fitting a bike

As a newbie I have read many of the posts while lurking.
I have read about a bike shops setting up a bike to suit you. Obviously this
was not done for me when I purchased my first new bike since the last one
about 40 years ago.
What is actually involved in setting up a bike for the rider. Any help would
be greatly appreciated. But don't forget to type real slow for this old
fart.
Thanks,
Denis

"Denis W Ellem" wrote:

What is actually involved in setting up a bike for the rider. Any help
would be greatly appreciated. But don't forget to type real slow for this
old fart.

Just my 2c. Others on the group will no doubt be able to add more technical
measures.

1. Frame size - the most crucial of course, difficult to change: Stand over
the top tube, feet flat on the floor. You should have clearance between
frame and crotch of at least 8cm, more for a MTB for off-road use.

2. Saddle height: Get someone to hold the bike, sit on the saddle and put
your heels on the pedals. At the bottom-most point of the pedal stroke your
leg should be pretty well straight. Adjust the seat post to achieve this.
Put your feet on the pedals in riding position (ball over pedal axle) and
back pedal. Your hips should stay level, no rocking as you pedal (get
someone else to check from the rear). With this saddle height you will
probably just be able to touch the ground with the tips of your toes, but
that's OK, you move off the saddle when you stop

3. Pedals: Position your cleats, if you use them, or get toe-clips of a
suitable length, so that your pedal axle lies immediately below the ball of
your foot.

4. Saddle: Position the saddle so that the a vertical line from its nose
falls about 5-6cm behind the crank axle. When sitting with feet on the
pedals, crank arms horizontal, a plumb line from your kneecap should pass
through the pedal axle.

5. Saddle tilt: The saddle should be level as a general rule or the nose may
be tilted up 5 degree. Adjust the clamp underneath the saddle. Some ride
with the nose down for comfort, although this may produce sore shoulders and
forearms.

6. Frame/stem reach: Put your elbow at the nose of the saddle, your
fingertips should fall about 8cm behind the handlebar (straight bars) closer
for a bike with drop bars, maybe 5-6cms.

7. Handlebar: Ideally should be about the same width as your shoulders,
allowing you to ride wtih your fore arms parallel. I find with MTB bars they
can be a fair bit wider, as the different grip and arm position means your
arms are parallel in a wider grip.

A few other position 'rules'
- when riding a well setup bike you should find in all positions that the
line between your upper arm and your torso forms a right angle
- in your normal riding position you should be able to sight your font hub,
just behind the handlebars
- move forward on your saddle when spinning fast, slide back on the saddle
if you grind the pedals slower up a hill.

All of these should be treated as guides. They will vary for some people
with different body proportions, and always go by what is comfortable for
you, but the first four measures are pretty crucial.

I am sure that others can suggest more ideas.

