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Road bike seat height?



 
 
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  #1  
Old September 7th 03, 03:36 PM
Ken Bessler
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Posts: n/a
Default Road bike seat height?

I have the following bike setup:

Bianchi Limited 12 speed, circa 1990 ($35 at the Salvation Army)
Derailurs & Shifters - Shimano 105's
Brakes - "Dia Compe"
Seat - FEC Alloy SX (Very light but nice)
Gooseneck - SR Royal
Handlebars - SR Road Champion
Crank arms - SR 170mm
Front gear - Sugino 52-42
Rear gear - 25-23-20-17-15-13
Rims - Sun Mistral USA 700mm - 36 spoke alloy
Tires - Discovery Kevlar CyclePro 700x25
Tubes - Slime 700x self healing ($15 for 2 tubes)
Skewers - Suzue
Wheel hubs - Suzue 36 spoke
Valve stems - Presta (bought an adapter for $2)
Computer - Cateye Astrale CC-CD100 N ($25)
GPS - Garmin Etrex Vista ($339)
Communications - Yaesu VX-7Rb handheld ($319)

How do I adjust the seat height? I'm thinking the formula
would be frame size + crank arm + distance from top of
frame to top of seat should equal my inseam, right? Or not?
Measuring my inseam is with my feet flat on the ground - I
don't ride flat footed but with the base of my toes on the
pedals. Should I figgure this in?

Also, how do I measure the frame size? Is it from crank
centerline to top tube centerline (at the seat post)? I got
exactly 50cm this way

Frame size = 50cm?
Crank arm = 17cm
Seat height= 10.5cm
Total = 77.5 cm

I measure 29" from crotch to floor = 73.66cm. If I add
my feet that's another 3.25" or 8.255cm for a total of
81.915cm. By that measure I need to raise my seat 1.738"
or 4.415cm My seat is currently as far down as it can go.
I can just reach the street with both toes when sitting on
the seat but when riding, at the bottom of each stroke,
my legs are still bent and at the top of each stroke I feel
a bit cramped......help?

Ken


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  #2  
Old September 7th 03, 04:42 PM
Harris
external usenet poster
 
Posts: n/a
Default Road bike seat height?

"Ken Bessler" wrote:

How do I adjust the seat height?


There are a couple of methods to get you in the ball park:

1) Center of BB to top of saddle = 0.883 x inseam.

2) Pedal axis (pedal down, aligned with seat tube) to top of saddle = 1.09 x
inseam.

3) Raise saddle in 1/8" increments until your hips just start rocking when
you pedal, then lower it until you stop rocking.

You also want to set the fore/aft position of the saddle properly. A good
starting place is to have the front of your knee directly over the pedal
axis with the pedals horizontal (3 o'clock position). Have someone help you
using a plumb line.

See: http://www.sbraweb.org/setup.htm

Also, how do I measure the frame size? Is it from crank
centerline to top tube centerline (at the seat post)? I got
exactly 50cm this way


Unfortunately, there is no established standard. There are at least three
ways of specifying frame size:

1) Center of BB to center of top tube
2) Center of BB to top of top tube
3) Center of BB to top of seat tube
(all measured along the seat tube.)

Take your pick. I prefer #1.

I measure 29" from crotch to floor = 73.66cm. If I add
my feet that's another 3.25" or 8.255cm for a total of
81.915cm. By that measure I need to raise my seat 1.738"
or 4.415cm My seat is currently as far down as it can go.
I can just reach the street with both toes when sitting on
the seat but when riding, at the bottom of each stroke,
my legs are still bent and at the top of each stroke I feel
a bit cramped......help?


Try 29" x .883 = 25.6" (25-5/8") from center of BB to saddle as a start.

Art Harris




  #3  
Old September 7th 03, 04:56 PM
Sheldon Brown
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Posts: n/a
Default Road bike seat height?

Ken Bessler asked:

How do I adjust the seat height?


Art Harris replied.

There are a couple of methods to get you in the ball park:

1) Center of BB to top of saddle = 0.883 x inseam.

2) Pedal axis (pedal down, aligned with seat tube) to top of saddle = 1.09 x
inseam.


These numerical "systems" are pure snake oil.

The first doesn't even take crank length into account!

Neither of them regards foot length or foot position on the pedal.

They also presume that it is possible to make a meaningful measurement
to an unspecified type of saddle to three significant digits, which is
pretty meaningless, given the range of shapes and flexibilities of saddles.

3) Raise saddle in 1/8" increments until your hips just start rocking when
you pedal, then lower it until you stop rocking.


That's the best way.

