2011 1:25 AM, OccasionalFlyer wrote:









I'm shopping for a new road
bike, with better components than the twenty-year-old 105 components
on my Trek 2100. *The main bikes in the price range I'm aiming for
include a Trek Madone, Cannondale Synapse or Supersix, or Cervelo
(like an R3). *I'm having trouble with finding a bike that fits.
Cannondale and Cervelo both seem to have frame sizes of 51 and 54 but
nothing in-between. My current road bike is 52cm and that feels
right. *I've tried both the 51' with the seat raised and the 54' with
the seat lowered. *The person at the bike store who worked with me
didn't really seem able to say, "You can tell if it's the right frame
size if..." *The 54' is too tall, even with the seat lowered, while
the 51' feels a bit too cramped. *I know that comfort (since I'm not
trying to race any more) is important but there are multiple
adjustments that could be made, like stem height, to make the right
sized frame feel more comfortable. *Is there any good technique
beyond
standing over the top tube and assessing how much space there is
between the bike and the rider to determine if I'm choosing the right
frame size? *There are probably bike shops where I could get more help
with this but I haven't found any yet in my area (Pasadena to Pomona
in LA county, southern California). *Any suggestions? Thanks.

Ken

Read, if you haven't, Sheldon Brown's article:http://sheldonbrown.com/frame-sizing.html

I agree with him that the critical dimension is top tube length. You can
tweak that a little with stem length, but too much can affect handling
and weight distribution.

When we ride less aggressively, we generally want higher bars and a
shallower seat tube angle. The saddle position should be used to tweak
effective seat tube angle, not to adjust cockpit length.

If you have unusual body proportions, like long torso and short legs,
finding the ideal top tube and seat tube proportional lengths may be
difficult in a stock frame.

It's very difficult to decide if a bike is a good fit based on a short
ride, more so if you're very accustomed to a particular geometry.
Anything different is going to feel strange. The thing that's difficult
to know is whether you'll like it better after the initial strangeness
wears off. I find that using a trainer for a relatively long spin allows
you to concentrate just on the bike fit. I typically spend a couple of
hours on a trainer when setting up a new bike, tweaking bar & saddle
height, saddle setback, swapping out stems and even handlebars and even
bar and lever rotational positions, until I get that feeling of perfect
balance on the bike.

Be picky, don't succumb to new bike fever, lest you suffer buyer's
remorse forever. If you're sure you like your current fit and don't want
to change anything, then take measurements and see if you can duplicate
them without compromising with unusual tweaks, otherwise pick a
different bike or go custom. That's the first question to answer,
whether you want a change in geometry.

Wise advice. Also, why not upgrade the current bike if it fits? If you
do your own work, a newish 105 groupset is $500, but well under $1K if
you pay retail and let your LBS swap things out.

Custom is a good option. If you're not racing, the pound or two
advantage of CFRP traded for fit is a bad choice. Around here, Andy at
Homegrown Bicycles could hook you up with a frame and color for under
$1500 last I checked.