--
Cheers
Peter

~~~ ~ _@
~~ ~ _- \,
~~ (*)/ (*)

Denis W Ellem wrote:
As a newbie I have read many of the posts while lurking.
I have read about a bike shops setting up a bike to suit you. Obviously this
was not done for me when I purchased my first new bike since the last one
about 40 years ago.
What is actually involved in setting up a bike for the rider. Any help would
be greatly appreciated. But don't forget to type real slow for this old
fart.

There's no one right way to do it, and there's a lot of myth and mumbo
jumbo too.
Some general principles :

As Peter says, frame size is important, but within certain values it's
maybe not as important as it may seem at first - you can get all sorts
of funky seatposts & stems to move you around.

KOPS is a myth (knee over pedal spindle) that won't go away and it
sometimes works by co-incidence (see :
http://www.aboc.com.au/docs/kops.html ). I look at how a rider stands
when pedaling and then try and replicate that when they're seated, then
move them fore or aft on the bike depending on how much weight they can
handle on their arms, as a general principle. But, there's no one
right way to do it, the only "right" way is the way that doesn't cause
discomfort or injury.

Sorry to be vague, but you cannot get a fit over the 'net.

Peter Signorini Wrote:


1. Frame size - the most crucial of course, difficult to change: Stand
over
the top tube, feet flat on the floor. You should have clearance between
frame and crotch of at least 8cm, more for a MTB for off-road use.


8cm is a bit extreme. You'd have me on a 24 inch kids bike

Standover height is not a great indicator of bike fit, particularly
with compact frames. There are a few well known formulas based on
simple measurements, but a good bike fit should be able to take all
factors into account. This includes leg length, height, back
flexibility, shoe size, power output and others. The formulas are only
a starting point.

One of the well known fomulas is Lemonds. Frame size = inseam * 0.67.


--
sinus

rooman Wrote:
absolutely spot on...

plus I'd add ...formulas are for babies to drink & scientists to
postulate over.

While I certainly wouldn't suggest that fitting formulas are infallible
and the be all and end all of bike fitting, they will provide a damn
good starting point. There is an enormous swathe of middle ground
between perfect and useless. I'd agree that 8cm of standover room is a
bit much but other than that in the absence of someone who knows what
they're talking about (and in order to work out whether the assistant
in the LBS knows what they're talking about) a few basic rules can be
extremely valuable.


--
Resound

rooman wrote:

Sorry to be vague, but you cannot get a fit over the 'net.

absolutely spot on...

plus I'd add ...formulas are for babies to drink & scientists to
postulate over.



When I bought my OCR2 I had it fitted and have been very happy with it
from day 1. Out of interest I made some comparisons between the OCR and
my old road bike which had taken me a year of tinkering with to feel
comfortable. Although the frame sizes were quite different (the old
frame was a donation from a mate), various modifications to headstem,
seatpost etc on the old bike meant that for seat to pedal, and seat to
handlebars measurements, I had almost identical measurements for the two
different bikes. So although formulas are only for babies and
scientists, once you have a good fit, can that be translated to another
bike through measurements or does an experienced opinion still play the
major part?

DaveB

DaveB Wrote:

When I bought my OCR2 I had it fitted and have been very happy with it
from day 1. Out of interest I made some comparisons between the OCR
and
my old road bike which had taken me a year of tinkering with to feel
comfortable. Although the frame sizes were quite different (the old
frame was a donation from a mate), various modifications to headstem,
seatpost etc on the old bike meant that for seat to pedal, and seat to
handlebars measurements, I had almost identical measurements for the
two
different bikes. So although formulas are only for babies and
scientists, once you have a good fit, can that be translated to
another
bike through measurements or does an experienced opinion still play
the
major part?

DaveB

There's probably a degree of horses for courses going on with fit.
Different types and intensities of riding would determine a different
approach as well as unusual proportions. One of my friends has a very
long torso and short legs. She's also very much a novice cyclist and so
would ride at a much lower intensity. So despite being essentially the
same height as me, she'd want a distinctly different fit. Someone who's
experienced in dealing with different cycling styles and body types
would probably be able to make some pertinent changes to a basic
formula straight off. A basic formula would still be a good starting
point in the absence of such a person though.


--
Resound

DaveB Wrote:
rooman wrote:

Sorry to be vague, but you cannot get a fit over the 'net.

absolutely spot on...

plus I'd add ...formulas are for babies to drink & scientists to
postulate over.



When I bought my OCR2 I had it fitted and have been very happy with it
from day 1. Out of interest I made some comparisons between the OCR and
my old road bike which had taken me a year of tinkering with to feel
comfortable. Although the frame sizes were quite different (the old
frame was a donation from a mate), various modifications to headstem,
seatpost etc on the old bike meant that for seat to pedal, and seat to
handlebars measurements, I had almost identical measurements for the
two
different bikes. So although formulas are only for babies and
scientists, once you have a good fit, can that be translated to another
bike through measurements or does an experienced opinion still play the
major part?

DaveB
your physiology, riding style and aspirations dicate your position in
space that is most comfortable or provides max performance or whatever
in between you have arrived at that feels perfectly fine to you...you
managed to replicate that ...well done... that is what it is all
about...your position never changed, you adapted your ride to that
position you had comfort with...that is achieved by adjusting the many
and almost infinite variables at play...what doesnt change is you and
your subjective feeling about riding comfort/performance you have
settled on as optimum for you...still with me?

so you can get any new frame within dimensional limits and adapt it to
place you in space where it feels right...some do this the hard way and
play and twiddle for ages till they get what they perceive as fine for
them...others seek experienced professionals to help them along the
journey...and far too many never find nirvana for whatever
reason...that's why we have this Forum I guess

whatever...ride..to enjoy and if it don't fit, fix it, then ride and
enjoy..and ride and enjoy................


--
rooman

Denis

Noticed from your posts that you were a car-boy. Good to see a convert.
I hope this wasn't a troll, seeing all of these nice people have worked
so hard to answer your question!

Donga