See also: http://sheldonbrown.com/saddles.html

You also want to set the fore/aft position of the saddle properly. A good
starting place is to have the front of your knee directly over the pedal
axis with the pedals horizontal (3 o'clock position). Have someone help you
using a plumb line.

See: http://www.sbraweb.org/setup.htm


See also http://sheldonbrown.com/kops.html

Also, how do I measure the frame size? Is it from crank
centerline to top tube centerline (at the seat post)? I got
exactly 50cm this way



Unfortunately, there is no established standard. There are at least three
ways of specifying frame size:

1) Center of BB to center of top tube
2) Center of BB to top of top tube
3) Center of BB to top of seat tube
(all measured along the seat tube.)


More than that, actually! Some sloping-top-tube frames are measured by
where the seat tube would end up if the top tube didn't slope down from
the head tube!

Take your pick. I prefer #1.


I prefer #3, but to me the top tube length is the much more important
dimension, see: http://sheldonbrown.com/frame-sizing.html.

Sheldon "Traial And Error" Brown
+--------------------------------------------------------------------+
| We engaged in innumerable discussions, and often after an hour |
| or so of heated argument, we would discover that we were as far |
| from agreement as when we started, but that both had changed to |
| the other's original position in the discussion.--Orville Wright |
+--------------------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

  #4  
Old September 7th 03, 05:11 PM
Ken Bessler
external usenet poster
 
Posts: n/a
Default Road bike seat height?


"Harris" wrote in message
. net...


Try 29" x .883 = 25.6" (25-5/8") from center of BB to saddle as a start.

Art Harris


I tried the butt rocking meathod and with slight rocking, I measured
25.625".
Backed off 1/4" and it feels fine. Adjusted the seat position back for knee
alignment - all the way back gave me almost perfect alignment......

Thanks, Art!

P.S. 72's es 73's OM es gl de Ken KG0WX/QRP DM79nr sk sk k

Ken


  #5  
Old September 7th 03, 07:56 PM
Scic
external usenet poster
 
Posts: n/a
Default Discovery Tires...was...Road bike seat height?

From: "Ken Bessler"

I have the following bike setup:
snip


Tires - Discovery Kevlar CyclePro 700x25


First time that I've seen these tires mentioned here.
I've been buying them for years from REI but they've since been replaced by the
Avenir Discovery Kevlar Belted 700x25c which are said to be identical (same
tire) to the Cycle Pro albeit now made in Korea. I can't tell the difference.
At $15.00 per, it might be a tire to consider for those who ride city streets
like I do and often lose tires to cuts. Had to give up $30.00+ tires...too
expensive.
I obviously like them and wouldn't mind seeing a review from someone more
knowledgable than me.
I wish they still made the Schwinn Record, a good, expendable tire, I thought.


Sig
Chicago
  #6  
Old September 7th 03, 08:14 PM
Mark Wolfe
external usenet poster
 
Posts: n/a
Default Road bike seat height?

First off, you should slide forward off the seat when you stop. Otherwise
you could possibly entertain anyone in the area when you fall over.
Read the other replies and goto Sheldon's site.


Ken Bessler wrote:

I have the following bike setup:

Bianchi Limited 12 speed, circa 1990 ($35 at the Salvation Army)
Derailurs & Shifters - Shimano 105's
Brakes - "Dia Compe"
Seat - FEC Alloy SX (Very light but nice)
Gooseneck - SR Royal
Handlebars - SR Road Champion
Crank arms - SR 170mm
Front gear - Sugino 52-42
Rear gear - 25-23-20-17-15-13
Rims - Sun Mistral USA 700mm - 36 spoke alloy
Tires - Discovery Kevlar CyclePro 700x25
Tubes - Slime 700x self healing ($15 for 2 tubes)
Skewers - Suzue
Wheel hubs - Suzue 36 spoke
Valve stems - Presta (bought an adapter for $2)
Computer - Cateye Astrale CC-CD100 N ($25)
GPS - Garmin Etrex Vista ($339)
Communications - Yaesu VX-7Rb handheld ($319)

How do I adjust the seat height? I'm thinking the formula
would be frame size + crank arm + distance from top of
frame to top of seat should equal my inseam, right? Or not?
Measuring my inseam is with my feet flat on the ground - I
don't ride flat footed but with the base of my toes on the
pedals. Should I figgure this in?

Also, how do I measure the frame size? Is it from crank
centerline to top tube centerline (at the seat post)? I got
exactly 50cm this way

Frame size = 50cm?
Crank arm = 17cm
Seat height= 10.5cm
Total = 77.5 cm

I measure 29" from crotch to floor = 73.66cm. If I add
my feet that's another 3.25" or 8.255cm for a total of
81.915cm. By that measure I need to raise my seat 1.738"
or 4.415cm My seat is currently as far down as it can go.
I can just reach the street with both toes when sitting on
the seat but when riding, at the bottom of each stroke,
my legs are still bent and at the top of each stroke I feel
a bit cramped......help?

Ken


--
Mark Wolfe http://www.wolfenet.org
gpg fingerprint = 42B6 EFEB 5414 AA18 01B7 64AC EF46 F7E6 82F6 8C71
Lottery: the closest thing we have to a tax on stupidity.
  #7  
Old September 8th 03, 01:04 AM
A Muzi
external usenet poster
 
Posts: n/a
Default Discovery Tires...was...Road bike seat height?

"Scic" wrote in message
...
From: "Ken Bessler"


I have the following bike setup:
snip


Tires - Discovery Kevlar CyclePro 700x25


First time that I've seen these tires mentioned here.
I've been buying them for years from REI but they've since been replaced

by the
Avenir Discovery Kevlar Belted 700x25c which are said to be identical

(same
tire) to the Cycle Pro albeit now made in Korea. I can't tell the

difference.
At $15.00 per, it might be a tire to consider for those who ride city

streets
like I do and often lose tires to cuts. Had to give up $30.00+

tires...too
expensive.
I obviously like them and wouldn't mind seeing a review from someone more
knowledgable than me.
I wish they still made the Schwinn Record, a good, expendable tire, I

thought.


CyclePro was the house brand* of West Coast Cycle ( Nishiki, nee American
Eagle; also Azuki). That company and many others were acquired by Raleigh.
The classic CyclePro tires were made by IRC as were the house brand
Avenir/TourMate tires from WSI/DiamondBack (Centurion). That company was
also folded into the Raleigh organization.

Last year after yet another corporate reorganization at Raleigh (will it
just be annual?) , the many carryover brands were "rationalized" so they
weren't selling twenty versions of the same product. Many line items/labels
were dropped or rebadged. Sounds to me as if your vendor is a Raleigh
customer. If you look around you'll find that tire available under various
labels both from IRC/Korea and still from IRC/Japan at a higher price.

Your Schwinn Puff, SuperSport and Record were by
Panasonic/Matsu****a/Panaracer in Japan. Equal quality to IRC if not better
in some cases.

IRC/Korea tires at $15 "expendable"? OK. IRC/Indonesia tires sell for
$7.50. That's expendable! (only in 27", not 700C)

*WCC also had a very cute brand name, "MIJON" , that was an acronym of "Made
in Japan -Or Nearby" . WCC used that for econo second-quality parts at one
time.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971


  #8  
Old September 8th 03, 02:24 AM
Scic
external usenet poster
 
Posts: n/a
Default Discovery Tires...was...Road bike seat height?

From: "A Muzi"

CyclePro was the house brand...
snip
If you look around you'll find that tire available under various
labels both from IRC/Korea and still from IRC/Japan at a higher price.


Thanks... and for the history as well.
Very informative, as your replies always are.

Sig
Chicago
  #9  
Old September 8th 03, 08:18 AM
A Muzi
external usenet poster
 
Posts: n/a
Default Discovery Tires...was...Road bike seat height?

From: "A Muzi"

CyclePro was the house brand...
snip
If you look around you'll find that tire available under various
labels both from IRC/Korea and still from IRC/Japan at a higher price.



"Scic" wrote in message
...
Thanks... and for the history as well.
Very informative, as your replies always are.


However, getting senile such that memory is less reliable now..
A kind soul pointed out that although many Schwin label tires were
Panaracers, the Puff wasn't among them.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971


  #10  
Old September 8th 03, 08:11 PM
Rick Onanian
external usenet poster
 
Posts: n/a
Default Road bike seat height?

On Sun, 7 Sep 2003 08:36:39 -0600, Ken Bessler wrote:
I have the following bike setup:

How do I adjust the seat height? I'm thinking the formula
would be frame size + crank arm + distance from top of
frame to top of seat should equal my inseam, right? Or not?


I can just reach the street with both toes when sitting on
the seat but when riding, at the bottom of each stroke,
my legs are still bent and at the top of each stroke I feel
a bit cramped......help?


See
http://www.sheldonbrown.com/saddles.html

Mostly, put it up as high as is comfortable. You
probably won't be able to touch the ground with a
toe if it's at the most efficient height. Your
legs should be almost straight at the bottom of
the stroke.

You seem to already know when it's too low; it's
too high when you're uncomfortable, or when your
hips rock side to side while you pedal. Somewhere
in between those extremes is your comfort zone.

Ken

--
Rick Onanian
 




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